Distributed programming: Difference between revisions
(→Server) |
m (→{{header|Wren}}: Minor tidy) |
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server.ads: |
server.ads: |
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< |
<syntaxhighlight lang="ada">package Server is |
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pragma Remote_Call_Interface; |
pragma Remote_Call_Interface; |
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procedure Foo; |
procedure Foo; |
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function Bar return Natural; |
function Bar return Natural; |
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end Server;</ |
end Server;</syntaxhighlight> |
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server.adb: |
server.adb: |
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< |
<syntaxhighlight lang="ada">package body Server is |
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Count : Natural := 0; |
Count : Natural := 0; |
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Line 35: | Line 35: | ||
return Count; |
return Count; |
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end Bar; |
end Bar; |
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end Server;</ |
end Server;</syntaxhighlight> |
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client.adb: |
client.adb: |
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< |
<syntaxhighlight lang="ada">with Server; |
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with Ada.Text_IO; |
with Ada.Text_IO; |
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Line 46: | Line 46: | ||
Server.Foo; |
Server.Foo; |
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Ada.Text_IO.Put_Line ("Calling Bar: " & Integer'Image (Server.Bar)); |
Ada.Text_IO.Put_Line ("Calling Bar: " & Integer'Image (Server.Bar)); |
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end Client;</ |
end Client;</syntaxhighlight> |
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required config (dsa.cfg): |
required config (dsa.cfg): |
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< |
<syntaxhighlight lang="ada">configuration DSA is |
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pragma Starter (None); |
pragma Starter (None); |
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Line 61: | Line 61: | ||
procedure Client; |
procedure Client; |
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for Client_Partition'Main use Client; |
for Client_Partition'Main use Client; |
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end DSA;</ |
end DSA;</syntaxhighlight> |
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compilation: |
compilation: |
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Line 118: | Line 118: | ||
=={{header|C}}== |
=={{header|C}}== |
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Using PVM [http://www.csm.ornl.gov/pvm/pvm_home.html] |
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{{incorrect|C|The protocol used is not sufficiently general-purpose.}} |
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This program is in a sense both a server and a client, depending on if its task is spawned with a command-line argument: if yes, it spawns another task of the same executible on the parallel virtual machine and waits for it to transmit data; if no, it transmits data and is done. |
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{{works with|Win32}} (Visual C/C++ 6.0) |
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<syntaxhighlight lang="c">#include <stdio.h> |
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The changes needed to work with Linux/Unix should be small. |
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The example server serves only one client at a time. The protocol has 3 messages. The |
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first character determines the server action. |
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:'0' - echo string reversed '1' - echo string '2' - shutdown the server. |
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===Server=== |
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<lang c>#include <stdio.h> |
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#include <stdlib.h> |
#include <stdlib.h> |
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#include < |
#include <pvm3.h> |
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//#include <sys/socket.h> |
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//#include <inet.h> |
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#include <string.h> |
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//#include <time.h> |
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#include <windows.h> |
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#pragma comment(lib, "wsock32.lib") |
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int main(int c, char **v) |
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typedef struct sockaddr_in * InetSockAddr; |
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typedef int (*Handler)( InetSockAddr client, int socket ); |
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typedef struct sServer { |
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Handler handler; |
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int running; |
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int sock; |
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struct sockaddr_in addr; |
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} *Server; |
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Server NewServer( short port, Handler handler) |
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{ |
{ |
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int tids[10]; |
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int parent, spawn; |
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struct sockaddr_in svrAddr; |
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int i_data, i2; |
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Server srv= malloc(sizeof(struct sServer)); |
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double f_data; |
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if (!srv) return srv; |
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srv->handler = handler; |
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srv->running = 1; |
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sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); |
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if (sock <0 ) { |
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printf("Couldn't open socket. -failed %d \n", sock); |
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exit(1); |
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} |
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srv->sock = sock; |
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if (c > 1) { |
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memset(&svrAddr, 0, sizeof(struct sockaddr_in)); |
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spawn = pvm_spawn("/tmp/a.out", 0, PvmTaskDefault, 0, 1, tids); |
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svrAddr.sin_family = AF_INET; |
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if (spawn <= 0) { |
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svrAddr.sin_addr.s_addr = htonl(INADDR_ANY); //any incoming addr ok |
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printf("Can't spawn task\n"); |
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svrAddr.sin_port = htons(port); |
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return 1; |
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srv->addr = svrAddr; |
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} |
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printf("Spawning successful\n"); |
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if (bind(sock, (struct sockaddr *)&svrAddr, sizeof(svrAddr)) <0) { |
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printf("Bind to port %d failed\n", port); |
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exit(1); |
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} |
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return srv; |
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} |
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/* pvm_recv(task_id, msgtag). msgtag identifies what kind of data it is, |
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#define MAXPENDING SOMAXCONN |
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* for here: 1 = (int, double), 2 = (int, int) |
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#define close(sock) closesocket(sock) |
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* The receiving order is intentionally swapped, just to show. |
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* task_id = -1 means "receive from any task" |
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*/ |
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pvm_recv(-1, 2); |
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pvm_unpackf("%d %d", &i_data, &i2); |
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printf("got msg type 2: %d %d\n", i_data, i2); |
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pvm_recv(-1, 1); |
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int ServerServe( Server svr) |
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pvm_unpackf("%d %lf", &i_data, &f_data); |
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{ |
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printf("got msg type 1: %d %f\n", i_data, f_data); |
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struct sockaddr_in cli_addr; |
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} else { |
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int clen = sizeof(cli_addr); |
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parent = pvm_parent(); |
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if (listen(svr->sock, MAXPENDING) < 0) { |
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printf("listen() call failed.\n"); |
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return -1; |
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} |
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while (svr->running) { |
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int sock = accept(svr->sock, (struct sockaddr *) &cli_addr, &clen); |
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if (sock < 0) { |
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printf("accept call failed in ServerServ.\n"); |
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svr->running = 0; |
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} |
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else |
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svr->running = (*(svr->handler))( &cli_addr, sock ); |
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} |
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} |
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pvm_initsend(PvmDataDefault); |
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#define ServerDelete( svr ) \ |
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i_data = rand(); |
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{ if(svr->sock>0) close(svr->sock); \ |
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f_data = (double)rand() / RAND_MAX; |
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free(svr); svr = NULL; } |
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pvm_packf("%d %lf", i_data, f_data); |
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pvm_send(parent, 1); /* send msg type 1 */ |
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pvm_initsend(PvmDataDefault); |
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#define BUFR_SIZE 256 |
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i2 = rand(); |
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/* - return 0 on success, nonzero on done; */ |
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pvm_packf("%d %d", i_data, i2); |
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int SimpleHandler( InetSockAddr cli_addr, int cli_sock ) |
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pvm_send(parent, 2); /* send msg type 2 */ |
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{ |
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} |
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char msgBufr[BUFR_SIZE]; |
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int msgSize; |
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int rplySize; |
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const char *rplyMsg; |
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int mcode; |
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pvm_exit(); |
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do { |
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return 0; |
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msgSize = recv(cli_sock, msgBufr, sizeof(msgBufr), 0) ; |
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}</syntaxhighlight>{{out}}(running it on PVM console, exe is /tmp/a.out)<syntaxhighlight lang="text">pvm> spawn -> /tmp/a.out 1 |
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if (msgSize < 0) { |
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spawn -> /tmp/a.out 1 |
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printf("done receiving\n"); |
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[2] |
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return 1; |
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1 successful |
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} |
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t40028 |
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mcode = msgBufr[0]; |
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pvm> [2:t40029] EOF |
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switch(mcode) { |
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[2:t40028] Spawning successful |
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default: |
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[2:t40028] got msg type 2: 1804289383 1681692777 |
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case '0': { |
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[2:t40028] got msg type 1: 1804289383 0.394383 |
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char *p1 = msgBufr+1; |
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[2:t40028] EOF |
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char *p2 = msgBufr+msgSize-2; |
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[2] finished</syntaxhighlight> |
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while (p2>p1) { |
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*p1 = *p1 + *p2; *p2 = *p1 - *p2; *p1 = *p1 - *p2; |
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p1++; p2--; |
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} |
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rplyMsg = msgBufr; |
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} |
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break; |
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case '1': |
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rplyMsg = msgBufr; |
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break; |
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case '2': |
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rplyMsg = "Server Quitting"; |
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// server should quit |
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break; |
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} |
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rplySize = strlen(rplyMsg)+1; |
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if (rplySize > 0) { |
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int bytesSent = send(cli_sock, rplyMsg, rplySize, 0); |
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if (bytesSent < rplySize) { |
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printf("Not All bytes sent back from msg."); |
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msgSize = 0; |
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} |
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} |
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} while ((msgSize > 0) && (mcode !=2)); |
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return (mcode == 2); // true if server should quit |
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} |
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=={{header|C sharp|C#}}== |
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int main( int argc, char *argv[]) |
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Start the program with "server" parameter to start the server, and "client" to start the client. The client will send data to the server and receive a response. The server will wait for data, display the data received, and send a response. |
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{ |
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short port; |
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Server server; |
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WORD sockVrsn; |
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WSADATA wsaData; |
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<syntaxhighlight lang="csharp"> |
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sockVrsn = MAKEWORD(1,1); |
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using System; |
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using System.IO; |
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using System.Net; |
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using System.Net.Sockets; |
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using System.Runtime.Serialization.Formatters.Binary; |
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using System.Threading.Tasks; |
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using static System.Console; |
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if (argc < 2) { |
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printf("Usage %s <port number>\n",argv[0]); |
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exit(1); |
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} |
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WSAStartup(sockVrsn, &wsaData); |
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port = (short)atoi(argv[1]); |
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server = NewServer( port, &SimpleHandler); |
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if (server){ |
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ServerServe(server); |
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ServerDelete(server); |
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} |
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return 0; |
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}</lang> |
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===Client=== |
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<lang c>#include <stdio.h> |
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#include <stdlib.h> |
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#include <winsock.h> |
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//#include <sys/socket.h> |
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//#include <inet.h> |
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#include <string.h> |
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//#include <time.h> |
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#include <windows.h> |
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#pragma comment(lib, "wsock32.lib") |
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class DistributedProgramming |
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typedef struct sockaddr_in * InetSockAddr; |
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typedef struct sClient { |
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int sock; |
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struct sockaddr_in addr; |
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} *Client; |
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Client NewClient( const char *ipAddr, short port ) |
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{ |
{ |
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int |
const int Port = 555; |
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struct sockaddr_in svrAddr; |
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Client clint= malloc(sizeof(struct sClient)); |
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if (!clint) return clint; |
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async static Task RunClient() |
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sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); |
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{ |
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WriteLine("Connecting"); |
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var client = new TcpClient(); |
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await client.ConnectAsync("localhost", Port); |
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} |
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clint->sock = sock; |
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using (var stream = client.GetStream()) |
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memset(&svrAddr, 0, sizeof(struct sockaddr_in)); |
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{ |
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svrAddr.sin_family = AF_INET; |
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WriteLine("Sending loot"); |
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svrAddr.sin_addr.s_addr = inet_addr(ipAddr); |
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var data = Serialize(new SampleData()); |
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printf("IP addr: %x", inet_addr(ipAddr)); |
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await stream.WriteAsync(data, 0, data.Length); |
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svrAddr.sin_port = htons(port); |
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clint->addr = svrAddr; |
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WriteLine("Receiving thanks"); |
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if (connect(sock, (struct sockaddr *)&svrAddr, sizeof(svrAddr)) <0) { |
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var buffer = new byte[80000]; |
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perror("connect failed"); |
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var bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length); |
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printf("Connect to Server %s:%d failed\n", ipAddr,port); |
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var thanks = (string)Deserialize(buffer, bytesRead); |
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exit(1); |
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WriteLine(thanks); |
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} |
} |
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return clint; |
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} |
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client.Close(); |
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#define close(sock) closesocket(sock) |
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} |
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async static Task RunServer() |
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#define BUFR_SIZE 128 |
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{ |
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WriteLine("Listening"); |
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var listener = new TcpListener(IPAddress.Any, Port); |
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listener.Start(); |
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var client = await listener.AcceptTcpClientAsync(); |
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using (var stream = client.GetStream()) |
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int ClientDoProcs( Client clint, const char *mlist[]) |
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{ |
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{ |
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WriteLine("Receiving loot"); |
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char rcvBufr[BUFR_SIZE]; |
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var buffer = new byte[80000]; |
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const char **msg; |
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var bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length); |
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int v; |
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var data = (SampleData)Deserialize(buffer, bytesRead); |
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WriteLine($"{data.Loot} at {data.Latitude}, {data.Longitude}"); |
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WriteLine("Sending thanks"); |
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for (msg = mlist; *msg; msg++) { |
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var thanks = Serialize("Thanks!"); |
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await stream.WriteAsync(thanks, 0, thanks.Length); |
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v = send(clint->sock, *msg, mlen, 0); |
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if (v != mlen ) { |
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printf("MessageSend error: %d %d\n", v,mlen); |
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} |
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else { |
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int bytesRcvd = 0; |
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bytesRcvd = recv( clint->sock, rcvBufr, BUFR_SIZE-1, 0); |
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if (bytesRcvd < 0) { |
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printf("Error Rcvg Bytes\n"); |
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break; |
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} |
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printf("Recvd: %s\n", rcvBufr); |
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} |
} |
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client.Close(); |
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listener.Stop(); |
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Write("Press a key"); |
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ReadKey(); |
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} |
} |
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return 0; |
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} |
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static byte[] Serialize(object data) |
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#define ClientDelete( cli ) \ |
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{ |
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{ if(cli->sock>0) close(cli->sock); \ |
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using (var mem = new MemoryStream()) |
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{ |
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new BinaryFormatter().Serialize(mem, data); |
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const char *msglist[] = { |
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return mem.ToArray(); |
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"0Hello World!!!", |
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} |
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"1This should echo back same", |
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"0This should echo back reversed", |
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"2 ByeBye", |
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NULL }; |
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int main( int argc, char *argv[]) |
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{ |
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short port; |
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Client clint; |
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WORD sockVrsn; |
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WSADATA wsaData; |
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sockVrsn = MAKEWORD(1,1); |
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WSAStartup(sockVrsn, &wsaData); |
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if (argc < 3) { |
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printf("Usage %s <serverIP> <port number>\n",argv[0]); |
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exit(1); |
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} |
} |
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static object Deserialize(byte[] data, int length) |
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port = (short)atoi(argv[2]); |
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{ |
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// argv[1]="127.0.0.1"; |
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using (var mem = new MemoryStream(data, 0, length)) |
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clint = NewClient( argv[1], port ); |
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{ |
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return new BinaryFormatter().Deserialize(mem); |
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ClientDoProcs(clint, msglist); |
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} |
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} |
} |
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Sleep(10); |
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return 0; |
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}</lang> |
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static void Main(string[] args) |
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=={{header|C sharp|C#}}== |
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{ |
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{{incorrect|C sharp|The protocol used is not sufficiently general-purpose.}} |
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if (args.Length == 0) return; |
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The example server can handle one client at any one time. It will read what the client writes, and respond with "Hello World!". The client will write "Hello World!" and read the response from the server. |
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switch (args[0]) |
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===Server=== |
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{ |
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<lang csharp> |
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case "client": RunClient().Wait(); break; |
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using System.Net.Sockets; |
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case "server": RunServer().Wait(); break; |
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} |
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} |
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} |
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[Serializable] |
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class Program |
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class SampleData |
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{ |
{ |
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public decimal Latitude = 44.33190m; |
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static void Main(string[] args) |
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public decimal Longitude = 114.84129m; |
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{ |
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public string Loot = "140 tonnes of jade"; |
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TcpListener server = new TcpListener(8000); |
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} |
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server.Start(); |
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</syntaxhighlight> |
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=={{header|D}}== |
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Console.WriteLine("Listening, port 8000"); |
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Uses the <b>rpc</b> library: |
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https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff/blob/master/rpc.d |
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This library is not standard, so this code (by Adam D. Ruppe) could and should be rewritten using more standard means. |
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TcpClient client; |
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<syntaxhighlight lang="d">import arsd.rpc; |
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do |
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{ |
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// Accept client |
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client = server.AcceptTcpClient(); |
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Console.WriteLine("Recieved client: " + client.Client.AddressFamily.ToString()); |
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struct S1 { |
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// Recieve |
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int number; |
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string tRecieve = ""; |
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string name; |
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char t; |
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} |
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do |
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{ |
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if (client.Available > 0) |
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{ |
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t = (char)client.GetStream().ReadByte(); |
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struct S2 { |
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if (t == 0) |
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string name; |
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break; |
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int number; |
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} |
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interface ExampleNetworkFunctions { |
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tRecieve += t; |
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string sayHello(string name); |
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} |
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int add(in int a, in int b) const pure nothrow; |
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} while (true); |
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S2 structTest(S1); |
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void die(); |
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} |
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// The server must implement the interface. |
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Console.WriteLine("Recieved: " + tRecieve); |
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class ExampleServer : ExampleNetworkFunctions { |
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override string sayHello(string name) { |
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return "Hello, " ~ name; |
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} |
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override int add(in int a, in int b) const pure nothrow { |
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// Send |
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return a + b; |
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byte[] tSend = Encoding.ASCII.GetBytes("Hello World!"); |
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} |
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client.GetStream().Write(tSend, 0, tSend.Length); |
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client.GetStream().WriteByte(0); |
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override S2 structTest(S1 a) { |
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Console.WriteLine("Sent: " + Encoding.ASCII.GetString(tSend)); |
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return S2(a.name, a.number); |
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} |
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override void die() { |
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// Close |
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throw new Exception("death requested"); |
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client.Close(); |
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} |
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} while (true); |
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mixin NetworkServer!ExampleNetworkFunctions; |
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} |
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} |
} |
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</lang> |
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class Client { |
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mixin NetworkClient!ExampleNetworkFunctions; |
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<lang csharp> |
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using System.Net.Sockets; |
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class Program |
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{ |
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static void Main(string[] args) |
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{ |
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TcpClient client; |
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// Connect |
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do |
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{ |
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client = new TcpClient(); |
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client.Connect(new System.Net.IPEndPoint(System.Net.IPAddress.Parse("127.0.0.1"), 8000)); |
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Console.WriteLine("Connected"); |
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// Send |
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byte[] tSend = Encoding.ASCII.GetBytes("Hello World!"); |
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client.GetStream().Write(tSend, 0, tSend.Length); |
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client.GetStream().WriteByte(0); |
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Console.WriteLine("Sent: " + Encoding.ASCII.GetString(tSend)); |
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// Read |
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string tRecieve = ""; |
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char t; |
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do |
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{ |
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if (client.Available > 0) |
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{ |
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t = (char)client.GetStream().ReadByte(); |
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if (t == 0) |
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break; |
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tRecieve += t; |
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} |
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} while (true); |
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Console.WriteLine("Recieved: " + tRecieve); |
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client.Close(); |
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Console.Read(); |
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} while (true); |
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} |
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} |
} |
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</lang> |
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void main(in string[] args) { |
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=={{header|D}}== |
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import std.stdio; |
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{{incorrect|D|The protocol used is not sufficiently general-purpose.}} |
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if (args.length > 1) { |
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{{works with|Tango}} |
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auto client = new Client("localhost", 5005); |
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=== Server === |
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// These work like the interface above, but instead of |
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<lang D>module distributedserver ; |
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// returning the value, they take callbacks for success (where |
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import tango.net.ServerSocket, tango.text.convert.Integer, |
|||
// the arg is the retval) and failure (the arg is the |
|||
tango.text.Util, tango.io.Stdout ; |
|||
// exception). |
|||
client.sayHello("whoa", (a) { writeln(a); }, null); |
|||
void main() { |
|||
client.add(1,2, (a){ writeln(a); }, null); |
|||
auto Ip = new InternetAddress("localhost", 12345) ; |
|||
client.add(10,20, (a){ writeln(a); }, null); |
|||
auto server = new ServerSocket(Ip) ; |
|||
client.structTest(S1(20, "cool!"), |
|||
auto socket = server.accept ; |
|||
(a){ writeln(a.name, " -- ", a.number); }, |
|||
auto buffer = new char[socket.bufferSize] ; |
|||
null); |
|||
client.die(delegate(){ writeln("shouldn't happen"); }, |
|||
bool quit = false ; |
|||
delegate(a){ writeln(a); }); |
|||
client.eventLoop; |
|||
while(!quit) { |
|||
} else { |
|||
bool error = false ; |
|||
auto server = new ExampleServer(5005); |
|||
server.eventLoop; |
|||
try { |
|||
} |
|||
auto len = socket.input.read(buffer) ; |
|||
}</syntaxhighlight> |
|||
auto cmd = (len > 0) ? delimit(buffer[0..len], " ") : [""] ; |
|||
Stdout(cmd).newline.flush ; |
|||
switch (cmd[0]) { |
|||
case "square": |
|||
socket.output.write(toString(toInt(cmd[1]) * toInt(cmd[1]))) ; break ; |
|||
case"add": |
|||
socket.output.write(toString(toInt(cmd[1]) + toInt(cmd[2]))) ; break ; |
|||
case "quit": |
|||
socket.output.write("Server Shut down") ; |
|||
quit = true ; break ; |
|||
default: error = true ; |
|||
} |
|||
} catch (Exception e) |
|||
error = true ; |
|||
if(error) socket.output.write("<Error>") ; |
|||
if(socket) socket.close ; |
|||
if(!quit) socket = server.accept ; |
|||
} |
|||
if(socket) socket.close ; |
|||
}</lang> |
|||
=== Client === |
|||
<lang D>module distributedclient ; |
|||
import tango.net.SocketConduit, tango.net.InternetAddress, |
|||
tango.text.Util, tango.io.Stdout ; |
|||
void main(char[][] args) { |
|||
if(args.length> 1) { |
|||
try { |
|||
auto Ip = new InternetAddress("localhost", 12345) ; |
|||
auto socket = new SocketConduit ; |
|||
socket.connect(Ip) ; |
|||
auto buffer = new char[socket.bufferSize] ; |
|||
socket.output.write(join(args[1..$]," ")) ; |
|||
auto len = socket.input.read(buffer) ; |
|||
if(len > 0) Stdout(buffer[0..len]).newline ; |
|||
if(socket) socket.close ; |
|||
} catch(Exception e) |
|||
Stdout(e.msg).newline ; |
|||
} else |
|||
Stdout("usage: supply argument as,\n\tquit\n" |
|||
"\tsquare <number>\n\tadd <number> <number>").newline ; |
|||
}</lang> |
|||
=={{header|E}}== |
=={{header|E}}== |
||
Line 573: | Line 366: | ||
(The protocol is symmetric; this program is the server only in that it is the one which is started first and exports an object.) |
(The protocol is symmetric; this program is the server only in that it is the one which is started first and exports an object.) |
||
< |
<syntaxhighlight lang="e">def storage := [].diverge() |
||
def logService { |
def logService { |
||
Line 591: | Line 384: | ||
def sturdyRef := makeSturdyRef.temp(logService) |
def sturdyRef := makeSturdyRef.temp(logService) |
||
println(<captp>.sturdyToURI(sturdyRef)) |
println(<captp>.sturdyToURI(sturdyRef)) |
||
interp.blockAtTop()</ |
interp.blockAtTop()</syntaxhighlight> |
||
This will print the URL of the service and run it until aborted. |
This will print the URL of the service and run it until aborted. |
||
Line 599: | Line 392: | ||
The URL provided by the server is given as the argument to this program. |
The URL provided by the server is given as the argument to this program. |
||
< |
<syntaxhighlight lang="e">def [uri] := interp.getArgs() |
||
introducer.onTheAir() |
introducer.onTheAir() |
||
def sturdyRef := <captp>.sturdyFromURI(uri) |
def sturdyRef := <captp>.sturdyFromURI(uri) |
||
Line 612: | Line 405: | ||
println(`At $time: $line`) |
println(`At $time: $line`) |
||
} |
} |
||
}</ |
}</syntaxhighlight> |
||
=={{header|Erlang}}== |
=={{header|Erlang}}== |
||
Line 619: | Line 412: | ||
srv.erl |
srv.erl |
||
< |
<syntaxhighlight lang="erlang">-module(srv). |
||
-export([start/0, wait/0]). |
-export([start/0, wait/0]). |
||
Line 637: | Line 430: | ||
wait(); |
wait(); |
||
Any -> io:fwrite("Error ~p~n", [Any]) |
Any -> io:fwrite("Error ~p~n", [Any]) |
||
end.</ |
end.</syntaxhighlight> |
||
=== Client === |
=== Client === |
||
client.erl |
client.erl |
||
< |
<syntaxhighlight lang="erlang">-module(client). |
||
-export([start/0, wait/0]). |
-export([start/0, wait/0]). |
||
Line 649: | Line 442: | ||
erlang:set_cookie(node(), rosetta), |
erlang:set_cookie(node(), rosetta), |
||
{ok,[[Srv]]} = init:get_argument(server), |
{ok,[[Srv]]} = init:get_argument(server), |
||
io:fwrite(" |
io:fwrite("connecting to ~p~n", [Srv]), |
||
{srv, list_to_atom(Srv)} ! {echo,self(), hi}, |
{srv, list_to_atom(Srv)} ! {echo,self(), hi}, |
||
wait(), |
wait(), |
||
Line 658: | Line 451: | ||
{hello, Any} -> io:fwrite("Received ~p~n", [Any]); |
{hello, Any} -> io:fwrite("Received ~p~n", [Any]); |
||
Any -> io:fwrite("Error ~p~n", [Any]) |
Any -> io:fwrite("Error ~p~n", [Any]) |
||
end.</ |
end.</syntaxhighlight> |
||
running it (*comes later) |
running it (*comes later) |
||
Line 668: | Line 461: | ||
|erlc client.erl |
|erlc client.erl |
||
|erl -run client start -run init stop -noshell -server srv@agneyam |
|erl -run client start -run init stop -noshell -server srv@agneyam |
||
connecting to "srv@agneyam" |
|||
Received hi |
Received hi |
||
=={{header|Factor}}== |
|||
The protocol is the one provided by Factor (concurrency.distributed, concurrency.messaging) |
|||
Example summary: |
|||
- A server node is listening for messages made of natural data types and structures, and simply prettyprint them. |
|||
- A client node is sending such data structure: an array of one string and one hashtable (with one key/value pair). |
|||
===Server=== |
|||
<syntaxhighlight lang="factor">USING: concurrency.distributed concurrency.messaging threads io.sockets io.servers ; |
|||
QUALIFIED: concurrency.messaging |
|||
: prettyprint-message ( -- ) concurrency.messaging:receive . flush prettyprint-message ; |
|||
[ prettyprint-message ] "logger" spawn dup name>> register-remote-thread |
|||
"127.0.0.1" 9000 <inet4> <node-server> start-server</syntaxhighlight> |
|||
Note: we are using QUALIFIED: with the concurrency.messaging vocabulary because the "receive" word is defined in io.sockets vocabulary too. If someone have a cleaner way to handle this. |
|||
===Client=== |
|||
<syntaxhighlight lang="factor">USING: concurrency.distributed io.sockets ; |
|||
QUALIFIED: concurrency.messaging |
|||
{ "Hello Remote Factor!" H{ { "key1" "value1" } } } |
|||
"127.0.0.1" 9000 <inet4> "logger" <remote-thread> concurrency.messaging:send</syntaxhighlight> |
|||
How to Run: |
|||
- Copy/Paste the server code in an instance of Factor Listener |
|||
- Copy/Paste the client code in another instance of Factor Listener. |
|||
The server node should prettyprint the data structure send by the client: { "Hello Remote Factor!" H{ { "key1" "value1" } } } |
|||
=={{header|Go}}== |
=={{header|Go}}== |
||
===Standard library net/rpc=== |
|||
Shown here is netchan, a standard Go library that enables Go channel operations across network connections. The significance is that these are type-safe data transfers of native Go types. Channels can be of any Go type although only an int channel is shown here. Netchans allow for arbitrary connections between computers, client and server roles are not mandatory. The netchan interface is independent of the type of network connection, TCP is used here. |
|||
Package net/rpc in the Go standard library serializes data with the Go-native "gob" type. The example here sends only a single floating point number, but the package will send any user-defined data type, including of course structs with multiple fields. |
|||
===Exporter=== |
|||
<lang go>package main |
|||
'''Server:''' |
|||
<syntaxhighlight lang="go">package main |
|||
import ( |
import ( |
||
" |
"errors" |
||
"log" |
|||
"net" |
"net" |
||
" |
"net/http" |
||
"net/rpc" |
|||
) |
) |
||
type TaxComputer float64 |
|||
func main() { |
|||
// channels to be exported, created as usual |
|||
squareCh := make(chan int) |
|||
resultCh := make(chan int) |
|||
func (taxRate TaxComputer) Tax(x float64, r *float64) error { |
|||
// create exporter for the two channels |
|||
if x < 0 { |
|||
exp := netchan.NewExporter() |
|||
return errors.New("Negative values not allowed") |
|||
err := exp.Export("square", squareCh, netchan.Recv) |
|||
} |
|||
*r = x * float64(taxRate) |
|||
return nil |
|||
} |
|||
func main() { |
|||
c := TaxComputer(.05) |
|||
rpc.Register(c) |
|||
rpc.HandleHTTP() |
|||
listener, err := net.Listen("tcp", ":1234") |
|||
if err != nil { |
if err != nil { |
||
log.Fatal(err) |
|||
return |
|||
} |
} |
||
http.Serve(listener, nil) |
|||
err = exp.Export("result", resultCh, netchan.Send) |
|||
}</syntaxhighlight> |
|||
'''Client:''' |
|||
<syntaxhighlight lang="go">package main |
|||
import ( |
|||
"fmt" |
|||
"log" |
|||
"net/rpc" |
|||
) |
|||
func main() { |
|||
client, err := rpc.DialHTTP("tcp", "localhost:1234") |
|||
if err != nil { |
if err != nil { |
||
fmt.Println(err) |
fmt.Println(err) |
||
Line 699: | Line 547: | ||
} |
} |
||
amount := 3. |
|||
// create a net connection on which to publish |
|||
var tax float64 |
|||
listener, err := net.Listen("tcp", "127.0.0.1:0") |
|||
err = client.Call("TaxComputer.Tax", amount, &tax) |
|||
if err != nil { |
if err != nil { |
||
log.Fatal(err) |
|||
return |
|||
} |
} |
||
fmt.Printf("Tax on %.2f: %.2f\n", amount, tax) |
|||
ta, _ := net.ResolveTCPAddr(listener.Addr().String()) |
|||
}</syntaxhighlight> |
|||
fmt.Println("square, result on port:", ta.Port) |
|||
{{out | Client output}} |
|||
<pre> |
|||
Tax on 3.00: 0.15 |
|||
</pre> |
|||
===gRPC=== |
|||
See http://www.grpc.io/ |
|||
The default serialization for gRPC is "protocol buffers." gRPC uses a .proto file to define an interface for the client and server. The .proto has its own syntax, independent of client and server implementation languages. Server and client programs here are Go however. |
|||
// publish channels |
|||
go exp.Serve(listener) |
|||
fmt.Println("Waiting for importer...") |
|||
'''.proto:''' |
|||
// use channels as usual. here, just process a single transaction. |
|||
<syntaxhighlight lang="proto">syntax = "proto3"; |
|||
n := <-squareCh |
|||
resultCh <- n * n |
|||
service TaxComputer { |
|||
// wait for communication to complete before allowing program to terminate |
|||
rpc Tax(Amount) returns (Amount) {} |
|||
err = exp.Drain(1e8) |
|||
} |
|||
message Amount { |
|||
int32 cents = 1; |
|||
}</syntaxhighlight> |
|||
'''Server:''' |
|||
<syntaxhighlight lang="go">package main |
|||
import ( |
|||
"errors" |
|||
"net" |
|||
"golang.org/x/net/context" |
|||
"google.golang.org/grpc" |
|||
"google.golang.org/grpc/grpclog" |
|||
"taxcomputer" |
|||
) |
|||
type taxServer struct { |
|||
rate float64 |
|||
} |
|||
func (s *taxServer) Tax(ctx context.Context, |
|||
amt *taxcomputer.Amount) (*taxcomputer.Amount, error) { |
|||
if amt.Cents < 0 { |
|||
return nil, errors.New("Negative amounts not allowed") |
|||
} |
|||
return &taxcomputer.Amount{int32(float64(amt.Cents)*s.rate + .5)}, nil |
|||
} |
|||
func main() { |
|||
listener, err := net.Listen("tcp", ":1234") |
|||
if err != nil { |
if err != nil { |
||
grpclog.Fatalf(err.Error()) |
|||
} |
} |
||
grpcServer := grpc.NewServer() |
|||
}</lang> |
|||
taxcomputer.RegisterTaxComputerServer(grpcServer, &taxServer{.05}) |
|||
===Importer=== |
|||
grpcServer.Serve(listener) |
|||
<lang go>package main |
|||
}</syntaxhighlight> |
|||
'''Client:''' |
|||
<syntaxhighlight lang="go">package main |
|||
import ( |
import ( |
||
"fmt" |
"fmt" |
||
"net" |
|||
"golang.org/x/net/context" |
|||
"netchan" |
|||
" |
"google.golang.org/grpc" |
||
"google.golang.org/grpc/grpclog" |
|||
"taxcomputer" |
|||
) |
) |
||
func main() { |
func main() { |
||
conn, err := grpc.Dial("localhost:1234", grpc.WithInsecure()) |
|||
if len(os.Args) != 2 { |
|||
if err != nil { |
|||
fmt.Println("usage: imp <port>") |
|||
grpclog.Fatalf(err.Error()) |
|||
} |
} |
||
defer conn.Close() |
|||
client := taxcomputer.NewTaxComputerClient(conn) |
|||
amt := &taxcomputer.Amount{300} |
|||
tax, err := client.Tax(context.Background(), amt) |
|||
if err != nil { |
|||
grpclog.Fatalf(err.Error()) |
|||
} |
|||
fmt.Println("Tax on", amt.Cents, "cents is", tax.Cents, "cents") |
|||
}</syntaxhighlight> |
|||
{{out | Client output}} |
|||
<pre> |
|||
Tax on 300 cents is 15 cents |
|||
</pre> |
|||
===Apache Thrift=== |
|||
// make network connection to exporter |
|||
See https://thrift.apache.org/ |
|||
conn, err := net.Dial("tcp", "", "127.0.0.1:"+os.Args[1]) |
|||
'''.thrift''' |
|||
Like gRPC, Thrift requires a language independent interface definition file: |
|||
<syntaxhighlight lang="thrift">service TaxService { |
|||
i32 tax(1: i32 amt) |
|||
}</syntaxhighlight> |
|||
'''Server:''' |
|||
<syntaxhighlight lang="go">package main |
|||
import ( |
|||
"errors" |
|||
"log" |
|||
"git.apache.org/thrift.git/lib/go/thrift" |
|||
"gen-go/tax" |
|||
) |
|||
type taxHandler float64 |
|||
func (r taxHandler) Tax(amt int32) (int32, error) { |
|||
if amt < 0 { |
|||
return 0, errors.New("Negative amounts not allowed") |
|||
} |
|||
return int32(float64(amt)*float64(r) + .5), nil |
|||
} |
|||
func main() { |
|||
transport, err := thrift.NewTServerSocket("localhost:3141") |
|||
if err != nil { |
if err != nil { |
||
log.Fatal(err) |
|||
return |
|||
} |
} |
||
transFac := thrift.NewTTransportFactory() |
|||
protoFac := thrift.NewTCompactProtocolFactory() |
|||
proc := tax.NewTaxServiceProcessor(taxHandler(.05)) |
|||
s := thrift.NewTSimpleServer4(proc, transport, transFac, protoFac) |
|||
if err := s.Serve(); err != nil { |
|||
log.Fatal(err) |
|||
} |
|||
}</syntaxhighlight> |
|||
'''Client:''' |
|||
<syntaxhighlight lang="go">package main |
|||
import ( |
|||
// create channel importer |
|||
"fmt" |
|||
imp := netchan.NewImporter(conn) |
|||
"log" |
|||
"git.apache.org/thrift.git/lib/go/thrift" |
|||
// create channels of identical type as created in exporter process. |
|||
squareCh := make(chan int) |
|||
resultCh := make(chan int) |
|||
"gen-go/tax" |
|||
// import connects channels in this process to matching exported |
|||
) |
|||
// channels in exporter process. |
|||
err = imp.Import("square", squareCh, netchan.Send, 1) |
|||
func main() { |
|||
transport, err := thrift.NewTSocket("localhost:3141") |
|||
if err != nil { |
if err != nil { |
||
log.Fatal(err) |
|||
return |
|||
} |
} |
||
err = |
if err := transport.Open(); err != nil { |
||
log.Fatal(err) |
|||
} |
|||
protoFac := thrift.NewTCompactProtocolFactory() |
|||
client := tax.NewTaxServiceClientFactory(transport, protoFac) |
|||
amt := int32(300) |
|||
t, err := client.Tax(amt) |
|||
if err != nil { |
if err != nil { |
||
log.Print(err) |
|||
} else { |
|||
fmt.Println("tax on", amt, "is", t) |
|||
} |
} |
||
transport.Close() |
|||
}</syntaxhighlight> |
|||
// now use channels as usual |
|||
{{out | Client output}} |
|||
squareCh <- 12 |
|||
fmt.Println("12 squared is", <-resultCh) |
|||
}</lang> |
|||
Exporter is started first. Output: |
|||
<pre> |
<pre> |
||
tax on 300 is 15 |
|||
square, result on port: 51951 |
|||
Waiting for importer... |
|||
</pre> |
|||
Importer session: |
|||
<pre> |
|||
> imp 51951 |
|||
12 squared is 144 |
|||
</pre> |
</pre> |
||
=={{header|Haskell}}== |
|||
See: |
|||
* http://www.haskell.org/haskellwiki/HaXR#Server |
|||
* http://www.haskell.org/haskellwiki/HaXR#Client |
|||
Check license: |
|||
http://www.haskell.org/haskellwiki/HaskellWiki:Copyrights |
|||
=={{header|JavaScript}}== |
=={{header|JavaScript}}== |
||
Line 786: | Line 735: | ||
===Server=== |
===Server=== |
||
< |
<syntaxhighlight lang="javascript">var net = require('net') |
||
var server = net.createServer(function (c){ |
var server = net.createServer(function (c){ |
||
Line 794: | Line 743: | ||
server.listen(3000, 'localhost') |
server.listen(3000, 'localhost') |
||
</syntaxhighlight> |
|||
</lang> |
|||
===Client=== |
===Client=== |
||
< |
<syntaxhighlight lang="javascript">var net = require('net') |
||
conn = net.createConnection(3000, '192.168.1.x') |
conn = net.createConnection(3000, '192.168.1.x') |
||
Line 808: | Line 757: | ||
conn.on('data', function(msg){ |
conn.on('data', function(msg){ |
||
console.log(msg.toString()) |
console.log(msg.toString()) |
||
})</ |
})</syntaxhighlight> |
||
=={{header|Julia}}== |
|||
Julia was designed with distributed conmputing. in particular cluster computing, as a primary use target. |
|||
If a group of CPUs, including multiple cores on a single machine or a cluster running with paswordless ssh login, is used, |
|||
the following can be set up as an example: |
|||
<syntaxhighlight lang="julia"># From Julia 1.0's online docs. File countheads.jl available to all machines: |
|||
function count_heads(n) |
|||
c::Int = 0 |
|||
for i = 1:n |
|||
c += rand(Bool) |
|||
end |
|||
c |
|||
end</syntaxhighlight> |
|||
We then run the following on the primary client: |
|||
<syntaxhighlight lang="julia"> |
|||
using Distributed |
|||
@everywhere include_string(Main, $(read("count_heads.jl", String)), "count_heads.jl") |
|||
a = @spawn count_heads(100000000) # runs on an available processor |
|||
b = @spawn count_heads(100000000) # runs on another available processor |
|||
println(fetch(a)+fetch(b)) # total heads of 200 million coin flips, half on each CPU |
|||
</syntaxhighlight> {{output}} <pre> |
|||
100001564 |
|||
</pre> |
|||
=={{header|LFE}}== |
|||
The protocol used is the one native to Erlang (and thus native to LFE, Lisp Flavored Erlang). |
|||
These examples are done completely in the LFE REPL. |
|||
===Server=== |
|||
In one terminal window, start up the REPL |
|||
<syntaxhighlight lang="bash"> |
|||
$ ./bin/lfe |
|||
Erlang/OTP 17 [erts-6.2] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false] |
|||
LFE Shell V6.2 (abort with ^G) |
|||
> |
|||
</syntaxhighlight> |
|||
And then enter the following code |
|||
<syntaxhighlight lang="lisp"> |
|||
> (defun get-server-name () |
|||
(list_to_atom (++ "exampleserver@" (element 2 (inet:gethostname))))) |
|||
> (defun start () |
|||
(net_kernel:start `(,(get-server-name) shortnames)) |
|||
(erlang:set_cookie (node) 'rosettaexample) |
|||
(let ((pid (spawn #'listen/0))) |
|||
(register 'serverref pid) |
|||
(io:format "~p ready~n" (list (node pid))) |
|||
'ok)) |
|||
> (defun listen () |
|||
(receive |
|||
(`#(echo ,pid ,data) |
|||
(io:format "Got ~p from ~p~n" (list data (node pid))) |
|||
(! pid `#(hello ,data)) |
|||
(listen)) |
|||
(x |
|||
(io:format "Unexpected pattern: ~p~n" `(,x))))) |
|||
</syntaxhighlight> |
|||
===Client=== |
|||
In another terminal window, start up another LFE REPL and ender the following code: |
|||
<syntaxhighlight lang="lisp"> |
|||
> (defun get-server-name () |
|||
(list_to_atom (++ "exampleserver@" (element 2 (inet:gethostname))))) |
|||
> (defun send (data) |
|||
(net_kernel:start '(exampleclient shortnames)) |
|||
(erlang:set_cookie (node) 'rosettaexample) |
|||
(io:format "connecting to ~p~n" `(,(get-server-name))) |
|||
(! `#(serverref ,(get-server-name)) `#(echo ,(self) ,data)) |
|||
(receive |
|||
(`#(hello ,data) |
|||
(io:format "Received ~p~n" `(,data))) |
|||
(x |
|||
(io:format "Unexpected pattern: ~p~n" (list x)))) |
|||
'ok) |
|||
</syntaxhighlight> |
|||
To use this code, simply start the server in the server terminal: |
|||
<syntaxhighlight lang="lisp"> |
|||
> (start) |
|||
exampleserver@yourhostname ready |
|||
ok |
|||
(exampleserver@yourhostname)> |
|||
</syntaxhighlight> |
|||
Send some messages from the client terminal: |
|||
<syntaxhighlight lang="lisp"> |
|||
> (send "hi there") |
|||
connecting to exampleserver@yourhostname |
|||
Received "hi there" |
|||
ok |
|||
(exampleclient@yourhostname)> (send 42) |
|||
connecting to exampleserver@yourhostname |
|||
Received 42 |
|||
ok |
|||
(exampleclient@yourhostname)> (send #(key value)) |
|||
connecting to exampleserver@yourhostname |
|||
Received {key,value} |
|||
ok |
|||
(exampleclient@yourhostname)> |
|||
</syntaxhighlight> |
|||
And check out the results back in the server terminal window: |
|||
<syntaxhighlight lang="lisp"> |
|||
Got "hi there" from exampleclient@yourhostname |
|||
Got 42 from exampleclient@yourhostname |
|||
Got {key,value} from exampleclient@yourhostname |
|||
</syntaxhighlight> |
|||
=={{header|Mathematica}} / {{header|Wolfram Language}}== |
|||
The following sends a request for a random number to be generated on each of two nodes, these are then transmitted back to be assembled into an array with two elements. Omitting the first line, will cause the program to be run on all configured remote computers. |
|||
<syntaxhighlight lang="mathematica">LaunchKernels[2]; |
|||
ParallelEvaluate[RandomReal[]] |
|||
</syntaxhighlight> |
|||
=={{header|Nim}}== |
|||
{{libheader|nanomsg}} |
|||
<syntaxhighlight lang="nim">import os, nanomsg |
|||
proc sendMsg(s: cint, msg: string) = |
|||
echo "SENDING \"",msg,"\"" |
|||
let bytes = s.send(msg.cstring, msg.len + 1, 0) |
|||
assert bytes == msg.len + 1 |
|||
proc recvMsg(s: cint) = |
|||
var buf: cstring |
|||
let bytes = s.recv(addr buf, MSG, 0) |
|||
if bytes > 0: |
|||
echo "RECEIVED \"",buf,"\"" |
|||
discard freemsg buf |
|||
proc sendRecv(s: cint, msg: string) = |
|||
var to: cint = 100 |
|||
discard s.setSockOpt(SOL_SOCKET, RCVTIMEO, addr to, sizeof to) |
|||
while true: |
|||
s.recvMsg |
|||
sleep 1000 |
|||
s.sendMsg msg |
|||
proc node0(url: string) = |
|||
var s = socket(AF_SP, nanomsg.PAIR) |
|||
assert s >= 0 |
|||
let res = s.bindd url |
|||
assert res >= 0 |
|||
s.sendRecv "node0" |
|||
discard s.shutdown 0 |
|||
proc node1(url: string) = |
|||
var s = socket(AF_SP, nanomsg.PAIR) |
|||
assert s >= 0 |
|||
let res = s.connect url |
|||
assert res >= 0 |
|||
s.sendRecv "node1" |
|||
discard s.shutdown 0 |
|||
if paramStr(1) == "node0": |
|||
node0 paramStr(2) |
|||
elif paramStr(1) == "node1": |
|||
node1 paramStr(2)</syntaxhighlight> |
|||
Usage: |
|||
<pre>./pair node0 tcp://127.0.0.1:25000 |
|||
./pair node1 tcp://127.0.0.1:25000</pre> |
|||
=={{header|Objective-C}}== |
=={{header|Objective-C}}== |
||
Line 818: | Line 945: | ||
<tt>ActionObjectProtocol.h</tt> |
<tt>ActionObjectProtocol.h</tt> |
||
< |
<syntaxhighlight lang="objc">#import <Foundation/Foundation.h> |
||
// our protocol allows "sending" "strings", but we can implement |
// our protocol allows "sending" "strings", but we can implement |
||
// everything we could for a "local" object |
// everything we could for a "local" object |
||
@protocol ActionObjectProtocol |
@protocol ActionObjectProtocol |
||
- (NSString *)sendMessage: (NSString *)msg; |
- (NSString *)sendMessage: (NSString *)msg; |
||
@end</ |
@end</syntaxhighlight> |
||
<tt>ActionObject.h</tt> |
<tt>ActionObject.h</tt> |
||
< |
<syntaxhighlight lang="objc">#import <Foundation/Foundation.h> |
||
#import "ActionObjectProtocol.h" |
#import "ActionObjectProtocol.h" |
||
@interface ActionObject : NSObject <ActionObjectProtocol> |
@interface ActionObject : NSObject <ActionObjectProtocol> |
||
// we do not have much for this example! |
// we do not have much for this example! |
||
@end</ |
@end</syntaxhighlight> |
||
<tt>ActionObject.m</tt> |
<tt>ActionObject.m</tt> |
||
< |
<syntaxhighlight lang="objc">#import <Foundation/Foundation.h> |
||
#import "ActionObject.h" |
#import "ActionObject.h" |
||
Line 843: | Line 970: | ||
return @"server answers ..."; |
return @"server answers ..."; |
||
} |
} |
||
@end</ |
@end</syntaxhighlight> |
||
<tt>server.m</tt> |
<tt>server.m</tt> |
||
< |
<syntaxhighlight lang="objc">#import <Foundation/Foundation.h> |
||
#import "ActionObject.h" |
#import "ActionObject.h" |
||
int main (void) |
int main (void) |
||
{ |
{ |
||
@autoreleasepool { |
|||
NSAutoreleasePool *pool; |
|||
ActionObject *action; |
|||
NSConnection *connect; |
|||
NSSocketPort *port; |
|||
ActionObject *action = [[ActionObject alloc] init]; |
|||
action = [[ActionObject alloc] init]; |
|||
port = (NSSocketPort *)[NSSocketPort port]; |
NSSocketPort *port = (NSSocketPort *)[NSSocketPort port]; |
||
// initWithTCPPort: 1234 and other methods are not supported yet |
// initWithTCPPort: 1234 and other methods are not supported yet |
||
// by GNUstep |
// by GNUstep |
||
connect = [NSConnection |
NSConnection *connect = [NSConnection |
||
connectionWithReceivePort: port |
connectionWithReceivePort: port |
||
sendPort: port]; // or sendPort: nil |
sendPort: port]; // or sendPort: nil |
||
[connect setRootObject: action]; |
[connect setRootObject: action]; |
||
/* "vend" the object ActionObject as DistributedAction; on GNUstep |
/* "vend" the object ActionObject as DistributedAction; on GNUstep |
||
the Name Server that allows the resolution of the registered name |
the Name Server that allows the resolution of the registered name |
||
is bound to port 538 */ |
is bound to port 538 */ |
||
if ([connect registerName:@"DistributedAction" |
if (![connect registerName:@"DistributedAction" |
||
withNameServer: [NSSocketPortNameServer sharedInstance] ] |
withNameServer: [NSSocketPortNameServer sharedInstance] ]) |
||
{ |
{ |
||
NSLog(@"can't register the server DistributedAction"); |
NSLog(@"can't register the server DistributedAction"); |
||
exit(EXIT_FAILURE); |
exit(EXIT_FAILURE); |
||
} |
} |
||
NSLog(@"waiting for messages..."); |
NSLog(@"waiting for messages..."); |
||
[[NSRunLoop currentRunLoop] run]; |
[[NSRunLoop currentRunLoop] run]; |
||
} |
|||
[pool release]; |
|||
return 0; |
return 0; |
||
}</ |
}</syntaxhighlight> |
||
===Client=== |
===Client=== |
||
<tt>client.m</tt> |
<tt>client.m</tt> |
||
< |
<syntaxhighlight lang="objc">#import <Foundation/Foundation.h> |
||
#import "ActionObjectProtocol.h" |
#import "ActionObjectProtocol.h" |
||
int main(void) |
int main(void) |
||
{ |
{ |
||
@autoreleasepool { |
|||
NSAutoreleasePool *pool; |
|||
NSArray *args; |
|||
id <ActionObjectProtocol> action; |
|||
NSString *msg, *backmsg; |
|||
id <ActionObjectProtocol> action = (id <ActionObjectProtocol>) |
|||
pool = [[NSAutoreleasePool alloc] init]; |
|||
[NSConnection |
|||
rootProxyForConnectionWithRegisteredName: @"DistributedAction" |
|||
host: @"localhost" |
|||
usingNameServer: [NSSocketPortNameServer sharedInstance] ]; |
|||
if (action == nil) |
|||
action = (id <ActionObjectProtocol>) |
|||
{ |
|||
NSLog(@"can't connect to the server"); |
|||
rootProxyForConnectionWithRegisteredName: @"DistributedAction" |
|||
exit(EXIT_FAILURE); |
|||
} |
|||
usingNameServer: [NSSocketPortNameServer sharedInstance] ]; |
|||
if (action == nil) |
|||
{ |
|||
NSLog(@"can't connect to the server"); |
|||
exit(EXIT_FAILURE); |
|||
} |
|||
args = [[NSProcessInfo processInfo] arguments]; |
NSArray *args = [[NSProcessInfo processInfo] arguments]; |
||
if ([args count] == 1) |
if ([args count] == 1) |
||
{ |
{ |
||
NSLog(@"specify a message"); |
NSLog(@"specify a message"); |
||
exit(EXIT_FAILURE); |
exit(EXIT_FAILURE); |
||
} |
} |
||
msg = |
NSString *msg = args[1]; |
||
// "send" (call the selector "sendMessage:" of the (remote) object |
// "send" (call the selector "sendMessage:" of the (remote) object |
||
// action) the first argument's text as msg, store the message "sent |
// action) the first argument's text as msg, store the message "sent |
||
// back" and then show it in the log |
// back" and then show it in the log |
||
backmsg = [action sendMessage: msg]; |
NSString *backmsg = [action sendMessage: msg]; |
||
NSLog("%@", backmsg); |
NSLog("%@", backmsg); |
||
} |
|||
[pool release]; |
|||
return 0; |
return 0; |
||
}</ |
}</syntaxhighlight> |
||
=={{header|OCaml}}== |
=={{header|OCaml}}== |
||
Line 939: | Line 1,056: | ||
=== Server === |
=== Server === |
||
< |
<syntaxhighlight lang="ocaml">open Printf |
||
let create_logger () = |
let create_logger () = |
||
Line 961: | Line 1,078: | ||
register "search" search; |
register "search" search; |
||
Join.Site.listen (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345)); |
Join.Site.listen (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345)); |
||
wait ()</ |
wait ()</syntaxhighlight> |
||
=== Client === |
=== Client === |
||
< |
<syntaxhighlight lang="ocaml">open Printf |
||
let ns_there = Join.Ns.there (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345)) |
let ns_there = Join.Ns.there (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345)) |
||
Line 985: | Line 1,102: | ||
log "foo"; |
log "foo"; |
||
log "shoe"; |
log "shoe"; |
||
find "foo"</ |
find "foo"</syntaxhighlight> |
||
=={{header|Oz}}== |
=={{header|Oz}}== |
||
We show a program that starts a server on a remote machine, exchanges two messages with that server and finally shuts it down. |
We show a program that starts a server on a remote machine, exchanges two messages with that server and finally shuts it down. |
||
< |
<syntaxhighlight lang="oz">declare |
||
functor ServerCode |
functor ServerCode |
||
export |
export |
||
Line 1,029: | Line 1,146: | ||
%% shut down server |
%% shut down server |
||
{RM close}</ |
{RM close}</syntaxhighlight> |
||
=={{header|Perl}}== |
|||
Using Data::Dumper and Safe to transmit arbitrary data structures as serialized text between hosts. Same code works as both sender and receiver. |
|||
<syntaxhighlight lang="perl">use strict; |
|||
use warnings; |
|||
use Data::Dumper; |
|||
use IO::Socket::INET; |
|||
use Safe; |
|||
sub get_data { |
|||
my $sock = IO::Socket::INET->new( |
|||
LocalHost => "localhost", |
|||
LocalPort => "10000", |
|||
Proto => "tcp", |
|||
Listen => 1, |
|||
Reuse => 1); |
|||
unless ($sock) { die "Socket creation failure" } |
|||
my $cli = $sock->accept(); |
|||
# of course someone may be tempted to send you 'system("rm -rf /")', |
|||
# to be safe(r), use Safe:: |
|||
my $safe = Safe->new; |
|||
my $x = $safe->reval(join("", <$cli>)); |
|||
close $cli; |
|||
close $sock; |
|||
return $x; |
|||
} |
|||
sub send_data { |
|||
my $host = shift; |
|||
my $data = shift; |
|||
my $sock = IO::Socket::INET->new( |
|||
PeerAddr => "$host:10000", |
|||
Proto => "tcp", |
|||
Reuse => 1); |
|||
unless ($sock) { die "Socket creation failure" } |
|||
print $sock Data::Dumper->Dump([$data]); |
|||
close $sock; |
|||
} |
|||
if (@ARGV) { |
|||
my $x = get_data(); |
|||
print "Got data\n", Data::Dumper->Dump([$x]); |
|||
} else { |
|||
send_data('some_host', { a=>100, b=>[1 .. 10] }); |
|||
}</syntaxhighlight> |
|||
=={{header|Phix}}== |
|||
From/using [http://phix.x10.mx/pmwiki/pmwiki.php?n=Main.Libzmq the ZeroMQ wrapper from PCAN], a suitable simple publish/subscriber pair. |
|||
There is also a server/client/broker example. |
|||
Obviously you can trivially serialize() and deserialize() any Phix data to and from a string. |
|||
<!--<syntaxhighlight lang="phix">(notonline)--> |
|||
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (zmq dll/so)</span> |
|||
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"durapub:\n"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #008080;">include</span> <span style="color: #000000;">zmq</span><span style="color: #0000FF;">/</span><span style="color: #000000;">zmq</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span> |
|||
<span style="color: #004080;">atom</span> <span style="color: #000000;">context</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_init</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_assert</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"zmq_init"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000080;font-style:italic;">--// subscriber tells us when it's ready here</span> |
|||
<span style="color: #004080;">atom</span> <span style="color: #000000;">sync</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_PULL</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_bind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://*:5564"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000080;font-style:italic;">--// send update via this socket</span> |
|||
<span style="color: #004080;">atom</span> <span style="color: #000000;">publisher</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_PUB</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_bind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://*:5565"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000080;font-style:italic;">--// broadcast 10 updates, with pause</span> |
|||
<span style="color: #008080;">for</span> <span style="color: #000000;">update_nbr</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">10</span> <span style="color: #008080;">do</span> |
|||
<span style="color: #004080;">string</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Update %d"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">update_nbr</span> <span style="color: #0000FF;">})</span> |
|||
<span style="color: #000000;">zmq_s_send</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #7060A8;">sleep</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span> |
|||
<span style="color: #000000;">zmq_s_send</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"END"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #7060A8;">sleep</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_term</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">)</span> |
|||
<!--</syntaxhighlight>--> |
|||
<!--<syntaxhighlight lang="phix">(notonline)--> |
|||
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (zmq dll/so)</span> |
|||
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"durasub:\n"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #008080;">include</span> <span style="color: #000000;">zmq</span><span style="color: #0000FF;">/</span><span style="color: #000000;">zmq</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span> |
|||
<span style="color: #004080;">atom</span> <span style="color: #000000;">context</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_init</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_assert</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"zmq_init"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000080;font-style:italic;">--// connect our subscriber socket</span> |
|||
<span style="color: #004080;">atom</span> <span style="color: #000000;">subscriber</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_SUB</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #004080;">atom</span> <span style="color: #000000;">id</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">allocate_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Hello"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_setsockopt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_IDENTITY</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">id</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">5</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_setsockopt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_SUBSCRIBE</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_connect</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://localhost:5565"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #7060A8;">free</span><span style="color: #0000FF;">(</span><span style="color: #000000;">id</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000080;font-style:italic;">--// synchronise with publisher</span> |
|||
<span style="color: #004080;">atom</span> <span style="color: #000000;">sync</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_PUSH</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_connect</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://localhost:5564"</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_s_send</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">""</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000080;font-style:italic;">--// get updates, Ctrl-C break</span> |
|||
<span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span> |
|||
<span style="color: #004080;">string</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_s_recv</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"%s\n"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">s</span><span style="color: #0000FF;">})</span> |
|||
<span style="color: #008080;">if</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">==</span><span style="color: #008000;">"END"</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> |
|||
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span> |
|||
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">)</span> |
|||
<span style="color: #000000;">zmq_term</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">)</span> |
|||
<!--</syntaxhighlight>--> |
|||
=={{header|PicoLisp}}== |
=={{header|PicoLisp}}== |
||
===Server=== |
===Server=== |
||
< |
<syntaxhighlight lang="picolisp">(task (port 12321) # Background server task |
||
(let? Sock (accept @) |
(let? Sock (accept @) |
||
(unless (fork) # Handle request in child process |
(unless (fork) # Handle request in child process |
||
Line 1,041: | Line 1,274: | ||
(pr (eval @)) ) ) ) # Evaluate and send reply |
(pr (eval @)) ) ) ) # Evaluate and send reply |
||
(bye) ) # Exit child process |
(bye) ) # Exit child process |
||
(close Sock) ) ) # Close socket in parent process</ |
(close Sock) ) ) # Close socket in parent process</syntaxhighlight> |
||
===Client=== |
===Client=== |
||
< |
<syntaxhighlight lang="picolisp">(let? Sock (connect "localhost" 12321) |
||
(out Sock (pr '*Pid)) # Query PID from server |
(out Sock (pr '*Pid)) # Query PID from server |
||
(println 'PID (in Sock (rd))) # Receive and print reply |
(println 'PID (in Sock (rd))) # Receive and print reply |
||
(out Sock (pr '(* 3 4))) # Request some calculation |
(out Sock (pr '(* 3 4))) # Request some calculation |
||
(println 'Result (in Sock (rd))) # Print result |
(println 'Result (in Sock (rd))) # Print result |
||
(close Sock) ) # Close connection to server</ |
(close Sock) ) # Close connection to server</syntaxhighlight> |
||
Output: |
Output: |
||
<pre>PID 18372 |
<pre>PID 18372 |
||
Line 1,060: | Line 1,293: | ||
==== Server ==== |
==== Server ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/env python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,097: | Line 1,330: | ||
except KeyboardInterrupt: |
except KeyboardInterrupt: |
||
print 'Exiting...' |
print 'Exiting...' |
||
server.server_close()</ |
server.server_close()</syntaxhighlight> |
||
==== Client ==== |
==== Client ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/env python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,122: | Line 1,355: | ||
# control if foo_function returns True |
# control if foo_function returns True |
||
if rpc.foo_function(): |
if rpc.foo_function(): |
||
print 'Server says: foo_function returned True'</ |
print 'Server says: foo_function returned True'</syntaxhighlight> |
||
===HTTP=== |
===HTTP=== |
||
Line 1,128: | Line 1,361: | ||
==== Server ==== |
==== Server ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,157: | Line 1,390: | ||
except KeyboardInterrupt: |
except KeyboardInterrupt: |
||
print 'Exiting...' |
print 'Exiting...' |
||
server.server_close()</ |
server.server_close()</syntaxhighlight> |
||
==== Client ==== |
==== Client ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,174: | Line 1,407: | ||
print 'Server Status: %d' % response.status |
print 'Server Status: %d' % response.status |
||
print 'Server Message: %s' % response.read()</ |
print 'Server Message: %s' % response.read()</syntaxhighlight> |
||
===Socket, |
===Socket, Pickle format=== |
||
{{incomplete|Python}} |
|||
'''Protocol:''' Plain Text |
|||
'''Protocol:''' raw socket / pickle format |
|||
Use with Pythons [http://docs.python.org/library/pickle.html#module-pickle pickle module] for data serialization into printable text would allow the transfer of arbitrary Python data, but as it stands, this method is too low level to fulfill the task. |
|||
This example builds a very basic RPC mechanism on top of sockets and the [http://docs.python.org/library/pickle.html#module-pickle pickle module]. Please note that the pickle module is not secure - a malicious client can build malformed data to execute arbitrary code on the server. If untrusted clients can access the server, the [http://docs.python.org/library/json.html json module] could be used as a substitute, but we lose the ability to transfer arbitrary Python objects that way. |
|||
==== Server ==== |
==== Server ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
import SocketServer |
import SocketServer |
||
import pickle |
|||
HOST = "localhost" |
HOST = "localhost" |
||
PORT = 8000 |
PORT = 8000 |
||
class RPCServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer): |
|||
# our instance that will upper whatever it gets and send back to client |
|||
# The object_to_proxy member should be set to the object we want |
|||
class UpperCaseHandler(SocketServer.StreamRequestHandler): |
|||
# methods called on. Unfortunately, we can't do this in the constructor |
|||
# because the constructor should not be overridden in TCPServer... |
|||
daemon_threads = True |
|||
class RPCHandler(SocketServer.StreamRequestHandler): |
|||
def handle(self): |
def handle(self): |
||
in_channel = pickle.Unpickler(self.rfile) |
|||
print '%s connected' % self.client_address[0] |
|||
out_channel = pickle.Pickler(self.wfile, protocol=2) |
|||
# get what client sends |
|||
while True: |
|||
try: |
|||
name, args, kwargs = in_channel.load() |
|||
self.wfile.write(get.upper()) |
|||
print 'got %s %s %s' % (name, args, kwargs) |
|||
except EOFError: |
|||
# EOF means we're done with this request. |
|||
# Catching this exception to detect EOF is a bit hackish, |
|||
# but will work for a quick demo like this |
|||
break |
|||
try: |
|||
method = getattr(self.server.object_to_proxy, name) |
|||
result = method(*args, **kwargs) |
|||
except Exception, e: |
|||
out_channel.dump(('Error',e)) |
|||
else: |
|||
out_channel.dump(('OK',result)) |
|||
class MyHandlerInstance(object): |
|||
def echo(self, data): |
|||
'''Method for returning data got from client''' |
|||
return 'Server responded: %s' % data |
|||
def div(self, dividend, divisor): |
|||
'''Method to divide 2 numbers''' |
|||
return dividend/divisor |
|||
def is_computer_on(self): |
|||
return True |
|||
if __name__ == '__main__': |
if __name__ == '__main__': |
||
rpcserver = RPCServer((HOST, PORT), RPCHandler) |
|||
rpcserver.object_to_proxy = MyHandlerInstance() |
|||
try: |
try: |
||
rpcserver.serve_forever() |
|||
except KeyboardInterrupt: |
except KeyboardInterrupt: |
||
print 'Exiting...' |
print 'Exiting...' |
||
rpcserver.server_close() |
|||
</syntaxhighlight> |
|||
==== Client ==== |
==== Client ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
import socket |
import socket |
||
import pickle |
|||
HOST = "localhost" |
HOST = "localhost" |
||
PORT = 8000 |
PORT = 8000 |
||
class RPCClient(object): |
|||
DATA = "my name is eren" |
|||
def __init__(self, host, port): |
|||
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) |
|||
self.socket.connect((host, port)) |
|||
self.rfile = self.socket.makefile('rb') |
|||
self.wfile = self.socket.makefile('wb') |
|||
self.in_channel = pickle.Unpickler(self.rfile) |
|||
self.out_channel = pickle.Pickler(self.wfile, protocol=2) |
|||
def _close(self): |
|||
# connect to server and send data |
|||
self.socket.close() |
|||
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) |
|||
self.rfile.close() |
|||
sock.connect((HOST, PORT)) |
|||
self.wfile.close() |
|||
sock.send("%s\n" % DATA) |
|||
# Make calling remote methods easy by overriding attribute access. |
|||
# get |
|||
# Accessing any attribute on our instances will give a proxy method that |
|||
response = sock.recv(256) |
|||
# calls the method with the same name on the remote machine. |
|||
sock.close() |
|||
def __getattr__(self, name): |
|||
def proxy(*args, **kwargs): |
|||
self.out_channel.dump((name, args, kwargs)) |
|||
self.wfile.flush() # to make sure the server won't wait forever |
|||
status, result = self.in_channel.load() |
|||
if status == 'OK': |
|||
return result |
|||
else: |
|||
raise result |
|||
return proxy |
|||
if __name__ == '__main__': |
|||
# connect to server and send data |
|||
rpcclient = RPCClient(HOST, PORT) |
|||
print 'Testing the echo() method:' |
|||
print "We sent: %s" % DATA |
|||
print rpcclient.echo('Hello world!') |
|||
print 'Server responded: %s' % response</lang> |
|||
print |
|||
print 'Calculating 42/2 on the remote machine:' |
|||
print rpcclient.div(42, 2) |
|||
print |
|||
print 'is_computer_on on the remote machine returns:' |
|||
print rpcclient.is_computer_on() |
|||
print |
|||
print 'Testing keyword args:' |
|||
print '42/2 is:', rpcclient.div(divisor=2, dividend=42) |
|||
rpcclient._close() |
|||
del rpcclient</syntaxhighlight> |
|||
===Pyro=== |
===Pyro=== |
||
Line 1,235: | Line 1,536: | ||
==== Server ==== |
==== Server ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,260: | Line 1,561: | ||
except KeyboardInterrupt: |
except KeyboardInterrupt: |
||
print 'Exiting...' |
print 'Exiting...' |
||
server.shutdown()</ |
server.shutdown()</syntaxhighlight> |
||
==== Client ==== |
==== Client ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,279: | Line 1,580: | ||
print 'We sent two numbers to divide: %d and %d' % (NUM1, NUM2) |
print 'We sent two numbers to divide: %d and %d' % (NUM1, NUM2) |
||
print 'Server responded the result: %s' % math.div(NUM1, NUM2)</ |
print 'Server responded the result: %s' % math.div(NUM1, NUM2)</syntaxhighlight> |
||
=== Spread === |
=== Spread === |
||
Line 1,290: | Line 1,591: | ||
==== Client (Listener) ==== |
==== Client (Listener) ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,307: | Line 1,608: | ||
if hasattr(recv, 'sender') and hasattr(recv, 'message'): |
if hasattr(recv, 'sender') and hasattr(recv, 'message'): |
||
print 'Sender: %s' % recv.sender |
print 'Sender: %s' % recv.sender |
||
print 'Message: %s' % recv.message</ |
print 'Message: %s' % recv.message</syntaxhighlight> |
||
==== Client (Sender) ==== |
==== Client (Sender) ==== |
||
< |
<syntaxhighlight lang="python">#!/usr/bin/python |
||
# -*- coding: utf-8 -*- |
# -*- coding: utf-8 -*- |
||
Line 1,321: | Line 1,622: | ||
conn.multicast(spread.RELIABLE_MESS, 'test', 'hello, this is message sent from python') |
conn.multicast(spread.RELIABLE_MESS, 'test', 'hello, this is message sent from python') |
||
conn.disconnect()</ |
conn.disconnect()</syntaxhighlight> |
||
=={{header|Racket}}== |
|||
Server and client in the same piece of code, running a useless (fib 42) computation, four times, on four hosts (which all happen to be "localhost", but that can change, of course). |
|||
<syntaxhighlight lang="racket"> |
|||
#lang racket/base |
|||
(require racket/place/distributed racket/place) |
|||
(define (fib n) |
|||
(if (<= n 1) n (+ (fib (- n 1)) (fib (- n 2))))) |
|||
(provide work) |
|||
(define (work) |
|||
(place ch |
|||
(place-channel-put ch (fib (place-channel-get ch))))) |
|||
(module+ main |
|||
(define places |
|||
(for/list ([host '("localhost" "localhost" "localhost" "localhost")] |
|||
[port (in-naturals 12345)]) |
|||
(define-values [node place] |
|||
(spawn-node-supervise-place-at host #:listen-port port #:thunk #t |
|||
(quote-module-path "..") 'work)) |
|||
place)) |
|||
(message-router |
|||
(after-seconds 1 |
|||
(for ([p places]) (*channel-put p 42)) |
|||
(printf "Results: ~s\n" (map *channel-get places)) |
|||
(exit)))) |
|||
</syntaxhighlight> |
|||
=={{header|Raku}}== |
|||
(formerly Perl 6) |
|||
Server listens for JSON encoded messages. It processes requests for set|get|dump. 'set' stores a message, 'get' returns message, 'dump' returns all stored messages. Optional parameters for ip address and port. |
|||
Server.raku: |
|||
<pre>./server.raku --usage |
|||
Usage: |
|||
server.p6 [--server=<Any>] [--port=<Any>]</pre> |
|||
<syntaxhighlight lang="raku" line>#!/usr/bin/env raku |
|||
use JSON::Fast ; |
|||
sub MAIN( :$server='0.0.0.0' , :$port=3333 ) { |
|||
my %db ; |
|||
react { |
|||
whenever IO::Socket::Async.listen( $server , $port ) -> $conn { |
|||
whenever $conn.Supply.lines -> $line { |
|||
my %response = 'status' => '' ; |
|||
my $msg = from-json $line ; |
|||
say $msg.raku; |
|||
given $msg{"function"} { |
|||
when 'set' { |
|||
%db{ $msg<topic> } = $msg<message> ; |
|||
%response<status> = 'ok' ; |
|||
} |
|||
when 'get' { |
|||
%response<topic> = $msg<topic> ; |
|||
%response<message> = %db{ $msg<topic> } ; |
|||
%response<status> = 'ok' ; |
|||
} |
|||
when 'dump' { |
|||
%response = %db ; |
|||
} |
|||
when 'delete' { |
|||
%db{ $msg<topic> }:delete; |
|||
%response<status> = 'ok' ; |
|||
} |
|||
} |
|||
$conn.print( to-json(%response, :!pretty) ~ "\n" ) ; |
|||
LAST { $conn.close ; } |
|||
QUIT { default { $conn.close ; say "oh no, $_";}} |
|||
CATCH { default { say .^name, ': ', .Str , " handled in $?LINE";}} |
|||
} |
|||
} |
|||
} |
|||
}</syntaxhighlight> |
|||
client.raku: |
|||
<pre>Usage: |
|||
client.raku [--server=<Any>] [--port=<Any>] [--json=<Any>] set <topic> [<message>] |
|||
client.raku [--server=<Any>] [--port=<Any>] get <topic> |
|||
client.raku [--server=<Any>] [--port=<Any>] dump</pre> |
|||
<syntaxhighlight lang="raku" line>#!/usr/bin/env raku |
|||
use JSON::Fast ; |
|||
multi MAIN('set', $topic, $message='', :$server='localhost', :$port='3333', :$json='') { |
|||
my %msg = function => 'set' , topic=> $topic , message=> $message ; |
|||
%msg{"message"} = from-json( $json ) if $json ; |
|||
sendmsg( %msg , $server, $port) ; |
|||
} |
|||
multi MAIN('get', $topic, :$server='localhost', :$port='3333') { |
|||
my %msg = function => 'get' , topic=> $topic ; |
|||
sendmsg( %msg , $server, $port) ; |
|||
} |
|||
multi MAIN('delete', $topic, :$server='localhost', :$port='3333') { |
|||
my %msg = function => 'delete' , topic=> $topic ; |
|||
sendmsg( %msg , $server, $port) ; |
|||
} |
|||
multi MAIN('dump', :$server='localhost', :$port='3333') { |
|||
my %msg = function => 'dump' ; |
|||
sendmsg( %msg , $server, $port) ; |
|||
} |
|||
sub sendmsg( %msg , $server, $port){ |
|||
my $conn = await IO::Socket::Async.connect( $server , $port ); |
|||
$conn.print: to-json( %msg,:!pretty)~"\n"; |
|||
react { |
|||
whenever $conn.Supply -> $data { |
|||
print $data; |
|||
$conn.close; |
|||
} |
|||
} |
|||
}</syntaxhighlight> |
|||
examples: |
|||
<pre>echo '{"function":"set","topic":"push","message":["perl5","raku","rakudo"]}' | nc localhost 3333 |
|||
./client.raku set version raku |
|||
{"status": "ok"} |
|||
./client.raku get version |
|||
{"status": "ok","topic": "version","message": "raku"} |
|||
./client.raku --json='["one","two","three"]' set mylist |
|||
{"status": "ok"} |
|||
./client.raku dump |
|||
{"push": ["perl5","raku","rakudo"],"version": "raku","mylist": ["one","two","three"]} |
|||
./client.raku delete version |
|||
{"status": "ok"} |
|||
server output: |
|||
${:function("set"), :message($["perl5", "raku", "rakudo"]), :topic("push")} |
|||
${:function("set"), :message("raku"), :topic("version")} |
|||
${:function("get"), :topic("version")} |
|||
${:function("set"), :message($["one", "two", "three"]), :topic("mylist")} |
|||
${:function("dump")} |
|||
${:function("delete"), :topic("version")}</pre> |
|||
=={{header|Ruby}}== |
=={{header|Ruby}}== |
||
Uses the distributed Ruby (dRuby) from the standard library. The "druby:" protocol uses TCP/IP sockets for communication. |
|||
Uses {{libheader|dRuby}} |
|||
The "druby:" protocol uses TCP/IP sockets for communication. |
|||
'''Server''' |
'''Server''' |
||
< |
<syntaxhighlight lang="ruby">require 'drb/drb' |
||
# The URI for the server to connect to |
# The URI for the server to connect to |
||
Line 1,348: | Line 1,779: | ||
DRb.start_service(URI, FRONT_OBJECT) |
DRb.start_service(URI, FRONT_OBJECT) |
||
# Wait for the drb server thread to finish before exiting. |
# Wait for the drb server thread to finish before exiting. |
||
DRb.thread.join</ |
DRb.thread.join</syntaxhighlight> |
||
'''Client''' |
'''Client''' |
||
< |
<syntaxhighlight lang="ruby">require 'drb/drb' |
||
# The URI to connect to |
# The URI to connect to |
||
Line 1,364: | Line 1,795: | ||
timeserver = DRbObject.new_with_uri(SERVER_URI) |
timeserver = DRbObject.new_with_uri(SERVER_URI) |
||
puts timeserver.get_current_time</ |
puts timeserver.get_current_time</syntaxhighlight> |
||
=={{header|Tcl}}== |
=={{header|Tcl}}== |
||
A rudimentary IRC Server |
A rudimentary IRC Server |
||
< |
<syntaxhighlight lang="tcl">proc main {} { |
||
global connections |
global connections |
||
set connections [dict create] |
set connections [dict create] |
||
Line 1,430: | Line 1,861: | ||
} |
} |
||
main</ |
main</syntaxhighlight> |
||
Client |
Client |
||
< |
<syntaxhighlight lang="tcl">proc main {} { |
||
global argv argc |
global argv argc |
||
if {$argc != 2} { |
if {$argc != 2} { |
||
Line 1,467: | Line 1,898: | ||
} |
} |
||
main</ |
main</syntaxhighlight> |
||
=={{header|UnixPipes}}== |
=={{header|UnixPipes}}== |
||
{{libheader|nc}} |
|||
Uses netcat and a buffer to cycle the server shell's stdout back to netcat's stdin |
|||
Uses netcat and a buffer to cycle the server shell's stdout back to netcat's stdin. |
|||
===Server=== |
===Server=== |
||
{{alertbox|yellow|'''Security risk!''' Anything, able to reach 127.0.0.1 port 1234, can run shell commands as the user who runs the server. This allows other users to gain privileges.}} |
|||
<lang bash>tail -F /tmp/buffer | nc -l -p 1234 | &> /tmp/buffer</lang> |
|||
<syntaxhighlight lang="bash">: >/tmp/buffer |
|||
tail -f /tmp/buffer | nc -l 127.0.0.1 1234 | sh >/tmp/buffer 2>&1</syntaxhighlight> |
|||
Limitations: |
|||
* The server can accept only one connection (but continues to run, not exit, after this connection dies). |
|||
* With some systems, <code>tail -f</code> might be slow to notice changes to /tmp/buffer. |
|||
===Client=== |
===Client=== |
||
<lang |
<syntaxhighlight lang="bash">nc 127.0.0.1 1234</syntaxhighlight> |
||
Now you can enter commands in the client terminal and get the output back through the same connection. |
Now you can enter commands in the client terminal and get the output back through the same connection. |
||
=={{header|Wren}}== |
|||
{{trans|Go}} |
|||
{{libheader|WrenGo}} |
|||
{{libheader|Wren-fmt}} |
|||
As Wren has no networking support at present, we use embedded programs for both the server and client with a Go host using the net/rpc package in its standard library. |
|||
Moreover, as Wren's VM is not re-entrant, we need to run two VMs from the server side, one to call Go from Wren and the other to call Wren from Go. |
|||
'''Server:''' |
|||
<br> |
|||
We need two Wren scripts one for each VM: |
|||
<syntaxhighlight lang="wren">/* Distributed_programming_server.wren */ |
|||
class Rpc { |
|||
foreign static register() |
|||
foreign static handleHTTP() |
|||
} |
|||
foreign class Listener { |
|||
construct listen(network, address) {} |
|||
} |
|||
class HTTP { |
|||
foreign static serve(listener) |
|||
} |
|||
Rpc.register() |
|||
Rpc.handleHTTP() |
|||
var listener = Listener.listen("tcp", ":1234") |
|||
HTTP.serve(listener)</syntaxhighlight> |
|||
<br> |
|||
<syntaxhighlight lang="wren">/* Distributed_programming_server_2.wren */ |
|||
class TaxComputer { |
|||
static tax(amount, rate) { |
|||
if (amount < 0) Fiber.abort("Negative values not allowed.") |
|||
return amount * rate |
|||
} |
|||
}</syntaxhighlight> |
|||
<br> |
|||
We now embed these scripts in the following Go program and run it on one terminal. |
|||
<syntaxhighlight lang="go">/* go run Distributed_programming_server.go */ |
|||
package main |
|||
import( |
|||
wren "github.com/crazyinfin8/WrenGo" |
|||
"log" |
|||
"net" |
|||
"net/http" |
|||
"net/rpc" |
|||
) |
|||
type any = interface{} |
|||
type TaxComputer float64 |
|||
var vm2 *wren.VM |
|||
var fileName = "Distributed_programming_server.wren" |
|||
var fileName2 = "Distributed_programming_server_2.wren" |
|||
func (taxRate TaxComputer) Tax(x float64, r *float64) error { |
|||
wrenVar, _ := vm2.GetVariable(fileName2, "TaxComputer") |
|||
wrenClass, _ := wrenVar.(*wren.Handle) |
|||
defer wrenClass.Free() |
|||
wrenMethod, _ := wrenClass.Func("tax(_,_)") |
|||
defer wrenMethod.Free() |
|||
ret, _ := wrenMethod.Call(x, float64(taxRate)) |
|||
*r = ret.(float64) |
|||
return nil |
|||
} |
|||
func register(vm *wren.VM, parameters []any) (any, error) { |
|||
c := TaxComputer(0.05) // 5% tax rate |
|||
rpc.Register(c) |
|||
return nil, nil |
|||
} |
|||
func handleHTTP(vm *wren.VM, parameters []any) (any, error) { |
|||
rpc.HandleHTTP() |
|||
return nil, nil |
|||
} |
|||
func serve(vm *wren.VM, parameters []any) (any, error) { |
|||
handle := parameters[1].(*wren.ForeignHandle) |
|||
ifc, _ := handle.Get() |
|||
listener := ifc.(*net.Listener) |
|||
http.Serve(*listener, nil) |
|||
return nil, nil |
|||
} |
|||
func listen(vm *wren.VM, parameters []any) (any, error) { |
|||
network := parameters[1].(string) |
|||
address := parameters[2].(string) |
|||
listener, err := net.Listen(network, address) |
|||
if err != nil { |
|||
log.Fatal(err) |
|||
} |
|||
return &listener, nil |
|||
} |
|||
func main() { |
|||
vm := wren.NewVM() |
|||
vm2 = wren.NewVM() |
|||
vm2.InterpretFile(fileName2) |
|||
rpcMethodMap := wren.MethodMap { |
|||
"static register()": register, |
|||
"static handleHTTP()": handleHTTP, |
|||
} |
|||
httpMethodMap := wren.MethodMap { "static serve(_)":serve } |
|||
classMap := wren.ClassMap { |
|||
"Listener": wren.NewClass(listen, nil, nil), |
|||
"Rpc" : wren.NewClass(nil, nil, rpcMethodMap), |
|||
"HTTP" : wren.NewClass(nil, nil, httpMethodMap), |
|||
} |
|||
module := wren.NewModule(classMap) |
|||
vm.SetModule(fileName, module) |
|||
vm.InterpretFile(fileName) |
|||
vm.Free() |
|||
vm2.Free() |
|||
}</syntaxhighlight> |
|||
<br> |
|||
'''Client:''' |
|||
<br> |
|||
Just one Wren script needed here: |
|||
<syntaxhighlight lang="wren">/* Distributed_programming_client.wren */ |
|||
import "./fmt" for Fmt |
|||
foreign class Client { |
|||
construct dialHTTP(network, address) {} |
|||
foreign call(serviceMethod, arg) |
|||
} |
|||
var client = Client.dialHTTP("tcp", "localhost:1234") |
|||
var amounts = [3, 5.6] |
|||
for (amount in amounts) { |
|||
var tax = client.call("TaxComputer.Tax", amount) |
|||
Fmt.print("Tax on $0.2f = $0.2f", amount, tax) |
|||
}</syntaxhighlight> |
|||
<br> |
|||
which we embed in the following Go program and run it on a different terminal. |
|||
<syntaxhighlight lang="go">/* go run Distributed_programming_client.go */ |
|||
package main |
|||
import( |
|||
wren "github.com/crazyinfin8/WrenGo" |
|||
"log" |
|||
"net/rpc" |
|||
"strings" |
|||
) |
|||
type any = interface{} |
|||
func dialHTTP(vm *wren.VM, parameters []any) (any, error) { |
|||
network := parameters[1].(string) |
|||
address := parameters[2].(string) |
|||
client, err := rpc.DialHTTP(network, address) |
|||
if err != nil { |
|||
log.Fatal(err) |
|||
} |
|||
return &client, nil |
|||
} |
|||
func call(vm *wren.VM, parameters []any) (any, error) { |
|||
handle := parameters[0].(*wren.ForeignHandle) |
|||
ifc, _ := handle.Get() |
|||
client := ifc.(**rpc.Client) |
|||
serviceMethod := parameters[1].(string) |
|||
amount := parameters[2].(float64) |
|||
var tax float64 |
|||
err := (*client).Call(serviceMethod, amount, &tax) |
|||
if err != nil { |
|||
log.Fatal(err) |
|||
} |
|||
return tax, nil |
|||
} |
|||
func moduleFn(vm *wren.VM, name string) (string, bool) { |
|||
if name != "meta" && name != "random" && !strings.HasSuffix(name, ".wren") { |
|||
name += ".wren" |
|||
} |
|||
return wren.DefaultModuleLoader(vm, name) |
|||
} |
|||
func main() { |
|||
cfg := wren.NewConfig() |
|||
cfg.LoadModuleFn = moduleFn |
|||
vm := cfg.NewVM() |
|||
fileName := "Distributed_programming_client.wren" |
|||
clientMethodMap := wren.MethodMap { "call(_,_)": call } |
|||
classMap := wren.ClassMap { "Client": wren.NewClass(dialHTTP, nil, clientMethodMap) } |
|||
module := wren.NewModule(classMap) |
|||
vm.SetModule(fileName, module) |
|||
vm.InterpretFile(fileName) |
|||
vm.Free() |
|||
}</syntaxhighlight> |
|||
{{out}} |
|||
Output on the client terminal: |
|||
<pre> |
|||
Tax on 3.00 = 0.15 |
|||
Tax on 5.60 = 0.28 |
|||
</pre> |
|||
{{omit from|Lotus 123 Macro Scripting}} |
|||
{{omit from|Maxima}} |
|||
{{omit from|PARI/GP}} |
{{omit from|PARI/GP}} |
||
{{omit from|Retro}} |
{{omit from|Retro}} |
Latest revision as of 11:48, 26 November 2023
![Task](http://static.miraheze.org/rosettacodewiki/thumb/b/ba/Rcode-button-task-crushed.png/64px-Rcode-button-task-crushed.png)
You are encouraged to solve this task according to the task description, using any language you may know.
Write two programs (or one program with two modes) which run on networked computers, and send some messages between them.
The protocol used may be language-specific or not, and should be suitable for general distributed programming; that is, the protocol should be generic (not designed just for the particular example application), readily capable of handling the independent communications of many different components of a single application, and the transferring of arbitrary data structures natural for the language.
This task is intended to demonstrate high-level communication facilities beyond just creating sockets.
Ada
Ada defines facilities for distributed systems in its standard (Annex E, also called DSA).
This example works with PolyORB and the GNAT GPL 2010 compiler from AdaCore.
server.ads:
package Server is
pragma Remote_Call_Interface;
procedure Foo;
function Bar return Natural;
end Server;
server.adb:
package body Server is
Count : Natural := 0;
procedure Foo is
begin
Count := Count + 1;
end Foo;
function Bar return Natural is
begin
return Count;
end Bar;
end Server;
client.adb:
with Server;
with Ada.Text_IO;
procedure Client is
begin
Ada.Text_IO.Put_Line ("Calling Foo...");
Server.Foo;
Ada.Text_IO.Put_Line ("Calling Bar: " & Integer'Image (Server.Bar));
end Client;
required config (dsa.cfg):
configuration DSA is
pragma Starter (None);
-- Server
Server_Partition : Partition := (Server);
procedure Run_Server is in Server_Partition;
-- Client
Client_Partition : Partition;
for Client_Partition'Termination use Local_Termination;
procedure Client;
for Client_Partition'Main use Client;
end DSA;
compilation:
$po_gnatdist dsa.cfg [...] ------------------------------ ---- Configuration report ---- ------------------------------ Configuration : Name : dsa Main : run_server Starter : none Partition server_partition Main : run_server Units : - server (rci) - run_server (normal) - polyorb.dsa_p.partitions (rci, from PCS) Environment variables : - "POLYORB_DSA_NAME_SERVICE" Partition client_partition Main : client Termination : local Units : - client (normal) Environment variables : - "POLYORB_DSA_NAME_SERVICE" ------------------------------- [...]
preparation (run PolyORB name service):
$ po_ioc_naming POLYORB_CORBA_NAME_SERVICE=IOR:010000002b00000049444[...] POLYORB_CORBA_NAME_SERVICE=corbaloc:iiop:1.2@10.200.[...]
You have to set the environment variable POLYORB_DSA_NAME_SERVICE to one of the two values given by po_ioc_naming for the server/client partitions.
running server:
$ ./server_partition
running client:
$ ./client_partition Calling Foo... Calling Bar: 1 $ ./client_partition Calling Foo... Calling Bar: 2
AutoHotkey
See Distributed program/AutoHotkey.
C
Using PVM [1] This program is in a sense both a server and a client, depending on if its task is spawned with a command-line argument: if yes, it spawns another task of the same executible on the parallel virtual machine and waits for it to transmit data; if no, it transmits data and is done.
#include <stdio.h>
#include <stdlib.h>
#include <pvm3.h>
int main(int c, char **v)
{
int tids[10];
int parent, spawn;
int i_data, i2;
double f_data;
if (c > 1) {
spawn = pvm_spawn("/tmp/a.out", 0, PvmTaskDefault, 0, 1, tids);
if (spawn <= 0) {
printf("Can't spawn task\n");
return 1;
}
printf("Spawning successful\n");
/* pvm_recv(task_id, msgtag). msgtag identifies what kind of data it is,
* for here: 1 = (int, double), 2 = (int, int)
* The receiving order is intentionally swapped, just to show.
* task_id = -1 means "receive from any task"
*/
pvm_recv(-1, 2);
pvm_unpackf("%d %d", &i_data, &i2);
printf("got msg type 2: %d %d\n", i_data, i2);
pvm_recv(-1, 1);
pvm_unpackf("%d %lf", &i_data, &f_data);
printf("got msg type 1: %d %f\n", i_data, f_data);
} else {
parent = pvm_parent();
pvm_initsend(PvmDataDefault);
i_data = rand();
f_data = (double)rand() / RAND_MAX;
pvm_packf("%d %lf", i_data, f_data);
pvm_send(parent, 1); /* send msg type 1 */
pvm_initsend(PvmDataDefault);
i2 = rand();
pvm_packf("%d %d", i_data, i2);
pvm_send(parent, 2); /* send msg type 2 */
}
pvm_exit();
return 0;
}
- Output:
(running it on PVM console, exe is /tmp/a.out)
pvm> spawn -> /tmp/a.out 1
spawn -> /tmp/a.out 1
[2]
1 successful
t40028
pvm> [2:t40029] EOF
[2:t40028] Spawning successful
[2:t40028] got msg type 2: 1804289383 1681692777
[2:t40028] got msg type 1: 1804289383 0.394383
[2:t40028] EOF
[2] finished
C#
Start the program with "server" parameter to start the server, and "client" to start the client. The client will send data to the server and receive a response. The server will wait for data, display the data received, and send a response.
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Runtime.Serialization.Formatters.Binary;
using System.Threading.Tasks;
using static System.Console;
class DistributedProgramming
{
const int Port = 555;
async static Task RunClient()
{
WriteLine("Connecting");
var client = new TcpClient();
await client.ConnectAsync("localhost", Port);
using (var stream = client.GetStream())
{
WriteLine("Sending loot");
var data = Serialize(new SampleData());
await stream.WriteAsync(data, 0, data.Length);
WriteLine("Receiving thanks");
var buffer = new byte[80000];
var bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
var thanks = (string)Deserialize(buffer, bytesRead);
WriteLine(thanks);
}
client.Close();
}
async static Task RunServer()
{
WriteLine("Listening");
var listener = new TcpListener(IPAddress.Any, Port);
listener.Start();
var client = await listener.AcceptTcpClientAsync();
using (var stream = client.GetStream())
{
WriteLine("Receiving loot");
var buffer = new byte[80000];
var bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
var data = (SampleData)Deserialize(buffer, bytesRead);
WriteLine($"{data.Loot} at {data.Latitude}, {data.Longitude}");
WriteLine("Sending thanks");
var thanks = Serialize("Thanks!");
await stream.WriteAsync(thanks, 0, thanks.Length);
}
client.Close();
listener.Stop();
Write("Press a key");
ReadKey();
}
static byte[] Serialize(object data)
{
using (var mem = new MemoryStream())
{
new BinaryFormatter().Serialize(mem, data);
return mem.ToArray();
}
}
static object Deserialize(byte[] data, int length)
{
using (var mem = new MemoryStream(data, 0, length))
{
return new BinaryFormatter().Deserialize(mem);
}
}
static void Main(string[] args)
{
if (args.Length == 0) return;
switch (args[0])
{
case "client": RunClient().Wait(); break;
case "server": RunServer().Wait(); break;
}
}
}
[Serializable]
class SampleData
{
public decimal Latitude = 44.33190m;
public decimal Longitude = 114.84129m;
public string Loot = "140 tonnes of jade";
}
D
Uses the rpc library: https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff/blob/master/rpc.d
This library is not standard, so this code (by Adam D. Ruppe) could and should be rewritten using more standard means.
import arsd.rpc;
struct S1 {
int number;
string name;
}
struct S2 {
string name;
int number;
}
interface ExampleNetworkFunctions {
string sayHello(string name);
int add(in int a, in int b) const pure nothrow;
S2 structTest(S1);
void die();
}
// The server must implement the interface.
class ExampleServer : ExampleNetworkFunctions {
override string sayHello(string name) {
return "Hello, " ~ name;
}
override int add(in int a, in int b) const pure nothrow {
return a + b;
}
override S2 structTest(S1 a) {
return S2(a.name, a.number);
}
override void die() {
throw new Exception("death requested");
}
mixin NetworkServer!ExampleNetworkFunctions;
}
class Client {
mixin NetworkClient!ExampleNetworkFunctions;
}
void main(in string[] args) {
import std.stdio;
if (args.length > 1) {
auto client = new Client("localhost", 5005);
// These work like the interface above, but instead of
// returning the value, they take callbacks for success (where
// the arg is the retval) and failure (the arg is the
// exception).
client.sayHello("whoa", (a) { writeln(a); }, null);
client.add(1,2, (a){ writeln(a); }, null);
client.add(10,20, (a){ writeln(a); }, null);
client.structTest(S1(20, "cool!"),
(a){ writeln(a.name, " -- ", a.number); },
null);
client.die(delegate(){ writeln("shouldn't happen"); },
delegate(a){ writeln(a); });
client.eventLoop;
} else {
auto server = new ExampleServer(5005);
server.eventLoop;
}
}
E
Protocol: Pluribus
This service cannot be used except by clients which know the URL designating it, messages are encrypted, and the client authenticates the server. However, it is vulnerable to denial-of-service by any client knowing the URL.
Server
(The protocol is symmetric; this program is the server only in that it is the one which is started first and exports an object.)
def storage := [].diverge()
def logService {
to log(line :String) {
storage.push([timer.now(), line])
}
to search(substring :String) {
var matches := []
for [time, line] ? (line.startOf(substring) != -1) in storage {
matches with= [time, line]
}
return matches
}
}
introducer.onTheAir()
def sturdyRef := makeSturdyRef.temp(logService)
println(<captp>.sturdyToURI(sturdyRef))
interp.blockAtTop()
This will print the URL of the service and run it until aborted.
Client
The URL provided by the server is given as the argument to this program.
def [uri] := interp.getArgs()
introducer.onTheAir()
def sturdyRef := <captp>.sturdyFromURI(uri)
def logService := sturdyRef.getRcvr()
logService <- log("foot")
logService <- log("shoe")
println("Searching...")
when (def result := logService <- search("foo")) -> {
for [time, line] in result {
println(`At $time: $line`)
}
}
Erlang
The protocol is erlang's own
Server
srv.erl
-module(srv).
-export([start/0, wait/0]).
start() ->
net_kernel:start([srv,shortnames]),
erlang:set_cookie(node(), rosetta),
Pid = spawn(srv,wait,[]),
register(srv,Pid),
io:fwrite("~p ready~n",[node(Pid)]),
ok.
wait() ->
receive
{echo, Pid, Any} ->
io:fwrite("-> ~p from ~p~n", [Any, node(Pid)]),
Pid ! {hello, Any},
wait();
Any -> io:fwrite("Error ~p~n", [Any])
end.
Client
client.erl
-module(client).
-export([start/0, wait/0]).
start() ->
net_kernel:start([client,shortnames]),
erlang:set_cookie(node(), rosetta),
{ok,[[Srv]]} = init:get_argument(server),
io:fwrite("connecting to ~p~n", [Srv]),
{srv, list_to_atom(Srv)} ! {echo,self(), hi},
wait(),
ok.
wait() ->
receive
{hello, Any} -> io:fwrite("Received ~p~n", [Any]);
Any -> io:fwrite("Error ~p~n", [Any])
end.
running it (*comes later)
|erlc srv.erl |erl -run srv start -noshell srv@agneyam ready *-> hi from client@agneyam
|erlc client.erl |erl -run client start -run init stop -noshell -server srv@agneyam connecting to "srv@agneyam" Received hi
Factor
The protocol is the one provided by Factor (concurrency.distributed, concurrency.messaging)
Example summary:
- A server node is listening for messages made of natural data types and structures, and simply prettyprint them.
- A client node is sending such data structure: an array of one string and one hashtable (with one key/value pair).
Server
USING: concurrency.distributed concurrency.messaging threads io.sockets io.servers ;
QUALIFIED: concurrency.messaging
: prettyprint-message ( -- ) concurrency.messaging:receive . flush prettyprint-message ;
[ prettyprint-message ] "logger" spawn dup name>> register-remote-thread
"127.0.0.1" 9000 <inet4> <node-server> start-server
Note: we are using QUALIFIED: with the concurrency.messaging vocabulary because the "receive" word is defined in io.sockets vocabulary too. If someone have a cleaner way to handle this.
Client
USING: concurrency.distributed io.sockets ;
QUALIFIED: concurrency.messaging
{ "Hello Remote Factor!" H{ { "key1" "value1" } } }
"127.0.0.1" 9000 <inet4> "logger" <remote-thread> concurrency.messaging:send
How to Run:
- Copy/Paste the server code in an instance of Factor Listener
- Copy/Paste the client code in another instance of Factor Listener.
The server node should prettyprint the data structure send by the client: { "Hello Remote Factor!" H{ { "key1" "value1" } } }
Go
Standard library net/rpc
Package net/rpc in the Go standard library serializes data with the Go-native "gob" type. The example here sends only a single floating point number, but the package will send any user-defined data type, including of course structs with multiple fields.
Server:
package main
import (
"errors"
"log"
"net"
"net/http"
"net/rpc"
)
type TaxComputer float64
func (taxRate TaxComputer) Tax(x float64, r *float64) error {
if x < 0 {
return errors.New("Negative values not allowed")
}
*r = x * float64(taxRate)
return nil
}
func main() {
c := TaxComputer(.05)
rpc.Register(c)
rpc.HandleHTTP()
listener, err := net.Listen("tcp", ":1234")
if err != nil {
log.Fatal(err)
}
http.Serve(listener, nil)
}
Client:
package main
import (
"fmt"
"log"
"net/rpc"
)
func main() {
client, err := rpc.DialHTTP("tcp", "localhost:1234")
if err != nil {
fmt.Println(err)
return
}
amount := 3.
var tax float64
err = client.Call("TaxComputer.Tax", amount, &tax)
if err != nil {
log.Fatal(err)
}
fmt.Printf("Tax on %.2f: %.2f\n", amount, tax)
}
- Client output:
Tax on 3.00: 0.15
gRPC
The default serialization for gRPC is "protocol buffers." gRPC uses a .proto file to define an interface for the client and server. The .proto has its own syntax, independent of client and server implementation languages. Server and client programs here are Go however.
.proto:
syntax = "proto3";
service TaxComputer {
rpc Tax(Amount) returns (Amount) {}
}
message Amount {
int32 cents = 1;
}
Server:
package main
import (
"errors"
"net"
"golang.org/x/net/context"
"google.golang.org/grpc"
"google.golang.org/grpc/grpclog"
"taxcomputer"
)
type taxServer struct {
rate float64
}
func (s *taxServer) Tax(ctx context.Context,
amt *taxcomputer.Amount) (*taxcomputer.Amount, error) {
if amt.Cents < 0 {
return nil, errors.New("Negative amounts not allowed")
}
return &taxcomputer.Amount{int32(float64(amt.Cents)*s.rate + .5)}, nil
}
func main() {
listener, err := net.Listen("tcp", ":1234")
if err != nil {
grpclog.Fatalf(err.Error())
}
grpcServer := grpc.NewServer()
taxcomputer.RegisterTaxComputerServer(grpcServer, &taxServer{.05})
grpcServer.Serve(listener)
}
Client:
package main
import (
"fmt"
"golang.org/x/net/context"
"google.golang.org/grpc"
"google.golang.org/grpc/grpclog"
"taxcomputer"
)
func main() {
conn, err := grpc.Dial("localhost:1234", grpc.WithInsecure())
if err != nil {
grpclog.Fatalf(err.Error())
}
defer conn.Close()
client := taxcomputer.NewTaxComputerClient(conn)
amt := &taxcomputer.Amount{300}
tax, err := client.Tax(context.Background(), amt)
if err != nil {
grpclog.Fatalf(err.Error())
}
fmt.Println("Tax on", amt.Cents, "cents is", tax.Cents, "cents")
}
- Client output:
Tax on 300 cents is 15 cents
Apache Thrift
See https://thrift.apache.org/
.thrift
Like gRPC, Thrift requires a language independent interface definition file:
service TaxService {
i32 tax(1: i32 amt)
}
Server:
package main
import (
"errors"
"log"
"git.apache.org/thrift.git/lib/go/thrift"
"gen-go/tax"
)
type taxHandler float64
func (r taxHandler) Tax(amt int32) (int32, error) {
if amt < 0 {
return 0, errors.New("Negative amounts not allowed")
}
return int32(float64(amt)*float64(r) + .5), nil
}
func main() {
transport, err := thrift.NewTServerSocket("localhost:3141")
if err != nil {
log.Fatal(err)
}
transFac := thrift.NewTTransportFactory()
protoFac := thrift.NewTCompactProtocolFactory()
proc := tax.NewTaxServiceProcessor(taxHandler(.05))
s := thrift.NewTSimpleServer4(proc, transport, transFac, protoFac)
if err := s.Serve(); err != nil {
log.Fatal(err)
}
}
Client:
package main
import (
"fmt"
"log"
"git.apache.org/thrift.git/lib/go/thrift"
"gen-go/tax"
)
func main() {
transport, err := thrift.NewTSocket("localhost:3141")
if err != nil {
log.Fatal(err)
}
if err := transport.Open(); err != nil {
log.Fatal(err)
}
protoFac := thrift.NewTCompactProtocolFactory()
client := tax.NewTaxServiceClientFactory(transport, protoFac)
amt := int32(300)
t, err := client.Tax(amt)
if err != nil {
log.Print(err)
} else {
fmt.Println("tax on", amt, "is", t)
}
transport.Close()
}
- Client output:
tax on 300 is 15
Haskell
See:
Check license: http://www.haskell.org/haskellwiki/HaskellWiki:Copyrights
JavaScript
Server
var net = require('net')
var server = net.createServer(function (c){
c.write('hello\r\n')
c.pipe(c) // echo messages back
})
server.listen(3000, 'localhost')
Client
var net = require('net')
conn = net.createConnection(3000, '192.168.1.x')
conn.on('connect', function(){
console.log('connected')
conn.write('test')
})
conn.on('data', function(msg){
console.log(msg.toString())
})
Julia
Julia was designed with distributed conmputing. in particular cluster computing, as a primary use target. If a group of CPUs, including multiple cores on a single machine or a cluster running with paswordless ssh login, is used, the following can be set up as an example:
# From Julia 1.0's online docs. File countheads.jl available to all machines:
function count_heads(n)
c::Int = 0
for i = 1:n
c += rand(Bool)
end
c
end
We then run the following on the primary client:
using Distributed
@everywhere include_string(Main, $(read("count_heads.jl", String)), "count_heads.jl")
a = @spawn count_heads(100000000) # runs on an available processor
b = @spawn count_heads(100000000) # runs on another available processor
println(fetch(a)+fetch(b)) # total heads of 200 million coin flips, half on each CPU
- Output:
100001564
LFE
The protocol used is the one native to Erlang (and thus native to LFE, Lisp Flavored Erlang).
These examples are done completely in the LFE REPL.
Server
In one terminal window, start up the REPL
$ ./bin/lfe
Erlang/OTP 17 [erts-6.2] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
LFE Shell V6.2 (abort with ^G)
>
And then enter the following code
> (defun get-server-name ()
(list_to_atom (++ "exampleserver@" (element 2 (inet:gethostname)))))
> (defun start ()
(net_kernel:start `(,(get-server-name) shortnames))
(erlang:set_cookie (node) 'rosettaexample)
(let ((pid (spawn #'listen/0)))
(register 'serverref pid)
(io:format "~p ready~n" (list (node pid)))
'ok))
> (defun listen ()
(receive
(`#(echo ,pid ,data)
(io:format "Got ~p from ~p~n" (list data (node pid)))
(! pid `#(hello ,data))
(listen))
(x
(io:format "Unexpected pattern: ~p~n" `(,x)))))
Client
In another terminal window, start up another LFE REPL and ender the following code:
> (defun get-server-name ()
(list_to_atom (++ "exampleserver@" (element 2 (inet:gethostname)))))
> (defun send (data)
(net_kernel:start '(exampleclient shortnames))
(erlang:set_cookie (node) 'rosettaexample)
(io:format "connecting to ~p~n" `(,(get-server-name)))
(! `#(serverref ,(get-server-name)) `#(echo ,(self) ,data))
(receive
(`#(hello ,data)
(io:format "Received ~p~n" `(,data)))
(x
(io:format "Unexpected pattern: ~p~n" (list x))))
'ok)
To use this code, simply start the server in the server terminal:
> (start)
exampleserver@yourhostname ready
ok
(exampleserver@yourhostname)>
Send some messages from the client terminal:
> (send "hi there")
connecting to exampleserver@yourhostname
Received "hi there"
ok
(exampleclient@yourhostname)> (send 42)
connecting to exampleserver@yourhostname
Received 42
ok
(exampleclient@yourhostname)> (send #(key value))
connecting to exampleserver@yourhostname
Received {key,value}
ok
(exampleclient@yourhostname)>
And check out the results back in the server terminal window:
Got "hi there" from exampleclient@yourhostname
Got 42 from exampleclient@yourhostname
Got {key,value} from exampleclient@yourhostname
Mathematica / Wolfram Language
The following sends a request for a random number to be generated on each of two nodes, these are then transmitted back to be assembled into an array with two elements. Omitting the first line, will cause the program to be run on all configured remote computers.
LaunchKernels[2];
ParallelEvaluate[RandomReal[]]
Nim
import os, nanomsg
proc sendMsg(s: cint, msg: string) =
echo "SENDING \"",msg,"\""
let bytes = s.send(msg.cstring, msg.len + 1, 0)
assert bytes == msg.len + 1
proc recvMsg(s: cint) =
var buf: cstring
let bytes = s.recv(addr buf, MSG, 0)
if bytes > 0:
echo "RECEIVED \"",buf,"\""
discard freemsg buf
proc sendRecv(s: cint, msg: string) =
var to: cint = 100
discard s.setSockOpt(SOL_SOCKET, RCVTIMEO, addr to, sizeof to)
while true:
s.recvMsg
sleep 1000
s.sendMsg msg
proc node0(url: string) =
var s = socket(AF_SP, nanomsg.PAIR)
assert s >= 0
let res = s.bindd url
assert res >= 0
s.sendRecv "node0"
discard s.shutdown 0
proc node1(url: string) =
var s = socket(AF_SP, nanomsg.PAIR)
assert s >= 0
let res = s.connect url
assert res >= 0
s.sendRecv "node1"
discard s.shutdown 0
if paramStr(1) == "node0":
node0 paramStr(2)
elif paramStr(1) == "node1":
node1 paramStr(2)
Usage:
./pair node0 tcp://127.0.0.1:25000 ./pair node1 tcp://127.0.0.1:25000
Objective-C
Distributed Objects are natural to Objective-C, and OpenStep and derivated framework offers an easy way of using remote objects as if it were local. The client must only know the protocol the remote object support. For the rest, calling a remote object's method or local object's method is transparent.
Server
The server vending the object with the name DistributedAction
ActionObjectProtocol.h
#import <Foundation/Foundation.h>
// our protocol allows "sending" "strings", but we can implement
// everything we could for a "local" object
@protocol ActionObjectProtocol
- (NSString *)sendMessage: (NSString *)msg;
@end
ActionObject.h
#import <Foundation/Foundation.h>
#import "ActionObjectProtocol.h"
@interface ActionObject : NSObject <ActionObjectProtocol>
// we do not have much for this example!
@end
ActionObject.m
#import <Foundation/Foundation.h>
#import "ActionObject.h"
@implementation ActionObject
-(NSString *)sendMessage: (NSString *)msg
{
NSLog(@"client sending message %@", msg);
return @"server answers ...";
}
@end
server.m
#import <Foundation/Foundation.h>
#import "ActionObject.h"
int main (void)
{
@autoreleasepool {
ActionObject *action = [[ActionObject alloc] init];
NSSocketPort *port = (NSSocketPort *)[NSSocketPort port];
// initWithTCPPort: 1234 and other methods are not supported yet
// by GNUstep
NSConnection *connect = [NSConnection
connectionWithReceivePort: port
sendPort: port]; // or sendPort: nil
[connect setRootObject: action];
/* "vend" the object ActionObject as DistributedAction; on GNUstep
the Name Server that allows the resolution of the registered name
is bound to port 538 */
if (![connect registerName:@"DistributedAction"
withNameServer: [NSSocketPortNameServer sharedInstance] ])
{
NSLog(@"can't register the server DistributedAction");
exit(EXIT_FAILURE);
}
NSLog(@"waiting for messages...");
[[NSRunLoop currentRunLoop] run];
}
return 0;
}
Client
client.m
#import <Foundation/Foundation.h>
#import "ActionObjectProtocol.h"
int main(void)
{
@autoreleasepool {
id <ActionObjectProtocol> action = (id <ActionObjectProtocol>)
[NSConnection
rootProxyForConnectionWithRegisteredName: @"DistributedAction"
host: @"localhost"
usingNameServer: [NSSocketPortNameServer sharedInstance] ];
if (action == nil)
{
NSLog(@"can't connect to the server");
exit(EXIT_FAILURE);
}
NSArray *args = [[NSProcessInfo processInfo] arguments];
if ([args count] == 1)
{
NSLog(@"specify a message");
exit(EXIT_FAILURE);
}
NSString *msg = args[1];
// "send" (call the selector "sendMessage:" of the (remote) object
// action) the first argument's text as msg, store the message "sent
// back" and then show it in the log
NSString *backmsg = [action sendMessage: msg];
NSLog("%@", backmsg);
}
return 0;
}
OCaml
Minimalistic distributed logger with synchronous channels using the join calculus on top of OCaml.
Server
open Printf
let create_logger () =
def log(text) & logs(l) =
printf "Logged: %s\n%!" text;
logs((text, Unix.gettimeofday ())::l) & reply to log
or search(text) & logs(l) =
logs(l) & reply List.filter (fun (line, _) -> line = text) l to search
in
spawn logs([]);
(log, search)
def wait() & finished() = reply to wait
let register name service = Join.Ns.register Join.Ns.here name service
let () =
let log, search = create_logger () in
register "log" log;
register "search" search;
Join.Site.listen (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345));
wait ()
Client
open Printf
let ns_there = Join.Ns.there (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345))
let lookup name = Join.Ns.lookup ns_there name
let log : string -> unit = lookup "log"
let search : string -> (string * float) list = lookup "search"
let find txt =
printf "Looking for %s...\n" txt;
List.iter (fun (line, time) ->
printf "Found: '%s' at t = %f\n%!" (String.escaped line) time)
(search txt)
let () =
log "bar";
find "foo";
log "foo";
log "shoe";
find "foo"
Oz
We show a program that starts a server on a remote machine, exchanges two messages with that server and finally shuts it down.
declare
functor ServerCode
export
port:Prt
define
Stream
Prt = {NewPort ?Stream}
thread
for Request#Reply in Stream do
case Request
of echo(Data) then Reply = Data
[] compute(Function) then Reply = {Function}
end
end
end
end
%% create the server on some machine
%% (just change "localhost" to some machine
%% that you can use with a passwordless rsh login
%% and that has the same Mozart version installed)
RM = {New Remote.manager init(host:localhost)}
%% execute the code encapsulated in the ServerCode functor
Server = {RM apply(ServerCode $)}
%% Shortcut: send a message to Server and receive a reply
fun {Send X}
{Port.sendRecv Server.port X}
end
in
%% echo
{System.showInfo "Echo reply: "#{Send echo(hello)}}
%% compute
{System.showInfo "Result of computation: "#
{Send compute(fun {$} 8 div 4 end)}}
%% shut down server
{RM close}
Perl
Using Data::Dumper and Safe to transmit arbitrary data structures as serialized text between hosts. Same code works as both sender and receiver.
use strict;
use warnings;
use Data::Dumper;
use IO::Socket::INET;
use Safe;
sub get_data {
my $sock = IO::Socket::INET->new(
LocalHost => "localhost",
LocalPort => "10000",
Proto => "tcp",
Listen => 1,
Reuse => 1);
unless ($sock) { die "Socket creation failure" }
my $cli = $sock->accept();
# of course someone may be tempted to send you 'system("rm -rf /")',
# to be safe(r), use Safe::
my $safe = Safe->new;
my $x = $safe->reval(join("", <$cli>));
close $cli;
close $sock;
return $x;
}
sub send_data {
my $host = shift;
my $data = shift;
my $sock = IO::Socket::INET->new(
PeerAddr => "$host:10000",
Proto => "tcp",
Reuse => 1);
unless ($sock) { die "Socket creation failure" }
print $sock Data::Dumper->Dump([$data]);
close $sock;
}
if (@ARGV) {
my $x = get_data();
print "Got data\n", Data::Dumper->Dump([$x]);
} else {
send_data('some_host', { a=>100, b=>[1 .. 10] });
}
Phix
From/using the ZeroMQ wrapper from PCAN, a suitable simple publish/subscriber pair. There is also a server/client/broker example. Obviously you can trivially serialize() and deserialize() any Phix data to and from a string.
without js -- (zmq dll/so) puts(1, "durapub:\n") include zmq/zmq.e atom context = zmq_init(1) zmq_assert(context, "zmq_init") --// subscriber tells us when it's ready here atom sync = zmq_socket(context, ZMQ_PULL) zmq_bind(sync, "tcp://*:5564") --// send update via this socket atom publisher = zmq_socket(context, ZMQ_PUB) zmq_bind(publisher, "tcp://*:5565") --// broadcast 10 updates, with pause for update_nbr = 1 to 10 do string s = sprintf("Update %d", { update_nbr }) zmq_s_send(publisher, s) sleep(1) end for zmq_s_send(publisher, "END") sleep(1) zmq_close(sync) zmq_close(publisher) zmq_term(context)
without js -- (zmq dll/so) puts(1, "durasub:\n") include zmq/zmq.e atom context = zmq_init(1) zmq_assert(context, "zmq_init") --// connect our subscriber socket atom subscriber = zmq_socket(context, ZMQ_SUB) atom id = allocate_string("Hello") zmq_setsockopt(subscriber, ZMQ_IDENTITY, id, 5) zmq_setsockopt(subscriber, ZMQ_SUBSCRIBE, 0, 0) zmq_connect(subscriber, "tcp://localhost:5565") free(id) --// synchronise with publisher atom sync = zmq_socket(context, ZMQ_PUSH) zmq_connect(sync, "tcp://localhost:5564") zmq_s_send(sync, "") --// get updates, Ctrl-C break while true do string s = zmq_s_recv(subscriber) printf(1, "%s\n", {s}) if s=="END" then exit end if end while zmq_close(sync) zmq_close(subscriber) zmq_term(context)
PicoLisp
Server
(task (port 12321) # Background server task
(let? Sock (accept @)
(unless (fork) # Handle request in child process
(in Sock
(while (rd) # Handle requests
(out Sock
(pr (eval @)) ) ) ) # Evaluate and send reply
(bye) ) # Exit child process
(close Sock) ) ) # Close socket in parent process
Client
(let? Sock (connect "localhost" 12321)
(out Sock (pr '*Pid)) # Query PID from server
(println 'PID (in Sock (rd))) # Receive and print reply
(out Sock (pr '(* 3 4))) # Request some calculation
(println 'Result (in Sock (rd))) # Print result
(close Sock) ) # Close connection to server
Output:
PID 18372 Result 12
Python
XML-RPC
Protocol: XML-RPC
Server
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import SimpleXMLRPCServer
class MyHandlerInstance:
def echo(self, data):
'''Method for returning data got from client'''
return 'Server responded: %s' % data
def div(self, num1, num2):
'''Method for divide 2 numbers'''
return num1/num2
def foo_function():
'''A function (not an instance method)'''
return True
HOST = "localhost"
PORT = 8000
server = SimpleXMLRPCServer.SimpleXMLRPCServer((HOST, PORT))
# register built-in system.* functions.
server.register_introspection_functions()
# register our instance
server.register_instance(MyHandlerInstance())
# register our function as well
server.register_function(foo_function)
try:
# serve forever
server.serve_forever()
except KeyboardInterrupt:
print 'Exiting...'
server.server_close()
Client
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import xmlrpclib
HOST = "localhost"
PORT = 8000
rpc = xmlrpclib.ServerProxy("http://%s:%d" % (HOST, PORT))
# print what functions does server support
print 'Server supports these functions:',
print ' '.join(rpc.system.listMethods())
# echo something
rpc.echo("We sent this data to server")
# div numbers
print 'Server says: 8 / 4 is: %d' % rpc.div(8, 4)
# control if foo_function returns True
if rpc.foo_function():
print 'Server says: foo_function returned True'
HTTP
Protocol: HTTP
Server
#!/usr/bin/python
# -*- coding: utf-8 -*-
import BaseHTTPServer
HOST = "localhost"
PORT = 8000
# we just want to write own class, we replace do_GET method. This could be extended, I just added basics
# see; http://docs.python.org/lib/module-BaseHTTPServer.html
class MyHTTPHandler(BaseHTTPServer.BaseHTTPRequestHandler):
def do_GET(self):
# send 200 (OK) message
self.send_response(200)
# send header
self.send_header("Content-type", "text/html")
self.end_headers()
# send context
self.wfile.write("<html><head><title>Our Web Title</title></head>")
self.wfile.write("<body><p>This is our body. You wanted to visit <b>%s</b> page</p></body>" % self.path)
self.wfile.write("</html>")
if __name__ == '__main__':
server = BaseHTTPServer.HTTPServer((HOST, PORT), MyHTTPHandler)
try:
server.serve_forever()
except KeyboardInterrupt:
print 'Exiting...'
server.server_close()
Client
#!/usr/bin/python
# -*- coding: utf-8 -*-
import httplib
HOST = "localhost"
PORT = 8000
conn = httplib.HTTPConnection(HOST, PORT)
conn.request("GET", "/somefile")
response = conn.getresponse()
print 'Server Status: %d' % response.status
print 'Server Message: %s' % response.read()
Socket, Pickle format
Protocol: raw socket / pickle format
This example builds a very basic RPC mechanism on top of sockets and the pickle module. Please note that the pickle module is not secure - a malicious client can build malformed data to execute arbitrary code on the server. If untrusted clients can access the server, the json module could be used as a substitute, but we lose the ability to transfer arbitrary Python objects that way.
Server
#!/usr/bin/python
# -*- coding: utf-8 -*-
import SocketServer
import pickle
HOST = "localhost"
PORT = 8000
class RPCServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer):
# The object_to_proxy member should be set to the object we want
# methods called on. Unfortunately, we can't do this in the constructor
# because the constructor should not be overridden in TCPServer...
daemon_threads = True
class RPCHandler(SocketServer.StreamRequestHandler):
def handle(self):
in_channel = pickle.Unpickler(self.rfile)
out_channel = pickle.Pickler(self.wfile, protocol=2)
while True:
try:
name, args, kwargs = in_channel.load()
print 'got %s %s %s' % (name, args, kwargs)
except EOFError:
# EOF means we're done with this request.
# Catching this exception to detect EOF is a bit hackish,
# but will work for a quick demo like this
break
try:
method = getattr(self.server.object_to_proxy, name)
result = method(*args, **kwargs)
except Exception, e:
out_channel.dump(('Error',e))
else:
out_channel.dump(('OK',result))
class MyHandlerInstance(object):
def echo(self, data):
'''Method for returning data got from client'''
return 'Server responded: %s' % data
def div(self, dividend, divisor):
'''Method to divide 2 numbers'''
return dividend/divisor
def is_computer_on(self):
return True
if __name__ == '__main__':
rpcserver = RPCServer((HOST, PORT), RPCHandler)
rpcserver.object_to_proxy = MyHandlerInstance()
try:
rpcserver.serve_forever()
except KeyboardInterrupt:
print 'Exiting...'
rpcserver.server_close()
Client
#!/usr/bin/python
# -*- coding: utf-8 -*-
import socket
import pickle
HOST = "localhost"
PORT = 8000
class RPCClient(object):
def __init__(self, host, port):
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.socket.connect((host, port))
self.rfile = self.socket.makefile('rb')
self.wfile = self.socket.makefile('wb')
self.in_channel = pickle.Unpickler(self.rfile)
self.out_channel = pickle.Pickler(self.wfile, protocol=2)
def _close(self):
self.socket.close()
self.rfile.close()
self.wfile.close()
# Make calling remote methods easy by overriding attribute access.
# Accessing any attribute on our instances will give a proxy method that
# calls the method with the same name on the remote machine.
def __getattr__(self, name):
def proxy(*args, **kwargs):
self.out_channel.dump((name, args, kwargs))
self.wfile.flush() # to make sure the server won't wait forever
status, result = self.in_channel.load()
if status == 'OK':
return result
else:
raise result
return proxy
if __name__ == '__main__':
# connect to server and send data
rpcclient = RPCClient(HOST, PORT)
print 'Testing the echo() method:'
print rpcclient.echo('Hello world!')
print
print 'Calculating 42/2 on the remote machine:'
print rpcclient.div(42, 2)
print
print 'is_computer_on on the remote machine returns:'
print rpcclient.is_computer_on()
print
print 'Testing keyword args:'
print '42/2 is:', rpcclient.div(divisor=2, dividend=42)
rpcclient._close()
del rpcclient
Pyro
Note: You should install Pyro (http://pyro.sourceforge.net) first and run pyro-ns binary to run code below.
Server
#!/usr/bin/python
# -*- coding: utf-8 -*-
import Pyro.core
import Pyro.naming
# create instance that will return upper case
class StringInstance(Pyro.core.ObjBase):
def makeUpper(self, data):
return data.upper()
class MathInstance(Pyro.core.ObjBase):
def div(self, num1, num2):
return num1/num2
if __name__ == '__main__':
server = Pyro.core.Daemon()
name_server = Pyro.naming.NameServerLocator().getNS()
server.useNameServer(name_server)
server.connect(StringInstance(), 'string')
server.connect(MathInstance(), 'math')
try:
server.requestLoop()
except KeyboardInterrupt:
print 'Exiting...'
server.shutdown()
Client
#!/usr/bin/python
# -*- coding: utf-8 -*-
import Pyro.core
DATA = "my name is eren"
NUM1 = 10
NUM2 = 5
string = Pyro.core.getProxyForURI("PYRONAME://string")
math = Pyro.core.getProxyForURI("PYRONAME://math")
print 'We sent: %s' % DATA
print 'Server responded: %s\n' % string.makeUpper(DATA)
print 'We sent two numbers to divide: %d and %d' % (NUM1, NUM2)
print 'Server responded the result: %s' % math.div(NUM1, NUM2)
Spread
Note: You should install Spread (http://www.spread.org) and its python bindings (http://www.python.org/other/spread/)
Server
You don't need any code for server. You should start "spread" daemon by typing "spread -c /etc/spread.conf -n localhost". If you want more configuration, look at /etc/spread.conf.
After starting daemon, if you want to make sure that it is running, enter spuser -s 4803 command where 4803 is your port set in spread.conf, you will see prompt, type j user, you should see something like this message: Received REGULAR membership for group test with 3 members, where I am member 2
Client (Listener)
#!/usr/bin/python
# -*- coding: utf-8 -*-
import spread
PORT = '4803'
# connect spread daemon
conn = spread.connect(PORT)
# join the room
conn.join('test')
print 'Waiting for messages... If you want to stop this script, please stop spread daemon'
while True:
recv = conn.receive()
if hasattr(recv, 'sender') and hasattr(recv, 'message'):
print 'Sender: %s' % recv.sender
print 'Message: %s' % recv.message
Client (Sender)
#!/usr/bin/python
# -*- coding: utf-8 -*-
import spread
PORT = '4803'
conn = spread.connect(PORT)
conn.join('test')
conn.multicast(spread.RELIABLE_MESS, 'test', 'hello, this is message sent from python')
conn.disconnect()
Racket
Server and client in the same piece of code, running a useless (fib 42) computation, four times, on four hosts (which all happen to be "localhost", but that can change, of course).
#lang racket/base
(require racket/place/distributed racket/place)
(define (fib n)
(if (<= n 1) n (+ (fib (- n 1)) (fib (- n 2)))))
(provide work)
(define (work)
(place ch
(place-channel-put ch (fib (place-channel-get ch)))))
(module+ main
(define places
(for/list ([host '("localhost" "localhost" "localhost" "localhost")]
[port (in-naturals 12345)])
(define-values [node place]
(spawn-node-supervise-place-at host #:listen-port port #:thunk #t
(quote-module-path "..") 'work))
place))
(message-router
(after-seconds 1
(for ([p places]) (*channel-put p 42))
(printf "Results: ~s\n" (map *channel-get places))
(exit))))
Raku
(formerly Perl 6)
Server listens for JSON encoded messages. It processes requests for set|get|dump. 'set' stores a message, 'get' returns message, 'dump' returns all stored messages. Optional parameters for ip address and port.
Server.raku:
./server.raku --usage Usage: server.p6 [--server=<Any>] [--port=<Any>]
#!/usr/bin/env raku
use JSON::Fast ;
sub MAIN( :$server='0.0.0.0' , :$port=3333 ) {
my %db ;
react {
whenever IO::Socket::Async.listen( $server , $port ) -> $conn {
whenever $conn.Supply.lines -> $line {
my %response = 'status' => '' ;
my $msg = from-json $line ;
say $msg.raku;
given $msg{"function"} {
when 'set' {
%db{ $msg<topic> } = $msg<message> ;
%response<status> = 'ok' ;
}
when 'get' {
%response<topic> = $msg<topic> ;
%response<message> = %db{ $msg<topic> } ;
%response<status> = 'ok' ;
}
when 'dump' {
%response = %db ;
}
when 'delete' {
%db{ $msg<topic> }:delete;
%response<status> = 'ok' ;
}
}
$conn.print( to-json(%response, :!pretty) ~ "\n" ) ;
LAST { $conn.close ; }
QUIT { default { $conn.close ; say "oh no, $_";}}
CATCH { default { say .^name, ': ', .Str , " handled in $?LINE";}}
}
}
}
}
client.raku:
Usage: client.raku [--server=<Any>] [--port=<Any>] [--json=<Any>] set <topic> [<message>] client.raku [--server=<Any>] [--port=<Any>] get <topic> client.raku [--server=<Any>] [--port=<Any>] dump
#!/usr/bin/env raku
use JSON::Fast ;
multi MAIN('set', $topic, $message='', :$server='localhost', :$port='3333', :$json='') {
my %msg = function => 'set' , topic=> $topic , message=> $message ;
%msg{"message"} = from-json( $json ) if $json ;
sendmsg( %msg , $server, $port) ;
}
multi MAIN('get', $topic, :$server='localhost', :$port='3333') {
my %msg = function => 'get' , topic=> $topic ;
sendmsg( %msg , $server, $port) ;
}
multi MAIN('delete', $topic, :$server='localhost', :$port='3333') {
my %msg = function => 'delete' , topic=> $topic ;
sendmsg( %msg , $server, $port) ;
}
multi MAIN('dump', :$server='localhost', :$port='3333') {
my %msg = function => 'dump' ;
sendmsg( %msg , $server, $port) ;
}
sub sendmsg( %msg , $server, $port){
my $conn = await IO::Socket::Async.connect( $server , $port );
$conn.print: to-json( %msg,:!pretty)~"\n";
react {
whenever $conn.Supply -> $data {
print $data;
$conn.close;
}
}
}
examples:
echo '{"function":"set","topic":"push","message":["perl5","raku","rakudo"]}' | nc localhost 3333 ./client.raku set version raku {"status": "ok"} ./client.raku get version {"status": "ok","topic": "version","message": "raku"} ./client.raku --json='["one","two","three"]' set mylist {"status": "ok"} ./client.raku dump {"push": ["perl5","raku","rakudo"],"version": "raku","mylist": ["one","two","three"]} ./client.raku delete version {"status": "ok"} server output: ${:function("set"), :message($["perl5", "raku", "rakudo"]), :topic("push")} ${:function("set"), :message("raku"), :topic("version")} ${:function("get"), :topic("version")} ${:function("set"), :message($["one", "two", "three"]), :topic("mylist")} ${:function("dump")} ${:function("delete"), :topic("version")}
Ruby
Uses the distributed Ruby (dRuby) from the standard library. The "druby:" protocol uses TCP/IP sockets for communication.
Server
require 'drb/drb'
# The URI for the server to connect to
URI="druby://localhost:8787"
class TimeServer
def get_current_time
return Time.now
end
end
# The object that handles requests on the server
FRONT_OBJECT = TimeServer.new
$SAFE = 1 # disable eval() and friends
DRb.start_service(URI, FRONT_OBJECT)
# Wait for the drb server thread to finish before exiting.
DRb.thread.join
Client
require 'drb/drb'
# The URI to connect to
SERVER_URI = "druby://localhost:8787"
# Start a local DRbServer to handle callbacks.
#
# Not necessary for this small example, but will be required
# as soon as we pass a non-marshallable object as an argument
# to a dRuby call.
DRb.start_service
timeserver = DRbObject.new_with_uri(SERVER_URI)
puts timeserver.get_current_time
Tcl
A rudimentary IRC Server
proc main {} {
global connections
set connections [dict create]
socket -server handleConnection 12345
vwait dummyVar ;# enter the event loop
}
proc handleConnection {channel clientaddr clientport} {
global connections
dict set connections $channel address "$clientaddr:$clientport"
fconfigure $channel -buffering line
fileevent $channel readable [list handleMessage $channel]
}
proc handleMessage {channel} {
global connections
if {[gets $channel line] == -1} {
disconnect $channel
} else {
if {[string index [string trimleft $line] 0] eq "/"} {
set words [lassign [split [string trim $line]] command]
handleCommand $command $words $channel
} else {
echo $line $channel
}
}
}
proc disconnect {channel} {
global connections
dict unset connections $channel
fileevent $channel readable ""
close $channel
}
proc handleCommand {command words channel} {
global connections
switch -exact -- [string tolower $command] {
/nick {
dict set connections $channel nick [lindex $words 0]
}
/quit {
echo bye $channel
disconnect $channel
}
default {
puts $channel "\"$command\" not implemented"
}
}
}
proc echo {message senderchannel} {
global connections
foreach channel [dict keys $connections] {
if {$channel ne $senderchannel} {
set time [clock format [clock seconds] -format "%T"]
set nick [dict get $connections $channel nick]
puts $channel [format "\[%s\] %s: %s" $time $nick $message]
}
}
}
main
Client
proc main {} {
global argv argc
if {$argc != 2} {
error "usage: [info script] serveraddress serverport"
}
connect {*}$argv
vwait dummyVar
}
proc connect {addr port} {
global sock
set sock [socket $addr $port]
fconfigure $sock -buffering line
fileevent $sock readable getFromServer
fileevent stdin readable sendToServer
}
proc getFromServer {} {
global sock
if {[gets $sock line] == -1} {
puts "disconnected..."
exit
} else {
puts $line
}
}
proc sendToServer {} {
global sock
set msg [string trim [gets stdin]]
if {[string length $msg] > 0} {
puts $sock $msg
}
}
main
UnixPipes
Uses netcat and a buffer to cycle the server shell's stdout back to netcat's stdin.
Server
: >/tmp/buffer
tail -f /tmp/buffer | nc -l 127.0.0.1 1234 | sh >/tmp/buffer 2>&1
Limitations:
- The server can accept only one connection (but continues to run, not exit, after this connection dies).
- With some systems,
tail -f
might be slow to notice changes to /tmp/buffer.
Client
nc 127.0.0.1 1234
Now you can enter commands in the client terminal and get the output back through the same connection.
Wren
As Wren has no networking support at present, we use embedded programs for both the server and client with a Go host using the net/rpc package in its standard library.
Moreover, as Wren's VM is not re-entrant, we need to run two VMs from the server side, one to call Go from Wren and the other to call Wren from Go.
Server:
We need two Wren scripts one for each VM:
/* Distributed_programming_server.wren */
class Rpc {
foreign static register()
foreign static handleHTTP()
}
foreign class Listener {
construct listen(network, address) {}
}
class HTTP {
foreign static serve(listener)
}
Rpc.register()
Rpc.handleHTTP()
var listener = Listener.listen("tcp", ":1234")
HTTP.serve(listener)
/* Distributed_programming_server_2.wren */
class TaxComputer {
static tax(amount, rate) {
if (amount < 0) Fiber.abort("Negative values not allowed.")
return amount * rate
}
}
We now embed these scripts in the following Go program and run it on one terminal.
/* go run Distributed_programming_server.go */
package main
import(
wren "github.com/crazyinfin8/WrenGo"
"log"
"net"
"net/http"
"net/rpc"
)
type any = interface{}
type TaxComputer float64
var vm2 *wren.VM
var fileName = "Distributed_programming_server.wren"
var fileName2 = "Distributed_programming_server_2.wren"
func (taxRate TaxComputer) Tax(x float64, r *float64) error {
wrenVar, _ := vm2.GetVariable(fileName2, "TaxComputer")
wrenClass, _ := wrenVar.(*wren.Handle)
defer wrenClass.Free()
wrenMethod, _ := wrenClass.Func("tax(_,_)")
defer wrenMethod.Free()
ret, _ := wrenMethod.Call(x, float64(taxRate))
*r = ret.(float64)
return nil
}
func register(vm *wren.VM, parameters []any) (any, error) {
c := TaxComputer(0.05) // 5% tax rate
rpc.Register(c)
return nil, nil
}
func handleHTTP(vm *wren.VM, parameters []any) (any, error) {
rpc.HandleHTTP()
return nil, nil
}
func serve(vm *wren.VM, parameters []any) (any, error) {
handle := parameters[1].(*wren.ForeignHandle)
ifc, _ := handle.Get()
listener := ifc.(*net.Listener)
http.Serve(*listener, nil)
return nil, nil
}
func listen(vm *wren.VM, parameters []any) (any, error) {
network := parameters[1].(string)
address := parameters[2].(string)
listener, err := net.Listen(network, address)
if err != nil {
log.Fatal(err)
}
return &listener, nil
}
func main() {
vm := wren.NewVM()
vm2 = wren.NewVM()
vm2.InterpretFile(fileName2)
rpcMethodMap := wren.MethodMap {
"static register()": register,
"static handleHTTP()": handleHTTP,
}
httpMethodMap := wren.MethodMap { "static serve(_)":serve }
classMap := wren.ClassMap {
"Listener": wren.NewClass(listen, nil, nil),
"Rpc" : wren.NewClass(nil, nil, rpcMethodMap),
"HTTP" : wren.NewClass(nil, nil, httpMethodMap),
}
module := wren.NewModule(classMap)
vm.SetModule(fileName, module)
vm.InterpretFile(fileName)
vm.Free()
vm2.Free()
}
Client:
Just one Wren script needed here:
/* Distributed_programming_client.wren */
import "./fmt" for Fmt
foreign class Client {
construct dialHTTP(network, address) {}
foreign call(serviceMethod, arg)
}
var client = Client.dialHTTP("tcp", "localhost:1234")
var amounts = [3, 5.6]
for (amount in amounts) {
var tax = client.call("TaxComputer.Tax", amount)
Fmt.print("Tax on $0.2f = $0.2f", amount, tax)
}
which we embed in the following Go program and run it on a different terminal.
/* go run Distributed_programming_client.go */
package main
import(
wren "github.com/crazyinfin8/WrenGo"
"log"
"net/rpc"
"strings"
)
type any = interface{}
func dialHTTP(vm *wren.VM, parameters []any) (any, error) {
network := parameters[1].(string)
address := parameters[2].(string)
client, err := rpc.DialHTTP(network, address)
if err != nil {
log.Fatal(err)
}
return &client, nil
}
func call(vm *wren.VM, parameters []any) (any, error) {
handle := parameters[0].(*wren.ForeignHandle)
ifc, _ := handle.Get()
client := ifc.(**rpc.Client)
serviceMethod := parameters[1].(string)
amount := parameters[2].(float64)
var tax float64
err := (*client).Call(serviceMethod, amount, &tax)
if err != nil {
log.Fatal(err)
}
return tax, nil
}
func moduleFn(vm *wren.VM, name string) (string, bool) {
if name != "meta" && name != "random" && !strings.HasSuffix(name, ".wren") {
name += ".wren"
}
return wren.DefaultModuleLoader(vm, name)
}
func main() {
cfg := wren.NewConfig()
cfg.LoadModuleFn = moduleFn
vm := cfg.NewVM()
fileName := "Distributed_programming_client.wren"
clientMethodMap := wren.MethodMap { "call(_,_)": call }
classMap := wren.ClassMap { "Client": wren.NewClass(dialHTTP, nil, clientMethodMap) }
module := wren.NewModule(classMap)
vm.SetModule(fileName, module)
vm.InterpretFile(fileName)
vm.Free()
}
- Output:
Output on the client terminal:
Tax on 3.00 = 0.15 Tax on 5.60 = 0.28