X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/30820942d6f98e57261592bb826e7da80f65a41e..d5c51ff22d4e040c8236af16518a08ab47db3683:/examples/gras/ping/ping.c?ds=sidebyside

diff --git a/examples/gras/ping/ping.c b/examples/gras/ping/ping.c
index 460e30400e..3c6592ac36 100644
--- a/examples/gras/ping/ping.c
+++ b/examples/gras/ping/ping.c
@@ -2,37 +2,25 @@
 
 /* ping - ping/pong demo of GRAS features                                   */
 
-/* Copyright (c) 2003, 2004 Martin Quinson. All rights reserved.            */
+/* Copyright (c) 2003, 2004, 2005 Martin Quinson. All rights reserved.      */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <signal.h>
-
 #include "gras.h"
 
 XBT_LOG_NEW_DEFAULT_CATEGORY(Ping,"Messages specific to this example");
 
-/* **********************************************************************
- * Comon code
- * **********************************************************************/
-
-typedef struct {
-  int dummy;
-} msg_ping_t;
-
-/* Function prototypes */
-void register_messages(void);
-
-/* Code */
-void register_messages(void) {
-
+/* register messages which may be sent (common to client and server) */
+static void register_messages(void) {
   gras_msgtype_declare("ping", gras_datadesc_by_name("int"));
   gras_msgtype_declare("pong", gras_datadesc_by_name("int"));
 }
 
+/* Function prototypes */
+int server (int argc,char *argv[]);
+int client (int argc,char *argv[]);
+
 /* **********************************************************************
  * Server code
  * **********************************************************************/
@@ -43,102 +31,114 @@ typedef struct {
   int endcondition;
 } server_data_t;
 
-/* Function prototypes */
-int server_cb_ping_handler(gras_socket_t  expeditor,
-			   void          *payload_data);
-int server (int argc,char *argv[]);
-
 
-int server_cb_ping_handler(gras_socket_t  expeditor,
-			   void          *payload_data) {
+static int server_cb_ping_handler(gras_socket_t  expeditor,
+   			          void          *payload_data) {
 			     
   xbt_error_t errcode;
+  /* 1. Get the payload into the msg variable */
   int msg=*(int*)payload_data;
-  gras_msgtype_t *pong_t=NULL;
 
-  server_data_t *g=(server_data_t*)gras_userdata_get();
+  /* 2. Retrieve the server's state (globals) */
 
-  g->endcondition = 0;
+  server_data_t *globals=(server_data_t*)gras_userdata_get();
+  globals->endcondition = 0;
+   
+  /* 3. Log which client connected */
   INFO3("SERVER: >>>>>>>> Got message PING(%d) from %s:%d <<<<<<<<", 
 	msg, 
- 	gras_socket_peer_name(expeditor),
-	gras_socket_peer_port(expeditor));
+ 	gras_socket_peer_name(expeditor), gras_socket_peer_port(expeditor));
   
+  /* 4. Change the value of the msg variable */
   msg = 4321;
+  /* 5. Send it back as payload of a pong message to the expeditor */
   errcode = gras_msg_send(expeditor, gras_msgtype_by_name("pong"), &msg);
 
+  /* 6. Deal with errors */
   if (errcode != no_error) {
     ERROR1("SERVER: Unable answer with PONG: %s\n", xbt_error_name(errcode));
-    gras_socket_close(g->sock);
+    gras_socket_close(globals->sock);
     return 1;
   }
 
   INFO0("SERVER: >>>>>>>> Answed with PONG(4321) <<<<<<<<");
-  g->endcondition = 1;
+   
+  /* 7. Set the endcondition boolean to true (and make sure the server stops after receiving it). */
+  globals->endcondition = 1;
+  
+  /* 8. Make sure we don't leak sockets */
   gras_socket_close(expeditor);
+   
+  /* 9. Tell GRAS that we consummed this message */
   return 1;
-}
+} /* end_of_server_cb_ping_handler */
 
 int server (int argc,char *argv[]) {
   xbt_error_t errcode;
-  server_data_t *g;
-  gras_msgtype_t *ping_msg=NULL;
+  server_data_t *globals;
 
   int port = 4000;
   
+  /* 1. Init the GRAS infrastructure and declare my globals */
   gras_init(&argc,argv, NULL);
-  g=gras_userdata_new(server_data_t);
+  globals=gras_userdata_new(server_data_t);
    
+  /* 2. Get the port I should listen on from the command line, if specified */
   if (argc == 2) {
     port=atoi(argv[1]);
   }
 
   INFO1("Launch server (port=%d)", port);
 
-  if ((errcode=gras_socket_server(port,&(g->sock)))) { 
+  /* 3. Create my master socket */
+  if ((errcode=gras_socket_server(port,&(globals->sock)))) { 
     CRITICAL1("Error %s encountered while opening the server socket",
 	      xbt_error_name(errcode));
     return 1;
   }
 
+  /* 4. Register the known messages. This function is called twice here, but it's because
+        this file also acts as regression test, no need to do so yourself of course. */
   register_messages();
-  register_messages();
+  register_messages(); /* just to make sure it works ;) */
+   
+  /* 5. Register my callback */
   gras_cb_register(gras_msgtype_by_name("ping"),&server_cb_ping_handler);
 
-  INFO1("SERVER: >>>>>>>> Listening on port %d <<<<<<<<",
-	gras_socket_my_port(g->sock));
-  g->endcondition=0;
+  INFO1("SERVER: >>>>>>>> Listening on port %d <<<<<<<<", gras_socket_my_port(globals->sock));
+  globals->endcondition=0;
 
+  /* 6. Wait up to 10 minutes for an incomming message to handle */
   errcode = gras_msg_handle(600.0);
+   
+  /* 7. Housekeeping */
   if (errcode != no_error)
     return errcode;
-  if (g->endcondition)
+  if (!globals->endcondition)
+     WARN0("An error occured, the endcondition was not set by the callback");
   
+  /* 8. Sleep one second, but only in real life, not in simulation */
   if (!gras_if_RL())
-    gras_os_sleep(1,0);
+    gras_os_sleep(1, 0);
 
-  gras_socket_close(g->sock);
-  free(g);
+  /* 9. Free the allocated resources, and shut GRAS down */
+  gras_socket_close(globals->sock);
+  free(globals);
   gras_exit();
+   
   INFO0("SERVER: Done.");
   return no_error;
-}
+} /* end_of_server */
 
 /* **********************************************************************
  * Client code
  * **********************************************************************/
 
-/* Global private data */
-typedef struct {
-  gras_socket_t sock;
-} client_data_t;
-
 /* Function prototypes */
-int client (int argc,char *argv[]);
 
 int client(int argc,char *argv[]) {
-  xbt_error_t errcode;
-  client_data_t *g;
+  xbt_error_t errcode; 
+  gras_socket_t toserver; /* peer */
 
   gras_socket_t from;
   int ping, pong;
@@ -146,17 +146,22 @@ int client(int argc,char *argv[]) {
   const char *host = "127.0.0.1";
         int   port = 4000;
 
+  /* 1. Init the GRAS's infrastructure */
   gras_init(&argc, argv, NULL);
-  g=gras_userdata_new(client_data_t);
    
+  /* 2. Get the server's address from the command line, if specified */
   if (argc == 3) {
     host=argv[1];
     port=atoi(argv[2]);
   } 
 
   INFO2("Launch client (server on %s:%d)",host,port);
-  gras_os_sleep(1,0); /* Wait for the server startup */
-  if ((errcode=gras_socket_client(host,port,&(g->sock)))) {
+   
+  /* 3. Wait for the server startup */
+  gras_os_sleep(1,0);
+   
+  /* 4. Create a socket to speak to the server */
+  if ((errcode=gras_socket_client(host,port,&toserver))) {
     ERROR1("Client: Unable to connect to the server. Got %s",
 	   xbt_error_name(errcode));
     return 1;
@@ -164,38 +169,44 @@ int client(int argc,char *argv[]) {
   INFO2("Client: Connected to %s:%d.",host,port);    
 
 
+  /* 5. Register the messages. 
+        See, it doesn't have to be done completely at the beginning, only before use */
   register_messages();
 
+  /* 6. Keep the user informed of what's going on */
   INFO2("Client: >>>>>>>> Connected to server which is on %s:%d <<<<<<<<", 
-	gras_socket_peer_name(g->sock),gras_socket_peer_port(g->sock));
+	gras_socket_peer_name(toserver),gras_socket_peer_port(toserver));
 
+  /* 7. Prepare and send the ping message to the server */
   ping = 1234;
-  errcode = gras_msg_send(g->sock, gras_msgtype_by_name("ping"), &ping);
+  errcode = gras_msg_send(toserver, gras_msgtype_by_name("ping"), &ping);
   if (errcode != no_error) {
     fprintf(stderr, "Client: Unable send PING to server (%s)\n",
 	    xbt_error_name(errcode));
-    gras_socket_close(g->sock);
+    gras_socket_close(toserver);
     return 1;
   }
   INFO3("Client: >>>>>>>> Message PING(%d) sent to %s:%d <<<<<<<<",
 	ping,
-	gras_socket_peer_name(g->sock),gras_socket_peer_port(g->sock));
+	gras_socket_peer_name(toserver),gras_socket_peer_port(toserver));
 
+  /* 8. Wait for the answer from the server, and deal with issues */
   if ((errcode=gras_msg_wait(6000,gras_msgtype_by_name("pong"),
 			     &from,&pong))) {
     ERROR1("Client: Why can't I get my PONG message like everyone else (%s)?",
 	   xbt_error_name(errcode));
-    gras_socket_close(g->sock);
+    gras_socket_close(toserver);
     return 1;
   }
 
+  /* 9. Keep the user informed of what's going on, again */
   INFO3("Client: >>>>>>>> Got PONG(%d) got from %s:%d <<<<<<<<", 
 	pong,
 	gras_socket_peer_name(from),gras_socket_peer_port(from));
 
-  gras_socket_close(g->sock);
-  free(g);
+  /* 10. Free the allocated resources, and shut GRAS down */
+  gras_socket_close(toserver);
   gras_exit();
   INFO0("Client: Done.");
   return 0;
-}
+} /* end_of_client */