X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/acbc8f35e5a8520356ce5a527971e6685a4e5793..79b7fcc6dfb026ac94df11b5610ba84dde5b2c84:/src/gras/Transport/rl_transport.c

diff --git a/src/gras/Transport/rl_transport.c b/src/gras/Transport/rl_transport.c
index 5b6b6ecdda..031c1e62bb 100644
--- a/src/gras/Transport/rl_transport.c
+++ b/src/gras/Transport/rl_transport.c
@@ -12,6 +12,9 @@
 #include "gras/Transport/transport_private.h"
 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(gras_trp);
 
+/* check transport_private.h for an explanation of this variable */
+gras_socket_t _gras_lastly_selected_socket = NULL;
+
 /**
  * gras_trp_select:
  *
@@ -37,29 +40,37 @@ gras_socket_t gras_trp_select(double timeout) {
      with this tiny optimisation on BillWare */
   fd_set FDS;
   int ready; /* return of select: number of socket ready to be serviced */
-  int fd_setsize; /* FD_SETSIZE not always defined. Get this portably */
+  static int fd_setsize=-1; /* FD_SETSIZE not always defined. Get this portably */
 
   gras_socket_t sock_iter; /* iterating over all sockets */
   int cursor;              /* iterating over all sockets */
 
-   
-  /* Compute FD_SETSIZE */
+  /* Check whether there is more data to read from the socket we selected last time.
+     This can happen with tcp buffered sockets since we try to get as much data as we can for them */
+  if (_gras_lastly_selected_socket && _gras_lastly_selected_socket->moredata) {
+     VERB0("Returning _gras_lastly_selected_socket since there is more data on it");
+     return _gras_lastly_selected_socket;
+  }
+  
+  /* Compute FD_SETSIZE on need */
+  if (fd_setsize < 0) {	
 #ifdef HAVE_SYSCONF
-   fd_setsize = sysconf( _SC_OPEN_MAX );
+     fd_setsize = sysconf( _SC_OPEN_MAX );
 #else
 #  ifdef HAVE_GETDTABLESIZE 
-   fd_setsize = getdtablesize();
+     fd_setsize = getdtablesize();
 #  else
-   fd_setsize = FD_SETSIZE;
+     fd_setsize = FD_SETSIZE;
 #  endif /* !USE_SYSCONF */
 #endif
+  }
 
   while (done == -1) {
     if (timeout > 0) { /* did we timeout already? */
       now = gras_os_time();
       DEBUG2("wakeup=%f now=%f",wakeup, now);
       if (now == -1 || now >= wakeup) {
-	/* didn't find anything */
+	/* didn't find anything; no need to update _gras_lastly_selected_socket since its moredata is 0 (or we would have returned it directly) */
 	THROW1(timeout_error,0,
 	       "Timeout (%f) elapsed with selecting for incomming connexions",
 	       timeout);
@@ -70,11 +81,17 @@ gras_socket_t gras_trp_select(double timeout) {
     FD_ZERO(&FDS);
     max_fds = -1;
     xbt_dynar_foreach(sockets,cursor,sock_iter) {
+      if (!sock_iter->valid)
+	 continue;
+       
       if (sock_iter->incoming) {
 	DEBUG1("Considering socket %d for select",sock_iter->sd);
 #ifndef HAVE_WINSOCK_H
 	if (max_fds < sock_iter->sd)
 	  max_fds = sock_iter->sd;
+#else
+      max_fds = 0;
+
 #endif
 	FD_SET(sock_iter->sd, &FDS);
       } else {
@@ -144,7 +161,7 @@ gras_socket_t gras_trp_select(double timeout) {
       continue;	 /* this was a timeout */
     }
 
-    xbt_dynar_foreach(sockets,cursor,sock_iter) { 
+    xbt_dynar_foreach(sockets,cursor,sock_iter) {
        if(!FD_ISSET(sock_iter->sd, &FDS)) { /* this socket is not ready */
 	continue;
        }
@@ -157,9 +174,13 @@ gras_socket_t gras_trp_select(double timeout) {
 	 /* not a socket but an ear. accept on it and serve next socket */
 	 gras_socket_t accepted=NULL;
 	 
+	 /* release mutex before accept */
+	 xbt_dynar_cursor_unlock(sockets);
 	 accepted = (sock_iter->plugin->socket_accept)(sock_iter);
+
 	 DEBUG2("accepted=%p,&accepted=%p",accepted,&accepted);
 	 accepted->meas = sock_iter->meas;
+	 break;
 
        } else if (sock_iter->recv_ok) {
 	 /* Make sure the socket is still alive by reading the first byte */
@@ -175,30 +196,38 @@ gras_socket_t gras_trp_select(double timeout) {
 	 } else if (recvd == 0) {
 	   /* Connection reset (=closed) by peer. */
 	   DEBUG1("Connection %d reset by peer", sock_iter->sd);
-	   gras_socket_close(sock_iter); 
-	   cursor--; 
+	   sock_iter->valid=0; /* don't close it. User may keep references to it */
 	 } else { 
 	   /* Got a suited socket ! */
 	   XBT_OUT;
+	   _gras_lastly_selected_socket = sock_iter;
+		 /* break sync dynar iteration */
+		 xbt_dynar_cursor_unlock(sockets);
 	   return sock_iter;
 	 }
 
        } else {
 	 /* This is a file socket. Cannot recv() on it, but it must be alive */
 	   XBT_OUT;
+	   _gras_lastly_selected_socket = sock_iter;
+		 xbt_dynar_cursor_unlock(sockets);
 	   return sock_iter;
        }
 
        
        /* if we're here, the socket we found wasn't really ready to be served */
-       if (ready == 0) /* exausted all sockets given by select. Request new ones */
-	 break; 
+       if (ready == 0) { /* exausted all sockets given by select. Request new ones */
+
+				 xbt_dynar_cursor_unlock(sockets);
+				 break; 
+			 }
     }
 
   }
 
-  XBT_OUT;
-  return NULL;
+  /* No socket found. Maybe we had timeout=0 and nothing to do */
+  DEBUG0("TIMEOUT");
+  THROW0(timeout_error,0,"Timeout");
 }
 
 void gras_trp_sg_setup(gras_trp_plugin_t plug) {