[GNUnet-SVN] r9157 - in libmicrohttpd: . src/daemon

[gnunet]

Author: grothoff
Date: 2009-10-14 06:39:50 -0600 (Wed, 14 Oct 2009)
New Revision: 9157

Modified:
   libmicrohttpd/ChangeLog
   libmicrohttpd/src/daemon/daemon.c
Log:
Trying to fix the issue reported on the mailinglist at

http://lists.gnu.org/archive/html/libmicrohttpd/2009-10/msg00013.html


Modified: libmicrohttpd/ChangeLog
===================================================================
--- libmicrohttpd/ChangeLog     2009-10-14 12:26:42 UTC (rev 9156)
+++ libmicrohttpd/ChangeLog     2009-10-14 12:39:50 UTC (rev 9157)
@@ -1,3 +1,10 @@
+Wed Oct 14 14:37:37 CEST 2009
+       Fixing (rare) deadlock due to SELECT missing SIGALRM by
+       making all SELECT calls block for at most 1s.  While this
+       can in (rare) situations delay the shutdown by 1s, I think
+       this is prefereable (both performance and possibly portability-wise)
+       over using a pipe for the signal. -CG
+
 Sun Oct 11 14:57:29 CEST 2009
        Adding eCos license as an additional license for the
        non-HTTPS code of MHD. -CG

Modified: libmicrohttpd/src/daemon/daemon.c
===================================================================
--- libmicrohttpd/src/daemon/daemon.c   2009-10-14 12:26:42 UTC (rev 9156)
+++ libmicrohttpd/src/daemon/daemon.c   2009-10-14 12:39:50 UTC (rev 9157)
@@ -477,18 +477,22 @@
       now = time (NULL);
       tv.tv_usec = 0;
       if (timeout > (now - con->last_activity))
-        tv.tv_sec = timeout - (now - con->last_activity);
+       {
+         /* in case we are missing the SIGALRM, keep going after
+            at most 1s; see 
http://lists.gnu.org/archive/html/libmicrohttpd/2009-10/msg00013.html */
+         tv.tv_sec = 1;
+         if ((con->state == MHD_CONNECTION_NORMAL_BODY_UNREADY) ||
+             (con->state == MHD_CONNECTION_CHUNKED_BODY_UNREADY))
+           {
+             /* do not block (we're waiting for our callback to succeed) */
+             tv.tv_sec = 0;
+           }   
+       }
       else
-        tv.tv_sec = 0;
-      if ((con->state == MHD_CONNECTION_NORMAL_BODY_UNREADY) ||
-          (con->state == MHD_CONNECTION_CHUNKED_BODY_UNREADY))
-       {
-          /* do not block (we're waiting for our callback to succeed) */
-          timeout = 1;
-          tv.tv_sec = 0;
-      }
-      num_ready = SELECT (max + 1,
-                          &rs, &ws, &es, (timeout != 0) ? &tv : NULL);
+       {
+         tv.tv_sec = 0;
+       }
+      num_ready = SELECT (max + 1, &rs, &ws, &es, &tv);
       if (num_ready < 0)
         {
           if (errno == EINTR)
@@ -901,7 +905,11 @@
         return MHD_NO;
       FD_SET (max, &rs);
     }
-
+  
+  /* in case we are missing the SIGALRM, keep going after
+     at most 1s; see 
http://lists.gnu.org/archive/html/libmicrohttpd/2009-10/msg00013.html */
+  timeout.tv_usec = 0;
+  timeout.tv_sec = 1; 
   if (may_block == MHD_NO)
     {
       timeout.tv_usec = 0;
@@ -910,17 +918,15 @@
   else
     {
       /* ltimeout is in ms */
-      if (MHD_YES == MHD_get_timeout (daemon, &ltimeout))
-        {
-          timeout.tv_usec = (ltimeout % 1000) * 1000;
-          timeout.tv_sec = ltimeout / 1000;
-          may_block = MHD_NO;
+      if ( (MHD_YES == MHD_get_timeout (daemon, &ltimeout)) &&
+          (ltimeout < 1000) )
+       {
+          timeout.tv_usec = ltimeout * 1000;
+          timeout.tv_sec = 0;
         }
     }
+  num_ready = SELECT (max + 1, &rs, &ws, &es, &timeout);
 
-  num_ready = select (max + 1, &rs, &ws, &es, may_block == MHD_NO ? &timeout
-                      : NULL);
-
   if (daemon->shutdown == MHD_YES)
     return MHD_NO;
   if (num_ready < 0)