[MPlayer-cvslog] r31738 - trunk/stream/cache2.c

[reimar]

Author: reimar
Date: Thu Jul 15 20:09:14 2010
New Revision: 31738

Log:
Use sigaction() instead of signal(), the latter has a unavoidable
race-condition on "broken by backwards-compatibility" systems like Solaris.
(upon receiving a signal, the handler is reset to SIG_DFL, thus a
second signal will kill the process, the problem could also be reduced
by re-installing the handler inside the handler, but there's still a
race-condition and the risk of the handler being called inside the handler).

Modified:
   trunk/stream/cache2.c

Modified: trunk/stream/cache2.c
==============================================================================
--- trunk/stream/cache2.c	Thu Jul 15 19:59:46 2010	(r31737)
+++ trunk/stream/cache2.c	Thu Jul 15 20:09:14 2010	(r31738)
@@ -366,7 +366,8 @@ static void dummy_sighandler(int x) {
 static void cache_mainloop(cache_vars_t *s) {
     int sleep_count = 0;
 #if FORKED_CACHE
-    signal(SIGUSR1, SIG_IGN);
+    struct sigaction sa = { .sa_handler = SIG_IGN };
+    sigaction(SIGUSR1, &sa, NULL);
 #endif
     do {
         if (!cache_fill(s)) {
@@ -374,7 +375,8 @@ static void cache_mainloop(cache_vars_t 
             // Let signal wake us up, we cannot leave this
             // enabled since we do not handle EINTR in most places.
             // This might need extra code to work on BSD.
-            signal(SIGUSR1, dummy_sighandler);
+            sa.sa_handler = dummy_sighandler;
+            sigaction(SIGUSR1, &sa, NULL);
 #endif
             if (sleep_count < INITIAL_FILL_USLEEP_COUNT) {
                 sleep_count++;
@@ -382,7 +384,8 @@ static void cache_mainloop(cache_vars_t 
             } else
                 usec_sleep(FILL_USLEEP_TIME); // idle
 #if FORKED_CACHE
-            signal(SIGUSR1, SIG_IGN);
+            sa.sa_handler = SIG_IGN;
+            sigaction(SIGUSR1, &sa, NULL);
 #endif
         } else
             sleep_count = 0;