* signal.c: Make the signal handler thread-safe, so that it can safely be

	  invoked concurrently from multiple threads.

svn path=/trunk/mono/; revision=95140

2 files changed, 16 insertions, 6 deletions

diff --git a/support/ChangeLog b/support/ChangeLog
index 4e9419b6f4d..0d17de5bca8 100644
--- a/support/ChangeLog
+++ b/support/ChangeLog
@@ -1,3 +1,8 @@
+2008-02-07  Jonathan Pryor  <jpryor@novell.com>
+
+	* signal.c: Make the signal handler thread-safe, so that it can safely be
+	  invoked concurrently from multiple threads.
+
 2008-02-05  Jonathan Pryor  <jpryor@novell.com>
 
 	* signal.c: Fix the Win32 build.
diff --git a/support/signal.c b/support/signal.c
index fd95bb14db8..d995fa970d3 100644
--- a/support/signal.c
+++ b/support/signal.c
@@ -71,13 +71,15 @@ default_handler (int signum)
 {
 	int i;
 	for (i = 0; i < NUM_SIGNALS; ++i) {
+		int fd;
 		signal_info* h = &signals [i];
-		if (h->signum != signum)
+		if (g_atomic_int_get (&h->signum) != signum)
 			continue;
-		++h->count;
-		if (h->write_fd > 0) {
+		g_atomic_int_inc (&h->count);
+		fd = g_atomic_int_get (&h->write_fd);
+		if (fd > 0) {
 			char c = signum;
-			write (h->write_fd, &c, 1);
+			write (fd, &c, 1);
 		}
 	}
 }
@@ -108,8 +110,6 @@ Mono_Unix_UnixSignal_install (int sig)
 				break;
 			}
 			else {
-				h->signum       = sig;
-				h->count        = 0;
 				h->have_handler = 1;
 			}
 		}
@@ -127,6 +127,11 @@ Mono_Unix_UnixSignal_install (int sig)
 		h->handler      = handler;
 	}
 
+	if (h) {
+		g_atomic_int_set (&h->count, 0);
+		g_atomic_int_set (&h->signum, sig);
+	}
+
 	pthread_mutex_unlock (&signals_mutex);
 
 	return h;