[asterisk-commits] kpfleming: branch 1.4 r94824 - /branches/1.4/main/manager.c

[SVN commits to the Asterisk project]

Author: kpfleming
Date: Wed Dec 26 19:01:47 2007
New Revision: 94824

URL: http://svn.digium.com/view/asterisk?view=rev&rev=94824
Log:
make this comment explain the situation in an even more explicit fashion

Modified:
    branches/1.4/main/manager.c

Modified: branches/1.4/main/manager.c
URL: http://svn.digium.com/view/asterisk/branches/1.4/main/manager.c?view=diff&rev=94824&r1=94823&r2=94824
==============================================================================
--- branches/1.4/main/manager.c (original)
+++ branches/1.4/main/manager.c Wed Dec 26 19:01:47 2007
@@ -2284,11 +2284,17 @@
 		ast_log(LOG_EVENT, "Failed attempt from %s\n", ast_inet_ntoa(s->sin.sin_addr));
 	}
 
-	/* If the entire session occurs in a single context switch, then it's
-	 * possible to get an unsafe memory condition by free()ing the memory
-	 * before letting other threads run at least once.  This actually seems
-	 * like a workaround for a glibc bug.
-	 */
+	/* It is possible under certain circumstances for this session thread
+	   to complete its work and exit *before* the thread that created it
+	   has finished executing the ast_pthread_create_background() function.
+	   If this occurs, some versions of glibc appear to act in a buggy
+	   fashion and attempt to write data into memory that it thinks belongs
+	   to the thread but is in fact not owned by the thread (or may have
+	   been freed completely).
+
+	   Causing this thread to yield to other threads at least one time
+	   appears to work around this bug.
+	*/
 	usleep(1);
 
 	destroy_session(s);