Fixes for two benign race conditions and one bug detected

by kcc's thread sanitizer:
1) remove extra '&' char; this fix is already upstream in libevent
2) delete unused and deprecated event_sigcb interface
3) avoid setting use_monotonic repeatedly.  (Should
really be protected with a mutex, but a simple init
check seems to quiet the race detector.)

Review URL: http://codereview.chromium.org/95012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@14467 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 7 insertions, 21 deletions

diff --git a/third_party/libevent/event.c b/third_party/libevent/event.c
index 3396b35..726ffad 100644
--- a/third_party/libevent/event.c
+++ b/third_party/libevent/event.c
@@ -108,10 +108,7 @@ const struct eventop *eventops[] = {
 struct event_base *current_base = NULL;
 extern struct event_base *evsignal_base;
 static int use_monotonic;
-
-/* Handle signals - This is a deprecated interface */
-int (*event_sigcb)(void);		/* Signal callback when gotsig is set */
-volatile sig_atomic_t event_gotsig;	/* Set in signal handler */
+static int use_monotonic_initialized;
 
 /* Prototypes */
 static void	event_queue_insert(struct event_base *, struct event *, int);
@@ -128,10 +125,14 @@ static void
 detect_monotonic(void)
 {
 #if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
+	if (use_monotonic_initialized)
+		return;
+
 	struct timespec	ts;
 
 	if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
 		use_monotonic = 1;
+	use_monotonic_initialized = 1;
 #endif
 }
 
@@ -179,9 +180,6 @@ event_base_new(void)
 	if ((base = calloc(1, sizeof(struct event_base))) == NULL)
 		event_err(1, "%s: calloc", __func__);
 
-	event_sigcb = NULL;
-	event_gotsig = 0;
-
 	detect_monotonic();
 	gettime(base, &base->event_tv);
 	
@@ -385,7 +383,7 @@ event_process_active(struct event_base *base)
 			ncalls--;
 			ev->ev_ncalls = ncalls;
 			(*ev->ev_callback)((int)ev->ev_fd, ev->ev_res, ev->ev_arg);
-			if (event_gotsig || base->event_break)
+			if (base->event_break)
 				return;
 		}
 	}
@@ -472,7 +470,7 @@ event_base_loop(struct event_base *base, int flags)
 	struct timeval *tv_p;
 	int res, done;
 
-	if (&base->sig.ev_signal_added)
+	if (base->sig.ev_signal_added)
 		evsignal_base = base;
 	done = 0;
 	while (!done) {
@@ -487,18 +485,6 @@ event_base_loop(struct event_base *base, int flags)
 			break;
 		}
 
-		/* You cannot use this interface for multi-threaded apps */
-		while (event_gotsig) {
-			event_gotsig = 0;
-			if (event_sigcb) {
-				res = (*event_sigcb)();
-				if (res == -1) {
-					errno = EINTR;
-					return (-1);
-				}
-			}
-		}
-
 		timeout_correct(base, &tv);
 
 		tv_p = &tv;