From: Ivan Maidanski <ivmai@mail.ru>
Date: Thu, 28 Dec 2017 08:18:25 +0000 (+0300)
Subject: Do not call sem_getvalue in stop_world if one thread exists
X-Git-Tag: v8.0.0~434
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=62d2d77df3e8da9760f82e327ee95ded94075073;p=platform%2Fupstream%2Flibgc.git

Do not call sem_getvalue in stop_world if one thread exists

* pthread_stop_world.c [!GC_OPENBSD_UTHREADS && !NACL] (GC_stop_world):
Do not call sem_getvalue() if n_live_threads is zero (matters only if
GC_retry_signals).
---

diff --git a/pthread_stop_world.c b/pthread_stop_world.c
index 6e9f406..bda842c 100644
--- a/pthread_stop_world.c
+++ b/pthread_stop_world.c
@@ -808,7 +808,7 @@ GC_INNER void GC_stop_world(void)
     AO_store_release(&GC_world_is_stopped, TRUE);
     n_live_threads = GC_suspend_all();
 
-    if (GC_retry_signals) {
+    if (GC_retry_signals && n_live_threads > 0) {
       unsigned long wait_usecs = 0;  /* Total wait since retry. */
 #     define WAIT_UNIT 3000
 #     define RETRY_INTERVAL 100000