Modified: branches/safari-604-branch/Source/WebCore/ChangeLog (223100 => 223101)
--- branches/safari-604-branch/Source/WebCore/ChangeLog 2017-10-10 00:08:16 UTC (rev 223100)
+++ branches/safari-604-branch/Source/WebCore/ChangeLog 2017-10-10 00:08:19 UTC (rev 223101)
@@ -1,5 +1,34 @@
2017-10-02 Jason Marcell <[email protected]>
+ Apply patch. rdar://problem/34770842
+
+ Cherry-pick r221083. rdar://problem/34770842, rdar://problem/34770849
+
+ 2017-10-02 Mark Lam <[email protected]>
+
+ Cherry-pick r221083. rdar://problem/34770842, rdar://problem/34770849
+
+ 2017-08-23 Yusuke Suzuki <[email protected]>
+
+ Race condition in StartWebThread causing crash
+ https://bugs.webkit.org/show_bug.cgi?id=175852
+
+ Reviewed by Mark Lam.
+
+ When starting web thread, the main thread waits for completion of web thread initialization
+ by using pthread_cond_t. However, the main thread may be woken up due to the existence of
+ the spurious wake up of pthread_cond_t.
+
+ Instead, we should use WTF::Lock and WTF::Condition. Since our StartWebThread already calls
+ WTF::initializeThreading, it is safe to use WTF::Lock and WTF::Condition. And our WTF::Condition
+ does not have the spurious wake up problem as described in Condition.h.
+
+ * platform/ios/wak/WebCoreThread.mm:
+ (RunWebThread):
+ (StartWebThread):
+
+2017-10-02 Jason Marcell <[email protected]>
+
Cherry-pick r222190. rdar://problem/34771470
2017-09-18 Tim Horton <[email protected]>
Modified: branches/safari-604-branch/Source/WebCore/platform/ios/wak/WebCoreThread.mm (223100 => 223101)
--- branches/safari-604-branch/Source/WebCore/platform/ios/wak/WebCoreThread.mm 2017-10-10 00:08:16 UTC (rev 223100)
+++ branches/safari-604-branch/Source/WebCore/platform/ios/wak/WebCoreThread.mm 2017-10-10 00:08:19 UTC (rev 223101)
@@ -127,8 +127,8 @@
static CFRunLoopObserverRef mainRunLoopAutoUnlockObserver;
-static pthread_mutex_t startupLock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t startupCondition = PTHREAD_COND_INITIALIZER;
+static StaticLock startupLock;
+static StaticCondition startupCondition;
static WebThreadContext *webThreadContext;
static pthread_key_t threadContextKey;
@@ -681,15 +681,11 @@
WebThreadReleaseSource = CFRunLoopSourceCreate(NULL, -1, &ReleaseSourceContext);
CFRunLoopAddSource(webThreadRunLoop, WebThreadReleaseSource, kCFRunLoopDefaultMode);
- int result = pthread_mutex_lock(&startupLock);
- ASSERT_WITH_MESSAGE(result == 0, "startup lock failed with code:%d", result);
+ {
+ LockHolder locker(startupLock);
+ startupCondition.notifyOne();
+ }
- result = pthread_cond_signal(&startupCondition);
- ASSERT_WITH_MESSAGE(result == 0, "startup signal failed with code:%d", result);
-
- result = pthread_mutex_unlock(&startupLock);
- ASSERT_WITH_MESSAGE(result == 0, "startup unlock failed with code:%d", result);
-
while (1)
CFRunLoopRunInMode(kCFRunLoopDefaultMode, DistantFuture, true);
@@ -702,6 +698,9 @@
{
webThreadStarted = TRUE;
+ // ThreadGlobalData touches AtomicString, which requires Threading initialization.
+ WTF::initializeThreading();
+
// Initialize ThreadGlobalData on the main UI thread so that the WebCore thread
// can later set it's thread-specific data to point to the same objects.
WebCore::ThreadGlobalData& unused = WebCore::threadGlobalData();
@@ -755,21 +754,18 @@
pthread_attr_setschedparam(&tattr, ¶m);
// Wait for the web thread to startup completely before we continue.
- int result = pthread_mutex_lock(&startupLock);
- ASSERT_WITH_MESSAGE(result == 0, "startup lock failed with code:%d", result);
+ {
+ LockHolder locker(startupLock);
- // Propagate the mainThread's fenv to workers & the web thread.
- FloatingPointEnvironment::singleton().saveMainThreadEnvironment();
+ // Propagate the mainThread's fenv to workers & the web thread.
+ FloatingPointEnvironment::singleton().saveMainThreadEnvironment();
- pthread_create(&webThread, &tattr, RunWebThread, NULL);
- pthread_attr_destroy(&tattr);
+ pthread_create(&webThread, &tattr, RunWebThread, NULL);
+ pthread_attr_destroy(&tattr);
- result = pthread_cond_wait(&startupCondition, &startupLock);
- ASSERT_WITH_MESSAGE(result == 0, "startup wait failed with code:%d", result);
+ startupCondition.wait(startupLock);
+ }
- result = pthread_mutex_unlock(&startupLock);
- ASSERT_WITH_MESSAGE(result == 0, "startup unlock failed with code:%d", result);
-
initializeApplicationUIThreadIdentifier();
}
