Changeset 256474 in webkit

Timestamp:

Feb 12, 2020 1:50:49 PM (4 years ago)

Author:

BJ Burg

Message:

Web Inspector: inspector/cpu-profiler/threads.html is flaky crashing
​https://bugs.webkit.org/show_bug.cgi?id=207588
<rdar://problem/57458123>

Reviewed by Yusuke Suzuki.

• page/cocoa/ResourceUsageThreadCocoa.mm:

(WebCore::ResourceUsageThread::platformCollectCPUData):
Use a fence to force Thread to be completely ready for use by other threads
prior to storing it. Otherwise, ResourceUsageThread may see it too early.

• workers/WorkerThread.cpp:

(WebCore::WorkerThread::start): Ignore worker threads that are
not fully initialized.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• page/cocoa/ResourceUsageThreadCocoa.mm (modified) (1 diff)
• workers/WorkerThread.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-02-12  Brian Burg  <bburg@apple.com>
+
+        Web Inspector: inspector/cpu-profiler/threads.html is flaky crashing
+        https://bugs.webkit.org/show_bug.cgi?id=207588
+        <rdar://problem/57458123>
+
+        Reviewed by Yusuke Suzuki.
+
+        * page/cocoa/ResourceUsageThreadCocoa.mm:
+        (WebCore::ResourceUsageThread::platformCollectCPUData):
+        Use a fence to force Thread to be completely ready for use by other threads
+        prior to storing it. Otherwise, ResourceUsageThread may see it too early.
+
+        * workers/WorkerThread.cpp:
+        (WebCore::WorkerThread::start): Ignore worker threads that are
+        not fully initialized.
+
 2020-02-12  Youenn Fablet  <youenn@apple.com>
 

trunk/Source/WebCore/page/cocoa/ResourceUsageThreadCocoa.mm

@@ -169 +169 @@
         LockHolder lock(WorkerThread::workerThreadsMutex());
         for (auto* thread : WorkerThread::workerThreads(lock)) {
+            // Ignore worker threads that have not been fully started yet.
+            if (!thread->thread())
+                continue;
             mach_port_t machThread = thread->thread()->machThread();
             if (machThread != MACH_PORT_NULL)

trunk/Source/WebCore/workers/WorkerThread.cpp

@@ -143 +143 @@
     m_evaluateCallback = WTFMove(evaluateCallback);
 
-    m_thread = Thread::create(isServiceWorkerThread() ? "WebCore: Service Worker" : "WebCore: Worker", [this] {
+    Ref<Thread> thread = Thread::create(isServiceWorkerThread() ? "WebCore: Service Worker" : "WebCore: Worker", [this] {
         workerThread();
     });
+    // Force the Thread object to be initialized fully before storing it to m_thread (and becoming visible to other threads).
+    WTF::storeStoreFence();
+    m_thread = WTFMove(thread);
 }