1 files changed, 40 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wtf/MainThread.cpp b/Source/JavaScriptCore/wtf/MainThread.cpp
index 915126589..f8686aa31 100644
--- a/Source/JavaScriptCore/wtf/MainThread.cpp
+++ b/Source/JavaScriptCore/wtf/MainThread.cpp
@@ -34,6 +34,7 @@
 #include "Functional.h"
 #include "StdLibExtras.h"
 #include "Threading.h"
+#include <wtf/ThreadSpecific.h>
 
 #if PLATFORM(CHROMIUM)
 #error Chromium uses a different main thread implementation
@@ -101,6 +102,7 @@ void initializeMainThread()
 
     mainThreadFunctionQueueMutex();
     initializeMainThreadPlatform();
+    initializeGCThreads();
 }
 
 #else
@@ -249,4 +251,42 @@ bool isMainThread()
 }
 #endif
 
+#if ENABLE(PARALLEL_GC)
+static ThreadSpecific<bool>* isGCThread;
+#endif
+
+void initializeGCThreads()
+{
+#if ENABLE(PARALLEL_GC)
+    isGCThread = new ThreadSpecific<bool>();
+#endif
+}
+
+#if ENABLE(PARALLEL_GC)
+void registerGCThread()
+{
+    if (!isGCThread) {
+        // This happens if we're running in a process that doesn't care about
+        // MainThread.
+        return;
+    }
+
+    **isGCThread = true;
+}
+
+bool isMainThreadOrGCThread()
+{
+    if (isGCThread->isSet() && **isGCThread)
+        return true;
+
+    return isMainThread();
+}
+#elif PLATFORM(MAC)
+// This is necessary because JavaScriptCore.exp doesn't support preprocessor macros.
+bool isMainThreadOrGCThread()
+{
+    return isMainThread();
+}
+#endif
+
 } // namespace WTF