Bug 633457 - "Firefox hangs at startup" (r=bent, a=hardblocker)

xpcom/base/nsCycleCollector.cpp

@@ -3285,6 +3285,7 @@ class nsCycleCollectorRunner : public nsRunnable
     CondVar mRequest;
     CondVar mReply;
     PRBool mRunning;
+    PRBool mShutdown;
     PRBool mCollected;
     PRBool mJSGCHasRun;
 
@@ -3305,6 +3306,9 @@ public:
 
         MutexAutoLock autoLock(mLock);
 
+        if (mShutdown)
+            return NS_OK;
+
         mRunning = PR_TRUE;
 
         while (1) {
@@ -3330,6 +3334,7 @@ public:
           mRequest(mLock, "cycle collector request condvar"),
           mReply(mLock, "cycle collector reply condvar"),
           mRunning(PR_FALSE),
+          mShutdown(PR_FALSE),
           mCollected(PR_FALSE),
           mJSGCHasRun(PR_FALSE)
     {
@@ -3374,6 +3379,8 @@ public:
 
         MutexAutoLock autoLock(mLock);
 
+        mShutdown = PR_TRUE;
+
         if (!mRunning)
             return;