Bug 593742 - nsDOMWorker has to set the right compartment. r=bent.

--HG--
extra : rebase_source : 1f309d333686fdad21a7b6940873994ccc64157d

dom/src/threads/nsDOMThreadService.cpp

@@ -395,35 +395,41 @@ public:
     JS_TriggerOperationCallback(cx);
 
     PRBool killWorkerWhenDone;
+    {
+      nsLazyAutoRequest ar;
+      JSAutoCrossCompartmentCall axcc;
 
-    // Tell the worker which context it will be using
-    if (mWorker->SetGlobalForContext(cx)) {
-      RunQueue(cx, &killWorkerWhenDone);
+      // Tell the worker which context it will be using
+      if (mWorker->SetGlobalForContext(cx, &ar, &axcc)) {
+        NS_ASSERTION(ar.entered(), "SetGlobalForContext must enter request on success");
+        NS_ASSERTION(axcc.entered(), "SetGlobalForContext must enter xcc on success");
 
-      // Code in XPConnect assumes that the context's global object won't be
-      // replaced outside of a request.
-      JSAutoRequest ar(cx);
+        RunQueue(cx, &killWorkerWhenDone);
 
-      // Remove the global object from the context so that it might be garbage
-      // collected.
-      JS_SetGlobalObject(cx, NULL);
-      JS_SetContextPrivate(cx, NULL);
-    }
-    else {
-      {
-        // Code in XPConnect assumes that the context's global object won't be
-        // replaced outside of a request.
-        JSAutoRequest ar(cx);
-
-        // This is usually due to a parse error in the worker script...
+        // Remove the global object from the context so that it might be garbage
+        // collected.
         JS_SetGlobalObject(cx, NULL);
         JS_SetContextPrivate(cx, NULL);
       }
+      else {
+        NS_ASSERTION(!ar.entered(), "SetGlobalForContext must not enter request on failure");
+        NS_ASSERTION(!axcc.entered(), "SetGlobalForContext must not enter xcc on failure");
 
-      nsAutoMonitor mon(gDOMThreadService->mMonitor);
-      killWorkerWhenDone = mKillWorkerWhenDone;
-      gDOMThreadService->WorkerComplete(this);
-      mon.NotifyAll();
+        {
+          // Code in XPConnect assumes that the context's global object won't be
+          // replaced outside of a request.
+          JSAutoRequest ar2(cx);
+
+          // This is usually due to a parse error in the worker script...
+          JS_SetGlobalObject(cx, NULL);
+          JS_SetContextPrivate(cx, NULL);
+        }
+
+        nsAutoMonitor mon(gDOMThreadService->mMonitor);
+        killWorkerWhenDone = mKillWorkerWhenDone;
+        gDOMThreadService->WorkerComplete(this);
+        mon.NotifyAll();
+      }
     }
 
     if (killWorkerWhenDone) {

dom/src/threads/nsDOMWorker.cpp

@@ -1560,26 +1560,41 @@ nsDOMWorker::PostMessageInternal(PRBool aToInner)
 }
 
 PRBool
-nsDOMWorker::SetGlobalForContext(JSContext* aCx)
+nsDOMWorker::SetGlobalForContext(JSContext* aCx, nsLazyAutoRequest *aRequest,
+                                 JSAutoCrossCompartmentCall *aCall)
 {
   NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
 
-  if (!CompileGlobalObject(aCx)) {
+  if (!CompileGlobalObject(aCx, aRequest, aCall)) {
     return PR_FALSE;
   }
 
-  JSAutoRequest ar(aCx);
-
   JS_SetGlobalObject(aCx, mGlobal);
   return PR_TRUE;
 }
 
 PRBool
-nsDOMWorker::CompileGlobalObject(JSContext* aCx)
+nsDOMWorker::CompileGlobalObject(JSContext* aCx, nsLazyAutoRequest *aRequest,
+                                 JSAutoCrossCompartmentCall *aCall)
 {
   NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
 
+  // On success, we enter a request and a cross-compartment call that both
+  // belong to the caller. But on failure, we must not remain in a request or
+  // cross-compartment call. So we enter both only locally at first. On
+  // failure, the local request and call will automatically get cleaned
+  // up. Once success is certain, we swap them into *aRequest and *aCall.
+  nsLazyAutoRequest localRequest;
+  JSAutoCrossCompartmentCall localCall;
+  localRequest.enter(aCx);
+
+  PRBool success;
   if (mGlobal) {
+    success = localCall.enter(aCx, mGlobal);
+    NS_ENSURE_TRUE(success, PR_FALSE);
+
+    aRequest->swap(localRequest);
+    aCall->swap(localCall);
     return PR_TRUE;
   }
 
@@ -1591,8 +1606,6 @@ nsDOMWorker::CompileGlobalObject(JSContext* aCx)
 
   NS_ASSERTION(!mScriptURL.IsEmpty(), "Must have a url here!");
 
-  JSAutoRequest ar(aCx);
-
   NS_ASSERTION(!JS_GetGlobalObject(aCx), "Global object should be unset!");
 
   nsRefPtr<nsDOMWorkerScope> scope = new nsDOMWorkerScope(this);
@@ -1622,6 +1635,9 @@ nsDOMWorker::CompileGlobalObject(JSContext* aCx)
 
   NS_ASSERTION(JS_GetGlobalObject(aCx) == global, "Global object mismatch!");
 
+  success = localCall.enter(aCx, global);
+  NS_ENSURE_TRUE(success, PR_FALSE);
+
 #ifdef DEBUG
   {
     jsval components;
@@ -1633,7 +1649,7 @@ nsDOMWorker::CompileGlobalObject(JSContext* aCx)
 #endif
 
   // Set up worker thread functions.
-  PRBool success = JS_DefineFunctions(aCx, global, gDOMWorkerFunctions);
+  success = JS_DefineFunctions(aCx, global, gDOMWorkerFunctions);
   NS_ENSURE_TRUE(success, PR_FALSE);
 
   if (mPrivilegeModel == CHROME) {
@@ -1690,6 +1706,8 @@ nsDOMWorker::CompileGlobalObject(JSContext* aCx)
 
   NS_ASSERTION(mPrincipal && mURI, "Script loader didn't set our principal!");
 
+  aRequest->swap(localRequest);
+  aCall->swap(localCall);
   return PR_TRUE;
 }
 

dom/src/threads/nsDOMWorker.h

@@ -105,6 +105,33 @@ private:
   PRPackedBool mHasOnerror;
 };
 
+class nsLazyAutoRequest
+{
+public:
+  nsLazyAutoRequest() : mCx(nsnull) {}
+
+  ~nsLazyAutoRequest() {
+    if (mCx)
+      JS_EndRequest(mCx);
+  }
+
+  void enter(JSContext *aCx) {
+    JS_BeginRequest(aCx);
+    mCx = aCx;
+  }
+
+  bool entered() const { return mCx != nsnull; }
+
+  void swap(nsLazyAutoRequest &other) {
+    JSContext *tmp = mCx;
+    mCx = other.mCx;
+    other.mCx = tmp;
+  }
+
+private:
+  JSContext *mCx;
+};
+
 class nsDOMWorker : public nsDOMWorkerMessageHandler,
                     public nsIChromeWorker,
                     public nsITimerCallback,
@@ -174,7 +201,7 @@ public:
   PRBool IsClosing();
   PRBool IsSuspended();
 
-  PRBool SetGlobalForContext(JSContext* aCx);
+  PRBool SetGlobalForContext(JSContext* aCx, nsLazyAutoRequest *aRequest, JSAutoCrossCompartmentCall *aCall);
 
   void SetPool(nsDOMWorkerPool* aPool);
 
@@ -258,7 +285,7 @@ private:
 
   nsresult PostMessageInternal(PRBool aToInner);
 
-  PRBool CompileGlobalObject(JSContext* aCx);
+  PRBool CompileGlobalObject(JSContext* aCx, nsLazyAutoRequest *aRequest, JSAutoCrossCompartmentCall *aCall);
 
   PRUint32 NextTimeoutId() {
     return ++mNextTimeoutId;

js/src/jsapi.h

@@ -968,10 +968,18 @@ class JS_PUBLIC_API(JSAutoCrossCompartmentCall)
 
     bool enter(JSContext *cx, JSObject *target);
 
+    bool entered() const { return call != NULL; }
+
     ~JSAutoCrossCompartmentCall() {
         if (call)
             JS_LeaveCrossCompartmentCall(call);
     }
+
+    void swap(JSAutoCrossCompartmentCall &other) {
+        JSCrossCompartmentCall *tmp = call;
+        call = other.call;
+        other.call = tmp;
+    }
 };
 
 class JS_FRIEND_API(JSAutoEnterCompartment)