Bug 455417 - "Exception provider not threadsafe". r+sr=jst.

dom/src/base/nsDOMScriptObjectFactory.cpp

@@ -68,6 +68,8 @@
 
 static NS_DEFINE_CID(kDOMScriptObjectFactoryCID, NS_DOM_SCRIPT_OBJECT_FACTORY_CID);
 
+nsIExceptionProvider* gExceptionProvider = nsnull;
+
 nsDOMScriptObjectFactory::nsDOMScriptObjectFactory() :
   mLoadedAllLanguages(PR_FALSE)
 {
@@ -78,18 +80,25 @@ nsDOMScriptObjectFactory::nsDOMScriptObjectFactory() :
     observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, PR_FALSE);
   }
 
-  nsCOMPtr<nsIExceptionService> xs =
-    do_GetService(NS_EXCEPTIONSERVICE_CONTRACTID);
+  nsCOMPtr<nsIExceptionProvider> provider(new nsDOMExceptionProvider());
+  if (provider) {
+    nsCOMPtr<nsIExceptionService> xs =
+      do_GetService(NS_EXCEPTIONSERVICE_CONTRACTID);
 
-  if (xs) {
-    xs->RegisterExceptionProvider(this, NS_ERROR_MODULE_DOM);
-    xs->RegisterExceptionProvider(this, NS_ERROR_MODULE_DOM_RANGE);
+    if (xs) {
+      xs->RegisterExceptionProvider(provider, NS_ERROR_MODULE_DOM);
+      xs->RegisterExceptionProvider(provider, NS_ERROR_MODULE_DOM_RANGE);
 #ifdef MOZ_SVG
-    xs->RegisterExceptionProvider(this, NS_ERROR_MODULE_SVG);
+      xs->RegisterExceptionProvider(provider, NS_ERROR_MODULE_SVG);
 #endif
-    xs->RegisterExceptionProvider(this, NS_ERROR_MODULE_DOM_XPATH);
-    xs->RegisterExceptionProvider(this, NS_ERROR_MODULE_XPCONNECT);
+      xs->RegisterExceptionProvider(provider, NS_ERROR_MODULE_DOM_XPATH);
+      xs->RegisterExceptionProvider(provider, NS_ERROR_MODULE_XPCONNECT);
+    }
+
+    NS_ASSERTION(!gExceptionProvider, "Registered twice?!");
+    provider.swap(gExceptionProvider);
   }
+
   // And pre-create the javascript language.
   NS_CreateJSRuntime(getter_AddRefs(mLanguageArray[NS_STID_INDEX(nsIProgrammingLanguage::JAVASCRIPT)]));
 }
@@ -97,7 +106,6 @@ nsDOMScriptObjectFactory::nsDOMScriptObjectFactory() :
 NS_INTERFACE_MAP_BEGIN(nsDOMScriptObjectFactory)
   NS_INTERFACE_MAP_ENTRY(nsIDOMScriptObjectFactory)
   NS_INTERFACE_MAP_ENTRY(nsIObserver)
-  NS_INTERFACE_MAP_ENTRY(nsIExceptionProvider)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMScriptObjectFactory)
 NS_INTERFACE_MAP_END
 
@@ -287,17 +295,26 @@ nsDOMScriptObjectFactory::Observe(nsISupports *aSubject,
     nsGlobalWindow::ShutDown();
     nsDOMClassInfo::ShutDown();
 
-    nsCOMPtr<nsIExceptionService> xs =
-      do_GetService(NS_EXCEPTIONSERVICE_CONTRACTID);
+    if (gExceptionProvider) {
+      nsCOMPtr<nsIExceptionService> xs =
+        do_GetService(NS_EXCEPTIONSERVICE_CONTRACTID);
 
-    if (xs) {
-      xs->UnregisterExceptionProvider(this, NS_ERROR_MODULE_DOM);
-      xs->UnregisterExceptionProvider(this, NS_ERROR_MODULE_DOM_RANGE);
+      if (xs) {
+        xs->UnregisterExceptionProvider(gExceptionProvider,
+                                        NS_ERROR_MODULE_DOM);
+        xs->UnregisterExceptionProvider(gExceptionProvider,
+                                        NS_ERROR_MODULE_DOM_RANGE);
 #ifdef MOZ_SVG
-      xs->UnregisterExceptionProvider(this, NS_ERROR_MODULE_SVG);
+        xs->UnregisterExceptionProvider(gExceptionProvider,
+                                        NS_ERROR_MODULE_SVG);
 #endif
-      xs->UnregisterExceptionProvider(this, NS_ERROR_MODULE_DOM_XPATH);
-      xs->UnregisterExceptionProvider(this, NS_ERROR_MODULE_XPCONNECT);
+        xs->UnregisterExceptionProvider(gExceptionProvider,
+                                        NS_ERROR_MODULE_DOM_XPATH);
+        xs->UnregisterExceptionProvider(gExceptionProvider,
+                                        NS_ERROR_MODULE_XPCONNECT);
+      }
+
+      NS_RELEASE(gExceptionProvider);
     }
   }
 
@@ -325,30 +342,6 @@ CreateXPConnectException(nsresult aResult, nsIException *aDefaultException,
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsDOMScriptObjectFactory::GetException(nsresult result,
-				       nsIException *aDefaultException,
-				       nsIException **_retval)
-{
-  switch (NS_ERROR_GET_MODULE(result))
-  {
-    case NS_ERROR_MODULE_DOM_RANGE:
-      return NS_NewRangeException(result, aDefaultException, _retval);
-#ifdef MOZ_SVG
-    case NS_ERROR_MODULE_SVG:
-      return NS_NewSVGException(result, aDefaultException, _retval);
-#endif
-    case NS_ERROR_MODULE_DOM_XPATH:
-      return NS_NewXPathException(result, aDefaultException, _retval);
-    case NS_ERROR_MODULE_XPCONNECT:
-      return CreateXPConnectException(result, aDefaultException, _retval);
-    case NS_ERROR_MODULE_DOM_FILE:
-      return NS_NewFileException(result, aDefaultException, _retval);
-    default:
-      return NS_NewDOMException(result, aDefaultException, _retval);
-  }
-}
-
 NS_IMETHODIMP
 nsDOMScriptObjectFactory::RegisterDOMClassInfo(const char *aName,
 					       nsDOMClassInfoExternalConstructorFnc aConstructorFptr,
@@ -394,3 +387,31 @@ nsresult NS_GetScriptRuntimeByID(PRUint32 aScriptTypeID,
     return rv;
   return factory->GetScriptRuntimeByID(aScriptTypeID, aLanguage);
 }
+
+NS_IMPL_THREADSAFE_ISUPPORTS1(nsDOMExceptionProvider, nsIExceptionProvider)
+
+NS_IMETHODIMP
+nsDOMExceptionProvider::GetException(nsresult result,
+                                     nsIException *aDefaultException,
+                                     nsIException **_retval)
+{
+  switch (NS_ERROR_GET_MODULE(result))
+  {
+    case NS_ERROR_MODULE_DOM_RANGE:
+      return NS_NewRangeException(result, aDefaultException, _retval);
+#ifdef MOZ_SVG
+    case NS_ERROR_MODULE_SVG:
+      return NS_NewSVGException(result, aDefaultException, _retval);
+#endif
+    case NS_ERROR_MODULE_DOM_XPATH:
+      return NS_NewXPathException(result, aDefaultException, _retval);
+    case NS_ERROR_MODULE_XPCONNECT:
+      return CreateXPConnectException(result, aDefaultException, _retval);
+    case NS_ERROR_MODULE_DOM_FILE:
+      return NS_NewFileException(result, aDefaultException, _retval);
+    default:
+      return NS_NewDOMException(result, aDefaultException, _retval);
+  }
+  NS_NOTREACHED("Not reached");
+  return NS_ERROR_UNEXPECTED;
+}

dom/src/base/nsDOMScriptObjectFactory.h

@@ -57,8 +57,7 @@
 #include "nsIScriptGlobalObject.h" // for misplaced NS_STID_ macros.
 
 class nsDOMScriptObjectFactory : public nsIDOMScriptObjectFactory,
-                                 public nsIObserver,
-                                 public nsIExceptionProvider
+                                 public nsIObserver
 {
 public:
   nsDOMScriptObjectFactory();
@@ -68,9 +67,6 @@ public:
   // nsIObserver
   NS_DECL_NSIOBSERVER
 
-  // nsIExceptionProvider
-  NS_DECL_NSIEXCEPTIONPROVIDER
-
   // nsIDOMScriptObjectFactory
   NS_IMETHOD GetScriptRuntime(const nsAString &aLanguageName,
                               nsIScriptRuntime **aLanguage);
@@ -100,3 +96,10 @@ protected:
   PRBool mLoadedAllLanguages;
   nsCOMPtr<nsIScriptRuntime> mLanguageArray[NS_STID_ARRAY_UBOUND];
 };
+
+class nsDOMExceptionProvider : public nsIExceptionProvider
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIEXCEPTIONPROVIDER
+};