Relanding bug 326777, r=bsmedberg, sr=jst

js/src/xpconnect/src/nsXPConnect.cpp

@@ -50,8 +50,12 @@
 #include "jsfun.h"
 #include "jsobj.h"
 #include "jsscript.h"
+#include "nsThreadUtilsInternal.h"
 
-NS_IMPL_THREADSAFE_ISUPPORTS2(nsXPConnect,nsIXPConnect,nsISupportsWeakReference)
+NS_IMPL_THREADSAFE_ISUPPORTS3(nsXPConnect,
+                              nsIXPConnect,
+                              nsISupportsWeakReference,
+                              nsIThreadObserver)
 
 nsXPConnect* nsXPConnect::gSelf = nsnull;
 JSBool       nsXPConnect::gOnceAliveNowDead = JS_FALSE;
@@ -286,6 +290,10 @@ nsXPConnect::GetXPConnect()
             // Initial extra ref to keep the singleton alive
             // balanced by explicit call to ReleaseXPConnectSingleton()
             NS_ADDREF(gSelf);
+            if (NS_FAILED(NS_SetGlobalThreadObserver(gSelf))) {
+                NS_RELEASE(gSelf);
+                // Fall through to returning null
+            }
         }
     }
     return gSelf;
@@ -307,6 +315,7 @@ nsXPConnect::ReleaseXPConnectSingleton()
     nsXPConnect* xpc = gSelf;
     if(xpc)
     {
+        NS_SetGlobalThreadObserver(nsnull);
 
 #ifdef XPC_TOOLS_SUPPORT
         if(xpc->mProfiler)
@@ -2014,6 +2023,31 @@ nsXPConnect::FlagSystemFilenamePrefix(const char *aFilenamePrefix)
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsXPConnect::OnProcessNextEvent(nsIThreadInternal *aThread, PRBool aMayWait,
+                                PRUint32 aRecursionDepth)
+{
+    // Push a null JSContext so that we don't see any script during
+    // event processing.
+    NS_ENSURE_STATE(mContextStack);
+    return mContextStack->Push(nsnull);
+}
+
+NS_IMETHODIMP
+nsXPConnect::AfterProcessNextEvent(nsIThreadInternal *aThread,
+                                   PRUint32 aRecursionDepth)
+{
+    NS_ENSURE_STATE(mContextStack);
+    return mContextStack->Pop(nsnull);
+}
+
+NS_IMETHODIMP
+nsXPConnect::OnDispatchedEvent(nsIThreadInternal* aThread)
+{
+    NS_NOTREACHED("Why tell us?");
+    return NS_ERROR_UNEXPECTED;
+}
+
 #ifdef DEBUG
 /* These are here to be callable from a debugger */
 JS_BEGIN_EXTERN_C

js/src/xpconnect/src/xpcprivate.h

@@ -126,6 +126,8 @@
 #include "nsIXPCToolsProfiler.h"
 #endif
 
+#include "nsIThreadInternal.h"
+
 #ifdef XPC_IDISPATCH_SUPPORT
 // This goop was added because of EXCEPINFO in ThrowCOMError
 // This include is here, because it needs to occur before the undefines below
@@ -426,6 +428,7 @@ const PRBool OBJ_IS_NOT_GLOBAL = PR_FALSE;
 struct JSObjectRefcounts;
 
 class nsXPConnect : public nsIXPConnect,
+                    public nsIThreadObserver,
                     public nsSupportsWeakReference,
                     public nsCycleCollectionLanguageRuntime,
                     public nsCycleCollectionParticipant
@@ -434,6 +437,7 @@ public:
     // all the interface method declarations...
     NS_DECL_ISUPPORTS
     NS_DECL_NSIXPCONNECT
+    NS_DECL_NSITHREADOBSERVER
 
     // non-interface implementation
 public:

xpcom/threads/Makefile.in

@@ -69,6 +69,7 @@ CPPSRCS		= \
 EXPORTS		= \
 		nsProcess.h \
 		nsEventQueue.h \
+		nsThreadUtilsInternal.h \
 		$(NULL)
 
 XPIDLSRCS	= \

xpcom/threads/nsThread.cpp

@@ -44,6 +44,7 @@
 #include "nsAutoPtr.h"
 #include "nsCOMPtr.h"
 #include "prlog.h"
+#include "nsThreadUtilsInternal.h"
 
 #ifdef PR_LOGGING
 static PRLogModuleInfo *sLog = PR_NewLogModule("nsThread");
@@ -52,6 +53,8 @@ static PRLogModuleInfo *sLog = PR_NewLogModule("nsThread");
 
 NS_DECL_CI_INTERFACE_GETTER(nsThread)
 
+nsIThreadObserver* nsThread::sGlobalObserver;
+
 //-----------------------------------------------------------------------------
 // Because we do not have our own nsIFactory, we have to implement nsIClassInfo
 // somewhat manually.
@@ -464,6 +467,10 @@ nsThread::ProcessNextEvent(PRBool mayWait, PRBool *result)
 
   NS_ENSURE_STATE(PR_GetCurrentThread() == mThread);
 
+  if (sGlobalObserver) 
+    sGlobalObserver->OnProcessNextEvent(this, mayWait && !ShuttingDown(),
+                                        mRunningEvent);
+
   nsCOMPtr<nsIThreadObserver> obs = mObserver;
   if (obs)
     obs->OnProcessNextEvent(this, mayWait && !ShuttingDown(), mRunningEvent);
@@ -489,6 +496,9 @@ nsThread::ProcessNextEvent(PRBool mayWait, PRBool *result)
   if (obs)
     obs->AfterProcessNextEvent(this, mRunningEvent);
 
+  if (sGlobalObserver)
+    sGlobalObserver->AfterProcessNextEvent(this, mRunningEvent);
+
   return rv;
 }
 
@@ -618,3 +628,18 @@ nsThreadSyncDispatch::Run()
   }
   return NS_OK;
 }
+
+nsresult
+NS_SetGlobalThreadObserver(nsIThreadObserver* aObserver)
+{
+  if (aObserver && nsThread::sGlobalObserver) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (!NS_IsMainThread()) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsThread::sGlobalObserver = aObserver;
+  return NS_OK;
+}

xpcom/threads/nsThread.h

@@ -72,6 +72,9 @@ public:
   // nsIThreadManager::NewThread.
   PRBool ShutdownRequired() { return mShutdownRequired; }
 
+  // The global thread observer
+  static nsIThreadObserver* sGlobalObserver;
+
 private:
   friend class nsThreadShutdownEvent;