Bug 1457157 P2 Clear a worker's ClientSource when it reaches Terminating. r=baku

dom/fetch/Fetch.cpp

@@ -535,8 +535,14 @@ FetchRequest(nsIGlobalObject* aGlobal, const RequestOrUSVString& aInput,
       return nullptr;
     }
 
+    Maybe<ClientInfo> clientInfo(worker->GetClientInfo());
+    if (clientInfo.isNothing()) {
+      aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+      return nullptr;
+    }
+
     RefPtr<MainThreadFetchRunnable> run =
-      new MainThreadFetchRunnable(resolver, worker->GetClientInfo(),
+      new MainThreadFetchRunnable(resolver, clientInfo.ref(),
                                   worker->GetController(), r);
     worker->DispatchToMainThread(run.forget());
   }

dom/workers/ScriptLoader.cpp

@@ -1910,7 +1910,9 @@ public:
     : WorkerMainThreadRunnable(aParentWorker,
                                NS_LITERAL_CSTRING("ScriptLoader :: ChannelGetter"))
     , mScriptURL(aScriptURL)
-    , mClientInfo(aParentWorker->GetClientInfo())
+    // ClientInfo should always be present since this should not be called
+    // if parent's status is greater than Running.
+    , mClientInfo(aParentWorker->GetClientInfo().ref())
     , mLoadInfo(aLoadInfo)
     , mResult(NS_ERROR_FAILURE)
   {
@@ -2246,7 +2248,7 @@ LoadAllScripts(WorkerPrivate* aWorkerPrivate,
   Maybe<ClientInfo> clientInfo;
   Maybe<ServiceWorkerDescriptor> controller;
   if (!aIsMainScript) {
-    clientInfo.emplace(aWorkerPrivate->GetClientInfo());
+    clientInfo = aWorkerPrivate->GetClientInfo();
     controller = aWorkerPrivate->GetController();
   }
 
@@ -2390,7 +2392,7 @@ LoadMainScript(WorkerPrivate* aWorkerPrivate,
 
   // We are loading the main script, so the worker's Client must be
   // reserved.
-  info->mReservedClientInfo.emplace(aWorkerPrivate->GetClientInfo());
+  info->mReservedClientInfo = aWorkerPrivate->GetClientInfo();
 
   LoadAllScripts(aWorkerPrivate, loadInfos, true, aWorkerScriptType, aRv);
 }

dom/workers/WorkerPrivate.cpp

@@ -3278,12 +3278,14 @@ WorkerPrivate::DoRunLoop(JSContext* aCx)
 
       // If we're supposed to die then we should exit the loop.
       if (currentStatus == Killing) {
+        // The ClientSource should be cleared in NotifyInternal() when we reach
+        // or pass Terminating.
+        MOZ_DIAGNOSTIC_ASSERT(!mClientSource);
+
         // Flush uncaught rejections immediately, without
         // waiting for a next tick.
         PromiseDebugging::FlushUncaughtRejections();
 
-        mClientSource = nullptr;
-
         ShutdownGCTimers();
 
         DisableMemoryReporter();
@@ -3500,12 +3502,17 @@ WorkerPrivate::EnsurePerformanceStorage()
   }
 }
 
-const ClientInfo&
+Maybe<ClientInfo>
 WorkerPrivate::GetClientInfo() const
 {
   AssertIsOnWorkerThread();
-  MOZ_DIAGNOSTIC_ASSERT(mClientSource);
-  return mClientSource->Info();
+  Maybe<ClientInfo> clientInfo;
+  if (!mClientSource) {
+    MOZ_DIAGNOSTIC_ASSERT(mStatus >= Terminating);
+    return Move(clientInfo);
+  }
+  clientInfo.emplace(mClientSource->Info());
+  return Move(clientInfo);
 }
 
 const ClientState
@@ -3540,6 +3547,12 @@ void
 WorkerPrivate::ExecutionReady()
 {
   AssertIsOnWorkerThread();
+  {
+    MutexAutoLock lock(mMutex);
+    if (mStatus >= Terminating) {
+      return;
+    }
+  }
   MOZ_DIAGNOSTIC_ASSERT(mClientSource);
   mClientSource->WorkerExecutionReady(this);
 }
@@ -4514,8 +4527,9 @@ WorkerPrivate::NotifyInternal(WorkerStatus aStatus)
     }
 
     if (aStatus >= Terminating) {
+      MutexAutoUnlock unlock(mMutex);
+      mClientSource.reset();
       if (mScope) {
-        MutexAutoUnlock unlock(mMutex);
         mScope->NoteTerminating();
       }
     }

dom/workers/WorkerPrivate.h

@@ -553,7 +553,7 @@ public:
   void
   EnsurePerformanceCounter();
 
-  const ClientInfo&
+  Maybe<ClientInfo>
   GetClientInfo() const;
 
   const ClientState

dom/workers/WorkerScope.cpp

@@ -546,9 +546,7 @@ WorkerGlobalScope::AbstractMainThreadFor(TaskCategory aCategory)
 Maybe<ClientInfo>
 WorkerGlobalScope::GetClientInfo() const
 {
-  Maybe<ClientInfo> info;
-  info.emplace(mWorkerPrivate->GetClientInfo());
-  return Move(info);
+  return mWorkerPrivate->GetClientInfo();
 }
 
 Maybe<ClientState>

dom/xhr/XMLHttpRequestWorker.cpp

@@ -1875,7 +1875,12 @@ XMLHttpRequestWorker::Open(const nsACString& aMethod,
     }
   }
   else {
-    mProxy = new Proxy(this, mWorkerPrivate->GetClientInfo(),
+    Maybe<ClientInfo> clientInfo(mWorkerPrivate->GetClientInfo());
+    if (clientInfo.isNothing()) {
+      aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+      return;
+    }
+    mProxy = new Proxy(this, clientInfo.ref(),
                        mWorkerPrivate->GetController(), mMozAnon, mMozSystem);
   }