Bug 1742438 - Part 11: Replace Finished() check with IsAwaitingPromise() and move state change to worker thread; r=asuth,jonco

We don't need the mExecutionScheduled state, as the mLoadingFinished state was only used to
determine if the promise for a given request had resolved. In fact -- we already know that it is in
a possibly resolved state when we call MaybeExecuteFinishedScripts. So, we can remove this state,
and only have the meaningful check (whether or not a promise on the service worker case hasn't
resolved yet) instead.

Differential Revision: https://phabricator.services.mozilla.com/D146183

dom/workers/ScriptLoader.cpp

@@ -530,7 +530,6 @@ void WorkerScriptLoader::LoadingFinished(ScriptLoadRequest* aRequest,
   WorkerLoadContext* loadContext = aRequest->GetWorkerLoadContext();
 
   loadContext->mLoadResult = aRv;
-  aRequest->SetReady();
 
   if (IsMainWorkerScript() && NS_SUCCEEDED(aRv)) {
     MOZ_DIAGNOSTIC_ASSERT(mWorkerPrivate->PrincipalURIMatchesScriptURL());
@@ -546,7 +545,7 @@ void WorkerScriptLoader::MaybeExecuteFinishedScripts(
   // We execute the last step if we don't have a pending operation with the
   // cache and the loading is completed.
   WorkerLoadContext* loadContext = aRequest->GetWorkerLoadContext();
-  if (loadContext->Finished()) {
+  if (!loadContext->IsAwaitingPromise()) {
     loadContext->ClearCacheCreator();
     DispatchMaybeMoveToLoadedList(aRequest);
   }
@@ -554,13 +553,11 @@ void WorkerScriptLoader::MaybeExecuteFinishedScripts(
 
 void WorkerScriptLoader::MaybeMoveToLoadedList(ScriptLoadRequest* aRequest) {
   mWorkerPrivate->AssertIsOnWorkerThread();
-  WorkerLoadContext* loadContext = aRequest->GetWorkerLoadContext();
-  MOZ_ASSERT(!loadContext->mExecutionScheduled);
-  loadContext->mExecutionScheduled = true;
+  aRequest->SetReady();
 
   while (!mLoadingRequests.isEmpty()) {
     ScriptLoadRequest* request = mLoadingRequests.getFirst();
-    if (!request->GetWorkerLoadContext()->mExecutionScheduled) {
+    if (!request->IsReadyToRun()) {
       break;
     }
 
@@ -898,7 +895,7 @@ bool WorkerScriptLoader::EvaluateScript(JSContext* aCx,
 
   WorkerLoadContext* loadContext = aRequest->GetWorkerLoadContext();
 
-  NS_ASSERTION(loadContext->mExecutionScheduled, "Should be scheduled!");
+  NS_ASSERTION(aRequest->IsReadyToRun(), "Should be scheduled!");
 
   MOZ_ASSERT(!mRv.Failed(), "Who failed it and why?");
   mRv.MightThrowJSException();

dom/workers/loader/WorkerLoadContext.h

@@ -60,8 +60,6 @@ class WorkerLoadContext : public JS::loader::LoadContextBase {
 
   RefPtr<workerinternals::loader::CacheCreator> GetCacheCreator();
 
-  bool mExecutionScheduled = false;
-
   Maybe<nsString> mSourceMapURL;
 
   enum CacheStatus {
@@ -88,7 +86,7 @@ class WorkerLoadContext : public JS::loader::LoadContextBase {
 
   Maybe<bool> mMutedErrorFlag;
 
-  bool Finished() const { return mRequest->IsReadyToRun() && !mCachePromise; }
+  bool IsAwaitingPromise() const { return bool(mCachePromise); }
 };
 
 }  // namespace mozilla::dom