Bug 1256424. Get rid of ThreadsafeAutoSafeJSContext. r=bholley

dom/base/DOMRequest.cpp

@@ -9,6 +9,7 @@
 #include "DOMError.h"
 #include "nsThreadUtils.h"
 #include "DOMCursor.h"
+#include "mozilla/CycleCollectedJSRuntime.h"
 #include "mozilla/ErrorResult.h"
 #include "mozilla/dom/Event.h"
 #include "mozilla/dom/Promise.h"
@@ -297,11 +298,10 @@ DOMRequestService::FireDetailedError(nsIDOMDOMRequest* aRequest,
 class FireSuccessAsyncTask : public nsRunnable
 {
 
-  FireSuccessAsyncTask(JSContext* aCx,
-                       DOMRequest* aRequest,
+  FireSuccessAsyncTask(DOMRequest* aRequest,
                        const JS::Value& aResult) :
     mReq(aRequest),
-    mResult(aCx, aResult)
+    mResult(CycleCollectedJSRuntime::Get()->Runtime(), aResult)
   {
   }
 
@@ -314,8 +314,8 @@ public:
   Dispatch(DOMRequest* aRequest,
            const JS::Value& aResult)
   {
-    mozilla::ThreadsafeAutoSafeJSContext cx;
-    RefPtr<FireSuccessAsyncTask> asyncTask = new FireSuccessAsyncTask(cx, aRequest, aResult);
+    RefPtr<FireSuccessAsyncTask> asyncTask =
+      new FireSuccessAsyncTask(aRequest, aResult);
     MOZ_ALWAYS_TRUE(NS_SUCCEEDED(NS_DispatchToCurrentThread(asyncTask)));
     return NS_OK;
   }

dom/base/ScriptSettings.cpp

@@ -825,26 +825,4 @@ AutoSafeJSContext::AutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMP
 {
 }
 
-ThreadsafeAutoSafeJSContext::ThreadsafeAutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMPL)
-{
-  MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-
-  if (NS_IsMainThread()) {
-    mCx = nullptr;
-    mAutoSafeJSContext.emplace();
-  } else {
-    mCx = mozilla::dom::workers::GetCurrentThreadJSContext();
-    mRequest.emplace(mCx);
-  }
-}
-
-ThreadsafeAutoSafeJSContext::operator JSContext*() const
-{
-  if (mCx) {
-    return mCx;
-  } else {
-    return *mAutoSafeJSContext;
-  }
-}
-
 } // namespace mozilla

dom/base/ScriptSettings.h

@@ -468,22 +468,6 @@ private:
   JSAutoCompartment mAc;
 };
 
-/**
- * Like AutoSafeJSContext but can be used safely on worker threads.
- */
-class MOZ_RAII ThreadsafeAutoSafeJSContext {
-public:
-  explicit ThreadsafeAutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
-  operator JSContext*() const;
-
-private:
-  JSContext* mCx; // Used on workers.  Null means mainthread.
-  Maybe<JSAutoRequest> mRequest; // Used on workers.
-  Maybe<AutoSafeJSContext> mAutoSafeJSContext; // Used on main thread.
-  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
-};
-
-
 } // namespace mozilla
 
 #endif // mozilla_dom_ScriptSettings_h

dom/promise/Promise.cpp

@@ -1762,21 +1762,22 @@ public:
   {
     MOZ_ASSERT(mCountdown > 0);
 
-    ThreadsafeAutoSafeJSContext cx;
-    JSAutoCompartment ac(cx, mValues);
-    {
+    AutoJSAPI jsapi;
+    if (!jsapi.Init(mValues)) {
+      // Now what?
+      return;
+    }
+    jsapi.TakeOwnershipOfErrorReporting();
+    JSContext* cx = jsapi.cx();
 
-      AutoDontReportUncaught silenceReporting(cx);
-      JS::Rooted<JS::Value> value(cx, aValue);
-      JS::Rooted<JSObject*> values(cx, mValues);
-      if (!JS_WrapValue(cx, &value) ||
-          !JS_DefineElement(cx, values, index, value, JSPROP_ENUMERATE)) {
-        MOZ_ASSERT(JS_IsExceptionPending(cx));
-        JS::Rooted<JS::Value> exn(cx);
-        JS_GetPendingException(cx, &exn);
-
-        mPromise->MaybeReject(cx, exn);
-      }
+    JS::Rooted<JS::Value> value(cx, aValue);
+    JS::Rooted<JSObject*> values(cx, mValues);
+    if (!JS_WrapValue(cx, &value) ||
+        !JS_DefineElement(cx, values, index, value, JSPROP_ENUMERATE)) {
+      MOZ_ASSERT(JS_IsExceptionPending(cx));
+      JS::Rooted<JS::Value> exn(cx);
+      jsapi.StealException(&exn);
+      mPromise->MaybeReject(cx, exn);
     }
 
     --mCountdown;