Bug 1378342 - AbortSignal/AbortController - part 3 - Removing the following algorithm, r=bkelly

dom/abort/AbortController.cpp

@@ -12,8 +12,7 @@
 namespace mozilla {
 namespace dom {
 
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(AbortController, mGlobal, mSignal,
-                                      mFollowingSignal)
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(AbortController, mGlobal, mSignal)
 
 NS_IMPL_CYCLE_COLLECTING_ADDREF(AbortController)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(AbortController)
@@ -95,33 +94,5 @@ AbortController::Abort()
   }
 }
 
-void
-AbortController::Follow(AbortSignal& aSignal)
-{
-  AbortSignal::Follower::Follow(&aSignal);
-}
-
-void
-AbortController::Unfollow(AbortSignal& aSignal)
-{
-  if (mFollowingSignal != &aSignal) {
-    return;
-  }
-
-  AbortSignal::Follower::Unfollow();
-}
-
-AbortSignal*
-AbortController::Following() const
-{
-  return mFollowingSignal;
-}
-
-void
-AbortController::Aborted()
-{
-  Abort();
-}
-
 } // dom namespace
 } // mozilla namespace

dom/abort/AbortController.h

@@ -8,16 +8,19 @@
 #define mozilla_dom_AbortController_h
 
 #include "mozilla/dom/BindingDeclarations.h"
-#include "mozilla/dom/AbortSignal.h"
+#include "mozilla/ErrorResult.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsWrapperCache.h"
 
+class nsIGlobalObject;
+
 namespace mozilla {
 namespace dom {
 
+class AbortSignal;
+
 class AbortController final : public nsISupports
                             , public nsWrapperCache
-                            , public AbortSignal::Follower
 {
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
@@ -43,19 +46,6 @@ public:
   void
   Abort();
 
-  void
-  Follow(AbortSignal& aSignal);
-
-  void
-  Unfollow(AbortSignal& aSignal);
-
-  AbortSignal*
-  Following() const;
-
-  // AbortSignal::Follower
-
-  void Aborted() override;
-
 private:
   ~AbortController() = default;
 

dom/abort/AbortSignal.cpp

@@ -67,8 +67,6 @@ AbortSignal::Abort()
   init.mBubbles = false;
   init.mCancelable = false;
 
-  // TODO which kind of event should we dispatch here?
-
   RefPtr<Event> event =
     Event::Constructor(this, NS_LITERAL_STRING("abort"), init);
   event->SetTrusted(true);
@@ -93,27 +91,6 @@ AbortSignal::RemoveFollower(AbortSignal::Follower* aFollower)
   mFollowers.RemoveElement(aFollower);
 }
 
-bool
-AbortSignal::CanAcceptFollower(AbortSignal::Follower* aFollower) const
-{
-  MOZ_DIAGNOSTIC_ASSERT(aFollower);
-
-  if (!mController) {
-    return true;
-  }
-
-  if (aFollower == mController) {
-    return false;
-  }
-
-  AbortSignal* following = mController->Following();
-  if (!following) {
-    return true;
-  }
-
-  return following->CanAcceptFollower(aFollower);
-}
-
 // AbortSignal::Follower
 // ----------------------------------------------------------------------------
 
@@ -127,10 +104,6 @@ AbortSignal::Follower::Follow(AbortSignal* aSignal)
 {
   MOZ_DIAGNOSTIC_ASSERT(aSignal);
 
-  if (!aSignal->CanAcceptFollower(this)) {
-    return;
-  }
-
   Unfollow();
 
   mFollowingSignal = aSignal;

dom/abort/AbortSignal.h

@@ -59,9 +59,6 @@ public:
   void
   RemoveFollower(Follower* aFollower);
 
-  bool
-  CanAcceptFollower(Follower* aFollower) const;
-
 private:
   ~AbortSignal() = default;
 

dom/abort/tests/file_abort_controller.html

@@ -32,49 +32,6 @@ function testUpdateData() {
   next();
 }
  
-function testFollowingOurself() {
-  // Let's follow ourself
-  var ac = new AbortController();
-  ac.follow(ac.signal);
- 
-  ac.abort();
-  is(ac.signal.aborted, true, "Signal is aborted");
- 
-  next();
-}
- 
-function testFollowingOther() {
-  // Let's follow another one
-  var ac1 = new AbortController();
-  var ac2 = new AbortController();
-  ac1.follow(ac2.signal);
- 
-  ac2.abort();
- 
-  is(ac1.signal.aborted, true, "Signal is aborted");
-  is(ac2.signal.aborted, true, "Signal is aborted");
- 
-  next();
-}
-
-function testFollowingLoop() {
-  // ac1 -> ac2 -> ac3 -> ac1
-  var ac1 = new AbortController();
-  var ac2 = new AbortController();
-  var ac3 = new AbortController();
-  ac1.follow(ac2.signal);
-  ac2.follow(ac3.signal);
-  ac3.follow(ac1.signal);
- 
-  ac3.abort();
- 
-  is(ac1.signal.aborted, true, "Signal is aborted");
-  is(ac2.signal.aborted, true, "Signal is aborted");
-  is(ac3.signal.aborted, true, "Signal is aborted");
- 
-  next();
-}
- 
 function testAbortEvent() {
   var ac = new AbortController();
   ac.signal.onabort = function(e) {
@@ -131,11 +88,6 @@ var steps = [
   testWebIDL,
   testUpdateData,
 
-  // Following algorithm
-  testFollowingOurself,
-  testFollowingOther,
-  testFollowingLoop,
-
   // Event propagation
   testAbortEvent,
 

dom/webidl/AbortController.webidl

@@ -13,6 +13,4 @@ interface AbortController {
   readonly attribute AbortSignal signal;
 
   void abort();
-  void follow(AbortSignal signal);
-  void unfollow(AbortSignal signal);
 };