Bug 1657404 - Change PGamepadEventChannel to "refcounted protocol" r=handyman

Differential Revision: https://phabricator.services.mozilla.com/D93119

dom/gamepad/GamepadManager.cpp

@@ -115,8 +115,9 @@ GamepadManager::Observe(nsISupports* aSubject, const char* aTopic,
 }
 
 void GamepadManager::StopMonitoring() {
-  for (uint32_t i = 0; i < mChannelChildren.Length(); ++i) {
-    PGamepadEventChannelChild::Send__delete__(mChannelChildren[i]);
+  for (auto& channelChild : mChannelChildren) {
+    PGamepadEventChannelChild::Send__delete__(channelChild);
+    channelChild = nullptr;
   }
   if (gfx::VRManagerChild::IsCreated()) {
     gfx::VRManagerChild* vm = gfx::VRManagerChild::Get();
@@ -149,15 +150,12 @@ void GamepadManager::AddListener(nsGlobalWindowInner* aWindow) {
       return;
     }
 
-    GamepadEventChannelChild* child = new GamepadEventChannelChild();
-    PGamepadEventChannelChild* initedChild =
-        actor->SendPGamepadEventChannelConstructor(child);
-    if (NS_WARN_IF(!initedChild)) {
+    RefPtr<GamepadEventChannelChild> child(GamepadEventChannelChild::Create());
+    if (!actor->SendPGamepadEventChannelConstructor(child.get())) {
       // We are probably shutting down.
       return;
     }
 
-    MOZ_ASSERT(initedChild == child);
     mChannelChildren.AppendElement(child);
 
     if (gfx::VRManagerChild::IsCreated()) {

dom/gamepad/GamepadManager.h

@@ -119,11 +119,7 @@ class GamepadManager final : public nsIObserver {
   // true when shutdown has begun
   bool mShuttingDown;
 
-  // Gamepad IPDL child
-  // This pointer is only used by this singleton instance and
-  // will be destroyed during the IPDL shutdown chain, so we
-  // don't need to refcount it here.
-  nsTArray<GamepadEventChannelChild*> mChannelChildren;
+  nsTArray<RefPtr<GamepadEventChannelChild>> mChannelChildren;
 
  private:
   nsresult Init();

dom/gamepad/ipc/GamepadEventChannelChild.cpp

@@ -29,6 +29,11 @@ class GamepadUpdateRunnable final : public Runnable {
 
 }  // namespace
 
+already_AddRefed<GamepadEventChannelChild> GamepadEventChannelChild::Create() {
+  return RefPtr<GamepadEventChannelChild>(new GamepadEventChannelChild())
+      .forget();
+}
+
 mozilla::ipc::IPCResult GamepadEventChannelChild::RecvGamepadUpdate(
     const GamepadChangeEvent& aGamepadEvent) {
   DebugOnly<nsresult> rv =

dom/gamepad/ipc/GamepadEventChannelChild.h

@@ -14,15 +14,24 @@ namespace dom {
 
 class GamepadEventChannelChild final : public PGamepadEventChannelChild {
  public:
-  GamepadEventChannelChild() = default;
-  ~GamepadEventChannelChild() = default;
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadEventChannelChild, override)
+
+  static already_AddRefed<GamepadEventChannelChild> Create();
 
   mozilla::ipc::IPCResult RecvGamepadUpdate(
       const GamepadChangeEvent& aGamepadEvent);
   mozilla::ipc::IPCResult RecvReplyGamepadPromise(const uint32_t& aPromiseID);
   void AddPromise(const uint32_t& aID, dom::Promise* aPromise);
 
+  GamepadEventChannelChild(const GamepadEventChannelChild&) = delete;
+  GamepadEventChannelChild(GamepadEventChannelChild&&) = delete;
+  GamepadEventChannelChild& operator=(const GamepadEventChannelChild&) = delete;
+  GamepadEventChannelChild& operator=(GamepadEventChannelChild&&) = delete;
+
  private:
+  GamepadEventChannelChild() = default;
+  ~GamepadEventChannelChild() = default;
+
   nsRefPtrHashtable<nsUint32HashKey, dom::Promise> mPromiseList;
 };
 

dom/gamepad/ipc/GamepadEventChannelParent.cpp

@@ -38,7 +38,13 @@ class SendGamepadUpdateRunnable final : public Runnable {
 
 }  // namespace
 
-bool GamepadEventChannelParent::Init() {
+already_AddRefed<GamepadEventChannelParent>
+GamepadEventChannelParent::Create() {
+  return RefPtr<GamepadEventChannelParent>(new GamepadEventChannelParent())
+      .forget();
+}
+
+GamepadEventChannelParent::GamepadEventChannelParent() {
   AssertIsOnBackgroundThread();
 
   mBackgroundEventTarget = GetCurrentEventTarget();
@@ -48,8 +54,6 @@ bool GamepadEventChannelParent::Init() {
   MOZ_ASSERT(service);
 
   service->AddChannelParent(this);
-
-  return true;
 }
 
 void GamepadEventChannelParent::ActorDestroy(ActorDestroyReason aWhy) {

dom/gamepad/ipc/GamepadEventChannelParent.h

@@ -13,10 +13,9 @@ namespace dom {
 
 class GamepadEventChannelParent final : public PGamepadEventChannelParent {
  public:
-  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadEventChannelParent)
-  GamepadEventChannelParent() = default;
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadEventChannelParent, override)
 
-  bool Init();
+  static already_AddRefed<GamepadEventChannelParent> Create();
   void ActorDestroy(ActorDestroyReason aWhy) override;
 
   mozilla::ipc::IPCResult RecvVibrateHaptic(const uint32_t& aControllerIdx,
@@ -31,8 +30,16 @@ class GamepadEventChannelParent final : public PGamepadEventChannelParent {
       const uint32_t& aPromiseID);
   void DispatchUpdateEvent(const GamepadChangeEvent& aEvent);
 
+  GamepadEventChannelParent(const GamepadEventChannelParent&) = delete;
+  GamepadEventChannelParent(GamepadEventChannelParent&&) = delete;
+  GamepadEventChannelParent& operator=(const GamepadEventChannelParent&) =
+      delete;
+  GamepadEventChannelParent& operator=(GamepadEventChannelParent&&) = delete;
+
  private:
+  GamepadEventChannelParent();
   ~GamepadEventChannelParent() = default;
+
   nsCOMPtr<nsIEventTarget> mBackgroundEventTarget;
 };
 

dom/gamepad/ipc/PGamepadEventChannel.ipdl

@@ -7,7 +7,7 @@ include GamepadEventTypes;
 namespace mozilla {
 namespace dom {
 
-async protocol PGamepadEventChannel {
+refcounted protocol PGamepadEventChannel {
   manager PBackground;
   parent:
     async __delete__();

ipc/glue/BackgroundChildImpl.cpp

@@ -605,20 +605,6 @@ bool BackgroundChildImpl::DeallocPMIDIManagerChild(PMIDIManagerChild* aActor) {
   return true;
 }
 
-// Gamepad API Background IPC
-dom::PGamepadEventChannelChild*
-BackgroundChildImpl::AllocPGamepadEventChannelChild() {
-  MOZ_CRASH("PGamepadEventChannelChild actor should be manually constructed!");
-  return nullptr;
-}
-
-bool BackgroundChildImpl::DeallocPGamepadEventChannelChild(
-    PGamepadEventChannelChild* aActor) {
-  MOZ_ASSERT(aActor);
-  delete static_cast<dom::GamepadEventChannelChild*>(aActor);
-  return true;
-}
-
 dom::PGamepadTestChannelChild*
 BackgroundChildImpl::AllocPGamepadTestChannelChild() {
   MOZ_CRASH("PGamepadTestChannelChild actor should be manually constructed!");

ipc/glue/BackgroundChildImpl.h

@@ -223,12 +223,6 @@ class BackgroundChildImpl : public PBackgroundChild,
 
   virtual bool DeallocPQuotaChild(PQuotaChild* aActor) override;
 
-  // Gamepad API Background IPC
-  virtual PGamepadEventChannelChild* AllocPGamepadEventChannelChild() override;
-
-  virtual bool DeallocPGamepadEventChannelChild(
-      PGamepadEventChannelChild* aActor) override;
-
   virtual PGamepadTestChannelChild* AllocPGamepadTestChannelChild() override;
 
   virtual bool DeallocPGamepadTestChannelChild(

ipc/glue/BackgroundParentImpl.cpp

@@ -1135,30 +1135,9 @@ mozilla::ipc::IPCResult BackgroundParentImpl::RecvPFileSystemRequestConstructor(
 }
 
 // Gamepad API Background IPC
-dom::PGamepadEventChannelParent*
+already_AddRefed<dom::PGamepadEventChannelParent>
 BackgroundParentImpl::AllocPGamepadEventChannelParent() {
-  RefPtr<dom::GamepadEventChannelParent> parent =
-      new dom::GamepadEventChannelParent();
-
-  return parent.forget().take();
-}
-
-bool BackgroundParentImpl::DeallocPGamepadEventChannelParent(
-    dom::PGamepadEventChannelParent* aActor) {
-  MOZ_ASSERT(aActor);
-  RefPtr<dom::GamepadEventChannelParent> parent =
-      dont_AddRef(static_cast<dom::GamepadEventChannelParent*>(aActor));
-  return true;
-}
-
-mozilla::ipc::IPCResult
-BackgroundParentImpl::RecvPGamepadEventChannelConstructor(
-    PGamepadEventChannelParent* aActor) {
-  MOZ_ASSERT(aActor);
-  if (!static_cast<dom::GamepadEventChannelParent*>(aActor)->Init()) {
-    return IPC_FAIL_NO_REASON(this);
-  }
-  return IPC_OK();
+  return dom::GamepadEventChannelParent::Create();
 }
 
 dom::PGamepadTestChannelParent*

ipc/glue/BackgroundParentImpl.h

@@ -333,14 +333,8 @@ class BackgroundParentImpl : public PBackgroundParent,
       PFileSystemRequestParent* actor, const FileSystemParams& params) override;
 
   // Gamepad API Background IPC
-  virtual PGamepadEventChannelParent* AllocPGamepadEventChannelParent()
-      override;
-
-  virtual bool DeallocPGamepadEventChannelParent(
-      PGamepadEventChannelParent* aActor) override;
-
-  virtual mozilla::ipc::IPCResult RecvPGamepadEventChannelConstructor(
-      PGamepadEventChannelParent* aActor) override;
+  virtual already_AddRefed<PGamepadEventChannelParent>
+  AllocPGamepadEventChannelParent() override;
 
   virtual PGamepadTestChannelParent* AllocPGamepadTestChannelParent() override;