Bug 1650996 - P3. Have RemoteDecoderManagerChild use a TaskQueue over a media threadpool. r=mjf

Differential Revision: https://phabricator.services.mozilla.com/D82503

build/clang-plugin/ThreadAllows.txt

@@ -65,7 +65,6 @@ ProxyResolution
 RemoteLzyStream
 RWLockTester
 RacingServMan
-RemVidChild
 Sandbox Testing
 SaveScripts
 Socket Thread

dom/media/ipc/GpuDecoderModule.cpp

@@ -5,13 +5,11 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "GpuDecoderModule.h"
 
-#include "base/thread.h"
-#include "mozilla/layers/SynchronousTask.h"
-#include "mozilla/StaticPrefs_media.h"
-#include "RemoteVideoDecoder.h"
 #include "RemoteDecoderManagerChild.h"
-
 #include "RemoteMediaDataDecoder.h"
+#include "RemoteVideoDecoder.h"
+#include "mozilla/StaticPrefs_media.h"
+#include "mozilla/SyncRunnable.h"
 
 namespace mozilla {
 
@@ -50,19 +48,20 @@ already_AddRefed<MediaDataDecoder> GpuDecoderModule::CreateVideoDecoder(
   }
 
   RefPtr<GpuRemoteVideoDecoderChild> child = new GpuRemoteVideoDecoderChild();
-  SynchronousTask task("InitIPDL");
   MediaResult result(NS_OK);
-  RemoteDecoderManagerChild::GetManagerThread()->Dispatch(
-      NS_NewRunnableFunction(
-          "dom::GpuDecoderModule::CreateVideoDecoder",
-          [&, child]() {
-            AutoCompleteTask complete(&task);
-            result = child->InitIPDL(
-                aParams.VideoConfig(), aParams.mRate.mValue, aParams.mOptions,
-                aParams.mKnowsCompositor->GetTextureFactoryIdentifier());
-          }),
-      NS_DISPATCH_NORMAL);
-  task.Wait();
+  RefPtr<Runnable> task = NS_NewRunnableFunction(
+      "dom::GpuDecoderModule::CreateVideoDecoder", [&]() {
+        result = child->InitIPDL(
+            aParams.VideoConfig(), aParams.mRate.mValue, aParams.mOptions,
+            aParams.mKnowsCompositor->GetTextureFactoryIdentifier());
+        if (NS_FAILED(result)) {
+          // Release GpuRemoteVideoDecoderChild here, while we're on
+          // manager thread.  Don't just let the RefPtr go out of scope.
+          child = nullptr;
+        }
+      });
+  SyncRunnable::DispatchToThread(RemoteDecoderManagerChild::GetManagerThread(),
+                                 task);
 
   if (NS_FAILED(result)) {
     if (aParams.mError) {

dom/media/ipc/RemoteDecoderChild.cpp

@@ -254,7 +254,7 @@ MediaDataDecoder::ConversionRequired RemoteDecoderChild::NeedsConversion()
 }
 
 void RemoteDecoderChild::AssertOnManagerThread() const {
-  MOZ_ASSERT(NS_GetCurrentThread() == mThread);
+  MOZ_ASSERT(mThread->IsOnCurrentThread());
 }
 
 RemoteDecoderManagerChild* RemoteDecoderChild::GetManager() {

dom/media/ipc/RemoteDecoderChild.h

@@ -55,7 +55,7 @@ class RemoteDecoderChild : public PRemoteDecoderChild,
   MediaDataDecoder::DecodedData mDecodedData;
 
  private:
-  RefPtr<nsIThread> mThread;
+  const nsCOMPtr<nsISerialEventTarget> mThread;
 
   MozPromiseHolder<MediaDataDecoder::InitPromise> mInitPromise;
   MozPromiseRequestHolder<PRemoteDecoderChild::InitPromise> mInitPromiseRequest;

dom/media/ipc/RemoteDecoderManagerChild.cpp

@@ -5,15 +5,14 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "RemoteDecoderManagerChild.h"
 
-#include "base/task.h"
-
 #include "RemoteDecoderChild.h"
+#include "VideoUtils.h"
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/gfx/2D.h"
-#include "mozilla/ipc/ProtocolUtils.h"
-#include "mozilla/layers/SynchronousTask.h"
 #include "mozilla/gfx/DataSurfaceHelpers.h"
+#include "mozilla/ipc/ProtocolUtils.h"
 #include "mozilla/layers/ISurfaceAllocator.h"
+#include "mozilla/layers/SynchronousTask.h"
 
 namespace mozilla {
 
@@ -21,7 +20,7 @@ using namespace layers;
 using namespace gfx;
 
 // Only modified on the main-thread
-StaticRefPtr<nsIThread> sRemoteDecoderManagerChildThread;
+StaticRefPtr<TaskQueue> sRemoteDecoderManagerChildThread;
 
 // Only accessed from sRemoteDecoderManagerChildThread
 static StaticRefPtr<RemoteDecoderManagerChild>
@@ -36,10 +35,12 @@ void RemoteDecoderManagerChild::InitializeThread() {
   MOZ_ASSERT(NS_IsMainThread());
 
   if (!sRemoteDecoderManagerChildThread) {
-    RefPtr<nsIThread> childThread;
-    nsresult rv = NS_NewNamedThread("RemVidChild", getter_AddRefs(childThread));
-    NS_ENSURE_SUCCESS_VOID(rv);
-    sRemoteDecoderManagerChildThread = childThread;
+    // We can't use a MediaThreadType::PLAYBACK as the GpuDecoderModule and
+    // RemoteDecoderModule runs on it and dispatch synchronous tasks to the
+    // manager thread, should more than 4 concurrent videos being instantiated
+    // at the same time, we could end up in a deadlock.
+    sRemoteDecoderManagerChildThread = new TaskQueue(
+        GetMediaThreadPool(MediaThreadType::PLATFORM_DECODER), "RemVidChild");
 
     sRecreateTasks = MakeUnique<nsTArray<RefPtr<Runnable>>>();
   }
@@ -49,20 +50,18 @@ void RemoteDecoderManagerChild::InitializeThread() {
 void RemoteDecoderManagerChild::InitForRDDProcess(
     Endpoint<PRemoteDecoderManagerChild>&& aVideoManager) {
   InitializeThread();
-  sRemoteDecoderManagerChildThread->Dispatch(
+  MOZ_ALWAYS_SUCCEEDS(sRemoteDecoderManagerChildThread->Dispatch(
       NewRunnableFunction("InitForContentRunnable", &OpenForRDDProcess,
-                          std::move(aVideoManager)),
-      NS_DISPATCH_NORMAL);
+                          std::move(aVideoManager))));
 }
 
 /* static */
 void RemoteDecoderManagerChild::InitForGPUProcess(
     Endpoint<PRemoteDecoderManagerChild>&& aVideoManager) {
   InitializeThread();
-  sRemoteDecoderManagerChildThread->Dispatch(
+  MOZ_ALWAYS_SUCCEEDS(sRemoteDecoderManagerChildThread->Dispatch(
       NewRunnableFunction("InitForContentRunnable", &OpenForGPUProcess,
-                          std::move(aVideoManager)),
-      NS_DISPATCH_NORMAL);
+                          std::move(aVideoManager))));
 }
 
 /* static */
@@ -70,24 +69,23 @@ void RemoteDecoderManagerChild::Shutdown() {
   MOZ_ASSERT(NS_IsMainThread());
 
   if (sRemoteDecoderManagerChildThread) {
-    sRemoteDecoderManagerChildThread->Dispatch(
-        NS_NewRunnableFunction(
-            "dom::RemoteDecoderManagerChild::Shutdown",
-            []() {
+    MOZ_ALWAYS_SUCCEEDS(
+        sRemoteDecoderManagerChildThread->Dispatch(NS_NewRunnableFunction(
+            "dom::RemoteDecoderManagerChild::Shutdown", []() {
               if (sRemoteDecoderManagerChildForRDDProcess &&
                   sRemoteDecoderManagerChildForRDDProcess->CanSend()) {
                 sRemoteDecoderManagerChildForRDDProcess->Close();
-                sRemoteDecoderManagerChildForRDDProcess = nullptr;
               }
+              sRemoteDecoderManagerChildForRDDProcess = nullptr;
               if (sRemoteDecoderManagerChildForGPUProcess &&
                   sRemoteDecoderManagerChildForGPUProcess->CanSend()) {
                 sRemoteDecoderManagerChildForGPUProcess->Close();
-                sRemoteDecoderManagerChildForGPUProcess = nullptr;
               }
-            }),
-        NS_DISPATCH_NORMAL);
+              sRemoteDecoderManagerChildForGPUProcess = nullptr;
+            })));
 
-    sRemoteDecoderManagerChildThread->Shutdown();
+    sRemoteDecoderManagerChildThread->BeginShutdown();
+    sRemoteDecoderManagerChildThread->AwaitShutdownAndIdle();
     sRemoteDecoderManagerChildThread = nullptr;
 
     sRecreateTasks = nullptr;
@@ -96,7 +94,7 @@ void RemoteDecoderManagerChild::Shutdown() {
 
 void RemoteDecoderManagerChild::RunWhenGPUProcessRecreated(
     already_AddRefed<Runnable> aTask) {
-  MOZ_ASSERT(NS_GetCurrentThread() == GetManagerThread());
+  MOZ_ASSERT(GetManagerThread() && GetManagerThread()->IsOnCurrentThread());
 
   // If we've already been recreated, then run the task immediately.
   if (GetGPUProcessSingleton() && GetGPUProcessSingleton() != this &&
@@ -110,18 +108,18 @@ void RemoteDecoderManagerChild::RunWhenGPUProcessRecreated(
 
 /* static */
 RemoteDecoderManagerChild* RemoteDecoderManagerChild::GetRDDProcessSingleton() {
-  MOZ_ASSERT(NS_GetCurrentThread() == GetManagerThread());
+  MOZ_ASSERT(GetManagerThread() && GetManagerThread()->IsOnCurrentThread());
   return sRemoteDecoderManagerChildForRDDProcess;
 }
 
 /* static */
 RemoteDecoderManagerChild* RemoteDecoderManagerChild::GetGPUProcessSingleton() {
-  MOZ_ASSERT(NS_GetCurrentThread() == GetManagerThread());
+  MOZ_ASSERT(GetManagerThread() && GetManagerThread()->IsOnCurrentThread());
   return sRemoteDecoderManagerChildForGPUProcess;
 }
 
 /* static */
-nsIThread* RemoteDecoderManagerChild::GetManagerThread() {
+nsISerialEventTarget* RemoteDecoderManagerChild::GetManagerThread() {
   return sRemoteDecoderManagerChildThread;
 }
 
@@ -151,7 +149,7 @@ RemoteDecoderManagerChild::RemoteDecoderManagerChild(
 
 void RemoteDecoderManagerChild::OpenForRDDProcess(
     Endpoint<PRemoteDecoderManagerChild>&& aEndpoint) {
-  MOZ_ASSERT(NS_GetCurrentThread() == GetManagerThread());
+  MOZ_ASSERT(GetManagerThread() && GetManagerThread()->IsOnCurrentThread());
   // Only create RemoteDecoderManagerChild, bind new endpoint and init
   // ipdl if:
   // 1) haven't init'd sRemoteDecoderManagerChild
@@ -199,18 +197,17 @@ void RemoteDecoderManagerChild::InitIPDL() {
 void RemoteDecoderManagerChild::ActorDealloc() { mIPDLSelfRef = nullptr; }
 
 bool RemoteDecoderManagerChild::DeallocShmem(mozilla::ipc::Shmem& aShmem) {
-  if (NS_GetCurrentThread() != sRemoteDecoderManagerChildThread) {
+  if (!sRemoteDecoderManagerChildThread->IsOnCurrentThread()) {
     RefPtr<RemoteDecoderManagerChild> self = this;
     mozilla::ipc::Shmem shmem = aShmem;
-    sRemoteDecoderManagerChildThread->Dispatch(
-        NS_NewRunnableFunction("RemoteDecoderManagerChild::DeallocShmem",
-                               [self, shmem]() {
-                                 if (self->CanSend()) {
-                                   mozilla::ipc::Shmem shmemCopy = shmem;
-                                   self->DeallocShmem(shmemCopy);
-                                 }
-                               }),
-        NS_DISPATCH_NORMAL);
+    MOZ_ALWAYS_SUCCEEDS(
+        sRemoteDecoderManagerChildThread->Dispatch(NS_NewRunnableFunction(
+            "RemoteDecoderManagerChild::DeallocShmem", [self, shmem]() {
+              if (self->CanSend()) {
+                mozilla::ipc::Shmem shmemCopy = shmem;
+                self->DeallocShmem(shmemCopy);
+              }
+            })));
     return true;
   }
   return PRemoteDecoderManagerChild::DeallocShmem(aShmem);
@@ -242,14 +239,12 @@ already_AddRefed<SourceSurface> RemoteDecoderManagerChild::Readback(
   RefPtr<RemoteDecoderManagerChild> ref = this;
   SurfaceDescriptor sd;
   if (NS_FAILED(sRemoteDecoderManagerChildThread->Dispatch(
-          NS_NewRunnableFunction("RemoteDecoderManagerChild::Readback",
-                                 [&]() {
-                                   AutoCompleteTask complete(&task);
-                                   if (ref->CanSend()) {
-                                     ref->SendReadback(aSD, &sd);
-                                   }
-                                 }),
-          NS_DISPATCH_NORMAL))) {
+          NS_NewRunnableFunction("RemoteDecoderManagerChild::Readback", [&]() {
+            AutoCompleteTask complete(&task);
+            if (ref->CanSend()) {
+              ref->SendReadback(aSD, &sd);
+            }
+          })))) {
     return nullptr;
   }
 
@@ -278,15 +273,14 @@ void RemoteDecoderManagerChild::DeallocateSurfaceDescriptor(
     const SurfaceDescriptorGPUVideo& aSD) {
   RefPtr<RemoteDecoderManagerChild> ref = this;
   SurfaceDescriptorGPUVideo sd = std::move(aSD);
-  sRemoteDecoderManagerChildThread->Dispatch(
-      NS_NewRunnableFunction(
+  MOZ_ALWAYS_SUCCEEDS(
+      sRemoteDecoderManagerChildThread->Dispatch(NS_NewRunnableFunction(
           "RemoteDecoderManagerChild::DeallocateSurfaceDescriptor",
           [ref, sd]() {
             if (ref->CanSend()) {
               ref->SendDeallocateSurfaceDescriptorGPUVideo(sd);
             }
-          }),
-      NS_DISPATCH_NORMAL);
+          })));
 }
 
 void RemoteDecoderManagerChild::HandleFatalError(const char* aMsg) const {

dom/media/ipc/RemoteDecoderManagerChild.h

@@ -5,9 +5,9 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef include_dom_media_ipc_RemoteDecoderManagerChild_h
 #define include_dom_media_ipc_RemoteDecoderManagerChild_h
+#include "GPUVideoImage.h"
 #include "mozilla/PRemoteDecoderManagerChild.h"
 #include "mozilla/layers/VideoBridgeUtils.h"
-#include "GPUVideoImage.h"
 
 namespace mozilla {
 
@@ -25,7 +25,7 @@ class RemoteDecoderManagerChild final
   static RemoteDecoderManagerChild* GetGPUProcessSingleton();
 
   // Can be called from any thread.
-  static nsIThread* GetManagerThread();
+  static nsISerialEventTarget* GetManagerThread();
 
   // Can be called from any thread, dispatches the request to the IPDL thread
   // internally and will be ignored if the IPDL actor has been destroyed.
@@ -51,6 +51,7 @@ class RemoteDecoderManagerChild final
   bool DeallocShmem(mozilla::ipc::Shmem& aShmem) override;
 
   // Main thread only
+  static void InitializeThread();
   static void InitForRDDProcess(
       Endpoint<PRemoteDecoderManagerChild>&& aVideoManager);
   static void InitForGPUProcess(
@@ -80,9 +81,6 @@ class RemoteDecoderManagerChild final
   bool DeallocPRemoteDecoderChild(PRemoteDecoderChild* actor);
 
  private:
-  // Main thread only
-  static void InitializeThread();
-
   explicit RemoteDecoderManagerChild(layers::VideoBridgeSource aSource);
   ~RemoteDecoderManagerChild() = default;
 

dom/media/ipc/RemoteDecoderModule.cpp

@@ -5,20 +5,19 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "RemoteDecoderModule.h"
 
-#include "base/thread.h"
-#include "mozilla/dom/ContentChild.h"  // for launching RDD w/ ContentChild
-#include "mozilla/layers/SynchronousTask.h"
 #include "mozilla/StaticPrefs_media.h"
 #include "mozilla/SyncRunnable.h"
+#include "mozilla/dom/ContentChild.h"  // for launching RDD w/ ContentChild
+#include "mozilla/layers/SynchronousTask.h"
 
 #ifdef MOZ_AV1
 #  include "AOMDecoder.h"
 #endif
+#include "OpusDecoder.h"
 #include "RemoteAudioDecoder.h"
 #include "RemoteDecoderManagerChild.h"
 #include "RemoteMediaDataDecoder.h"
 #include "RemoteVideoDecoder.h"
-#include "OpusDecoder.h"
 #include "VideoUtils.h"
 #include "VorbisDecoder.h"
 #include "WAVDecoder.h"