Bug 1392216 - Part 1: Create VR listener thread in GPU process; r=dvander,kip

MozReview-Commit-ID: Img0HT9ax90

--HG--
extra : rebase_source : ef3e2dac31f498454121639aa46657c0cd16f949

gfx/ipc/GPUParent.cpp

@@ -37,6 +37,7 @@
 #include "ProcessUtils.h"
 #include "VRManager.h"
 #include "VRManagerParent.h"
+#include "VRThread.h"
 #include "VsyncBridgeParent.h"
 #if defined(XP_WIN)
 # include "mozilla/gfx/DeviceManagerDx.h"
@@ -120,6 +121,8 @@ GPUParent::Init(base::ProcessId aParentPid,
   }
 
   CompositorThreadHolder::Start();
+  // TODO: Bug 1406327, Start VRListenerThreadHolder when loading VR content.
+  VRListenerThreadHolder::Start();
   APZThreadUtils::SetControllerThread(CompositorThreadHolder::Loop());
   APZCTreeManager::InitializeGlobalState();
   LayerTreeOwnerTracker::Initialize();
@@ -431,6 +434,7 @@ GPUParent::ActorDestroy(ActorDestroyReason aWhy)
   }
   dom::VideoDecoderManagerParent::ShutdownVideoBridge();
   CompositorThreadHolder::Shutdown();
+  VRListenerThreadHolder::Shutdown();
   if (gfxVars::UseWebRender()) {
     wr::RenderThread::ShutDown();
   }

gfx/layers/ipc/CompositorVsyncScheduler.cpp

@@ -35,6 +35,7 @@
 #endif
 #include "mozilla/widget/CompositorWidget.h"
 #include "VRManager.h"
+#include "VRThread.h"
 
 namespace mozilla {
 
@@ -83,6 +84,8 @@ CompositorVsyncScheduler::CompositorVsyncScheduler(CompositorVsyncSchedulerOwner
   , mCurrentCompositeTask(nullptr)
   , mSetNeedsCompositeMonitor("SetNeedsCompositeMonitor")
   , mSetNeedsCompositeTask(nullptr)
+  , mCurrentVRListenerTaskMonitor("CurrentVRTaskMonitor")
+  , mCurrentVRListenerTask(nullptr)
 {
   mVsyncObserver = new Observer(this);
 
@@ -130,6 +133,16 @@ CompositorVsyncScheduler::PostCompositeTask(TimeStamp aCompositeTimestamp)
     mCurrentCompositeTask = task;
     ScheduleTask(task.forget(), 0);
   }
+  if (mCurrentVRListenerTask == nullptr && VRListenerThreadHolder::Loop()) {
+    RefPtr<CancelableRunnable> task = NewCancelableRunnableMethod<TimeStamp>(
+      "layers::CompositorVsyncScheduler::DispatchVREvents",
+      this,
+      &CompositorVsyncScheduler::DispatchVREvents,
+      aCompositeTimestamp);
+    mCurrentVRListenerTask = task;
+    MOZ_ASSERT(VRListenerThreadHolder::Loop());
+    VRListenerThreadHolder::Loop()->PostDelayedTask(Move(task.forget()), 0);
+  }
 }
 
 void
@@ -254,7 +267,6 @@ CompositorVsyncScheduler::Composite(TimeStamp aVsyncTimestamp)
   }
 
   DispatchTouchEvents(aVsyncTimestamp);
-  DispatchVREvents(aVsyncTimestamp);
 
   if (mNeedsComposite || mAsapScheduling) {
     mNeedsComposite = 0;
@@ -327,7 +339,11 @@ CompositorVsyncScheduler::DispatchTouchEvents(TimeStamp aVsyncTimestamp)
 void
 CompositorVsyncScheduler::DispatchVREvents(TimeStamp aVsyncTimestamp)
 {
-  MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread());
+  MOZ_ASSERT(VRListenerThreadHolder::IsInVRListenerThread());
+  {
+    MonitorAutoLock lock(mCurrentVRListenerTaskMonitor);
+    mCurrentVRListenerTask = nullptr;
+  }
 
   VRManager* vm = VRManager::Get();
   vm->NotifyVsync(aVsyncTimestamp);

gfx/layers/ipc/CompositorVsyncScheduler.h

@@ -117,6 +117,9 @@ private:
 
   mozilla::Monitor mSetNeedsCompositeMonitor;
   RefPtr<CancelableRunnable> mSetNeedsCompositeTask;
+
+  mozilla::Monitor mCurrentVRListenerTaskMonitor;
+  RefPtr<CancelableRunnable> mCurrentVRListenerTask;
 };
 
 } // namespace layers

gfx/thebes/gfxPlatform.cpp

@@ -28,6 +28,7 @@
 #include "gfxUserFontSet.h"
 #include "gfxConfig.h"
 #include "MediaPrefs.h"
+#include "VRThread.h"
 
 #ifdef XP_WIN
 #include <process.h>
@@ -1038,6 +1039,7 @@ gfxPlatform::InitLayersIPC()
     }
 
     layers::CompositorThreadHolder::Start();
+    gfx::VRListenerThreadHolder::Start();
   }
 }
 
@@ -1066,6 +1068,7 @@ gfxPlatform::ShutdownLayersIPC()
         layers::ImageBridgeChild::ShutDown();
         // This has to happen after shutting down the child protocols.
         layers::CompositorThreadHolder::Shutdown();
+        gfx::VRListenerThreadHolder::Shutdown();
         if (gfxVars::UseWebRender()) {
           wr::RenderThread::ShutDown();
 

gfx/vr/VRThread.cpp

@@ -0,0 +1,123 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#include "VRThread.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+
+namespace gfx {
+
+static StaticRefPtr<VRListenerThreadHolder> sVRListenerThreadHolder;
+static bool sFinishedVRListenerShutDown = false;
+
+VRListenerThreadHolder* GetVRListenerThreadHolder()
+{
+  return sVRListenerThreadHolder;
+}
+
+base::Thread*
+VRListenerThread()
+{
+  return sVRListenerThreadHolder
+         ? sVRListenerThreadHolder->GetThread()
+         : nullptr;
+}
+
+/* static */ MessageLoop*
+VRListenerThreadHolder::Loop()
+{
+  return VRListenerThread() ? VRListenerThread()->message_loop() : nullptr;
+}
+
+VRListenerThreadHolder*
+VRListenerThreadHolder::GetSingleton()
+{
+  return sVRListenerThreadHolder;
+}
+
+VRListenerThreadHolder::VRListenerThreadHolder()
+ : mThread(CreateThread())
+{
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+VRListenerThreadHolder::~VRListenerThreadHolder()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  DestroyThread(mThread);
+}
+
+/* static */ void
+VRListenerThreadHolder::DestroyThread(base::Thread* aThread)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!sVRListenerThreadHolder,
+             "We shouldn't be destroying the VR listener thread yet.");
+  delete aThread;
+  sFinishedVRListenerShutDown = true;
+}
+
+/* static */ base::Thread*
+VRListenerThreadHolder::CreateThread()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!sVRListenerThreadHolder, "The VR listener thread has already been started!");
+
+  base::Thread* vrThread = new base::Thread("VRListener");
+  base::Thread::Options options;
+  /* Timeout values are powers-of-two to enable us get better data.
+     128ms is chosen for transient hangs because 8Hz should be the minimally
+     acceptable goal for Compositor responsiveness (normal goal is 60Hz). */
+  options.transient_hang_timeout = 128; // milliseconds
+  /* 2048ms is chosen for permanent hangs because it's longer than most
+   * Compositor hangs seen in the wild, but is short enough to not miss getting
+   * native hang stacks. */
+  options.permanent_hang_timeout = 2048; // milliseconds
+
+  if (!vrThread->StartWithOptions(options)) {
+    delete vrThread;
+    return nullptr;
+  }
+
+  return vrThread;
+}
+
+void
+VRListenerThreadHolder::Start()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main thread!");
+  MOZ_ASSERT(!sVRListenerThreadHolder, "The VR listener thread has already been started!");
+
+  sVRListenerThreadHolder = new VRListenerThreadHolder();
+}
+
+void
+VRListenerThreadHolder::Shutdown()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main thread!");
+  MOZ_ASSERT(sVRListenerThreadHolder, "The VR listener thread has already been shut down!");
+
+  sVRListenerThreadHolder = nullptr;
+
+  SpinEventLoopUntil([&]() { return sFinishedVRListenerShutDown; });
+}
+
+/* static */ bool
+VRListenerThreadHolder::IsInVRListenerThread()
+{
+  return VRListenerThread() &&
+		 VRListenerThread()->thread_id() == PlatformThread::CurrentId();
+}
+
+} // namespace gfx
+} // namespace mozilla
+
+bool
+NS_IsInVRListenerThread()
+{
+  return mozilla::gfx::VRListenerThreadHolder::IsInVRListenerThread();
+}

gfx/vr/VRThread.h

@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+ #ifndef GFX_VR_THREAD_H
+ #define GFX_VR_THREAD_H
+
+#include "ThreadSafeRefcountingWithMainThreadDestruction.h"
+#include "base/thread.h"                // for Thread
+
+namespace mozilla {
+namespace gfx {
+
+class VRListenerThreadHolder final
+{
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_MAIN_THREAD_DESTRUCTION(VRListenerThreadHolder)
+
+public:
+  VRListenerThreadHolder();
+
+  base::Thread* GetThread() const {
+    return mThread;
+  }
+
+  static VRListenerThreadHolder* GetSingleton();
+
+  static bool IsActive() {
+    return !!GetSingleton();
+  }
+
+  static void Start();
+  static void Shutdown();
+  static MessageLoop* Loop();
+  static bool IsInVRListenerThread();
+
+private:
+  ~VRListenerThreadHolder();
+
+  base::Thread* const mThread;
+
+  static base::Thread* CreateThread();
+  static void DestroyThread(base::Thread* aThread);
+};
+
+base::Thread* VRListenerThread();
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif // GFX_VR_THREAD_H

gfx/vr/moz.build

@@ -13,6 +13,7 @@ EXPORTS += [
     'VRDisplayClient.h',
     'VRDisplayPresentation.h',
     'VRManager.h',
+    'VRThread.h',
 ]
 
 LOCAL_INCLUDES += [
@@ -31,6 +32,7 @@ UNIFIED_SOURCES += [
     'VRDisplayClient.cpp',
     'VRDisplayPresentation.cpp',
     'VRManager.cpp',
+    'VRThread.cpp',
 ]
 
 # VRDisplayHost includes MacIOSurface.h which includes Mac headers

xpcom/threads/nsThreadUtils.h

@@ -344,6 +344,8 @@ SpinEventLoopUntil(Pred&& aPredicate, nsIThread* aThread = nullptr)
  */
 extern bool NS_IsInCompositorThread();
 
+extern bool NS_IsInVRThread();
+
 //-----------------------------------------------------------------------------
 // Helpers that work with nsCOMPtr: