/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "base/task.h"
#include "GeckoProfiler.h"
#include "RenderThread.h"
#include "nsThreadUtils.h"
#include "mtransport/runnable_utils.h"
#include "mozilla/layers/AsyncImagePipelineManager.h"
#include "mozilla/gfx/GPUParent.h"
#include "mozilla/layers/CompositorThread.h"
#include "mozilla/layers/CompositorBridgeParent.h"
#include "mozilla/layers/WebRenderBridgeParent.h"
#include "mozilla/layers/SharedSurfacesParent.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/Telemetry.h"
#include "mozilla/webrender/RendererOGL.h"
#include "mozilla/webrender/RenderTextureHost.h"
#include "mozilla/widget/CompositorWidget.h"

#ifdef XP_WIN
#  include "GLLibraryEGL.h"
#  include "mozilla/widget/WinCompositorWindowThread.h"
#endif

#ifdef MOZ_WIDGET_ANDROID
#  include "GLLibraryEGL.h"
#endif

using namespace mozilla;

static already_AddRefed<gl::GLContext> CreateGLContext();

MOZ_DEFINE_MALLOC_SIZE_OF(WebRenderRendererMallocSizeOf)

namespace mozilla {
namespace wr {

static StaticRefPtr<RenderThread> sRenderThread;

RenderThread::RenderThread(base::Thread* aThread)
    : mThread(aThread),
      mWindowInfos("RenderThread.mWindowInfos"),
      mRenderTextureMapLock("RenderThread.mRenderTextureMapLock"),
      mHasShutdown(false),
      mHandlingDeviceReset(false) {}

RenderThread::~RenderThread() {
  MOZ_ASSERT(mRenderTexturesDeferred.empty());
  delete mThread;
}

// static
RenderThread* RenderThread::Get() { return sRenderThread; }

// static
void RenderThread::Start() {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(!sRenderThread);

  base::Thread* thread = new base::Thread("Renderer");

  base::Thread::Options options;
  // TODO(nical): The compositor thread has a bunch of specific options, see
  // which ones make sense here.
  if (!thread->StartWithOptions(options)) {
    delete thread;
    return;
  }

  sRenderThread = new RenderThread(thread);
#ifdef XP_WIN
  widget::WinCompositorWindowThread::Start();
#endif
  layers::SharedSurfacesParent::Initialize();

  RefPtr<Runnable> runnable = WrapRunnable(
      RefPtr<RenderThread>(sRenderThread.get()), &RenderThread::InitDeviceTask);
  sRenderThread->Loop()->PostTask(runnable.forget());
}

// static
void RenderThread::ShutDown() {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(sRenderThread);

  {
    MutexAutoLock lock(sRenderThread->mRenderTextureMapLock);
    sRenderThread->mHasShutdown = true;
  }

  layers::SynchronousTask task("RenderThread");
  RefPtr<Runnable> runnable =
      WrapRunnable(RefPtr<RenderThread>(sRenderThread.get()),
                   &RenderThread::ShutDownTask, &task);
  sRenderThread->Loop()->PostTask(runnable.forget());
  task.Wait();

  sRenderThread = nullptr;
#ifdef XP_WIN
  widget::WinCompositorWindowThread::ShutDown();
#endif
}

extern void ClearAllBlobImageResources();

void RenderThread::ShutDownTask(layers::SynchronousTask* aTask) {
  layers::AutoCompleteTask complete(aTask);
  MOZ_ASSERT(IsInRenderThread());

  // Releasing on the render thread will allow us to avoid dispatching to remove
  // remaining textures from the texture map.
  layers::SharedSurfacesParent::Shutdown();

  ClearAllBlobImageResources();
  ClearSharedGL();
}

// static
MessageLoop* RenderThread::Loop() {
  return sRenderThread ? sRenderThread->mThread->message_loop() : nullptr;
}

// static
bool RenderThread::IsInRenderThread() {
  return sRenderThread &&
         sRenderThread->mThread->thread_id() == PlatformThread::CurrentId();
}

void RenderThread::DoAccumulateMemoryReport(
    MemoryReport aReport,
    const RefPtr<MemoryReportPromise::Private>& aPromise) {
  MOZ_ASSERT(IsInRenderThread());

  for (auto& r : mRenderers) {
    r.second->AccumulateMemoryReport(&aReport);
  }

  // Note memory used by the shader cache, which is shared across all WR
  // instances.
  MOZ_ASSERT(aReport.shader_cache == 0);
  if (mProgramCache) {
    aReport.shader_cache = wr_program_cache_report_memory(
        mProgramCache->Raw(), &WebRenderRendererMallocSizeOf);
  }

  aPromise->Resolve(aReport, __func__);
}

// static
RefPtr<MemoryReportPromise> RenderThread::AccumulateMemoryReport(
    MemoryReport aInitial) {
  RefPtr<MemoryReportPromise::Private> p =
      new MemoryReportPromise::Private(__func__);
  MOZ_ASSERT(!IsInRenderThread());
  if (!Get() || !Get()->Loop()) {
    // This happens when the GPU process fails to start and we fall back to the
    // basic compositor in the parent process. We could assert against this if
    // we made the webrender detection code in gfxPlatform.cpp smarter. See bug
    // 1494430 comment 12.
    NS_WARNING("No render thread, returning empty memory report");
    p->Resolve(aInitial, __func__);
    return p;
  }

  Get()->Loop()->PostTask(
      NewRunnableMethod<MemoryReport, RefPtr<MemoryReportPromise::Private>>(
          "wr::RenderThread::DoAccumulateMemoryReport", Get(),
          &RenderThread::DoAccumulateMemoryReport, aInitial, p));

  return p;
}

void RenderThread::AddRenderer(wr::WindowId aWindowId,
                               UniquePtr<RendererOGL> aRenderer) {
  MOZ_ASSERT(IsInRenderThread());

  if (mHasShutdown) {
    return;
  }

  mRenderers[aWindowId] = std::move(aRenderer);

  auto windows = mWindowInfos.Lock();
  windows->emplace(AsUint64(aWindowId), new WindowInfo());
}

void RenderThread::RemoveRenderer(wr::WindowId aWindowId) {
  MOZ_ASSERT(IsInRenderThread());

  if (mHasShutdown) {
    return;
  }

  mRenderers.erase(aWindowId);

  if (mRenderers.size() == 0 && mHandlingDeviceReset) {
    mHandlingDeviceReset = false;
  }

  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  MOZ_ASSERT(it != windows->end());
  WindowInfo* toDelete = it->second;
  windows->erase(it);
  delete toDelete;
}

RendererOGL* RenderThread::GetRenderer(wr::WindowId aWindowId) {
  MOZ_ASSERT(IsInRenderThread());

  auto it = mRenderers.find(aWindowId);
  MOZ_ASSERT(it != mRenderers.end());

  if (it == mRenderers.end()) {
    return nullptr;
  }

  return it->second.get();
}

size_t RenderThread::RendererCount() {
  MOZ_ASSERT(IsInRenderThread());
  return mRenderers.size();
}

void RenderThread::HandleFrame(wr::WindowId aWindowId, bool aRender) {
  if (mHasShutdown) {
    return;
  }

  if (!IsInRenderThread()) {
    Loop()->PostTask(NewRunnableMethod<wr::WindowId, bool>(
        "wr::RenderThread::NewFrameReady", this, &RenderThread::HandleFrame,
        aWindowId, aRender));
    return;
  }

  if (IsDestroyed(aWindowId)) {
    return;
  }

  if (mHandlingDeviceReset) {
    return;
  }

  TimeStamp startTime;
  VsyncId startId;

  bool hadSlowFrame;
  {  // scope lock
    auto windows = mWindowInfos.Lock();
    auto it = windows->find(AsUint64(aWindowId));
    MOZ_ASSERT(it != windows->end());
    WindowInfo* info = it->second;
    MOZ_ASSERT(info->mPendingCount > 0);
    startTime = info->mStartTimes.front();
    startId = info->mStartIds.front();
    hadSlowFrame = info->mHadSlowFrame;
    info->mHadSlowFrame = false;
  }

  UpdateAndRender(aWindowId, startId, startTime, aRender,
                  /* aReadbackSize */ Nothing(),
                  /* aReadbackBuffer */ Nothing(), hadSlowFrame);
  FrameRenderingComplete(aWindowId);
}

void RenderThread::WakeUp(wr::WindowId aWindowId) {
  if (mHasShutdown) {
    return;
  }

  if (!IsInRenderThread()) {
    Loop()->PostTask(NewRunnableMethod<wr::WindowId>(
        "wr::RenderThread::WakeUp", this, &RenderThread::WakeUp, aWindowId));
    return;
  }

  if (IsDestroyed(aWindowId)) {
    return;
  }

  if (mHandlingDeviceReset) {
    return;
  }

  auto it = mRenderers.find(aWindowId);
  MOZ_ASSERT(it != mRenderers.end());
  if (it != mRenderers.end()) {
    it->second->Update();
  }
}

void RenderThread::RunEvent(wr::WindowId aWindowId,
                            UniquePtr<RendererEvent> aEvent) {
  if (!IsInRenderThread()) {
    Loop()->PostTask(
        NewRunnableMethod<wr::WindowId, UniquePtr<RendererEvent>&&>(
            "wr::RenderThread::RunEvent", this, &RenderThread::RunEvent,
            aWindowId, std::move(aEvent)));
    return;
  }

  aEvent->Run(*this, aWindowId);
  aEvent = nullptr;
}

static void NotifyDidRender(layers::CompositorBridgeParent* aBridge,
                            RefPtr<WebRenderPipelineInfo> aInfo,
                            VsyncId aCompositeStartId,
                            TimeStamp aCompositeStart, TimeStamp aRenderStart,
                            TimeStamp aEnd, bool aRender,
                            RendererStats aStats) {
  if (aRender && aBridge->GetWrBridge()) {
    // We call this here to mimic the behavior in LayerManagerComposite, as to
    // not change what Talos measures. That is, we do not record an empty frame
    // as a frame.
    aBridge->GetWrBridge()->RecordFrame();
  }

  auto info = aInfo->Raw();

  for (uintptr_t i = 0; i < info.epochs.length; i++) {
    aBridge->NotifyPipelineRendered(
        info.epochs.data[i].pipeline_id, info.epochs.data[i].epoch,
        aCompositeStartId, aCompositeStart, aRenderStart, aEnd, &aStats);
  }

  if (aBridge->GetWrBridge()) {
    aBridge->GetWrBridge()->CompositeIfNeeded();
  }
}

static void NotifyDidStartRender(layers::CompositorBridgeParent* aBridge) {
  // Starting a render will change increment mRenderingCount, and potentially
  // change whether we can allow the bridge to intiate another frame.
  if (aBridge->GetWrBridge()) {
    aBridge->GetWrBridge()->CompositeIfNeeded();
  }
}

void RenderThread::UpdateAndRender(wr::WindowId aWindowId,
                                   const VsyncId& aStartId,
                                   const TimeStamp& aStartTime, bool aRender,
                                   const Maybe<gfx::IntSize>& aReadbackSize,
                                   const Maybe<Range<uint8_t>>& aReadbackBuffer,
                                   bool aHadSlowFrame) {
  AUTO_PROFILER_TRACING("Paint", "Composite", GRAPHICS);
  MOZ_ASSERT(IsInRenderThread());
  MOZ_ASSERT(aRender || aReadbackBuffer.isNothing());

  auto it = mRenderers.find(aWindowId);
  MOZ_ASSERT(it != mRenderers.end());
  if (it == mRenderers.end()) {
    return;
  }

  TimeStamp start = TimeStamp::Now();

  auto& renderer = it->second;

  layers::CompositorThreadHolder::Loop()->PostTask(
      NewRunnableFunction("NotifyDidStartRenderRunnable", &NotifyDidStartRender,
                          renderer->GetCompositorBridge()));

  bool rendered = false;
  RendererStats stats = {0};
  if (aRender) {
    rendered = renderer->UpdateAndRender(aReadbackSize, aReadbackBuffer,
                                         aHadSlowFrame, &stats);
  } else {
    renderer->Update();
  }
  // Check graphics reset status even when rendering is skipped.
  renderer->CheckGraphicsResetStatus();

  TimeStamp end = TimeStamp::Now();
  auto info = renderer->FlushPipelineInfo();

  layers::CompositorThreadHolder::Loop()->PostTask(
      NewRunnableFunction("NotifyDidRenderRunnable", &NotifyDidRender,
                          renderer->GetCompositorBridge(), info, aStartId,
                          aStartTime, start, end, aRender, stats));

  if (rendered) {
    // Wait for GPU after posting NotifyDidRender, since the wait is not
    // necessary for the NotifyDidRender.
    // The wait is necessary for Textures recycling of AsyncImagePipelineManager
    // and for avoiding GPU queue is filled with too much tasks.
    // WaitForGPU's implementation is different for each platform.
    renderer->WaitForGPU();
  }

  RefPtr<layers::AsyncImagePipelineManager> pipelineMgr =
      renderer->GetCompositorBridge()->GetAsyncImagePipelineManager();
  // pipelineMgr should always be non-null here because it is only nulled out
  // after the WebRenderAPI instance for the CompositorBridgeParent is
  // destroyed, and that destruction blocks until the renderer thread has
  // removed the relevant renderer. And after that happens we should never reach
  // this code at all; it would bail out at the mRenderers.find check above.
  MOZ_ASSERT(pipelineMgr);
  pipelineMgr->NotifyPipelinesUpdated(info, aRender);
}

void RenderThread::Pause(wr::WindowId aWindowId) {
  MOZ_ASSERT(IsInRenderThread());

  auto it = mRenderers.find(aWindowId);
  MOZ_ASSERT(it != mRenderers.end());
  if (it == mRenderers.end()) {
    return;
  }
  auto& renderer = it->second;
  renderer->Pause();
}

bool RenderThread::Resume(wr::WindowId aWindowId) {
  MOZ_ASSERT(IsInRenderThread());

  auto it = mRenderers.find(aWindowId);
  MOZ_ASSERT(it != mRenderers.end());
  if (it == mRenderers.end()) {
    return false;
  }
  auto& renderer = it->second;
  return renderer->Resume();
}

bool RenderThread::TooManyPendingFrames(wr::WindowId aWindowId) {
  const int64_t maxFrameCount = 1;

  // Too many pending frames if pending frames exit more than maxFrameCount
  // or if RenderBackend is still processing a frame.

  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    MOZ_ASSERT(false);
    return true;
  }
  WindowInfo* info = it->second;

  if (info->mPendingCount > maxFrameCount) {
    return true;
  }
  MOZ_ASSERT(info->mPendingCount >= info->mRenderingCount);
  return info->mPendingCount > info->mRenderingCount;
}

bool RenderThread::IsDestroyed(wr::WindowId aWindowId) {
  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    return true;
  }

  return it->second->mIsDestroyed;
}

void RenderThread::SetDestroyed(wr::WindowId aWindowId) {
  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    MOZ_ASSERT(false);
    return;
  }
  it->second->mIsDestroyed = true;
}

void RenderThread::IncPendingFrameCount(wr::WindowId aWindowId,
                                        const VsyncId& aStartId,
                                        const TimeStamp& aStartTime,
                                        uint8_t aDocFrameCount) {
  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    MOZ_ASSERT(false);
    return;
  }
  it->second->mPendingCount++;
  it->second->mStartTimes.push(aStartTime);
  it->second->mStartIds.push(aStartId);
  it->second->mDocFrameCounts.push(aDocFrameCount);
}

void RenderThread::DecPendingFrameCount(wr::WindowId aWindowId) {
  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    MOZ_ASSERT(false);
    return;
  }
  WindowInfo* info = it->second;
  MOZ_ASSERT(info->mPendingCount > 0);
  if (info->mPendingCount <= 0) {
    return;
  }
  info->mPendingCount--;
  // This function gets called for "nop frames" where nothing was rendered or
  // composited. But we count this time because the non-WR codepath equivalent
  // in CompositorBridgeParent::ComposeToTarget also counts such frames. And
  // anyway this should be relatively infrequent so it shouldn't skew the
  // numbers much.
  mozilla::Telemetry::AccumulateTimeDelta(mozilla::Telemetry::COMPOSITE_TIME,
                                          info->mStartTimes.front());
  info->mStartTimes.pop();
  info->mStartIds.pop();
}

mozilla::Pair<bool, bool> RenderThread::IncRenderingFrameCount(
    wr::WindowId aWindowId, bool aRender) {
  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    MOZ_ASSERT(false);
    return MakePair(false, false);
  }

  it->second->mDocFramesSeen++;
  if (it->second->mDocFramesSeen < it->second->mDocFrameCounts.front()) {
    it->second->mRender |= aRender;
    return MakePair(false, it->second->mRender);
  } else {
    MOZ_ASSERT(it->second->mDocFramesSeen ==
               it->second->mDocFrameCounts.front());
    bool render = it->second->mRender || aRender;
    it->second->mRender = false;
    it->second->mRenderingCount++;
    it->second->mDocFrameCounts.pop();
    it->second->mDocFramesSeen = 0;
    return MakePair(true, render);
  }
}

void RenderThread::FrameRenderingComplete(wr::WindowId aWindowId) {
  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    MOZ_ASSERT(false);
    return;
  }
  WindowInfo* info = it->second;
  MOZ_ASSERT(info->mPendingCount > 0);
  MOZ_ASSERT(info->mRenderingCount > 0);
  if (info->mPendingCount <= 0) {
    return;
  }
  info->mPendingCount--;
  info->mRenderingCount--;

  // The start time is from WebRenderBridgeParent::CompositeToTarget. From that
  // point until now (when the frame is finally pushed to the screen) is
  // equivalent to the COMPOSITE_TIME metric in the non-WR codepath.
  mozilla::Telemetry::AccumulateTimeDelta(mozilla::Telemetry::COMPOSITE_TIME,
                                          info->mStartTimes.front());
  info->mStartTimes.pop();
  info->mStartIds.pop();
}

void RenderThread::NotifySlowFrame(wr::WindowId aWindowId) {
  auto windows = mWindowInfos.Lock();
  auto it = windows->find(AsUint64(aWindowId));
  if (it == windows->end()) {
    MOZ_ASSERT(false);
    return;
  }
  WindowInfo* info = it->second;
  info->mHadSlowFrame = true;
}

void RenderThread::RegisterExternalImage(
    uint64_t aExternalImageId, already_AddRefed<RenderTextureHost> aTexture) {
  MutexAutoLock lock(mRenderTextureMapLock);

  if (mHasShutdown) {
    return;
  }
  MOZ_ASSERT(mRenderTextures.find(aExternalImageId) == mRenderTextures.end());
  mRenderTextures.emplace(aExternalImageId, std::move(aTexture));
}

void RenderThread::UnregisterExternalImage(uint64_t aExternalImageId) {
  MutexAutoLock lock(mRenderTextureMapLock);
  if (mHasShutdown) {
    return;
  }
  auto it = mRenderTextures.find(aExternalImageId);
  MOZ_ASSERT(it != mRenderTextures.end());
  if (it == mRenderTextures.end()) {
    return;
  }
  if (!IsInRenderThread()) {
    // The RenderTextureHost should be released in render thread. So, post the
    // deletion task here.
    // The shmem and raw buffer are owned by compositor ipc channel. It's
    // possible that RenderTextureHost is still exist after the shmem/raw buffer
    // deletion. Then the buffer in RenderTextureHost becomes invalid. It's fine
    // for this situation. Gecko will only release the buffer if WR doesn't need
    // it. So, no one will access the invalid buffer in RenderTextureHost.
    RefPtr<RenderTextureHost> texture = it->second;
    mRenderTextures.erase(it);
    mRenderTexturesDeferred.emplace_back(std::move(texture));
    Loop()->PostTask(NewRunnableMethod(
        "RenderThread::DeferredRenderTextureHostDestroy", this,
        &RenderThread::DeferredRenderTextureHostDestroy));
  } else {
    mRenderTextures.erase(it);
  }
}

void RenderThread::PrepareForUse(uint64_t aExternalImageId) {
  if (!IsInRenderThread()) {
    Loop()->PostTask(NewRunnableMethod<uint64_t>(
        "RenderThread::PrepareForUse", this, &RenderThread::PrepareForUse,
        aExternalImageId));
    return;
  }

  MutexAutoLock lock(mRenderTextureMapLock);
  if (mHasShutdown) {
    return;
  }

  auto it = mRenderTextures.find(aExternalImageId);
  MOZ_ASSERT(it != mRenderTextures.end());
  if (it == mRenderTextures.end()) {
    return;
  }

  RefPtr<RenderTextureHost> texture = it->second;
  texture->PrepareForUse();
}

void RenderThread::NotifyNotUsed(uint64_t aExternalImageId) {
  if (!IsInRenderThread()) {
    Loop()->PostTask(NewRunnableMethod<uint64_t>(
        "RenderThread::NotifyNotUsed", this, &RenderThread::NotifyNotUsed,
        aExternalImageId));
    return;
  }

  MutexAutoLock lock(mRenderTextureMapLock);
  if (mHasShutdown) {
    return;
  }

  auto it = mRenderTextures.find(aExternalImageId);
  MOZ_ASSERT(it != mRenderTextures.end());
  if (it == mRenderTextures.end()) {
    return;
  }

  RefPtr<RenderTextureHost> texture = it->second;
  texture->NotifyNotUsed();
}

void RenderThread::UpdateRenderTextureHost(uint64_t aSrcExternalImageId,
                                           uint64_t aWrappedExternalImageId) {
  MOZ_ASSERT(aSrcExternalImageId != aWrappedExternalImageId);
  MOZ_ASSERT(RenderThread::IsInRenderThread());

  MutexAutoLock lock(mRenderTextureMapLock);
  if (mHasShutdown) {
    return;
  }
  auto src = mRenderTextures.find(aSrcExternalImageId);
  auto wrapped = mRenderTextures.find(aWrappedExternalImageId);
  if (src == mRenderTextures.end() || wrapped == mRenderTextures.end()) {
    return;
  }
  MOZ_ASSERT(src->second->AsRenderTextureHostWrapper());
  MOZ_ASSERT(!wrapped->second->AsRenderTextureHostWrapper());
  RenderTextureHostWrapper* wrapper = src->second->AsRenderTextureHostWrapper();
  if (!wrapper) {
    MOZ_ASSERT_UNREACHABLE("unexpected to happen");
    return;
  }
  wrapper->UpdateRenderTextureHost(wrapped->second);
}

void RenderThread::UnregisterExternalImageDuringShutdown(
    uint64_t aExternalImageId) {
  MOZ_ASSERT(IsInRenderThread());
  MutexAutoLock lock(mRenderTextureMapLock);
  MOZ_ASSERT(mHasShutdown);
  MOZ_ASSERT(mRenderTextures.find(aExternalImageId) != mRenderTextures.end());
  mRenderTextures.erase(aExternalImageId);
}

void RenderThread::DeferredRenderTextureHostDestroy() {
  MutexAutoLock lock(mRenderTextureMapLock);
  mRenderTexturesDeferred.clear();
}

RenderTextureHost* RenderThread::GetRenderTexture(
    wr::WrExternalImageId aExternalImageId) {
  MOZ_ASSERT(IsInRenderThread());

  MutexAutoLock lock(mRenderTextureMapLock);
  auto it = mRenderTextures.find(aExternalImageId.mHandle);
  MOZ_ASSERT(it != mRenderTextures.end());
  if (it == mRenderTextures.end()) {
    return nullptr;
  }
  return it->second;
}

void RenderThread::InitDeviceTask() {
  MOZ_ASSERT(IsInRenderThread());
  MOZ_ASSERT(!mSharedGL);

  mSharedGL = CreateGLContext();
  if (gfx::gfxVars::UseWebRenderProgramBinaryDisk()) {
    mProgramCache = MakeUnique<WebRenderProgramCache>(ThreadPool().Raw());
  }
  // Query the shared GL context to force the
  // lazy initialization to happen now.
  SharedGL();
}

void RenderThread::HandleDeviceReset(const char* aWhere, bool aNotify) {
  MOZ_ASSERT(IsInRenderThread());

  if (mHandlingDeviceReset) {
    return;
  }

  if (aNotify) {
    gfxCriticalNote << "GFX: RenderThread detected a device reset in "
                    << aWhere;
    if (XRE_IsGPUProcess()) {
      gfx::GPUParent::GetSingleton()->NotifyDeviceReset();
    }
  }

  {
    MutexAutoLock lock(mRenderTextureMapLock);
    mRenderTexturesDeferred.clear();
    for (const auto& entry : mRenderTextures) {
      entry.second->ClearCachedResources();
    }
  }

  mHandlingDeviceReset = true;
  // All RenderCompositors will be destroyed by
  // GPUChild::RecvNotifyDeviceReset()
}

bool RenderThread::IsHandlingDeviceReset() {
  MOZ_ASSERT(IsInRenderThread());
  return mHandlingDeviceReset;
}

void RenderThread::SimulateDeviceReset() {
  if (!IsInRenderThread()) {
    Loop()->PostTask(NewRunnableMethod("RenderThread::SimulateDeviceReset",
                                       this,
                                       &RenderThread::SimulateDeviceReset));
  } else {
    // When this function is called GPUProcessManager::SimulateDeviceReset()
    // already triggers destroying all CompositorSessions before re-creating
    // them.
    HandleDeviceReset("SimulateDeviceReset", /* aNotify */ false);
  }
}

gl::GLContext* RenderThread::SharedGL() {
  MOZ_ASSERT(IsInRenderThread());
  if (!mSharedGL) {
    mSharedGL = CreateGLContext();
    mShaders = nullptr;
  }
  if (mSharedGL && !mShaders) {
    mShaders = MakeUnique<WebRenderShaders>(mSharedGL, mProgramCache.get());
  }

  return mSharedGL.get();
}

void RenderThread::ClearSharedGL() {
  MOZ_ASSERT(IsInRenderThread());
  mShaders = nullptr;
  mSharedGL = nullptr;
}

WebRenderShaders::WebRenderShaders(gl::GLContext* gl,
                                   WebRenderProgramCache* programCache) {
  mGL = gl;
  mShaders = wr_shaders_new(gl, programCache ? programCache->Raw() : nullptr);
}

WebRenderShaders::~WebRenderShaders() {
  wr_shaders_delete(mShaders, mGL.get());
}

WebRenderPipelineInfo::WebRenderPipelineInfo(wr::WrPipelineInfo aPipelineInfo)
    : mPipelineInfo(aPipelineInfo) {}

WebRenderPipelineInfo::~WebRenderPipelineInfo() {
  wr_pipeline_info_delete(mPipelineInfo);
}

WebRenderThreadPool::WebRenderThreadPool() {
  mThreadPool = wr_thread_pool_new();
}

WebRenderThreadPool::~WebRenderThreadPool() {
  wr_thread_pool_delete(mThreadPool);
}

WebRenderProgramCache::WebRenderProgramCache(wr::WrThreadPool* aThreadPool) {
  MOZ_ASSERT(aThreadPool);

  nsAutoString path;
  if (gfxVars::UseWebRenderProgramBinaryDisk()) {
    path.Append(gfx::gfxVars::ProfDirectory());
  }
  mProgramCache = wr_program_cache_new(&path, aThreadPool);
  if (gfxVars::UseWebRenderProgramBinaryDisk()) {
    wr_try_load_shader_from_disk(mProgramCache);
  }
}

WebRenderProgramCache::~WebRenderProgramCache() {
  wr_program_cache_delete(mProgramCache);
}

}  // namespace wr
}  // namespace mozilla

#ifdef XP_WIN
static already_AddRefed<gl::GLContext> CreateGLContextANGLE() {
  nsCString discardFailureId;
  if (!gl::GLLibraryEGL::EnsureInitialized(/* forceAccel */ true,
                                           &discardFailureId)) {
    gfxCriticalNote << "Failed to load EGL library: " << discardFailureId.get();
    return nullptr;
  }

  auto* egl = gl::GLLibraryEGL::Get();
  auto flags = gl::CreateContextFlags::PREFER_ES3;

  if (egl->IsExtensionSupported(
          gl::GLLibraryEGL::MOZ_create_context_provoking_vertex_dont_care)) {
    flags |= gl::CreateContextFlags::PROVOKING_VERTEX_DONT_CARE;
  }

  // Create GLContext with dummy EGLSurface, the EGLSurface is not used.
  // Instread we override it with EGLSurface of SwapChain's back buffer.
  RefPtr<gl::GLContext> gl =
      gl::GLContextProviderEGL::CreateHeadless(flags, &discardFailureId);
  if (!gl || !gl->IsANGLE()) {
    gfxCriticalNote << "Failed ANGLE GL context creation for WebRender: "
                    << gfx::hexa(gl.get());
    return nullptr;
  }

  if (!gl->MakeCurrent()) {
    gfxCriticalNote << "Failed GL context creation for WebRender: "
                    << gfx::hexa(gl.get());
    return nullptr;
  }

  return gl.forget();
}
#endif

#ifdef MOZ_WIDGET_ANDROID
static already_AddRefed<gl::GLContext> CreateGLContextEGL() {
  nsCString discardFailureId;
  if (!gl::GLLibraryEGL::EnsureInitialized(/* forceAccel */ true,
                                           &discardFailureId)) {
    gfxCriticalNote << "Failed to load EGL library: " << discardFailureId.get();
    return nullptr;
  }
  // Create GLContext with dummy EGLSurface.
  RefPtr<gl::GLContext> gl =
      gl::GLContextProviderEGL::CreateForCompositorWidget(
          nullptr, /* aWebRender */ true, /* aForceAccelerated */ true);
  if (!gl || !gl->MakeCurrent()) {
    gfxCriticalNote << "Failed GL context creation for WebRender: "
                    << gfx::hexa(gl.get());
    return nullptr;
  }
  return gl.forget();
}
#endif

static already_AddRefed<gl::GLContext> CreateGLContext() {
#ifdef XP_WIN
  if (gfx::gfxVars::UseWebRenderANGLE()) {
    return CreateGLContextANGLE();
  }
#endif

#ifdef MOZ_WIDGET_ANDROID
  return CreateGLContextEGL();
#endif
  // We currently only support a shared GLContext
  // with ANGLE.
  return nullptr;
}

extern "C" {

static void HandleFrame(mozilla::wr::WrWindowId aWindowId, bool aRender) {
  auto incResult = mozilla::wr::RenderThread::Get()->IncRenderingFrameCount(
      aWindowId, aRender);
  if (incResult.first()) {
    mozilla::wr::RenderThread::Get()->HandleFrame(aWindowId,
                                                  incResult.second());
  }
}

void wr_notifier_wake_up(mozilla::wr::WrWindowId aWindowId) {
  mozilla::wr::RenderThread::Get()->WakeUp(aWindowId);
}

void wr_notifier_new_frame_ready(mozilla::wr::WrWindowId aWindowId) {
  HandleFrame(aWindowId, /* aRender */ true);
}

void wr_notifier_nop_frame_done(mozilla::wr::WrWindowId aWindowId) {
  HandleFrame(aWindowId, /* aRender */ false);
}

void wr_notifier_external_event(mozilla::wr::WrWindowId aWindowId,
                                size_t aRawEvent) {
  mozilla::UniquePtr<mozilla::wr::RendererEvent> evt(
      reinterpret_cast<mozilla::wr::RendererEvent*>(aRawEvent));
  mozilla::wr::RenderThread::Get()->RunEvent(mozilla::wr::WindowId(aWindowId),
                                             std::move(evt));
}

void wr_schedule_render(mozilla::wr::WrWindowId aWindowId,
                        mozilla::wr::WrDocumentId aDocumentId) {
  RefPtr<mozilla::layers::CompositorBridgeParent> cbp = mozilla::layers::
      CompositorBridgeParent::GetCompositorBridgeParentFromWindowId(aWindowId);
  if (cbp) {
    cbp->ScheduleRenderOnCompositorThread(
        Some(wr::RenderRootFromId(aDocumentId)));
  }
}

static void NotifyDidSceneBuild(RefPtr<layers::CompositorBridgeParent> aBridge,
                                wr::DocumentId aRenderRootId,
                                RefPtr<wr::WebRenderPipelineInfo> aInfo) {
  aBridge->NotifyDidSceneBuild(wr::RenderRootFromId(aRenderRootId), aInfo);
}

void wr_finished_scene_build(mozilla::wr::WrWindowId aWindowId,
                             mozilla::wr::WrDocumentId aDocumentId,
                             mozilla::wr::WrPipelineInfo aInfo) {
  RefPtr<mozilla::layers::CompositorBridgeParent> cbp = mozilla::layers::
      CompositorBridgeParent::GetCompositorBridgeParentFromWindowId(aWindowId);
  RefPtr<wr::WebRenderPipelineInfo> info = new wr::WebRenderPipelineInfo(aInfo);
  if (cbp) {
    layers::CompositorThreadHolder::Loop()->PostTask(NewRunnableFunction(
        "NotifyDidSceneBuild", &NotifyDidSceneBuild, cbp, aDocumentId, info));
  }
}

}  // extern C