/* -*- 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 "ImageBridgeParent.h"
#include <stdint.h>                     // for uint64_t, uint32_t
#include "CompositableHost.h"           // for CompositableParent, Create
#include "base/message_loop.h"          // for MessageLoop
#include "base/process.h"               // for ProcessId
#include "base/task.h"                  // for CancelableTask, DeleteTask, etc
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/gfx/Point.h"                   // for IntSize
#include "mozilla/Hal.h"                // for hal::SetCurrentThreadPriority()
#include "mozilla/HalTypes.h"           // for hal::THREAD_PRIORITY_COMPOSITOR
#include "mozilla/ipc/MessageChannel.h" // for MessageChannel, etc
#include "mozilla/ipc/ProtocolUtils.h"
#include "mozilla/ipc/Transport.h"      // for Transport
#include "mozilla/media/MediaSystemResourceManagerParent.h" // for MediaSystemResourceManagerParent
#include "mozilla/layers/CompositableTransactionParent.h"
#include "mozilla/layers/LayerManagerComposite.h"
#include "mozilla/layers/LayersMessages.h"  // for EditReply
#include "mozilla/layers/PImageBridgeParent.h"
#include "mozilla/layers/TextureHostOGL.h"  // for TextureHostOGL
#include "mozilla/layers/Compositor.h"
#include "mozilla/Monitor.h"
#include "mozilla/mozalloc.h"           // for operator new, etc
#include "mozilla/Unused.h"
#include "nsDebug.h"                    // for NS_ASSERTION, etc
#include "nsISupportsImpl.h"            // for ImageBridgeParent::Release, etc
#include "nsTArray.h"                   // for nsTArray, nsTArray_Impl
#include "nsTArrayForwardDeclare.h"     // for InfallibleTArray
#include "nsXULAppAPI.h"                // for XRE_GetIOMessageLoop
#include "mozilla/layers/TextureHost.h"
#include "nsThreadUtils.h"

namespace mozilla {
namespace layers {

using namespace mozilla::ipc;
using namespace mozilla::gfx;
using namespace mozilla::media;

ImageBridgeParent::ImageBridgeMap ImageBridgeParent::sImageBridges;

StaticAutoPtr<mozilla::Monitor> sImageBridgesLock;

static StaticRefPtr<ImageBridgeParent> sImageBridgeParentSingleton;

// defined in CompositorBridgeParent.cpp
CompositorThreadHolder* GetCompositorThreadHolder();

/* static */ void
ImageBridgeParent::Setup()
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!sImageBridgesLock) {
    sImageBridgesLock = new Monitor("ImageBridges");
    mozilla::ClearOnShutdown(&sImageBridgesLock);
  }
}

ImageBridgeParent::ImageBridgeParent(MessageLoop* aLoop,
                                     ProcessId aChildProcessId)
  : mMessageLoop(aLoop)
  , mSetChildThreadPriority(false)
  , mClosed(false)
  , mCompositorThreadHolder(CompositorThreadHolder::GetSingleton())
{
  MOZ_ASSERT(NS_IsMainThread());
  SetOtherProcessId(aChildProcessId);
}

ImageBridgeParent::~ImageBridgeParent()
{
}

/* static */ ImageBridgeParent*
ImageBridgeParent::CreateSameProcess()
{
  base::ProcessId pid = base::GetCurrentProcId();
  RefPtr<ImageBridgeParent> parent =
    new ImageBridgeParent(CompositorThreadHolder::Loop(), pid);
  parent->mSelfRef = parent;

  {
    MonitorAutoLock lock(*sImageBridgesLock);
    MOZ_RELEASE_ASSERT(sImageBridges.count(pid) == 0);
    sImageBridges[pid] = parent;
  }

  sImageBridgeParentSingleton = parent;
  return parent;
}

/* static */ bool
ImageBridgeParent::CreateForGPUProcess(Endpoint<PImageBridgeParent>&& aEndpoint)
{
  MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_GPU);

  MessageLoop* loop = CompositorThreadHolder::Loop();
  RefPtr<ImageBridgeParent> parent = new ImageBridgeParent(loop, aEndpoint.OtherPid());

  loop->PostTask(NewRunnableMethod<Endpoint<PImageBridgeParent>&&>(
    "layers::ImageBridgeParent::Bind",
    parent,
    &ImageBridgeParent::Bind,
    Move(aEndpoint)));

  sImageBridgeParentSingleton = parent;
  return true;
}

/* static */ void
ImageBridgeParent::ShutdownInternal()
{
  // We make a copy because we don't want to hold the lock while closing and we
  // don't want the object to get freed underneath us.
  nsTArray<RefPtr<ImageBridgeParent>> actors;
  {
    MonitorAutoLock lock(*sImageBridgesLock);
    for (const auto& iter : sImageBridges) {
      actors.AppendElement(iter.second);
    }
  }

  for (auto const& actor : actors) {
    MOZ_RELEASE_ASSERT(!actor->mClosed);
    actor->Close();
  }

  sImageBridgeParentSingleton = nullptr;
}

/* static */ void
ImageBridgeParent::Shutdown()
{
  CompositorThreadHolder::Loop()->PostTask(
    NS_NewRunnableFunction("ImageBridgeParent::Shutdown", []() -> void {
      ImageBridgeParent::ShutdownInternal();
  }));
}

void
ImageBridgeParent::ActorDestroy(ActorDestroyReason aWhy)
{
  // Can't alloc/dealloc shmems from now on.
  mClosed = true;
  mCompositables.clear();
  {
    MonitorAutoLock lock(*sImageBridgesLock);
    sImageBridges.erase(OtherPid());
  }
  MessageLoop::current()->PostTask(
    NewRunnableMethod("layers::ImageBridgeParent::DeferredDestroy",
                      this,
                      &ImageBridgeParent::DeferredDestroy));

  // It is very important that this method gets called at shutdown (be it a clean
  // or an abnormal shutdown), because DeferredDestroy is what clears mSelfRef.
  // If mSelfRef is not null and ActorDestroy is not called, the ImageBridgeParent
  // is leaked which causes the CompositorThreadHolder to be leaked and
  // CompsoitorParent's shutdown ends up spinning the event loop forever, waiting
  // for the compositor thread to terminate.
}

mozilla::ipc::IPCResult
ImageBridgeParent::RecvImageBridgeThreadId(const PlatformThreadId& aThreadId)
{
  MOZ_ASSERT(!mSetChildThreadPriority);
  if (mSetChildThreadPriority) {
    return IPC_FAIL_NO_REASON(this);
  }
  mSetChildThreadPriority = true;
  return IPC_OK();
}

class MOZ_STACK_CLASS AutoImageBridgeParentAsyncMessageSender
{
public:
  explicit AutoImageBridgeParentAsyncMessageSender(ImageBridgeParent* aImageBridge,
                                                   InfallibleTArray<OpDestroy>* aToDestroy = nullptr)
    : mImageBridge(aImageBridge)
    , mToDestroy(aToDestroy)
  {
    mImageBridge->SetAboutToSendAsyncMessages();
  }

  ~AutoImageBridgeParentAsyncMessageSender()
  {
    mImageBridge->SendPendingAsyncMessages();
    if (mToDestroy) {
      for (const auto& op : *mToDestroy) {
        mImageBridge->DestroyActor(op);
      }
    }
  }
private:
  ImageBridgeParent* mImageBridge;
  InfallibleTArray<OpDestroy>* mToDestroy;
};

mozilla::ipc::IPCResult
ImageBridgeParent::RecvInitReadLocks(ReadLockArray&& aReadLocks)
{
  if (!AddReadLocks(Move(aReadLocks))) {
    return IPC_FAIL_NO_REASON(this);
  }
  return IPC_OK();
}

mozilla::ipc::IPCResult
ImageBridgeParent::RecvUpdate(EditArray&& aEdits, OpDestroyArray&& aToDestroy,
                              const uint64_t& aFwdTransactionId)
{
  // This ensures that destroy operations are always processed. It is not safe
  // to early-return from RecvUpdate without doing so.
  AutoImageBridgeParentAsyncMessageSender autoAsyncMessageSender(this, &aToDestroy);
  UpdateFwdTransactionId(aFwdTransactionId);
  AutoClearReadLocks clearLocks(mReadLocks);

  for (EditArray::index_type i = 0; i < aEdits.Length(); ++i) {
    if (!ReceiveCompositableUpdate(aEdits[i])) {
      return IPC_FAIL_NO_REASON(this);
    }
  }

  if (!IsSameProcess()) {
    // Ensure that any pending operations involving back and front
    // buffers have completed, so that neither process stomps on the
    // other's buffer contents.
    LayerManagerComposite::PlatformSyncBeforeReplyUpdate();
  }

  return IPC_OK();
}

/* static */ bool
ImageBridgeParent::CreateForContent(Endpoint<PImageBridgeParent>&& aEndpoint)
{
  MessageLoop* loop = CompositorThreadHolder::Loop();

  RefPtr<ImageBridgeParent> bridge = new ImageBridgeParent(loop, aEndpoint.OtherPid());
  loop->PostTask(NewRunnableMethod<Endpoint<PImageBridgeParent>&&>(
    "layers::ImageBridgeParent::Bind",
    bridge,
    &ImageBridgeParent::Bind,
    Move(aEndpoint)));

  return true;
}

void
ImageBridgeParent::Bind(Endpoint<PImageBridgeParent>&& aEndpoint)
{
  if (!aEndpoint.Bind(this))
    return;
  mSelfRef = this;

  // If the child process ID was reused by the OS before the ImageBridgeParent
  // object was destroyed, we need to clean it up first.
  RefPtr<ImageBridgeParent> oldActor;
  {
    MonitorAutoLock lock(*sImageBridgesLock);
    ImageBridgeMap::const_iterator i = sImageBridges.find(OtherPid());
    if (i != sImageBridges.end()) {
      oldActor = i->second;
    }
  }

  // We can't hold the lock during Close because it erases itself from the map.
  if (oldActor) {
    MOZ_RELEASE_ASSERT(!oldActor->mClosed);
    oldActor->Close();
  }

  {
    MonitorAutoLock lock(*sImageBridgesLock);
    sImageBridges[OtherPid()] = this;
  }
}

mozilla::ipc::IPCResult ImageBridgeParent::RecvWillClose()
{
  // If there is any texture still alive we have to force it to deallocate the
  // device data (GL textures, etc.) now because shortly after SenStop() returns
  // on the child side the widget will be destroyed along with it's associated
  // GL context.
  InfallibleTArray<PTextureParent*> textures;
  ManagedPTextureParent(textures);
  for (unsigned int i = 0; i < textures.Length(); ++i) {
    RefPtr<TextureHost> tex = TextureHost::AsTextureHost(textures[i]);
    tex->DeallocateDeviceData();
  }
  return IPC_OK();
}

mozilla::ipc::IPCResult
ImageBridgeParent::RecvNewCompositable(const CompositableHandle& aHandle,
                                       const TextureInfo& aInfo,
                                       const LayersBackend& aLayersBackend)
{
  bool useWebRender = aLayersBackend == LayersBackend::LAYERS_WR;
  RefPtr<CompositableHost> host = AddCompositable(aHandle, aInfo, useWebRender);
  if (!host) {
    return IPC_FAIL_NO_REASON(this);
  }

  host->SetAsyncRef(AsyncCompositableRef(OtherPid(), aHandle));
  return IPC_OK();
}

mozilla::ipc::IPCResult
ImageBridgeParent::RecvReleaseCompositable(const CompositableHandle& aHandle)
{
  ReleaseCompositable(aHandle);
  return IPC_OK();
}

PTextureParent*
ImageBridgeParent::AllocPTextureParent(const SurfaceDescriptor& aSharedData,
                                       const LayersBackend& aLayersBackend,
                                       const TextureFlags& aFlags,
                                       const uint64_t& aSerial,
                                       const wr::MaybeExternalImageId& aExternalImageId)
{
  return TextureHost::CreateIPDLActor(this, aSharedData, aLayersBackend, aFlags, aSerial, aExternalImageId);
}

bool
ImageBridgeParent::DeallocPTextureParent(PTextureParent* actor)
{
  return TextureHost::DestroyIPDLActor(actor);
}

PMediaSystemResourceManagerParent*
ImageBridgeParent::AllocPMediaSystemResourceManagerParent()
{
  return new mozilla::media::MediaSystemResourceManagerParent();
}

bool
ImageBridgeParent::DeallocPMediaSystemResourceManagerParent(PMediaSystemResourceManagerParent* aActor)
{
  MOZ_ASSERT(aActor);
  delete static_cast<mozilla::media::MediaSystemResourceManagerParent*>(aActor);
  return true;
}

void
ImageBridgeParent::SendAsyncMessage(const InfallibleTArray<AsyncParentMessageData>& aMessage)
{
  mozilla::Unused << SendParentAsyncMessages(aMessage);
}

class ProcessIdComparator
{
public:
  bool Equals(const ImageCompositeNotificationInfo& aA,
              const ImageCompositeNotificationInfo& aB) const
  {
    return aA.mImageBridgeProcessId == aB.mImageBridgeProcessId;
  }
  bool LessThan(const ImageCompositeNotificationInfo& aA,
                const ImageCompositeNotificationInfo& aB) const
  {
    return aA.mImageBridgeProcessId < aB.mImageBridgeProcessId;
  }
};

/* static */ bool
ImageBridgeParent::NotifyImageComposites(nsTArray<ImageCompositeNotificationInfo>& aNotifications)
{
  // Group the notifications by destination process ID and then send the
  // notifications in one message per group.
  aNotifications.Sort(ProcessIdComparator());
  uint32_t i = 0;
  bool ok = true;
  while (i < aNotifications.Length()) {
    AutoTArray<ImageCompositeNotification,1> notifications;
    notifications.AppendElement(aNotifications[i].mNotification);
    uint32_t end = i + 1;
    MOZ_ASSERT(aNotifications[i].mNotification.compositable());
    ProcessId pid = aNotifications[i].mImageBridgeProcessId;
    while (end < aNotifications.Length() &&
           aNotifications[end].mImageBridgeProcessId == pid) {
      notifications.AppendElement(aNotifications[end].mNotification);
      ++end;
    }
    RefPtr<ImageBridgeParent> bridge = GetInstance(pid);
    if (!bridge || bridge->mClosed) {
      continue;
    }
    bridge->SendPendingAsyncMessages();
    if (!bridge->SendDidComposite(notifications)) {
      ok = false;
    }
    i = end;
  }
  return ok;
}

void
ImageBridgeParent::DeferredDestroy()
{
  mCompositorThreadHolder = nullptr;
  mSelfRef = nullptr; // "this" ImageBridge may get deleted here.
}

already_AddRefed<ImageBridgeParent>
ImageBridgeParent::GetInstance(ProcessId aId)
{
  MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread());
  MonitorAutoLock lock(*sImageBridgesLock);
  ImageBridgeMap::const_iterator i = sImageBridges.find(aId);
  if (i == sImageBridges.end()) {
    NS_ASSERTION(false, "Cannot find image bridge for process!");
    return nullptr;
  }
  RefPtr<ImageBridgeParent> bridge = i->second;
  return bridge.forget();
}

bool
ImageBridgeParent::AllocShmem(size_t aSize,
                      ipc::SharedMemory::SharedMemoryType aType,
                      ipc::Shmem* aShmem)
{
  if (mClosed) {
    return false;
  }
  return PImageBridgeParent::AllocShmem(aSize, aType, aShmem);
}

bool
ImageBridgeParent::AllocUnsafeShmem(size_t aSize,
                      ipc::SharedMemory::SharedMemoryType aType,
                      ipc::Shmem* aShmem)
{
  if (mClosed) {
    return false;
  }
  return PImageBridgeParent::AllocUnsafeShmem(aSize, aType, aShmem);
}

void
ImageBridgeParent::DeallocShmem(ipc::Shmem& aShmem)
{
  if (mClosed) {
    return;
  }
  PImageBridgeParent::DeallocShmem(aShmem);
}

bool ImageBridgeParent::IsSameProcess() const
{
  return OtherPid() == base::GetCurrentProcId();
}

void
ImageBridgeParent::NotifyNotUsed(PTextureParent* aTexture, uint64_t aTransactionId)
{
  RefPtr<TextureHost> texture = TextureHost::AsTextureHost(aTexture);
  if (!texture) {
    return;
  }

  if (!(texture->GetFlags() & TextureFlags::RECYCLE)) {
    return;
  }

  uint64_t textureId = TextureHost::GetTextureSerial(aTexture);
  mPendingAsyncMessage.push_back(
    OpNotifyNotUsed(textureId, aTransactionId));

  if (!IsAboutToSendAsyncMessages()) {
    SendPendingAsyncMessages();
  }
}

} // namespace layers
} // namespace mozilla