/* -*- 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/. */

#ifndef GFX_LAYERS_ISURFACEDEALLOCATOR

#define GFX_LAYERS_ISURFACEDEALLOCATOR

#include <stddef.h>                     // for size_t

#include <stdint.h>                     // for uint32_t

#include "gfxTypes.h"

#include "mozilla/gfx/Point.h"          // for IntSize

#include "mozilla/ipc/SharedMemory.h"   // for SharedMemory, etc

#include "mozilla/RefPtr.h"

#include "nsIMemoryReporter.h"          // for nsIMemoryReporter

#include "mozilla/Atomics.h"            // for Atomic

#include "mozilla/layers/LayersMessages.h" // for ShmemSection

#include "LayersTypes.h"

namespace mozilla {

namespace ipc {

class Shmem;

class IShmemAllocator;

} // namespace ipc

namespace gfx {

class DataSourceSurface;

} // namespace gfx

namespace layers {

class CompositableForwarder;

class CompositorBridgeParentBase;

class TextureForwarder;

class ShmemAllocator;

class ShmemSectionAllocator;

class LegacySurfaceDescriptorAllocator;

class ClientIPCAllocator;

class HostIPCAllocator;

class LayersIPCChannel;

enum BufferCapabilities {

  DEFAULT_BUFFER_CAPS = 0,

  /**

   * The allocated buffer must be efficiently mappable as a DataSourceSurface.

   */

  MAP_AS_IMAGE_SURFACE = 1 << 0,

  /**

   * The allocated buffer will be used for GL rendering only

   */

  USING_GL_RENDERING_ONLY = 1 << 1

};

class SurfaceDescriptor;

mozilla::ipc::SharedMemory::SharedMemoryType OptimalShmemType();

/**

 * An interface used to create and destroy surfaces that are shared with the

 * Compositor process (using shmem, or other platform specific memory)

 *

 * Most of the methods here correspond to methods that are implemented by IPDL

 * actors without a common polymorphic interface.

 * These methods should be only called in the ipdl implementor's thread, unless

 * specified otherwise in the implementing class.

 */

class ISurfaceAllocator

{

public:

  MOZ_DECLARE_REFCOUNTED_TYPENAME(ISurfaceAllocator)

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ISurfaceAllocator)

  ISurfaceAllocator() {}

  // down-casting

  virtual ShmemAllocator* AsShmemAllocator() { return nullptr; }

  virtual ShmemSectionAllocator* AsShmemSectionAllocator() { return nullptr; }

  virtual CompositableForwarder* AsCompositableForwarder() { return nullptr; }

  virtual TextureForwarder* GetTextureForwarder() { return nullptr; }

  virtual ClientIPCAllocator* AsClientAllocator() { return nullptr; }

  virtual HostIPCAllocator* AsHostIPCAllocator() { return nullptr; }

  virtual LegacySurfaceDescriptorAllocator*

  AsLegacySurfaceDescriptorAllocator() { return nullptr; }

  virtual CompositorBridgeParentBase* AsCompositorBridgeParentBase() { return nullptr; }

  // ipc info

  virtual bool IPCOpen() const { return true; }

  virtual bool IsSameProcess() const = 0;

  virtual bool UsesImageBridge() const { return false; }

  virtual bool UsesWebRenderBridge() const { return false; }

protected:

  void Finalize() {}

  virtual ~ISurfaceAllocator() {}

};

/// Methods that are specific to the client/child side.

class ClientIPCAllocator : public ISurfaceAllocator

{

public:

  ClientIPCAllocator() {}

  virtual ClientIPCAllocator* AsClientAllocator() override { return this; }

  virtual base::ProcessId GetParentPid() const = 0;

  virtual MessageLoop * GetMessageLoop() const = 0;

  virtual void CancelWaitForRecycle(uint64_t aTextureId) = 0;

};

/// Methods that are specific to the host/parent side.

class HostIPCAllocator : public ISurfaceAllocator

{

public:

  HostIPCAllocator() {}

  virtual HostIPCAllocator* AsHostIPCAllocator() override { return this; }

  /**

   * Get child side's process Id.

   */

  virtual base::ProcessId GetChildProcessId() = 0;

  virtual void NotifyNotUsed(PTextureParent* aTexture, uint64_t aTransactionId) = 0;

  virtual void SendAsyncMessage(const InfallibleTArray<AsyncParentMessageData>& aMessage) = 0;

  virtual void SendPendingAsyncMessages();

  virtual void SetAboutToSendAsyncMessages()

  {

    mAboutToSendAsyncMessages = true;

  }

  bool IsAboutToSendAsyncMessages()

  {

    return mAboutToSendAsyncMessages;

  }

protected:

  std::vector<AsyncParentMessageData> mPendingAsyncMessage;

  bool mAboutToSendAsyncMessages = false;

};

/// An allocator can provide shared memory.

///

/// The allocated shmems can be deallocated on either process, as long as they

/// belong to the same channel.

class ShmemAllocator

{

public:

  virtual bool AllocShmem(size_t aSize,

                          mozilla::ipc::SharedMemory::SharedMemoryType aShmType,

                          mozilla::ipc::Shmem* aShmem) = 0;

  virtual bool AllocUnsafeShmem(size_t aSize,

                                mozilla::ipc::SharedMemory::SharedMemoryType aShmType,

                                mozilla::ipc::Shmem* aShmem) = 0;

  virtual void DeallocShmem(mozilla::ipc::Shmem& aShmem) = 0;

};

/// An allocator that can group allocations in bigger chunks of shared memory.

///

/// The allocated shmem sections can only be deallocated by the same allocator

/// instance (and only in the child process).

class ShmemSectionAllocator

{

public:

  virtual bool AllocShmemSection(uint32_t aSize, ShmemSection* aShmemSection) = 0;

  virtual void DeallocShmemSection(ShmemSection& aShmemSection) = 0;

  virtual void MemoryPressure() {}

};

/// Some old stuff that's still around and used for screenshots.

///

/// New code should not need this (see TextureClient).

class LegacySurfaceDescriptorAllocator

{

public:

  virtual bool AllocSurfaceDescriptor(const gfx::IntSize& aSize,

                                      gfxContentType aContent,

                                      SurfaceDescriptor* aBuffer) = 0;

  virtual bool AllocSurfaceDescriptorWithCaps(const gfx::IntSize& aSize,

                                              gfxContentType aContent,

                                              uint32_t aCaps,

                                              SurfaceDescriptor* aBuffer) = 0;

  virtual void DestroySurfaceDescriptor(SurfaceDescriptor* aSurface) = 0;

};

bool

IsSurfaceDescriptorValid(const SurfaceDescriptor& aSurface);

already_AddRefed<gfx::DrawTarget>

GetDrawTargetForDescriptor(const SurfaceDescriptor& aDescriptor, gfx::BackendType aBackend);

already_AddRefed<gfx::DataSourceSurface>

GetSurfaceForDescriptor(const SurfaceDescriptor& aDescriptor);

uint8_t*

GetAddressFromDescriptor(const SurfaceDescriptor& aDescriptor);

void

DestroySurfaceDescriptor(mozilla::ipc::IShmemAllocator* aAllocator, SurfaceDescriptor* aSurface);

class GfxMemoryImageReporter final : public nsIMemoryReporter

{

  ~GfxMemoryImageReporter() {}

public:

  NS_DECL_ISUPPORTS

  GfxMemoryImageReporter()

  {

#ifdef DEBUG

    // There must be only one instance of this class, due to |sAmount|

    // being static.

    static bool hasRun = false;

    MOZ_ASSERT(!hasRun);

    hasRun = true;

#endif

  }

  MOZ_DEFINE_MALLOC_SIZE_OF_ON_ALLOC(MallocSizeOfOnAlloc)

  MOZ_DEFINE_MALLOC_SIZE_OF_ON_FREE(MallocSizeOfOnFree)

  static void DidAlloc(void* aPointer)

  {

    sAmount += MallocSizeOfOnAlloc(aPointer);

  }

  static void WillFree(void* aPointer)

  {

    sAmount -= MallocSizeOfOnFree(aPointer);

  }

  NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,

                            nsISupports* aData, bool aAnonymize) override

  {

    MOZ_COLLECT_REPORT(

      "explicit/gfx/heap-textures", KIND_HEAP, UNITS_BYTES, sAmount,

      "Heap memory shared between threads by texture clients and hosts.");

    return NS_OK;

  }

private:

  // Typically we use |size_t| in memory reporters, but in the past this

  // variable has sometimes gone negative due to missing DidAlloc() calls.

  // Therefore, we use a signed type so that any such negative values show up

  // as negative in about:memory, rather than as enormous positive numbers.

  static mozilla::Atomic<ptrdiff_t> sAmount;

};

/// A simple shmem section allocator that can only allocate small

/// fixed size elements (only intended to be used to store tile

/// copy-on-write locks for now).

class FixedSizeSmallShmemSectionAllocator final : public ShmemSectionAllocator

{

public:

  enum AllocationStatus

  {

    STATUS_ALLOCATED,

    STATUS_FREED

  };

  struct ShmemSectionHeapHeader

  {

    Atomic<uint32_t> mTotalBlocks;

    Atomic<uint32_t> mAllocatedBlocks;

  };

  struct ShmemSectionHeapAllocation

  {

    Atomic<uint32_t> mStatus;

    uint32_t mSize;

  };

  explicit FixedSizeSmallShmemSectionAllocator(LayersIPCChannel* aShmProvider);

  ~FixedSizeSmallShmemSectionAllocator();

  virtual bool AllocShmemSection(uint32_t aSize, ShmemSection* aShmemSection) override;

  virtual void DeallocShmemSection(ShmemSection& aShmemSection) override;

  virtual void MemoryPressure() override { ShrinkShmemSectionHeap(); }

  // can be called on the compositor process.

  static void FreeShmemSection(ShmemSection& aShmemSection);

  void ShrinkShmemSectionHeap();

  bool IPCOpen() const;

protected:

  std::vector<mozilla::ipc::Shmem> mUsedShmems;

  LayersIPCChannel* mShmProvider;

};

} // namespace layers

} // namespace mozilla

#endif