// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef GPU_IPC_SERVICE_COMMAND_BUFFER_STUB_H_
#define GPU_IPC_SERVICE_COMMAND_BUFFER_STUB_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <string>
#include <vector>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/time/time.h"
#include "build/build_config.h"
#include "gpu/command_buffer/common/command_buffer_id.h"
#include "gpu/command_buffer/common/constants.h"
#include "gpu/command_buffer/common/gpu_memory_allocation.h"
#include "gpu/command_buffer/service/command_buffer_service.h"
#include "gpu/command_buffer/service/context_group.h"
#include "gpu/command_buffer/service/decoder_client.h"
#include "gpu/command_buffer/service/sequence_id.h"
#include "gpu/ipc/common/surface_handle.h"
#include "gpu/ipc/service/gpu_ipc_service_export.h"
#include "ipc/ipc_listener.h"
#include "ipc/ipc_sender.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/gpu_fence_handle.h"
#include "ui/gfx/gpu_memory_buffer.h"
#include "ui/gfx/swap_result.h"
#include "ui/gl/gl_share_group.h"
#include "ui/gl/gl_surface.h"
#include "ui/gl/gpu_preference.h"
#include "url/gurl.h"

struct GPUCreateCommandBufferConfig;
struct GpuCommandBufferMsg_CreateImage_Params;

namespace gpu {
class DecoderContext;
struct Mailbox;
struct SyncToken;
struct WaitForCommandState;
class GpuChannel;
class SyncPointClientState;

class GPU_IPC_SERVICE_EXPORT CommandBufferStub
    : public IPC::Listener,
      public IPC::Sender,
      public CommandBufferServiceClient,
      public DecoderClient,
      public base::SupportsWeakPtr<CommandBufferStub> {
 public:
  class DestructionObserver {
   public:
    // Called in Destroy(), before the context/surface are released.
    // If |have_context| is false, then the context cannot be made current, else
    // it already is.
    virtual void OnWillDestroyStub(bool have_context) = 0;

   protected:
    virtual ~DestructionObserver() = default;
  };

  CommandBufferStub(GpuChannel* channel,
                    const GPUCreateCommandBufferConfig& init_params,
                    CommandBufferId command_buffer_id,
                    SequenceId sequence_id,
                    int32_t stream_id,
                    int32_t route_id);

  ~CommandBufferStub() override;

  // This must leave the GL context associated with the newly-created
  // CommandBufferStub current, so the GpuChannel can initialize
  // the gpu::Capabilities.
  virtual gpu::ContextResult Initialize(
      CommandBufferStub* share_group,
      const GPUCreateCommandBufferConfig& init_params,
      base::UnsafeSharedMemoryRegion shared_state_shm) = 0;

  // IPC::Listener implementation:
  bool OnMessageReceived(const IPC::Message& message) override;

  // IPC::Sender implementation:
  bool Send(IPC::Message* msg) override;

  // CommandBufferServiceClient implementation:
  CommandBatchProcessedResult OnCommandBatchProcessed() override;
  void OnParseError() override;

  // DecoderClient implementation:
  void OnConsoleMessage(int32_t id, const std::string& message) override;
  void CacheShader(const std::string& key, const std::string& shader) override;
  void OnFenceSyncRelease(uint64_t release) override;
  bool OnWaitSyncToken(const SyncToken& sync_token) override;
  void OnDescheduleUntilFinished() override;
  void OnRescheduleAfterFinished() override;
  void ScheduleGrContextCleanup() override;

  gles2::MemoryTracker* GetMemoryTracker() const;

  // Whether this command buffer can currently handle IPC messages.
  bool IsScheduled();

  // Whether there are commands in the buffer that haven't been processed.
  bool HasUnprocessedCommands();

  DecoderContext* decoder_context() const { return decoder_context_.get(); }
  GpuChannel* channel() const { return channel_; }

  // Unique command buffer ID for this command buffer stub.
  CommandBufferId command_buffer_id() const { return command_buffer_id_; }

  SequenceId sequence_id() const { return sequence_id_; }

  int32_t stream_id() const { return stream_id_; }

  gl::GLSurface* surface() const { return surface_.get(); }

  void AddDestructionObserver(DestructionObserver* observer);
  void RemoveDestructionObserver(DestructionObserver* observer);

  void MarkContextLost();

  scoped_refptr<gles2::ContextGroup> context_group() { return context_group_; }
  scoped_refptr<gl::GLShareGroup> share_group() { return share_group_; }

 protected:
  // FastSetActiveURL will shortcut the expensive call to SetActiveURL when the
  // url_hash matches.
  static void FastSetActiveURL(const GURL& url,
                               size_t url_hash,
                               GpuChannel* channel);

  std::unique_ptr<gles2::MemoryTracker> CreateMemoryTracker(
      const GPUCreateCommandBufferConfig init_params) const;

  // Must be called during Initialize(). Takes ownership to co-ordinate
  // teardown in Destroy().
  void set_decoder_context(std::unique_ptr<DecoderContext> decoder_context) {
    decoder_context_ = std::move(decoder_context);
  }

  // The lifetime of objects of this class is managed by a GpuChannel. The
  // GpuChannels destroy all the CommandBufferStubs that they own when
  // they are destroyed. So a raw pointer is safe.
  GpuChannel* const channel_;

  GURL active_url_;
  size_t active_url_hash_;

  // The group of contexts that share namespaces with this context.
  scoped_refptr<gles2::ContextGroup> context_group_;

  bool initialized_;
  const SurfaceHandle surface_handle_;
  bool use_virtualized_gl_context_;

  std::unique_ptr<CommandBufferService> command_buffer_;

  scoped_refptr<gl::GLSurface> surface_;
  scoped_refptr<SyncPointClientState> sync_point_client_state_;
  scoped_refptr<gl::GLShareGroup> share_group_;

  const CommandBufferId command_buffer_id_;
  const SequenceId sequence_id_;
  const int32_t stream_id_;
  const int32_t route_id_;

 private:
  void Destroy();

  bool MakeCurrent();

  // Message handlers:
  void OnSetGetBuffer(int32_t shm_id);
  virtual void OnTakeFrontBuffer(const Mailbox& mailbox) = 0;
  virtual void OnReturnFrontBuffer(const Mailbox& mailbox, bool is_lost) = 0;
  void OnGetState(IPC::Message* reply_message);
  void OnWaitForTokenInRange(int32_t start,
                             int32_t end,
                             IPC::Message* reply_message);
  void OnWaitForGetOffsetInRange(uint32_t set_get_buffer_count,
                                 int32_t start,
                                 int32_t end,
                                 IPC::Message* reply_message);
  void OnAsyncFlush(int32_t put_offset, uint32_t flush_id);
  void OnRegisterTransferBuffer(int32_t id,
                                base::UnsafeSharedMemoryRegion transfer_buffer);
  void OnDestroyTransferBuffer(int32_t id);
  void OnGetTransferBuffer(int32_t id, IPC::Message* reply_message);

  void OnEnsureBackbuffer();

  void OnSignalSyncToken(const SyncToken& sync_token, uint32_t id);
  void OnSignalAck(uint32_t id);
  void OnSignalQuery(uint32_t query, uint32_t id);
  void OnCreateGpuFenceFromHandle(uint32_t gpu_fence_id,
                                  const gfx::GpuFenceHandle& handle);
  void OnGetGpuFenceHandle(uint32_t gpu_fence_id);

  void OnWaitSyncTokenCompleted(const SyncToken& sync_token);

  void OnCreateImage(const GpuCommandBufferMsg_CreateImage_Params& params);
  void OnDestroyImage(int32_t id);
  void OnCreateStreamTexture(uint32_t texture_id,
                             int32_t stream_id,
                             bool* succeeded);

  void ReportState();

  // Poll the command buffer to execute work.
  void PollWork();
  void PerformWork();

  // Schedule processing of delayed work. This updates the time at which
  // delayed work should be processed. |process_delayed_work_time_| is
  // updated to current time + delay. Call this after processing some amount
  // of delayed work.
  void ScheduleDelayedWork(base::TimeDelta delay);

  bool CheckContextLost();
  void CheckCompleteWaits();

  // Set driver bug workarounds and disabled GL extensions to the context.
  static void SetContextGpuFeatureInfo(gl::GLContext* context,
                                       const GpuFeatureInfo& gpu_feature_info);

  std::unique_ptr<DecoderContext> decoder_context_;

  uint32_t last_flush_id_;

  base::ObserverList<DestructionObserver> destruction_observers_;

  bool waiting_for_sync_point_;

  base::TimeTicks process_delayed_work_time_;
  uint32_t previous_processed_num_;
  base::TimeTicks last_idle_time_;

  std::unique_ptr<WaitForCommandState> wait_for_token_;
  std::unique_ptr<WaitForCommandState> wait_for_get_offset_;
  uint32_t wait_set_get_buffer_count_;

  DISALLOW_COPY_AND_ASSIGN(CommandBufferStub);
};

}  // namespace gpu

#endif  // GPU_IPC_SERVICE_COMMAND_BUFFER_STUB_H_