engine/src/flutter/impeller/renderer/command_queue.h

// Copyright 2013 The Flutter 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 FLUTTER_IMPELLER_RENDERER_COMMAND_QUEUE_H_
#define FLUTTER_IMPELLER_RENDERER_COMMAND_QUEUE_H_

#include <functional>

#include "fml/status.h"
#include "impeller/renderer/command_buffer.h"

namespace impeller {

/// @brief An interface for submitting command buffers to the GPU for
///        encoding and execution.
class CommandQueue {
 public:
  using CompletionCallback = std::function<void(CommandBuffer::Status)>;

  CommandQueue();

  virtual ~CommandQueue();

  /// @brief Submit one or more command buffer objects to be encoded and
  ///        executed on the GPU.
  ///
  ///        The order of the provided buffers determines the ordering in which
  ///        they are submitted.
  ///
  ///        The returned status only indicates if the command buffer was
  ///        successfully submitted. Successful completion of the command buffer
  ///        can only be checked in the optional completion callback.
  ///
  ///        Only the Metal and Vulkan backends can give a status beyond
  ///        successful encoding. This callback may be called more than once and
  ///        potentially on a different thread.
  ///
  ///        If [block_on_schedule] is true, this function will not return until
  ///        the command buffer has been scheduled. This only impacts the Metal
  ///        backend.
  virtual fml::Status Submit(
      const std::vector<std::shared_ptr<CommandBuffer>>& buffers,
      const CompletionCallback& completion_callback = {},
      bool block_on_schedule = false);

 private:
  CommandQueue(const CommandQueue&) = delete;

  CommandQueue& operator=(const CommandQueue&) = delete;
};

}  // namespace impeller

#endif  // FLUTTER_IMPELLER_RENDERER_COMMAND_QUEUE_H_