/*

 * Copyright 2017 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#ifndef SkExecutor_DEFINED

#define SkExecutor_DEFINED

#include <functional>

#include <memory>

#include "include/core/SkTypes.h"

class SK_API SkExecutor {

public:

    virtual ~SkExecutor();

    // Create a thread pool SkExecutor with a fixed thread count, by default the number of cores.

    static std::unique_ptr<SkExecutor> MakeFIFOThreadPool(int threads = 0,

                                                          bool allowBorrowing = true);

    static std::unique_ptr<SkExecutor> MakeLIFOThreadPool(int threads = 0,

                                                          bool allowBorrowing = true);

    // There is always a default SkExecutor available by calling SkExecutor::GetDefault().

    static SkExecutor& GetDefault();

    static void SetDefault(SkExecutor*);  // Does not take ownership.  Not thread safe.

    // Add work to execute.

    virtual void add(std::function<void(void)>) = 0;

    // If it makes sense for this executor, use this thread to execute work for a little while.

    virtual void borrow() {}

protected:

    SkExecutor() = default;

    SkExecutor(const SkExecutor&) = delete;

    SkExecutor& operator=(const SkExecutor&) = delete;

};

#endif//SkExecutor_DEFINED