/*
  +----------------------------------------------------------------------+
  | Swoole                                                               |
  +----------------------------------------------------------------------+
  | This source file is subject to version 2.0 of the Apache license,    |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.apache.org/licenses/LICENSE-2.0.html                      |
  | If you did not receive a copy of the Apache2.0 license and are unable|
  | to obtain it through the world-wide-web, please send a note to       |
  | license@swoole.com so we can mail you a copy immediately.            |
  +----------------------------------------------------------------------+
  | Author: Tianfeng Han  <rango@swoole.com>                             |
  |         Twosee  <twose@qq.com>                                       |
  +----------------------------------------------------------------------+
*/

#pragma once

#include "swoole.h"

#ifdef SW_USE_THREAD_CONTEXT
#include <thread>
#include <mutex>
#elif !defined(SW_USE_ASM_CONTEXT)
#define USE_UCONTEXT 1
#ifndef _XOPEN_SOURCE
#define _XOPEN_SOURCE
#endif
#include <ucontext.h>
#else
#define USE_ASM_CONTEXT 1
#include "swoole_asm_context.h"
#endif

#if defined(HAVE_VALGRIND) && !defined(HAVE_KQUEUE)
#define USE_VALGRIND 1
#include <valgrind/valgrind.h>
#endif

#ifdef USE_UCONTEXT
typedef ucontext_t coroutine_context_t;
#elif defined(USE_ASM_CONTEXT)
typedef fcontext_t coroutine_context_t;
typedef transfer_t coroutine_transfer_t;
#endif

#if defined(USE_UCONTEXT) || defined(SW_USE_THREAD_CONTEXT)
typedef void * coroutine_transfer_t;
#endif

typedef std::function<void(void *)> CoroutineFunc;

namespace swoole {
namespace coroutine {

class Context {
  public:
    Context(size_t stack_size, CoroutineFunc fn, void *private_data);
    ~Context();
    bool swap_in();
    bool swap_out();
#if !defined(SW_USE_THREAD_CONTEXT) && defined(SW_CONTEXT_DETECT_STACK_USAGE)
    ssize_t get_stack_usage();
#endif
#ifndef SW_USE_THREAD_CONTEXT
    char *get_stack() const {
        return stack_;
    }

    size_t get_stack_size() const {
        return stack_size_;
    }
#endif
    bool is_end() const {
        return end_;
    }

  protected:
    CoroutineFunc fn_;
#ifdef SW_USE_THREAD_CONTEXT
    std::thread thread_;
    std::mutex lock_;
    std::mutex *swap_lock_;
#else
    coroutine_context_t ctx_;
    coroutine_context_t swap_ctx_;
    char *stack_;
    uint32_t stack_size_;
#endif
#ifdef USE_VALGRIND
    uint32_t valgrind_stack_id;
#endif
    void *private_data_;
    bool end_;

    static void context_func(coroutine_transfer_t arg);
};

}  // namespace coroutine
}  // namespace swoole
