/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

// TODO: switch to <mutex> and std::mutex when this code no longer needs
// to compile for pre-C++11...

#include  <sys/types.h>

#if !defined(_WIN32)
#include <pthread.h>
#else
#include <windows.h>
#endif

#ifdef __cplusplus
extern "C" {
#endif

#if !defined(_WIN32)

typedef pthread_mutex_t mutex_t;

static __inline__ void mutex_lock(mutex_t* lock) {
  pthread_mutex_lock(lock);
}

static __inline__ void mutex_unlock(mutex_t* lock) {
  pthread_mutex_unlock(lock);
}

static __inline__ int mutex_init(mutex_t* lock) {
  return pthread_mutex_init(lock, NULL);
}

static __inline__ void mutex_destroy(mutex_t* lock) {
  pthread_mutex_destroy(lock);
}

#else // !defined(_WIN32)

typedef struct {
  int init;
  CRITICAL_SECTION lock[1];
} mutex_t;

#define MUTEX_INITIALIZER  { 0, {{ NULL, 0, 0, NULL, NULL, 0 }} }

static __inline__ void mutex_lock(mutex_t* lock) {
  if (!lock->init) {
    lock->init = 1;
    InitializeCriticalSection( lock->lock );
    lock->init = 2;
  } else while (lock->init != 2) {
    Sleep(10);
  }
  EnterCriticalSection(lock->lock);
}

static __inline__ void mutex_unlock(mutex_t* lock) {
  LeaveCriticalSection(lock->lock);
}

static __inline__ int mutex_init(mutex_t* lock) {
  InitializeCriticalSection(lock->lock);
  lock->init = 2;
  return 0;
}

static __inline__ void mutex_destroy(mutex_t* lock) {
  if (lock->init) {
    lock->init = 0;
    DeleteCriticalSection(lock->lock);
  }
}

#endif // !defined(_WIN32)

#ifdef __cplusplus
}
#endif