/*
 * Copyright 2011-2013 Blender Foundation
 *
 * 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.
 */

#ifndef __UTIL_THREAD_H__
#define __UTIL_THREAD_H__

#include <thread>
#include <mutex>
#include <condition_variable>
#include <functional>
#include <queue>

#ifdef _WIN32
#  include "util_windows.h"
#else
#  include <pthread.h>
#endif

#ifdef __APPLE__
#  include <libkern/OSAtomic.h>
#endif

#include "util/util_function.h"

CCL_NAMESPACE_BEGIN

typedef std::mutex thread_mutex;
typedef std::unique_lock<std::mutex> thread_scoped_lock;
typedef std::condition_variable thread_condition_variable;

/* own pthread based implementation, to avoid boost version conflicts with
 * dynamically loaded blender plugins */

class thread {
public:
	/* NOTE: Node index of -1 means that affinity will be inherited from the
	 * parent thread and no override on top of that will happen. */
	thread(function<void()> run_cb, int node = -1);
	~thread();

	static void *run(void *arg);
	bool join();

protected:
	function<void()> run_cb_;
	std::thread thread_;
	bool joined_;
	int node_;
};

/* Own wrapper around pthread's spin lock to make it's use easier. */

class thread_spin_lock {
public:
#ifdef __APPLE__
	inline thread_spin_lock() {
		spin_ = OS_SPINLOCK_INIT;
	}

	inline void lock() {
		OSSpinLockLock(&spin_);
	}

	inline void unlock() {
		OSSpinLockUnlock(&spin_);
	}
#elif defined(_WIN32)
	inline thread_spin_lock() {
		const DWORD SPIN_COUNT = 50000;
		InitializeCriticalSectionAndSpinCount(&cs_, SPIN_COUNT);
	}

	inline ~thread_spin_lock() {
		DeleteCriticalSection(&cs_);
	}

	inline void lock() {
		EnterCriticalSection(&cs_);
	}

	inline void unlock() {
		LeaveCriticalSection(&cs_);
	}
#else
	inline thread_spin_lock() {
		pthread_spin_init(&spin_, 0);
	}

	inline ~thread_spin_lock() {
		pthread_spin_destroy(&spin_);
	}

	inline void lock() {
		pthread_spin_lock(&spin_);
	}

	inline void unlock() {
		pthread_spin_unlock(&spin_);
	}
#endif
protected:
#ifdef __APPLE__
	OSSpinLock spin_;
#elif defined(_WIN32)
	CRITICAL_SECTION cs_;
#else
	pthread_spinlock_t spin_;
#endif
};

class thread_scoped_spin_lock {
public:
	explicit thread_scoped_spin_lock(thread_spin_lock& lock)
	        : lock_(lock) {
		lock_.lock();
	}

	~thread_scoped_spin_lock() {
		lock_.unlock();
	}

	/* TODO(sergey): Implement manual control over lock/unlock. */

protected:
	thread_spin_lock& lock_;
};

CCL_NAMESPACE_END

#endif  /* __UTIL_THREAD_H__ */