// Licensed to the .NET Foundation under one or more agreements.

// The .NET Foundation licenses this file to you under the MIT license.

// See the LICENSE file in the project root for more information.

#ifndef _SIMPLE_BARRIER_H_

#define _SIMPLE_BARRIER_H_

#include <atomic>

#include <condition_variable>

#include <thread>

namespace lda

{

class SimpleBarrier

{

public:

SimpleBarrier(unsigned int n) :barrier_size_(n), num_of_waiting_(0), rounds_(0)

{};

void reset()

{

throw "not implemented yet.";

}

bool wait()

{

std::unique_lock<std::mutex> lock(mutex_);

if (num_of_waiting_.fetch_add(1) >= barrier_size_ - 1)

{

cond_.notify_all();

num_of_waiting_.store(0);

rounds_.fetch_add(1);

return true;

}

else

{

unsigned int i = rounds_.load();

cond_.wait(lock, [&]{return i != rounds_.load(); });

return false;

}

}

~SimpleBarrier()

{

num_of_waiting_ = 0;

rounds_ = 0;

}

protected:

const unsigned int barrier_size_;

std::atomic<unsigned int> num_of_waiting_;

std::atomic<unsigned int> rounds_;

std::condition_variable cond_;

std::mutex mutex_;

};

}

#endif // _SIMPLE_BARRIER_H_