boost/asio/detail/std_event.hpp
//
// detail/std_event.hpp
// ~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2013 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_ASIO_DETAIL_STD_EVENT_HPP
#define BOOST_ASIO_DETAIL_STD_EVENT_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include <boost/asio/detail/config.hpp>
#if defined(BOOST_ASIO_HAS_STD_MUTEX_AND_CONDVAR)
#include <chrono>
#include <condition_variable>
#include <boost/asio/detail/assert.hpp>
#include <boost/asio/detail/noncopyable.hpp>
#include <boost/asio/detail/push_options.hpp>
namespace boost {
namespace asio {
namespace detail {
class std_event
: private noncopyable
{
public:
// Constructor.
std_event()
: signalled_(false)
{
}
// Destructor.
~std_event()
{
}
// Signal the event.
template <typename Lock>
void signal(Lock& lock)
{
BOOST_ASIO_ASSERT(lock.locked());
(void)lock;
signalled_ = true;
cond_.notify_one();
}
// Signal the event and unlock the mutex.
template <typename Lock>
void signal_and_unlock(Lock& lock)
{
BOOST_ASIO_ASSERT(lock.locked());
signalled_ = true;
lock.unlock();
cond_.notify_one();
}
// Reset the event.
template <typename Lock>
void clear(Lock& lock)
{
BOOST_ASIO_ASSERT(lock.locked());
(void)lock;
signalled_ = false;
}
// Wait for the event to become signalled.
template <typename Lock>
void wait(Lock& lock)
{
BOOST_ASIO_ASSERT(lock.locked());
unique_lock_adapter u_lock(lock);
while (!signalled_)
cond_.wait(u_lock.unique_lock_);
}
// Timed wait for the event to become signalled.
template <typename Lock>
bool wait_for_usec(Lock& lock, long usec)
{
BOOST_ASIO_ASSERT(lock.locked());
unique_lock_adapter u_lock(lock);
if (!signalled_)
cond_.wait_for(u_lock.unique_lock_, std::chrono::microseconds(usec));
return signalled_;
}
private:
// Helper class to temporarily adapt a scoped_lock into a unique_lock so that
// it can be passed to std::condition_variable::wait().
struct unique_lock_adapter
{
template <typename Lock>
explicit unique_lock_adapter(Lock& lock)
: unique_lock_(lock.mutex().mutex_, std::adopt_lock)
{
}
~unique_lock_adapter()
{
unique_lock_.release();
}
std::unique_lock<std::mutex> unique_lock_;
};
std::condition_variable cond_;
bool signalled_;
};
} // namespace detail
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#endif // defined(BOOST_ASIO_HAS_STD_MUTEX_AND_CONDVAR)
#endif // BOOST_ASIO_DETAIL_STD_EVENT_HPP