Chris@16: //
Chris@16: // detail/win_event.hpp
Chris@16: // ~~~~~~~~~~~~~~~~~~~~
Chris@16: //
Chris@101: // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: 
Chris@16: #ifndef BOOST_ASIO_DETAIL_WIN_EVENT_HPP
Chris@16: #define BOOST_ASIO_DETAIL_WIN_EVENT_HPP
Chris@16: 
Chris@16: #if defined(_MSC_VER) && (_MSC_VER >= 1200)
Chris@16: # pragma once
Chris@16: #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
Chris@16: 
Chris@16: #include <boost/asio/detail/config.hpp>
Chris@16: 
Chris@16: #if defined(BOOST_ASIO_WINDOWS)
Chris@16: 
Chris@16: #include <boost/asio/detail/assert.hpp>
Chris@16: #include <boost/asio/detail/noncopyable.hpp>
Chris@16: #include <boost/asio/detail/socket_types.hpp>
Chris@16: 
Chris@16: #include <boost/asio/detail/push_options.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace asio {
Chris@16: namespace detail {
Chris@16: 
Chris@16: class win_event
Chris@16:   : private noncopyable
Chris@16: {
Chris@16: public:
Chris@16:   // Constructor.
Chris@16:   BOOST_ASIO_DECL win_event();
Chris@16: 
Chris@16:   // Destructor.
Chris@101:   BOOST_ASIO_DECL ~win_event();
Chris@16: 
Chris@101:   // Signal the event. (Retained for backward compatibility.)
Chris@16:   template <typename Lock>
Chris@16:   void signal(Lock& lock)
Chris@16:   {
Chris@101:     this->signal_all(lock);
Chris@101:   }
Chris@101: 
Chris@101:   // Signal all waiters.
Chris@101:   template <typename Lock>
Chris@101:   void signal_all(Lock& lock)
Chris@101:   {
Chris@16:     BOOST_ASIO_ASSERT(lock.locked());
Chris@16:     (void)lock;
Chris@101:     state_ |= 1;
Chris@101:     ::SetEvent(events_[0]);
Chris@16:   }
Chris@16: 
Chris@101:   // Unlock the mutex and signal one waiter.
Chris@16:   template <typename Lock>
Chris@101:   void unlock_and_signal_one(Lock& lock)
Chris@16:   {
Chris@16:     BOOST_ASIO_ASSERT(lock.locked());
Chris@101:     state_ |= 1;
Chris@101:     bool have_waiters = (state_ > 1);
Chris@16:     lock.unlock();
Chris@101:     if (have_waiters)
Chris@101:       ::SetEvent(events_[1]);
Chris@101:   }
Chris@101: 
Chris@101:   // If there's a waiter, unlock the mutex and signal it.
Chris@101:   template <typename Lock>
Chris@101:   bool maybe_unlock_and_signal_one(Lock& lock)
Chris@101:   {
Chris@101:     BOOST_ASIO_ASSERT(lock.locked());
Chris@101:     state_ |= 1;
Chris@101:     if (state_ > 1)
Chris@101:     {
Chris@101:       lock.unlock();
Chris@101:       ::SetEvent(events_[1]);
Chris@101:       return true;
Chris@101:     }
Chris@101:     return false;
Chris@16:   }
Chris@16: 
Chris@16:   // Reset the event.
Chris@16:   template <typename Lock>
Chris@16:   void clear(Lock& lock)
Chris@16:   {
Chris@16:     BOOST_ASIO_ASSERT(lock.locked());
Chris@16:     (void)lock;
Chris@101:     ::ResetEvent(events_[0]);
Chris@101:     state_ &= ~std::size_t(1);
Chris@16:   }
Chris@16: 
Chris@16:   // Wait for the event to become signalled.
Chris@16:   template <typename Lock>
Chris@16:   void wait(Lock& lock)
Chris@16:   {
Chris@16:     BOOST_ASIO_ASSERT(lock.locked());
Chris@101:     while ((state_ & 1) == 0)
Chris@101:     {
Chris@101:       state_ += 2;
Chris@101:       lock.unlock();
Chris@101:       ::WaitForMultipleObjects(2, events_, false, INFINITE);
Chris@101:       lock.lock();
Chris@101:       state_ -= 2;
Chris@101:     }
Chris@16:   }
Chris@16: 
Chris@16: private:
Chris@101:   HANDLE events_[2];
Chris@101:   std::size_t state_;
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: } // namespace asio
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/asio/detail/pop_options.hpp>
Chris@16: 
Chris@16: #if defined(BOOST_ASIO_HEADER_ONLY)
Chris@16: # include <boost/asio/detail/impl/win_event.ipp>
Chris@16: #endif // defined(BOOST_ASIO_HEADER_ONLY)
Chris@16: 
Chris@16: #endif // defined(BOOST_ASIO_WINDOWS)
Chris@16: 
Chris@16: #endif // BOOST_ASIO_DETAIL_WIN_EVENT_HPP