ext-boost/boost/asio/detail/posix_signal_blocker.hpp

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2019-08-24 13:39:04 +00:00
//
// detail/posix_signal_blocker.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2019 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_POSIX_SIGNAL_BLOCKER_HPP
#define BOOST_ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_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_PTHREADS)
#include <csignal>
#include <pthread.h>
#include <signal.h>
#include <boost/asio/detail/noncopyable.hpp>
#include <boost/asio/detail/push_options.hpp>
namespace boost {
namespace asio {
namespace detail {
class posix_signal_blocker
: private noncopyable
{
public:
// Constructor blocks all signals for the calling thread.
posix_signal_blocker()
: blocked_(false)
{
sigset_t new_mask;
sigfillset(&new_mask);
blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0);
}
// Destructor restores the previous signal mask.
~posix_signal_blocker()
{
if (blocked_)
pthread_sigmask(SIG_SETMASK, &old_mask_, 0);
}
// Block all signals for the calling thread.
void block()
{
if (!blocked_)
{
sigset_t new_mask;
sigfillset(&new_mask);
blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0);
}
}
// Restore the previous signal mask.
void unblock()
{
if (blocked_)
blocked_ = (pthread_sigmask(SIG_SETMASK, &old_mask_, 0) != 0);
}
private:
// Have signals been blocked.
bool blocked_;
// The previous signal mask.
sigset_t old_mask_;
};
} // namespace detail
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#endif // defined(BOOST_ASIO_HAS_PTHREADS)
#endif // BOOST_ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP