Mercurial > hg > vamp-build-and-test
diff DEPENDENCIES/generic/include/boost/asio/detail/impl/eventfd_select_interrupter.ipp @ 16:2665513ce2d3
Add boost headers
author | Chris Cannam |
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date | Tue, 05 Aug 2014 11:11:38 +0100 |
parents | |
children | c530137014c0 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DEPENDENCIES/generic/include/boost/asio/detail/impl/eventfd_select_interrupter.ipp Tue Aug 05 11:11:38 2014 +0100 @@ -0,0 +1,167 @@ +// +// detail/impl/eventfd_select_interrupter.ipp +// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2013 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// Copyright (c) 2008 Roelof Naude (roelof.naude at gmail 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_IMPL_EVENTFD_SELECT_INTERRUPTER_IPP +#define BOOST_ASIO_DETAIL_IMPL_EVENTFD_SELECT_INTERRUPTER_IPP + +#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_EVENTFD) + +#include <sys/stat.h> +#include <sys/types.h> +#include <fcntl.h> +#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 8 +# include <asm/unistd.h> +#else // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8 +# include <sys/eventfd.h> +#endif // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8 +#include <boost/asio/detail/cstdint.hpp> +#include <boost/asio/detail/eventfd_select_interrupter.hpp> +#include <boost/asio/detail/throw_error.hpp> +#include <boost/asio/error.hpp> + +#include <boost/asio/detail/push_options.hpp> + +namespace boost { +namespace asio { +namespace detail { + +eventfd_select_interrupter::eventfd_select_interrupter() +{ + open_descriptors(); +} + +void eventfd_select_interrupter::open_descriptors() +{ +#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 8 + write_descriptor_ = read_descriptor_ = syscall(__NR_eventfd, 0); + if (read_descriptor_ != -1) + { + ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK); + ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC); + } +#else // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8 +# if defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK) + write_descriptor_ = read_descriptor_ = + ::eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK); +# else // defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK) + errno = EINVAL; + write_descriptor_ = read_descriptor_ = -1; +# endif // defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK) + if (read_descriptor_ == -1 && errno == EINVAL) + { + write_descriptor_ = read_descriptor_ = ::eventfd(0, 0); + if (read_descriptor_ != -1) + { + ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK); + ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC); + } + } +#endif // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8 + + if (read_descriptor_ == -1) + { + int pipe_fds[2]; + if (pipe(pipe_fds) == 0) + { + read_descriptor_ = pipe_fds[0]; + ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK); + ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC); + write_descriptor_ = pipe_fds[1]; + ::fcntl(write_descriptor_, F_SETFL, O_NONBLOCK); + ::fcntl(write_descriptor_, F_SETFD, FD_CLOEXEC); + } + else + { + boost::system::error_code ec(errno, + boost::asio::error::get_system_category()); + boost::asio::detail::throw_error(ec, "eventfd_select_interrupter"); + } + } +} + +eventfd_select_interrupter::~eventfd_select_interrupter() +{ + close_descriptors(); +} + +void eventfd_select_interrupter::close_descriptors() +{ + if (write_descriptor_ != -1 && write_descriptor_ != read_descriptor_) + ::close(write_descriptor_); + if (read_descriptor_ != -1) + ::close(read_descriptor_); +} + +void eventfd_select_interrupter::recreate() +{ + close_descriptors(); + + write_descriptor_ = -1; + read_descriptor_ = -1; + + open_descriptors(); +} + +void eventfd_select_interrupter::interrupt() +{ + uint64_t counter(1UL); + int result = ::write(write_descriptor_, &counter, sizeof(uint64_t)); + (void)result; +} + +bool eventfd_select_interrupter::reset() +{ + if (write_descriptor_ == read_descriptor_) + { + for (;;) + { + // Only perform one read. The kernel maintains an atomic counter. + uint64_t counter(0); + errno = 0; + int bytes_read = ::read(read_descriptor_, &counter, sizeof(uint64_t)); + if (bytes_read < 0 && errno == EINTR) + continue; + bool was_interrupted = (bytes_read > 0); + return was_interrupted; + } + } + else + { + for (;;) + { + // Clear all data from the pipe. + char data[1024]; + int bytes_read = ::read(read_descriptor_, data, sizeof(data)); + if (bytes_read < 0 && errno == EINTR) + continue; + bool was_interrupted = (bytes_read > 0); + while (bytes_read == sizeof(data)) + bytes_read = ::read(read_descriptor_, data, sizeof(data)); + return was_interrupted; + } + } +} + +} // namespace detail +} // namespace asio +} // namespace boost + +#include <boost/asio/detail/pop_options.hpp> + +#endif // defined(BOOST_ASIO_HAS_EVENTFD) + +#endif // BOOST_ASIO_DETAIL_IMPL_EVENTFD_SELECT_INTERRUPTER_IPP