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| author | Remko Tronçon <git@el-tramo.be> | 2009-06-01 08:48:42 (GMT) |
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| committer | Remko Tronçon <git@el-tramo.be> | 2009-06-01 09:24:28 (GMT) |
| commit | 2812bddd81f8a1b804c7460f4e14cd0aa393d129 (patch) | |
| tree | d46294f35150c4f0f43deaf2d31fceaf945ae715 /3rdParty/Boost/boost/thread/pthread/once.hpp | |
| download | swift-contrib-2812bddd81f8a1b804c7460f4e14cd0aa393d129.zip swift-contrib-2812bddd81f8a1b804c7460f4e14cd0aa393d129.tar.bz2 | |
Import.
Diffstat (limited to '3rdParty/Boost/boost/thread/pthread/once.hpp')
| -rw-r--r-- | 3rdParty/Boost/boost/thread/pthread/once.hpp | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/3rdParty/Boost/boost/thread/pthread/once.hpp b/3rdParty/Boost/boost/thread/pthread/once.hpp new file mode 100644 index 0000000..f278a57 --- /dev/null +++ b/3rdParty/Boost/boost/thread/pthread/once.hpp @@ -0,0 +1,90 @@ +#ifndef BOOST_THREAD_PTHREAD_ONCE_HPP +#define BOOST_THREAD_PTHREAD_ONCE_HPP + +// once.hpp +// +// (C) Copyright 2007-8 Anthony Williams +// +// 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) + +#include <boost/thread/detail/config.hpp> + +#include <pthread.h> +#include <boost/assert.hpp> +#include "pthread_mutex_scoped_lock.hpp" +#include <boost/thread/pthread/pthread_mutex_scoped_lock.hpp> +#include <boost/cstdint.hpp> + +#include <boost/config/abi_prefix.hpp> + +namespace boost +{ + + struct once_flag + { + boost::uintmax_t epoch; + }; + + namespace detail + { + BOOST_THREAD_DECL boost::uintmax_t& get_once_per_thread_epoch(); + BOOST_THREAD_DECL extern boost::uintmax_t once_global_epoch; + BOOST_THREAD_DECL extern pthread_mutex_t once_epoch_mutex; + BOOST_THREAD_DECL extern pthread_cond_t once_epoch_cv; + } + +#define BOOST_ONCE_INITIAL_FLAG_VALUE 0 +#define BOOST_ONCE_INIT {BOOST_ONCE_INITIAL_FLAG_VALUE} + + + // Based on Mike Burrows fast_pthread_once algorithm as described in + // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2444.html + template<typename Function> + void call_once(once_flag& flag,Function f) + { + static boost::uintmax_t const uninitialized_flag=BOOST_ONCE_INITIAL_FLAG_VALUE; + static boost::uintmax_t const being_initialized=uninitialized_flag+1; + boost::uintmax_t const epoch=flag.epoch; + boost::uintmax_t& this_thread_epoch=detail::get_once_per_thread_epoch(); + + if(epoch<this_thread_epoch) + { + pthread::pthread_mutex_scoped_lock lk(&detail::once_epoch_mutex); + + while(flag.epoch<=being_initialized) + { + if(flag.epoch==uninitialized_flag) + { + flag.epoch=being_initialized; + try + { + pthread::pthread_mutex_scoped_unlock relocker(&detail::once_epoch_mutex); + f(); + } + catch(...) + { + flag.epoch=uninitialized_flag; + BOOST_VERIFY(!pthread_cond_broadcast(&detail::once_epoch_cv)); + throw; + } + flag.epoch=--detail::once_global_epoch; + BOOST_VERIFY(!pthread_cond_broadcast(&detail::once_epoch_cv)); + } + else + { + while(flag.epoch==being_initialized) + { + BOOST_VERIFY(!pthread_cond_wait(&detail::once_epoch_cv,&detail::once_epoch_mutex)); + } + } + } + this_thread_epoch=detail::once_global_epoch; + } + } +} + +#include <boost/config/abi_suffix.hpp> + +#endif |