// Copyright (C) 2007 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>
#ifdef BOOST_THREAD_ONCE_ATOMIC
#include "./once_atomic.cpp"
#else
#define __STDC_CONSTANT_MACROS
#include <boost/thread/once.hpp>
#include <boost/assert.hpp>
#include <boost/throw_exception.hpp>
#include <pthread.h>
#include <stdlib.h>
#include <memory>
#include <string.h> // memcmp.
namespace boost
{
 namespace thread_detail
 {
 BOOST_THREAD_DECL uintmax_atomic_t once_global_epoch=BOOST_THREAD_DETAIL_UINTMAX_ATOMIC_MAX_C;
 BOOST_THREAD_DECL pthread_mutex_t once_epoch_mutex=PTHREAD_MUTEX_INITIALIZER;
 BOOST_THREAD_DECL pthread_cond_t once_epoch_cv = PTHREAD_COND_INITIALIZER;

 namespace
 {
 pthread_key_t epoch_tss_key;
 pthread_once_t epoch_tss_key_flag=PTHREAD_ONCE_INIT;

 extern "C"
 {
 static void delete_epoch_tss_data(void* data)
 {
 free(data);
 }

 static void create_epoch_tss_key()
 {
 BOOST_VERIFY(!pthread_key_create(&epoch_tss_key,delete_epoch_tss_data));
 }
 }

#if defined BOOST_THREAD_PATCH
 const pthread_once_t pthread_once_init_value=PTHREAD_ONCE_INIT;
 struct BOOST_THREAD_DECL delete_epoch_tss_key_on_dlclose_t
 {
 delete_epoch_tss_key_on_dlclose_t()
 {
 }
 ~delete_epoch_tss_key_on_dlclose_t()
 {
 if(memcmp(&epoch_tss_key_flag, &pthread_once_init_value, sizeof(pthread_once_t)))
 {
 void* data = pthread_getspecific(epoch_tss_key);
 if (data)
 delete_epoch_tss_data(data);
 pthread_key_delete(epoch_tss_key);
 }
 }
 };
 delete_epoch_tss_key_on_dlclose_t delete_epoch_tss_key_on_dlclose;
#endif
 }

 uintmax_atomic_t& get_once_per_thread_epoch()
 {
 BOOST_VERIFY(!pthread_once(&epoch_tss_key_flag,create_epoch_tss_key));
 void* data=pthread_getspecific(epoch_tss_key);
 if(!data)
 {
 data=malloc(sizeof(thread_detail::uintmax_atomic_t));
 if(!data) BOOST_THROW_EXCEPTION(std::bad_alloc());
 BOOST_VERIFY(!pthread_setspecific(epoch_tss_key,data));
 *static_cast<thread_detail::uintmax_atomic_t*>(data)=BOOST_THREAD_DETAIL_UINTMAX_ATOMIC_MAX_C;
 }
 return *static_cast<thread_detail::uintmax_atomic_t*>(data);
 }
 }

}
#endif //