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Diffstat (limited to '3rdParty/Boost/src/libs/thread/src/pthread/once_atomic.cpp')
-rw-r--r--3rdParty/Boost/src/libs/thread/src/pthread/once_atomic.cpp90
1 files changed, 90 insertions, 0 deletions
diff --git a/3rdParty/Boost/src/libs/thread/src/pthread/once_atomic.cpp b/3rdParty/Boost/src/libs/thread/src/pthread/once_atomic.cpp
new file mode 100644
index 0000000..b7ee1dc
--- /dev/null
+++ b/3rdParty/Boost/src/libs/thread/src/pthread/once_atomic.cpp
@@ -0,0 +1,90 @@
+// (C) Copyright 2013 Andrey Semashev
+// (C) Copyright 2013 Vicente J. Botet Escriba
+//
+// 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)
+
+//#define __STDC_CONSTANT_MACROS
+#include <boost/thread/detail/config.hpp>
+#include <boost/thread/once.hpp>
+#include <boost/thread/pthread/pthread_mutex_scoped_lock.hpp>
+#include <boost/assert.hpp>
+#include <boost/static_assert.hpp>
+#include <boost/atomic.hpp>
+#include <boost/memory_order.hpp>
+#include <pthread.h>
+
+namespace boost
+{
+ namespace thread_detail
+ {
+
+ enum flag_states
+ {
+ uninitialized, in_progress, initialized
+ };
+
+
+#ifndef BOOST_THREAD_PROVIDES_ONCE_CXX11
+ BOOST_STATIC_ASSERT_MSG(sizeof(atomic_int_type) == sizeof(atomic_type), "Boost.Thread: unsupported platform");
+#endif
+
+ static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
+ static pthread_cond_t once_cv = PTHREAD_COND_INITIALIZER;
+
+ BOOST_THREAD_DECL bool enter_once_region(once_flag& flag) BOOST_NOEXCEPT
+ {
+ atomic_type& f = get_atomic_storage(flag);
+ if (f.load(memory_order_acquire) != initialized)
+ {
+ pthread::pthread_mutex_scoped_lock lk(&once_mutex);
+ if (f.load(memory_order_acquire) != initialized)
+ {
+ while (true)
+ {
+ atomic_int_type expected = uninitialized;
+ if (f.compare_exchange_strong(expected, in_progress, memory_order_acq_rel, memory_order_acquire))
+ {
+ // We have set the flag to in_progress
+ return true;
+ }
+ else if (expected == initialized)
+ {
+ // Another thread managed to complete the initialization
+ return false;
+ }
+ else
+ {
+ // Wait until the initialization is complete
+ //pthread::pthread_mutex_scoped_lock lk(&once_mutex);
+ BOOST_VERIFY(!pthread_cond_wait(&once_cv, &once_mutex));
+ }
+ }
+ }
+ }
+ return false;
+ }
+
+ BOOST_THREAD_DECL void commit_once_region(once_flag& flag) BOOST_NOEXCEPT
+ {
+ atomic_type& f = get_atomic_storage(flag);
+ {
+ pthread::pthread_mutex_scoped_lock lk(&once_mutex);
+ f.store(initialized, memory_order_release);
+ }
+ BOOST_VERIFY(!pthread_cond_broadcast(&once_cv));
+ }
+
+ BOOST_THREAD_DECL void rollback_once_region(once_flag& flag) BOOST_NOEXCEPT
+ {
+ atomic_type& f = get_atomic_storage(flag);
+ {
+ pthread::pthread_mutex_scoped_lock lk(&once_mutex);
+ f.store(uninitialized, memory_order_release);
+ }
+ BOOST_VERIFY(!pthread_cond_broadcast(&once_cv));
+ }
+
+ } // namespace thread_detail
+
+} // namespace boost