ceph/src/boost/libs/context/src/execution_context.cpp

   1
   2 //          Copyright Oliver Kowalke 2009.
   3 // Distributed under the Boost Software License, Version 1.0.
   4 //    (See accompanying file LICENSE_1_0.txt or copy at
   5 //          http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include "boost/context/execution_context.hpp"
   8
   9 #include <boost/config.hpp>
  10
  11 #ifdef BOOST_HAS_ABI_HEADERS
  12 # include BOOST_ABI_PREFIX
  13 #endif
  14
  15 #if (defined(BOOST_EXECUTION_CONTEXT) && (BOOST_EXECUTION_CONTEXT == 1))
  16 namespace boost {
  17 namespace context {
  18 namespace detail {
  19
  20 thread_local
  21 activation_record::ptr_t
  22 activation_record::current_rec;
  23
  24 // zero-initialization
  25 thread_local static std::size_t counter;
  26
  27 // schwarz counter
  28 activation_record_initializer::activation_record_initializer() noexcept {
  29     if ( 0 == counter++) {
  30         activation_record::current_rec.reset( new activation_record() );
  31     }
  32 }
  33
  34 activation_record_initializer::~activation_record_initializer() {
  35     if ( 0 == --counter) {
  36         BOOST_ASSERT( activation_record::current_rec->is_main_context() );
  37         delete activation_record::current_rec.detach();
  38     }
  39 }
  40
  41 }
  42
  43 execution_context
  44 execution_context::current() noexcept {
  45     // initialized the first time control passes; per thread
  46     thread_local static detail::activation_record_initializer initializer;
  47     return execution_context();
  48 }
  49
  50 }}
  51 #endif
  52
  53 #ifdef BOOST_HAS_ABI_HEADERS
  54 # include BOOST_ABI_SUFFIX
  55 #endif