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_CONTEXT_NO_CXX11)
  16 # if (defined(BOOST_EXECUTION_CONTEXT) && (BOOST_EXECUTION_CONTEXT == 1))
  17 namespace boost {
  18 namespace context {
  19 namespace detail {
  20
  21 thread_local
  22 activation_record::ptr_t
  23 activation_record::current_rec;
  24
  25 // zero-initialization
  26 thread_local static std::size_t counter;
  27
  28 // schwarz counter
  29 activation_record_initializer::activation_record_initializer() noexcept {
  30     if ( 0 == counter++) {
  31         activation_record::current_rec.reset( new activation_record() );
  32     }
  33 }
  34
  35 activation_record_initializer::~activation_record_initializer() {
  36     if ( 0 == --counter) {
  37         BOOST_ASSERT( activation_record::current_rec->is_main_context() );
  38         delete activation_record::current_rec.detach();
  39     }
  40 }
  41
  42 }
  43
  44 execution_context
  45 execution_context::current() noexcept {
  46     // initialized the first time control passes; per thread
  47     thread_local static detail::activation_record_initializer initializer;
  48     return execution_context();
  49 }
  50
  51 }}
  52 # endif
  53 #endif
  54
  55 # ifdef BOOST_HAS_ABI_HEADERS
  56 #  include BOOST_ABI_SUFFIX
  57 # endif