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

   1
   2 //          Copyright Oliver Kowalke 2017.
   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 #if defined(BOOST_USE_UCONTEXT)
   8 #include "boost/context/continuation_ucontext.hpp"
   9 #elif defined(BOOST_USE_WINFIB)
  10 #include "boost/context/continuation_winfib.hpp"
  11 #endif
  12
  13 #include <boost/config.hpp>
  14
  15 #ifdef BOOST_HAS_ABI_HEADERS
  16 # include BOOST_ABI_PREFIX
  17 #endif
  18
  19 namespace boost {
  20 namespace context {
  21 namespace detail {
  22
  23 // zero-initialization
  24 thread_local activation_record * current_rec;
  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         current_rec = new activation_record();
  31     }
  32 }
  33
  34 activation_record_initializer::~activation_record_initializer() {
  35     if ( 0 == --counter) {
  36         BOOST_ASSERT( current_rec->is_main_context() );
  37         delete current_rec;
  38     }
  39 }
  40
  41 }
  42
  43 namespace detail {
  44
  45 activation_record *&
  46 activation_record::current() noexcept {
  47     // initialized the first time control passes; per thread
  48     thread_local static activation_record_initializer initializer;
  49     return current_rec;
  50 }
  51
  52 }
  53
  54 }}
  55
  56 #ifdef BOOST_HAS_ABI_HEADERS
  57 # include BOOST_ABI_SUFFIX
  58 #endif