ceph/src/boost/libs/fiber/src/condition_variable.cpp

   1
   2 //          Copyright Oliver Kowalke 2013.
   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/fiber/condition_variable.hpp"
   8
   9 #include "boost/fiber/context.hpp"
  10
  11 #ifdef BOOST_HAS_ABI_HEADERS
  12 #  include BOOST_ABI_PREFIX
  13 #endif
  14
  15 namespace boost {
  16 namespace fibers {
  17
  18 void
  19 condition_variable_any::notify_one() noexcept {
  20     context * active_ctx = context::active();
  21     // get one context' from wait-queue
  22     detail::spinlock_lock lk{ wait_queue_splk_ };
  23     while ( ! wait_queue_.empty() ) {
  24         context * ctx = & wait_queue_.front();
  25         wait_queue_.pop_front();
  26         auto expected = reinterpret_cast< std::intptr_t >( this);
  27         if ( ctx->twstatus.compare_exchange_strong( expected, static_cast< std::intptr_t >( -1), std::memory_order_acq_rel) ) {
  28             // notify context
  29             active_ctx->schedule( ctx);
  30             break;
  31         }
  32         if ( static_cast< std::intptr_t >( 0) == expected) {
  33             // no timed-wait op.
  34             // notify context
  35             active_ctx->schedule( ctx);
  36             break;
  37         }
  38     }
  39 }
  40
  41 void
  42 condition_variable_any::notify_all() noexcept {
  43     context * active_ctx = context::active();
  44     // get all context' from wait-queue
  45     detail::spinlock_lock lk{ wait_queue_splk_ };
  46     // notify all context'
  47     while ( ! wait_queue_.empty() ) {
  48         context * ctx = & wait_queue_.front();
  49         wait_queue_.pop_front();
  50         auto expected = reinterpret_cast< std::intptr_t >( this);
  51         if ( ctx->twstatus.compare_exchange_strong( expected, static_cast< std::intptr_t >( -1), std::memory_order_acq_rel) ) {
  52             // notify context
  53             active_ctx->schedule( ctx);
  54         } else if ( static_cast< std::intptr_t >( 0) == expected) {
  55             // no timed-wait op.
  56             // notify context
  57             active_ctx->schedule( ctx);
  58         }
  59     }
  60 }
  61
  62 }}
  63
  64 #ifdef BOOST_HAS_ABI_HEADERS
  65 #  include BOOST_ABI_SUFFIX
  66 #endif