ceph/src/boost/boost/fiber/operations.hpp

   1 //          Copyright Oliver Kowalke 2013.
   2 // Distributed under the Boost Software License, Version 1.0.
   3 //    (See accompanying file LICENSE_1_0.txt or copy at
   4 //          http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifndef BOOST_THIS_FIBER_OPERATIONS_H
   7 #define BOOST_THIS_FIBER_OPERATIONS_H
   8
   9 #include <chrono>
  10
  11 #include <boost/config.hpp>
  12
  13 #include <boost/fiber/algo/algorithm.hpp>
  14 #include <boost/fiber/context.hpp>
  15 #include <boost/fiber/detail/config.hpp>
  16 #include <boost/fiber/detail/convert.hpp>
  17 #include <boost/fiber/fiber.hpp>
  18 #include <boost/fiber/scheduler.hpp>
  19
  20 #ifdef BOOST_HAS_ABI_HEADERS
  21 #  include BOOST_ABI_PREFIX
  22 #endif
  23
  24 namespace boost {
  25 namespace this_fiber {
  26
  27 inline
  28 fibers::fiber::id get_id() noexcept {
  29     return fibers::context::active()->get_id();
  30 }
  31
  32 inline
  33 void yield() noexcept {
  34     fibers::context::active()->yield();
  35 }
  36
  37 template< typename Clock, typename Duration >
  38 void sleep_until( std::chrono::time_point< Clock, Duration > const& sleep_time_) {
  39     std::chrono::steady_clock::time_point sleep_time = boost::fibers::detail::convert( sleep_time_);
  40     fibers::context * active_ctx = fibers::context::active();
  41     active_ctx->twstatus.store( static_cast< std::intptr_t >( 0), std::memory_order_release);
  42     active_ctx->wait_until( sleep_time);
  43 }
  44
  45 template< typename Rep, typename Period >
  46 void sleep_for( std::chrono::duration< Rep, Period > const& timeout_duration) {
  47     fibers::context * active_ctx = fibers::context::active();
  48     active_ctx->twstatus.store( static_cast< std::intptr_t >( 0), std::memory_order_release);
  49     active_ctx->wait_until( std::chrono::steady_clock::now() + timeout_duration);
  50 }
  51
  52 template< typename PROPS >
  53 PROPS & properties() {
  54     fibers::fiber_properties * props = fibers::context::active()->get_properties();
  55     if ( BOOST_LIKELY( nullptr == props) ) {
  56         // props could be nullptr if the thread's main fiber has not yet
  57         // yielded (not yet passed through algorithm_with_properties::
  58         // awakened()). Address that by yielding right now.
  59         yield();
  60         // Try again to obtain the fiber_properties subclass instance ptr.
  61         // Walk through the whole chain again because who knows WHAT might
  62         // have happened while we were yielding!
  63         props = fibers::context::active()->get_properties();
  64         // Could still be hosed if the running manager isn't a subclass of
  65         // algorithm_with_properties.
  66         BOOST_ASSERT_MSG( props, "this_fiber::properties not set");
  67     }
  68     return dynamic_cast< PROPS & >( * props );
  69 }
  70
  71 }
  72
  73 namespace fibers {
  74
  75 inline
  76 bool has_ready_fibers() noexcept {
  77     return boost::fibers::context::active()->get_scheduler()->has_ready_fibers();
  78 }
  79
  80 template< typename SchedAlgo, typename ... Args >
  81 void use_scheduling_algorithm( Args && ... args) noexcept {
  82     boost::fibers::context::active()->get_scheduler()
  83         ->set_algo( new SchedAlgo( std::forward< Args >( args) ... ) );
  84 }
  85
  86 }}
  87
  88 #ifdef BOOST_HAS_ABI_HEADERS
  89 #  include BOOST_ABI_SUFFIX
  90 #endif
  91
  92 #endif // BOOST_THIS_FIBER_OPERATIONS_H