boost::context::continuation
scheduler::dispatch() noexcept {
BOOST_ASSERT( context::active() == dispatcher_ctx_);
for (;;) {
if ( shutdown_) {
// notify sched-algorithm about termination
algo_->notify();
if ( worker_queue_.empty() ) {
break;
}
}
// release terminated context'
release_terminated_();
#if ! defined(BOOST_FIBERS_NO_ATOMICS)
// get context' from remote ready-queue
remote_ready2ready_();
#endif
// get sleeping context'
sleep2ready_();
// get next ready context
context * ctx = algo_->pick_next();
if ( nullptr != ctx) {
BOOST_ASSERT( ctx->is_resumable() );
BOOST_ASSERT( ! ctx->ready_is_linked() );
#if ! defined(BOOST_FIBERS_NO_ATOMICS)
BOOST_ASSERT( ! ctx->remote_ready_is_linked() );
#endif
BOOST_ASSERT( ! ctx->sleep_is_linked() );
BOOST_ASSERT( ! ctx->terminated_is_linked() );
// no test for '! ctx->wait_is_linked()' because
// context is registered in wait-queue of sync. primitives
// via wait_for()/wait_until()
// push dispatcher-context to ready-queue
// so that ready-queue never becomes empty
ctx->resume( dispatcher_ctx_.get() );
BOOST_ASSERT( context::active() == dispatcher_ctx_.get() );
} else {
// no ready context, wait till signaled
// set deadline to highest value
std::chrono::steady_clock::time_point suspend_time =
(std::chrono::steady_clock::time_point::max)();
// get lowest deadline from sleep-queue
sleep_queue_type::iterator i = sleep_queue_.begin();
if ( sleep_queue_.end() != i) {
suspend_time = i->tp_;
}
// no ready context, wait till signaled
algo_->suspend_until( suspend_time);
}
}
// release termianted context'
release_terminated_();
// return to main-context
return main_ctx_->suspend_with_cc();
}
void
scheduler::dispatch() noexcept {
#else
boost::context::execution_context< detail::data_t * >
scheduler::dispatch() noexcept {
#endif
BOOST_ASSERT( context::active() == dispatcher_ctx_);
for (;;) {
bool no_worker = worker_queue_.empty();
if ( shutdown_) {
// notify sched-algorithm about termination
algo_->notify();
if ( no_worker) {
break;
}
}
// release terminated context'
release_terminated_();
// get context' from remote ready-queue
remote_ready2ready_();
// get sleeping context'
sleep2ready_();
// get next ready context
context * ctx = get_next_();
if ( nullptr != ctx) {
// push dispatcher-context to ready-queue
// so that ready-queue never becomes empty
ctx->resume( dispatcher_ctx_.get() );
BOOST_ASSERT( context::active() == dispatcher_ctx_.get() );
} else {
// no ready context, wait till signaled
// set deadline to highest value
std::chrono::steady_clock::time_point suspend_time =
(std::chrono::steady_clock::time_point::max)();
// get lowest deadline from sleep-queue
sleep_queue_t::iterator i = sleep_queue_.begin();
if ( sleep_queue_.end() != i) {
suspend_time = i->tp_;
}
// no ready context, wait till signaled
algo_->suspend_until( suspend_time);
}
}
// release termianted context'
release_terminated_();
// return to main-context
#if (BOOST_EXECUTION_CONTEXT==1)
main_ctx_->resume();
#else
return main_ctx_->suspend_with_cc();
#endif
}
