660 lines
15 KiB
C++
660 lines
15 KiB
C++
//
|
|
// detail/impl/scheduler.ipp
|
|
// ~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
//
|
|
// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
|
|
#ifndef ASIO_DETAIL_IMPL_SCHEDULER_IPP
|
|
#define ASIO_DETAIL_IMPL_SCHEDULER_IPP
|
|
|
|
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
# pragma once
|
|
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
|
|
#include "asio/detail/config.hpp"
|
|
|
|
#include "asio/detail/concurrency_hint.hpp"
|
|
#include "asio/detail/event.hpp"
|
|
#include "asio/detail/limits.hpp"
|
|
#include "asio/detail/reactor.hpp"
|
|
#include "asio/detail/scheduler.hpp"
|
|
#include "asio/detail/scheduler_thread_info.hpp"
|
|
#include "asio/detail/signal_blocker.hpp"
|
|
|
|
#include "asio/detail/push_options.hpp"
|
|
|
|
namespace asio {
|
|
namespace detail {
|
|
|
|
class scheduler::thread_function
|
|
{
|
|
public:
|
|
explicit thread_function(scheduler* s)
|
|
: this_(s)
|
|
{
|
|
}
|
|
|
|
void operator()()
|
|
{
|
|
asio::error_code ec;
|
|
this_->run(ec);
|
|
}
|
|
|
|
private:
|
|
scheduler* this_;
|
|
};
|
|
|
|
struct scheduler::task_cleanup
|
|
{
|
|
~task_cleanup()
|
|
{
|
|
if (this_thread_->private_outstanding_work > 0)
|
|
{
|
|
asio::detail::increment(
|
|
scheduler_->outstanding_work_,
|
|
this_thread_->private_outstanding_work);
|
|
}
|
|
this_thread_->private_outstanding_work = 0;
|
|
|
|
// Enqueue the completed operations and reinsert the task at the end of
|
|
// the operation queue.
|
|
lock_->lock();
|
|
scheduler_->task_interrupted_ = true;
|
|
scheduler_->op_queue_.push(this_thread_->private_op_queue);
|
|
scheduler_->op_queue_.push(&scheduler_->task_operation_);
|
|
}
|
|
|
|
scheduler* scheduler_;
|
|
mutex::scoped_lock* lock_;
|
|
thread_info* this_thread_;
|
|
};
|
|
|
|
struct scheduler::work_cleanup
|
|
{
|
|
~work_cleanup()
|
|
{
|
|
if (this_thread_->private_outstanding_work > 1)
|
|
{
|
|
asio::detail::increment(
|
|
scheduler_->outstanding_work_,
|
|
this_thread_->private_outstanding_work - 1);
|
|
}
|
|
else if (this_thread_->private_outstanding_work < 1)
|
|
{
|
|
scheduler_->work_finished();
|
|
}
|
|
this_thread_->private_outstanding_work = 0;
|
|
|
|
#if defined(ASIO_HAS_THREADS)
|
|
if (!this_thread_->private_op_queue.empty())
|
|
{
|
|
lock_->lock();
|
|
scheduler_->op_queue_.push(this_thread_->private_op_queue);
|
|
}
|
|
#endif // defined(ASIO_HAS_THREADS)
|
|
}
|
|
|
|
scheduler* scheduler_;
|
|
mutex::scoped_lock* lock_;
|
|
thread_info* this_thread_;
|
|
};
|
|
|
|
scheduler::scheduler(asio::execution_context& ctx,
|
|
int concurrency_hint, bool own_thread)
|
|
: asio::detail::execution_context_service_base<scheduler>(ctx),
|
|
one_thread_(concurrency_hint == 1
|
|
|| !ASIO_CONCURRENCY_HINT_IS_LOCKING(
|
|
SCHEDULER, concurrency_hint)
|
|
|| !ASIO_CONCURRENCY_HINT_IS_LOCKING(
|
|
REACTOR_IO, concurrency_hint)),
|
|
mutex_(ASIO_CONCURRENCY_HINT_IS_LOCKING(
|
|
SCHEDULER, concurrency_hint)),
|
|
task_(0),
|
|
task_interrupted_(true),
|
|
outstanding_work_(0),
|
|
stopped_(false),
|
|
shutdown_(false),
|
|
concurrency_hint_(concurrency_hint),
|
|
thread_(0)
|
|
{
|
|
ASIO_HANDLER_TRACKING_INIT;
|
|
|
|
if (own_thread)
|
|
{
|
|
++outstanding_work_;
|
|
asio::detail::signal_blocker sb;
|
|
thread_ = new asio::detail::thread(thread_function(this));
|
|
}
|
|
}
|
|
|
|
scheduler::~scheduler()
|
|
{
|
|
if (thread_)
|
|
{
|
|
mutex::scoped_lock lock(mutex_);
|
|
shutdown_ = true;
|
|
stop_all_threads(lock);
|
|
lock.unlock();
|
|
thread_->join();
|
|
delete thread_;
|
|
}
|
|
}
|
|
|
|
void scheduler::shutdown()
|
|
{
|
|
mutex::scoped_lock lock(mutex_);
|
|
shutdown_ = true;
|
|
if (thread_)
|
|
stop_all_threads(lock);
|
|
lock.unlock();
|
|
|
|
// Join thread to ensure task operation is returned to queue.
|
|
if (thread_)
|
|
{
|
|
thread_->join();
|
|
delete thread_;
|
|
thread_ = 0;
|
|
}
|
|
|
|
// Destroy handler objects.
|
|
while (!op_queue_.empty())
|
|
{
|
|
operation* o = op_queue_.front();
|
|
op_queue_.pop();
|
|
if (o != &task_operation_)
|
|
o->destroy();
|
|
}
|
|
|
|
// Reset to initial state.
|
|
task_ = 0;
|
|
}
|
|
|
|
void scheduler::init_task()
|
|
{
|
|
mutex::scoped_lock lock(mutex_);
|
|
if (!shutdown_ && !task_)
|
|
{
|
|
task_ = &use_service<reactor>(this->context());
|
|
op_queue_.push(&task_operation_);
|
|
wake_one_thread_and_unlock(lock);
|
|
}
|
|
}
|
|
|
|
std::size_t scheduler::run(asio::error_code& ec)
|
|
{
|
|
ec = asio::error_code();
|
|
if (outstanding_work_ == 0)
|
|
{
|
|
stop();
|
|
return 0;
|
|
}
|
|
|
|
thread_info this_thread;
|
|
this_thread.private_outstanding_work = 0;
|
|
thread_call_stack::context ctx(this, this_thread);
|
|
|
|
mutex::scoped_lock lock(mutex_);
|
|
|
|
std::size_t n = 0;
|
|
for (; do_run_one(lock, this_thread, ec); lock.lock())
|
|
if (n != (std::numeric_limits<std::size_t>::max)())
|
|
++n;
|
|
return n;
|
|
}
|
|
|
|
std::size_t scheduler::run_one(asio::error_code& ec)
|
|
{
|
|
ec = asio::error_code();
|
|
if (outstanding_work_ == 0)
|
|
{
|
|
stop();
|
|
return 0;
|
|
}
|
|
|
|
thread_info this_thread;
|
|
this_thread.private_outstanding_work = 0;
|
|
thread_call_stack::context ctx(this, this_thread);
|
|
|
|
mutex::scoped_lock lock(mutex_);
|
|
|
|
return do_run_one(lock, this_thread, ec);
|
|
}
|
|
|
|
std::size_t scheduler::wait_one(long usec, asio::error_code& ec)
|
|
{
|
|
ec = asio::error_code();
|
|
if (outstanding_work_ == 0)
|
|
{
|
|
stop();
|
|
return 0;
|
|
}
|
|
|
|
thread_info this_thread;
|
|
this_thread.private_outstanding_work = 0;
|
|
thread_call_stack::context ctx(this, this_thread);
|
|
|
|
mutex::scoped_lock lock(mutex_);
|
|
|
|
return do_wait_one(lock, this_thread, usec, ec);
|
|
}
|
|
|
|
std::size_t scheduler::poll(asio::error_code& ec)
|
|
{
|
|
ec = asio::error_code();
|
|
if (outstanding_work_ == 0)
|
|
{
|
|
stop();
|
|
return 0;
|
|
}
|
|
|
|
thread_info this_thread;
|
|
this_thread.private_outstanding_work = 0;
|
|
thread_call_stack::context ctx(this, this_thread);
|
|
|
|
mutex::scoped_lock lock(mutex_);
|
|
|
|
#if defined(ASIO_HAS_THREADS)
|
|
// We want to support nested calls to poll() and poll_one(), so any handlers
|
|
// that are already on a thread-private queue need to be put on to the main
|
|
// queue now.
|
|
if (one_thread_)
|
|
if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
|
|
op_queue_.push(outer_info->private_op_queue);
|
|
#endif // defined(ASIO_HAS_THREADS)
|
|
|
|
std::size_t n = 0;
|
|
for (; do_poll_one(lock, this_thread, ec); lock.lock())
|
|
if (n != (std::numeric_limits<std::size_t>::max)())
|
|
++n;
|
|
return n;
|
|
}
|
|
|
|
std::size_t scheduler::poll_one(asio::error_code& ec)
|
|
{
|
|
ec = asio::error_code();
|
|
if (outstanding_work_ == 0)
|
|
{
|
|
stop();
|
|
return 0;
|
|
}
|
|
|
|
thread_info this_thread;
|
|
this_thread.private_outstanding_work = 0;
|
|
thread_call_stack::context ctx(this, this_thread);
|
|
|
|
mutex::scoped_lock lock(mutex_);
|
|
|
|
#if defined(ASIO_HAS_THREADS)
|
|
// We want to support nested calls to poll() and poll_one(), so any handlers
|
|
// that are already on a thread-private queue need to be put on to the main
|
|
// queue now.
|
|
if (one_thread_)
|
|
if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
|
|
op_queue_.push(outer_info->private_op_queue);
|
|
#endif // defined(ASIO_HAS_THREADS)
|
|
|
|
return do_poll_one(lock, this_thread, ec);
|
|
}
|
|
|
|
void scheduler::stop()
|
|
{
|
|
mutex::scoped_lock lock(mutex_);
|
|
stop_all_threads(lock);
|
|
}
|
|
|
|
bool scheduler::stopped() const
|
|
{
|
|
mutex::scoped_lock lock(mutex_);
|
|
return stopped_;
|
|
}
|
|
|
|
void scheduler::restart()
|
|
{
|
|
mutex::scoped_lock lock(mutex_);
|
|
stopped_ = false;
|
|
}
|
|
|
|
void scheduler::compensating_work_started()
|
|
{
|
|
thread_info_base* this_thread = thread_call_stack::contains(this);
|
|
++static_cast<thread_info*>(this_thread)->private_outstanding_work;
|
|
}
|
|
|
|
bool scheduler::can_dispatch()
|
|
{
|
|
return thread_call_stack::contains(this) != 0;
|
|
}
|
|
|
|
void scheduler::capture_current_exception()
|
|
{
|
|
if (thread_info_base* this_thread = thread_call_stack::contains(this))
|
|
this_thread->capture_current_exception();
|
|
}
|
|
|
|
void scheduler::post_immediate_completion(
|
|
scheduler::operation* op, bool is_continuation)
|
|
{
|
|
#if defined(ASIO_HAS_THREADS)
|
|
if (one_thread_ || is_continuation)
|
|
{
|
|
if (thread_info_base* this_thread = thread_call_stack::contains(this))
|
|
{
|
|
++static_cast<thread_info*>(this_thread)->private_outstanding_work;
|
|
static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
|
|
return;
|
|
}
|
|
}
|
|
#else // defined(ASIO_HAS_THREADS)
|
|
(void)is_continuation;
|
|
#endif // defined(ASIO_HAS_THREADS)
|
|
|
|
work_started();
|
|
mutex::scoped_lock lock(mutex_);
|
|
op_queue_.push(op);
|
|
wake_one_thread_and_unlock(lock);
|
|
}
|
|
|
|
void scheduler::post_immediate_completions(std::size_t n,
|
|
op_queue<scheduler::operation>& ops, bool is_continuation)
|
|
{
|
|
#if defined(ASIO_HAS_THREADS)
|
|
if (one_thread_ || is_continuation)
|
|
{
|
|
if (thread_info_base* this_thread = thread_call_stack::contains(this))
|
|
{
|
|
static_cast<thread_info*>(this_thread)->private_outstanding_work
|
|
+= static_cast<long>(n);
|
|
static_cast<thread_info*>(this_thread)->private_op_queue.push(ops);
|
|
return;
|
|
}
|
|
}
|
|
#else // defined(ASIO_HAS_THREADS)
|
|
(void)is_continuation;
|
|
#endif // defined(ASIO_HAS_THREADS)
|
|
|
|
increment(outstanding_work_, static_cast<long>(n));
|
|
mutex::scoped_lock lock(mutex_);
|
|
op_queue_.push(ops);
|
|
wake_one_thread_and_unlock(lock);
|
|
}
|
|
|
|
void scheduler::post_deferred_completion(scheduler::operation* op)
|
|
{
|
|
#if defined(ASIO_HAS_THREADS)
|
|
if (one_thread_)
|
|
{
|
|
if (thread_info_base* this_thread = thread_call_stack::contains(this))
|
|
{
|
|
static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
|
|
return;
|
|
}
|
|
}
|
|
#endif // defined(ASIO_HAS_THREADS)
|
|
|
|
mutex::scoped_lock lock(mutex_);
|
|
op_queue_.push(op);
|
|
wake_one_thread_and_unlock(lock);
|
|
}
|
|
|
|
void scheduler::post_deferred_completions(
|
|
op_queue<scheduler::operation>& ops)
|
|
{
|
|
if (!ops.empty())
|
|
{
|
|
#if defined(ASIO_HAS_THREADS)
|
|
if (one_thread_)
|
|
{
|
|
if (thread_info_base* this_thread = thread_call_stack::contains(this))
|
|
{
|
|
static_cast<thread_info*>(this_thread)->private_op_queue.push(ops);
|
|
return;
|
|
}
|
|
}
|
|
#endif // defined(ASIO_HAS_THREADS)
|
|
|
|
mutex::scoped_lock lock(mutex_);
|
|
op_queue_.push(ops);
|
|
wake_one_thread_and_unlock(lock);
|
|
}
|
|
}
|
|
|
|
void scheduler::do_dispatch(
|
|
scheduler::operation* op)
|
|
{
|
|
work_started();
|
|
mutex::scoped_lock lock(mutex_);
|
|
op_queue_.push(op);
|
|
wake_one_thread_and_unlock(lock);
|
|
}
|
|
|
|
void scheduler::abandon_operations(
|
|
op_queue<scheduler::operation>& ops)
|
|
{
|
|
op_queue<scheduler::operation> ops2;
|
|
ops2.push(ops);
|
|
}
|
|
|
|
std::size_t scheduler::do_run_one(mutex::scoped_lock& lock,
|
|
scheduler::thread_info& this_thread,
|
|
const asio::error_code& ec)
|
|
{
|
|
while (!stopped_)
|
|
{
|
|
if (!op_queue_.empty())
|
|
{
|
|
// Prepare to execute first handler from queue.
|
|
operation* o = op_queue_.front();
|
|
op_queue_.pop();
|
|
bool more_handlers = (!op_queue_.empty());
|
|
|
|
if (o == &task_operation_)
|
|
{
|
|
task_interrupted_ = more_handlers;
|
|
|
|
if (more_handlers && !one_thread_)
|
|
wakeup_event_.unlock_and_signal_one(lock);
|
|
else
|
|
lock.unlock();
|
|
|
|
task_cleanup on_exit = { this, &lock, &this_thread };
|
|
(void)on_exit;
|
|
|
|
// Run the task. May throw an exception. Only block if the operation
|
|
// queue is empty and we're not polling, otherwise we want to return
|
|
// as soon as possible.
|
|
task_->run(more_handlers ? 0 : -1, this_thread.private_op_queue);
|
|
}
|
|
else
|
|
{
|
|
std::size_t task_result = o->task_result_;
|
|
|
|
if (more_handlers && !one_thread_)
|
|
wake_one_thread_and_unlock(lock);
|
|
else
|
|
lock.unlock();
|
|
|
|
// Ensure the count of outstanding work is decremented on block exit.
|
|
work_cleanup on_exit = { this, &lock, &this_thread };
|
|
(void)on_exit;
|
|
|
|
// Complete the operation. May throw an exception. Deletes the object.
|
|
o->complete(this, ec, task_result);
|
|
this_thread.rethrow_pending_exception();
|
|
|
|
return 1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
wakeup_event_.clear(lock);
|
|
wakeup_event_.wait(lock);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
std::size_t scheduler::do_wait_one(mutex::scoped_lock& lock,
|
|
scheduler::thread_info& this_thread, long usec,
|
|
const asio::error_code& ec)
|
|
{
|
|
if (stopped_)
|
|
return 0;
|
|
|
|
operation* o = op_queue_.front();
|
|
if (o == 0)
|
|
{
|
|
wakeup_event_.clear(lock);
|
|
wakeup_event_.wait_for_usec(lock, usec);
|
|
usec = 0; // Wait at most once.
|
|
o = op_queue_.front();
|
|
}
|
|
|
|
if (o == &task_operation_)
|
|
{
|
|
op_queue_.pop();
|
|
bool more_handlers = (!op_queue_.empty());
|
|
|
|
task_interrupted_ = more_handlers;
|
|
|
|
if (more_handlers && !one_thread_)
|
|
wakeup_event_.unlock_and_signal_one(lock);
|
|
else
|
|
lock.unlock();
|
|
|
|
{
|
|
task_cleanup on_exit = { this, &lock, &this_thread };
|
|
(void)on_exit;
|
|
|
|
// Run the task. May throw an exception. Only block if the operation
|
|
// queue is empty and we're not polling, otherwise we want to return
|
|
// as soon as possible.
|
|
task_->run(more_handlers ? 0 : usec, this_thread.private_op_queue);
|
|
}
|
|
|
|
o = op_queue_.front();
|
|
if (o == &task_operation_)
|
|
{
|
|
if (!one_thread_)
|
|
wakeup_event_.maybe_unlock_and_signal_one(lock);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (o == 0)
|
|
return 0;
|
|
|
|
op_queue_.pop();
|
|
bool more_handlers = (!op_queue_.empty());
|
|
|
|
std::size_t task_result = o->task_result_;
|
|
|
|
if (more_handlers && !one_thread_)
|
|
wake_one_thread_and_unlock(lock);
|
|
else
|
|
lock.unlock();
|
|
|
|
// Ensure the count of outstanding work is decremented on block exit.
|
|
work_cleanup on_exit = { this, &lock, &this_thread };
|
|
(void)on_exit;
|
|
|
|
// Complete the operation. May throw an exception. Deletes the object.
|
|
o->complete(this, ec, task_result);
|
|
this_thread.rethrow_pending_exception();
|
|
|
|
return 1;
|
|
}
|
|
|
|
std::size_t scheduler::do_poll_one(mutex::scoped_lock& lock,
|
|
scheduler::thread_info& this_thread,
|
|
const asio::error_code& ec)
|
|
{
|
|
if (stopped_)
|
|
return 0;
|
|
|
|
operation* o = op_queue_.front();
|
|
if (o == &task_operation_)
|
|
{
|
|
op_queue_.pop();
|
|
lock.unlock();
|
|
|
|
{
|
|
task_cleanup c = { this, &lock, &this_thread };
|
|
(void)c;
|
|
|
|
// Run the task. May throw an exception. Only block if the operation
|
|
// queue is empty and we're not polling, otherwise we want to return
|
|
// as soon as possible.
|
|
task_->run(0, this_thread.private_op_queue);
|
|
}
|
|
|
|
o = op_queue_.front();
|
|
if (o == &task_operation_)
|
|
{
|
|
wakeup_event_.maybe_unlock_and_signal_one(lock);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (o == 0)
|
|
return 0;
|
|
|
|
op_queue_.pop();
|
|
bool more_handlers = (!op_queue_.empty());
|
|
|
|
std::size_t task_result = o->task_result_;
|
|
|
|
if (more_handlers && !one_thread_)
|
|
wake_one_thread_and_unlock(lock);
|
|
else
|
|
lock.unlock();
|
|
|
|
// Ensure the count of outstanding work is decremented on block exit.
|
|
work_cleanup on_exit = { this, &lock, &this_thread };
|
|
(void)on_exit;
|
|
|
|
// Complete the operation. May throw an exception. Deletes the object.
|
|
o->complete(this, ec, task_result);
|
|
this_thread.rethrow_pending_exception();
|
|
|
|
return 1;
|
|
}
|
|
|
|
void scheduler::stop_all_threads(
|
|
mutex::scoped_lock& lock)
|
|
{
|
|
stopped_ = true;
|
|
wakeup_event_.signal_all(lock);
|
|
|
|
if (!task_interrupted_ && task_)
|
|
{
|
|
task_interrupted_ = true;
|
|
task_->interrupt();
|
|
}
|
|
}
|
|
|
|
void scheduler::wake_one_thread_and_unlock(
|
|
mutex::scoped_lock& lock)
|
|
{
|
|
if (!wakeup_event_.maybe_unlock_and_signal_one(lock))
|
|
{
|
|
if (!task_interrupted_ && task_)
|
|
{
|
|
task_interrupted_ = true;
|
|
task_->interrupt();
|
|
}
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
} // namespace detail
|
|
} // namespace asio
|
|
|
|
#include "asio/detail/pop_options.hpp"
|
|
|
|
#endif // ASIO_DETAIL_IMPL_SCHEDULER_IPP
|