1 // Copyright (C) 2013,2014 Vicente J. Botet Escriba
3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 // 2013/11 Vicente J. Botet Escriba
7 // first implementation of a simple user scheduler.
8 // 2013/11 Vicente J. Botet Escriba
9 // rename loop_executor.
11 #ifndef BOOST_THREAD_EXECUTORS_LOOP_EXECUTOR_HPP
12 #define BOOST_THREAD_EXECUTORS_LOOP_EXECUTOR_HPP
14 #include <boost/thread/detail/config.hpp>
15 #include <boost/thread/detail/delete.hpp>
16 #include <boost/thread/detail/move.hpp>
17 #include <boost/thread/concurrent_queues/sync_queue.hpp>
18 #include <boost/thread/executors/work.hpp>
20 #include <boost/config/abi_prefix.hpp>
30 /// type-erasure to store the works to do
31 typedef executors::work work;
33 /// the thread safe work queue
34 concurrent::sync_queue<work > work_queue;
38 * Effects: try to execute one task.
39 * Returns: whether a task has been executed.
40 * Throws: whatever the current task constructor throws or the task() throws.
42 bool try_executing_one()
47 if (work_queue.try_pull(task) == queue_op_status::success)
62 * Effects: schedule one task or yields
63 * Throws: whatever the current task constructor throws or the task() throws.
65 void schedule_one_or_yield()
67 if ( ! try_executing_one())
77 /// loop_executor is not copyable.
78 BOOST_THREAD_NO_COPYABLE(loop_executor)
81 * \b Effects: creates a thread pool that runs closures using one of its closure-executing methods.
83 * \b Throws: Whatever exception is thrown while initializing the needed resources.
89 * \b Effects: Destroys the thread pool.
91 * \b Synchronization: The completion of all the closures happen before the completion of the \c loop_executor destructor.
95 // signal to all the worker thread that there will be no more submissions.
100 * The main loop of the worker thread
106 schedule_one_or_yield();
108 while (try_executing_one())
114 * \b Effects: close the \c loop_executor for submissions.
115 * The loop will work until there is no more closures to run.
123 * \b Returns: whether the pool is closed for submissions.
127 return work_queue.closed();
131 * \b Requires: \c Closure is a model of \c Callable(void()) and a model of \c CopyConstructible/MoveConstructible.
133 * \b Effects: The specified \c closure will be scheduled for execution at some point in the future.
134 * If invoked closure throws an exception the \c loop_executor will call \c std::terminate, as is the case with threads.
136 * \b Synchronization: completion of \c closure on a particular thread happens before destruction of thread's thread local variables.
138 * \b Throws: \c sync_queue_is_closed if the thread pool is closed.
139 * Whatever exception that can be throw while storing the closure.
141 void submit(BOOST_THREAD_RV_REF(work) closure) {
142 work_queue.push(boost::move(closure));
145 #if defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
146 template <typename Closure>
147 void submit(Closure & closure)
149 submit(work(closure));
153 void submit(void (*closure)())
155 submit(work(closure));
158 template <typename Closure>
159 void submit(BOOST_THREAD_FWD_REF(Closure) closure)
161 //work_queue.push(work(boost::forward<Closure>(closure)));
162 work w((boost::forward<Closure>(closure)));
163 submit(boost::move(w));
167 * \b Requires: This must be called from an scheduled task.
169 * \b Effects: reschedule functions until pred()
171 template <typename Pred>
172 bool reschedule_until(Pred const& pred)
175 if ( ! try_executing_one())
184 * run queued closures
186 void run_queued_closures()
188 sync_queue<work>::underlying_queue_type q = work_queue.underlying_queue();
191 work& task = q.front();
199 using executors::loop_executor;
203 #include <boost/config/abi_suffix.hpp>