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Diffstat (limited to 'src/third_party/boost-1.60.0/boost/thread/executors/serial_executor.hpp')
| -rw-r--r-- | src/third_party/boost-1.60.0/boost/thread/executors/serial_executor.hpp | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/third_party/boost-1.60.0/boost/thread/executors/serial_executor.hpp b/src/third_party/boost-1.60.0/boost/thread/executors/serial_executor.hpp new file mode 100644 index 00000000000..6d7ed9be97b --- /dev/null +++ b/src/third_party/boost-1.60.0/boost/thread/executors/serial_executor.hpp @@ -0,0 +1,216 @@ +// Copyright (C) 2013 Vicente J. Botet Escriba +// +// 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) +// +// 2013/11 Vicente J. Botet Escriba +// first implementation of a simple serial scheduler. + +#ifndef BOOST_THREAD_SERIAL_EXECUTOR_HPP +#define BOOST_THREAD_SERIAL_EXECUTOR_HPP + +#include <boost/thread/detail/config.hpp> +#include <boost/thread/detail/delete.hpp> +#include <boost/thread/detail/move.hpp> +#include <boost/thread/concurrent_queues/sync_queue.hpp> +#include <boost/thread/executors/work.hpp> +#include <boost/thread/executors/generic_executor_ref.hpp> +#include <boost/thread/future.hpp> +#include <boost/thread/scoped_thread.hpp> + +#include <boost/config/abi_prefix.hpp> + +namespace boost +{ +namespace executors +{ + class serial_executor + { + public: + /// type-erasure to store the works to do + typedef executors::work work; + private: + typedef scoped_thread<> thread_t; + + /// the thread safe work queue + concurrent::sync_queue<work > work_queue; + generic_executor_ref ex; + thread_t thr; + + struct try_executing_one_task { + work& task; + boost::promise<void> &p; + try_executing_one_task(work& task, boost::promise<void> &p) + : task(task), p(p) {} + void operator()() { + try { + task(); + p.set_value(); + } catch (...) + { + p.set_exception(current_exception()); + } + } + }; + public: + /** + * \par Returns + * The underlying executor wrapped on a generic executor reference. + */ + generic_executor_ref& underlying_executor() BOOST_NOEXCEPT { return ex; } + + /** + * Effects: try to execute one task. + * Returns: whether a task has been executed. + * Throws: whatever the current task constructor throws or the task() throws. + */ + bool try_executing_one() + { + work task; + try + { + if (work_queue.try_pull(task) == queue_op_status::success) + { + boost::promise<void> p; + try_executing_one_task tmp(task,p); + ex.submit(tmp); + p.get_future().wait(); + return true; + } + return false; + } + catch (...) + { + std::terminate(); + //return false; + } + } + private: + /** + * Effects: schedule one task or yields + * Throws: whatever the current task constructor throws or the task() throws. + */ + void schedule_one_or_yield() + { + if ( ! try_executing_one()) + { + this_thread::yield(); + } + } + + /** + * The main loop of the worker thread + */ + void worker_thread() + { + while (!closed()) + { + schedule_one_or_yield(); + } + while (try_executing_one()) + { + } + } + + public: + /// serial_executor is not copyable. + BOOST_THREAD_NO_COPYABLE(serial_executor) + + /** + * \b Effects: creates a thread pool that runs closures using one of its closure-executing methods. + * + * \b Throws: Whatever exception is thrown while initializing the needed resources. + */ + template <class Executor> + serial_executor(Executor& ex) + : ex(ex), thr(&serial_executor::worker_thread, this) + { + } + /** + * \b Effects: Destroys the thread pool. + * + * \b Synchronization: The completion of all the closures happen before the completion of the \c serial_executor destructor. + */ + ~serial_executor() + { + // signal to the worker thread that there will be no more submissions. + close(); + } + + /** + * \b Effects: close the \c serial_executor for submissions. + * The loop will work until there is no more closures to run. + */ + void close() + { + work_queue.close(); + } + + /** + * \b Returns: whether the pool is closed for submissions. + */ + bool closed() + { + return work_queue.closed(); + } + + /** + * \b Requires: \c Closure is a model of \c Callable(void()) and a model of \c CopyConstructible/MoveConstructible. + * + * \b Effects: The specified \c closure will be scheduled for execution at some point in the future. + * If invoked closure throws an exception the \c serial_executor will call \c std::terminate, as is the case with threads. + * + * \b Synchronization: completion of \c closure on a particular thread happens before destruction of thread's thread local variables. + * + * \b Throws: \c sync_queue_is_closed if the thread pool is closed. + * Whatever exception that can be throw while storing the closure. + */ + void submit(BOOST_THREAD_RV_REF(work) closure) + { + work_queue.push(boost::move(closure)); + } + +#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) + template <typename Closure> + void submit(Closure & closure) + { + submit(work(closure)); + } +#endif + void submit(void (*closure)()) + { + submit(work(closure)); + } + + template <typename Closure> + void submit(BOOST_THREAD_FWD_REF(Closure) closure) + { + work w((boost::forward<Closure>(closure))); + submit(boost::move(w)); + } + + /** + * \b Requires: This must be called from an scheduled task. + * + * \b Effects: reschedule functions until pred() + */ + template <typename Pred> + bool reschedule_until(Pred const& pred) + { + do { + if ( ! try_executing_one()) + { + return false; + } + } while (! pred()); + return true; + } + + }; +} +using executors::serial_executor; +} + +#include <boost/config/abi_suffix.hpp> + +#endif |