From e95946831f8ef53d29590735a2df661385edb008 Mon Sep 17 00:00:00 2001 From: "Matthias P. Braendli" Date: Mon, 6 Aug 2018 10:35:22 +0200 Subject: Replace boost by the standalone asio library --- lib/asio/detail/scheduler.hpp | 213 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+) create mode 100644 lib/asio/detail/scheduler.hpp (limited to 'lib/asio/detail/scheduler.hpp') diff --git a/lib/asio/detail/scheduler.hpp b/lib/asio/detail/scheduler.hpp new file mode 100644 index 0000000..10c29b7 --- /dev/null +++ b/lib/asio/detail/scheduler.hpp @@ -0,0 +1,213 @@ +// +// detail/scheduler.hpp +// ~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 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_SCHEDULER_HPP +#define ASIO_DETAIL_SCHEDULER_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" + +#include "asio/error_code.hpp" +#include "asio/execution_context.hpp" +#include "asio/detail/atomic_count.hpp" +#include "asio/detail/conditionally_enabled_event.hpp" +#include "asio/detail/conditionally_enabled_mutex.hpp" +#include "asio/detail/op_queue.hpp" +#include "asio/detail/reactor_fwd.hpp" +#include "asio/detail/scheduler_operation.hpp" +#include "asio/detail/thread_context.hpp" + +#include "asio/detail/push_options.hpp" + +namespace asio { +namespace detail { + +struct scheduler_thread_info; + +class scheduler + : public execution_context_service_base, + public thread_context +{ +public: + typedef scheduler_operation operation; + + // Constructor. Specifies the number of concurrent threads that are likely to + // run the scheduler. If set to 1 certain optimisation are performed. + ASIO_DECL scheduler(asio::execution_context& ctx, + int concurrency_hint = 0); + + // Destroy all user-defined handler objects owned by the service. + ASIO_DECL void shutdown(); + + // Initialise the task, if required. + ASIO_DECL void init_task(); + + // Run the event loop until interrupted or no more work. + ASIO_DECL std::size_t run(asio::error_code& ec); + + // Run until interrupted or one operation is performed. + ASIO_DECL std::size_t run_one(asio::error_code& ec); + + // Run until timeout, interrupted, or one operation is performed. + ASIO_DECL std::size_t wait_one( + long usec, asio::error_code& ec); + + // Poll for operations without blocking. + ASIO_DECL std::size_t poll(asio::error_code& ec); + + // Poll for one operation without blocking. + ASIO_DECL std::size_t poll_one(asio::error_code& ec); + + // Interrupt the event processing loop. + ASIO_DECL void stop(); + + // Determine whether the scheduler is stopped. + ASIO_DECL bool stopped() const; + + // Restart in preparation for a subsequent run invocation. + ASIO_DECL void restart(); + + // Notify that some work has started. + void work_started() + { + ++outstanding_work_; + } + + // Used to compensate for a forthcoming work_finished call. Must be called + // from within a scheduler-owned thread. + ASIO_DECL void compensating_work_started(); + + // Notify that some work has finished. + void work_finished() + { + if (--outstanding_work_ == 0) + stop(); + } + + // Return whether a handler can be dispatched immediately. + bool can_dispatch() + { + return thread_call_stack::contains(this) != 0; + } + + // Request invocation of the given operation and return immediately. Assumes + // that work_started() has not yet been called for the operation. + ASIO_DECL void post_immediate_completion( + operation* op, bool is_continuation); + + // Request invocation of the given operation and return immediately. Assumes + // that work_started() was previously called for the operation. + ASIO_DECL void post_deferred_completion(operation* op); + + // Request invocation of the given operations and return immediately. Assumes + // that work_started() was previously called for each operation. + ASIO_DECL void post_deferred_completions(op_queue& ops); + + // Enqueue the given operation following a failed attempt to dispatch the + // operation for immediate invocation. + ASIO_DECL void do_dispatch(operation* op); + + // Process unfinished operations as part of a shutdownoperation. Assumes that + // work_started() was previously called for the operations. + ASIO_DECL void abandon_operations(op_queue& ops); + + // Get the concurrency hint that was used to initialise the scheduler. + int concurrency_hint() const + { + return concurrency_hint_; + } + +private: + // The mutex type used by this scheduler. + typedef conditionally_enabled_mutex mutex; + + // The event type used by this scheduler. + typedef conditionally_enabled_event event; + + // Structure containing thread-specific data. + typedef scheduler_thread_info thread_info; + + // Run at most one operation. May block. + ASIO_DECL std::size_t do_run_one(mutex::scoped_lock& lock, + thread_info& this_thread, const asio::error_code& ec); + + // Run at most one operation with a timeout. May block. + ASIO_DECL std::size_t do_wait_one(mutex::scoped_lock& lock, + thread_info& this_thread, long usec, const asio::error_code& ec); + + // Poll for at most one operation. + ASIO_DECL std::size_t do_poll_one(mutex::scoped_lock& lock, + thread_info& this_thread, const asio::error_code& ec); + + // Stop the task and all idle threads. + ASIO_DECL void stop_all_threads(mutex::scoped_lock& lock); + + // Wake a single idle thread, or the task, and always unlock the mutex. + ASIO_DECL void wake_one_thread_and_unlock( + mutex::scoped_lock& lock); + + // Helper class to perform task-related operations on block exit. + struct task_cleanup; + friend struct task_cleanup; + + // Helper class to call work-related operations on block exit. + struct work_cleanup; + friend struct work_cleanup; + + // Whether to optimise for single-threaded use cases. + const bool one_thread_; + + // Mutex to protect access to internal data. + mutable mutex mutex_; + + // Event to wake up blocked threads. + event wakeup_event_; + + // The task to be run by this service. + reactor* task_; + + // Operation object to represent the position of the task in the queue. + struct task_operation : operation + { + task_operation() : operation(0) {} + } task_operation_; + + // Whether the task has been interrupted. + bool task_interrupted_; + + // The count of unfinished work. + atomic_count outstanding_work_; + + // The queue of handlers that are ready to be delivered. + op_queue op_queue_; + + // Flag to indicate that the dispatcher has been stopped. + bool stopped_; + + // Flag to indicate that the dispatcher has been shut down. + bool shutdown_; + + // The concurrency hint used to initialise the scheduler. + const int concurrency_hint_; +}; + +} // namespace detail +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#if defined(ASIO_HEADER_ONLY) +# include "asio/detail/impl/scheduler.ipp" +#endif // defined(ASIO_HEADER_ONLY) + +#endif // ASIO_DETAIL_SCHEDULER_HPP -- cgit v1.2.3