Swiftdiff options
Diffstat (limited to '3rdParty/Boost/src/boost/asio/detail/epoll_reactor.hpp')
| -rw-r--r-- | 3rdParty/Boost/src/boost/asio/detail/epoll_reactor.hpp | 747 |
1 files changed, 263 insertions, 484 deletions
diff --git a/3rdParty/Boost/src/boost/asio/detail/epoll_reactor.hpp b/3rdParty/Boost/src/boost/asio/detail/epoll_reactor.hpp index 6c6bfe3..4684944 100644 --- a/3rdParty/Boost/src/boost/asio/detail/epoll_reactor.hpp +++ b/3rdParty/Boost/src/boost/asio/detail/epoll_reactor.hpp @@ -23,115 +23,126 @@ #include <boost/asio/detail/push_options.hpp> #include <cstddef> -#include <vector> #include <sys/epoll.h> #include <boost/config.hpp> -#include <boost/date_time/posix_time/posix_time_types.hpp> #include <boost/throw_exception.hpp> #include <boost/system/system_error.hpp> #include <boost/asio/detail/pop_options.hpp> #include <boost/asio/error.hpp> #include <boost/asio/io_service.hpp> -#include <boost/asio/detail/bind_handler.hpp> #include <boost/asio/detail/hash_map.hpp> #include <boost/asio/detail/mutex.hpp> -#include <boost/asio/detail/task_io_service.hpp> -#include <boost/asio/detail/thread.hpp> -#include <boost/asio/detail/reactor_op_queue.hpp> +#include <boost/asio/detail/op_queue.hpp> +#include <boost/asio/detail/reactor_op.hpp> #include <boost/asio/detail/select_interrupter.hpp> #include <boost/asio/detail/service_base.hpp> -#include <boost/asio/detail/signal_blocker.hpp> #include <boost/asio/detail/socket_types.hpp> -#include <boost/asio/detail/timer_queue.hpp> +#include <boost/asio/detail/timer_op.hpp> +#include <boost/asio/detail/timer_queue_base.hpp> +#include <boost/asio/detail/timer_queue_fwd.hpp> +#include <boost/asio/detail/timer_queue_set.hpp> + +#if (__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 8) +# define BOOST_ASIO_HAS_TIMERFD 1 +#endif // (__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 8) + +#if defined(BOOST_ASIO_HAS_TIMERFD) +# include <boost/asio/detail/push_options.hpp> +# include <sys/timerfd.h> +# include <boost/asio/detail/pop_options.hpp> +#endif // defined(BOOST_ASIO_HAS_TIMERFD) namespace boost { namespace asio { namespace detail { -template <bool Own_Thread> class epoll_reactor - : public boost::asio::detail::service_base<epoll_reactor<Own_Thread> > + : public boost::asio::detail::service_base<epoll_reactor> { public: - // Per-descriptor data. - struct per_descriptor_data + enum { read_op = 0, write_op = 1, + connect_op = 1, except_op = 2, max_ops = 3 }; + + // Per-descriptor queues. + struct descriptor_state { - bool allow_speculative_read; - bool allow_speculative_write; + descriptor_state() {} + descriptor_state(const descriptor_state&) {} + void operator=(const descriptor_state&) {} + + mutex mutex_; + op_queue<reactor_op> op_queue_[max_ops]; + bool shutdown_; }; + // Per-descriptor data. + typedef descriptor_state* per_descriptor_data; + // Constructor. epoll_reactor(boost::asio::io_service& io_service) - : boost::asio::detail::service_base<epoll_reactor<Own_Thread> >(io_service), + : boost::asio::detail::service_base<epoll_reactor>(io_service), + io_service_(use_service<io_service_impl>(io_service)), mutex_(), epoll_fd_(do_epoll_create()), - wait_in_progress_(false), +#if defined(BOOST_ASIO_HAS_TIMERFD) + timer_fd_(timerfd_create(CLOCK_MONOTONIC, 0)), +#else // defined(BOOST_ASIO_HAS_TIMERFD) + timer_fd_(-1), +#endif // defined(BOOST_ASIO_HAS_TIMERFD) interrupter_(), - read_op_queue_(), - write_op_queue_(), - except_op_queue_(), - pending_cancellations_(), - stop_thread_(false), - thread_(0), - shutdown_(false), - need_epoll_wait_(true) + shutdown_(false) { - // Start the reactor's internal thread only if needed. - if (Own_Thread) - { - boost::asio::detail::signal_blocker sb; - thread_ = new boost::asio::detail::thread( - bind_handler(&epoll_reactor::call_run_thread, this)); - } - // Add the interrupter's descriptor to epoll. epoll_event ev = { 0, { 0 } }; - ev.events = EPOLLIN | EPOLLERR; - ev.data.fd = interrupter_.read_descriptor(); + ev.events = EPOLLIN | EPOLLERR | EPOLLET; + ev.data.ptr = &interrupter_; epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, interrupter_.read_descriptor(), &ev); + interrupter_.interrupt(); + + // Add the timer descriptor to epoll. + if (timer_fd_ != -1) + { + ev.events = EPOLLIN | EPOLLERR; + ev.data.ptr = &timer_fd_; + epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, timer_fd_, &ev); + } } // Destructor. ~epoll_reactor() { - shutdown_service(); close(epoll_fd_); + if (timer_fd_ != -1) + close(timer_fd_); } // Destroy all user-defined handler objects owned by the service. void shutdown_service() { - boost::asio::detail::mutex::scoped_lock lock(mutex_); + mutex::scoped_lock lock(mutex_); shutdown_ = true; - stop_thread_ = true; lock.unlock(); - if (thread_) + op_queue<operation> ops; + + descriptor_map::iterator iter = registered_descriptors_.begin(); + descriptor_map::iterator end = registered_descriptors_.end(); + while (iter != end) { - interrupter_.interrupt(); - thread_->join(); - delete thread_; - thread_ = 0; + for (int i = 0; i < max_ops; ++i) + ops.push(iter->second.op_queue_[i]); + iter->second.shutdown_ = true; + ++iter; } - read_op_queue_.destroy_operations(); - write_op_queue_.destroy_operations(); - except_op_queue_.destroy_operations(); - - for (std::size_t i = 0; i < timer_queues_.size(); ++i) - timer_queues_[i]->destroy_timers(); - timer_queues_.clear(); + timer_queues_.get_all_timers(ops); } - // Initialise the task, but only if the reactor is not in its own thread. + // Initialise the task. void init_task() { - if (!Own_Thread) - { - typedef task_io_service<epoll_reactor<Own_Thread> > task_io_service_type; - use_service<task_io_service_type>(this->get_io_service()).init_task(); - } + io_service_.init_task(); } // Register a socket with the reactor. Returns 0 on success, system error @@ -139,454 +150,274 @@ public: int register_descriptor(socket_type descriptor, per_descriptor_data& descriptor_data) { - // No need to lock according to epoll documentation. + mutex::scoped_lock lock(registered_descriptors_mutex_); - descriptor_data.allow_speculative_read = true; - descriptor_data.allow_speculative_write = true; + descriptor_map::iterator new_entry = registered_descriptors_.insert( + std::make_pair(descriptor, descriptor_state())).first; + descriptor_data = &new_entry->second; epoll_event ev = { 0, { 0 } }; - ev.events = 0; - ev.data.fd = descriptor; + ev.events = EPOLLIN | EPOLLERR | EPOLLHUP | EPOLLOUT | EPOLLPRI | EPOLLET; + ev.data.ptr = descriptor_data; int result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev); if (result != 0) return errno; + + descriptor_data->shutdown_ = false; + return 0; } - // Start a new read operation. The handler object will be invoked when the - // given descriptor is ready to be read, or an error has occurred. - template <typename Handler> - void start_read_op(socket_type descriptor, + // Start a new operation. The reactor operation will be performed when the + // given descriptor is flagged as ready, or an error has occurred. + void start_op(int op_type, socket_type descriptor, per_descriptor_data& descriptor_data, - Handler handler, bool allow_speculative_read = true) + reactor_op* op, bool allow_speculative) { - if (allow_speculative_read && descriptor_data.allow_speculative_read) - { - boost::system::error_code ec; - std::size_t bytes_transferred = 0; - if (handler.perform(ec, bytes_transferred)) - { - handler.complete(ec, bytes_transferred); - return; - } - - // We only get one shot at a speculative read in this function. - allow_speculative_read = false; - } - - boost::asio::detail::mutex::scoped_lock lock(mutex_); - - if (shutdown_) + mutex::scoped_lock descriptor_lock(descriptor_data->mutex_); + if (descriptor_data->shutdown_) return; - if (!allow_speculative_read) - need_epoll_wait_ = true; - else if (!read_op_queue_.has_operation(descriptor)) + if (descriptor_data->op_queue_[op_type].empty()) { - // Speculative reads are ok as there are no queued read operations. - descriptor_data.allow_speculative_read = true; - - boost::system::error_code ec; - std::size_t bytes_transferred = 0; - if (handler.perform(ec, bytes_transferred)) + if (allow_speculative + && (op_type != read_op + || descriptor_data->op_queue_[except_op].empty())) { - handler.complete(ec, bytes_transferred); - return; + if (op->perform()) + { + descriptor_lock.unlock(); + io_service_.post_immediate_completion(op); + return; + } } - } - - // Speculative reads are not ok as there will be queued read operations. - descriptor_data.allow_speculative_read = false; - - if (read_op_queue_.enqueue_operation(descriptor, handler)) - { - epoll_event ev = { 0, { 0 } }; - ev.events = EPOLLIN | EPOLLERR | EPOLLHUP; - if (write_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLOUT; - if (except_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLPRI; - ev.data.fd = descriptor; - - int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev); - if (result != 0 && errno == ENOENT) - result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev); - if (result != 0) + else { - boost::system::error_code ec(errno, - boost::asio::error::get_system_category()); - read_op_queue_.perform_all_operations(descriptor, ec); + epoll_event ev = { 0, { 0 } }; + ev.events = EPOLLIN | EPOLLERR | EPOLLHUP + | EPOLLOUT | EPOLLPRI | EPOLLET; + ev.data.ptr = descriptor_data; + epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev); } } + + descriptor_data->op_queue_[op_type].push(op); + io_service_.work_started(); } - // Start a new write operation. The handler object will be invoked when the - // given descriptor is ready to be written, or an error has occurred. - template <typename Handler> - void start_write_op(socket_type descriptor, - per_descriptor_data& descriptor_data, - Handler handler, bool allow_speculative_write = true) + // Cancel all operations associated with the given descriptor. The + // handlers associated with the descriptor will be invoked with the + // operation_aborted error. + void cancel_ops(socket_type descriptor, per_descriptor_data& descriptor_data) { - if (allow_speculative_write && descriptor_data.allow_speculative_write) - { - boost::system::error_code ec; - std::size_t bytes_transferred = 0; - if (handler.perform(ec, bytes_transferred)) - { - handler.complete(ec, bytes_transferred); - return; - } - - // We only get one shot at a speculative write in this function. - allow_speculative_write = false; - } - - boost::asio::detail::mutex::scoped_lock lock(mutex_); + mutex::scoped_lock descriptor_lock(descriptor_data->mutex_); - if (shutdown_) - return; - - if (!allow_speculative_write) - need_epoll_wait_ = true; - else if (!write_op_queue_.has_operation(descriptor)) + op_queue<operation> ops; + for (int i = 0; i < max_ops; ++i) { - // Speculative writes are ok as there are no queued write operations. - descriptor_data.allow_speculative_write = true; - - boost::system::error_code ec; - std::size_t bytes_transferred = 0; - if (handler.perform(ec, bytes_transferred)) + while (reactor_op* op = descriptor_data->op_queue_[i].front()) { - handler.complete(ec, bytes_transferred); - return; + op->ec_ = boost::asio::error::operation_aborted; + descriptor_data->op_queue_[i].pop(); + ops.push(op); } } - // Speculative writes are not ok as there will be queued write operations. - descriptor_data.allow_speculative_write = false; + descriptor_lock.unlock(); - if (write_op_queue_.enqueue_operation(descriptor, handler)) - { - epoll_event ev = { 0, { 0 } }; - ev.events = EPOLLOUT | EPOLLERR | EPOLLHUP; - if (read_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLIN; - if (except_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLPRI; - ev.data.fd = descriptor; - - int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev); - if (result != 0 && errno == ENOENT) - result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev); - if (result != 0) - { - boost::system::error_code ec(errno, - boost::asio::error::get_system_category()); - write_op_queue_.perform_all_operations(descriptor, ec); - } - } + io_service_.post_deferred_completions(ops); } - // Start a new exception operation. The handler object will be invoked when - // the given descriptor has exception information, or an error has occurred. - template <typename Handler> - void start_except_op(socket_type descriptor, - per_descriptor_data&, Handler handler) + // Cancel any operations that are running against the descriptor and remove + // its registration from the reactor. + void close_descriptor(socket_type descriptor, + per_descriptor_data& descriptor_data) { - boost::asio::detail::mutex::scoped_lock lock(mutex_); + mutex::scoped_lock descriptor_lock(descriptor_data->mutex_); + mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_); - if (shutdown_) - return; + // Remove the descriptor from the set of known descriptors. The descriptor + // will be automatically removed from the epoll set when it is closed. + descriptor_data->shutdown_ = true; - if (except_op_queue_.enqueue_operation(descriptor, handler)) + op_queue<operation> ops; + for (int i = 0; i < max_ops; ++i) { - epoll_event ev = { 0, { 0 } }; - ev.events = EPOLLPRI | EPOLLERR | EPOLLHUP; - if (read_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLIN; - if (write_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLOUT; - ev.data.fd = descriptor; - - int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev); - if (result != 0 && errno == ENOENT) - result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev); - if (result != 0) + while (reactor_op* op = descriptor_data->op_queue_[i].front()) { - boost::system::error_code ec(errno, - boost::asio::error::get_system_category()); - except_op_queue_.perform_all_operations(descriptor, ec); + op->ec_ = boost::asio::error::operation_aborted; + descriptor_data->op_queue_[i].pop(); + ops.push(op); } } - } - // Start a new write operation. The handler object will be invoked when the - // given descriptor is ready for writing or an error has occurred. Speculative - // writes are not allowed. - template <typename Handler> - void start_connect_op(socket_type descriptor, - per_descriptor_data& descriptor_data, Handler handler) - { - boost::asio::detail::mutex::scoped_lock lock(mutex_); + descriptor_lock.unlock(); - if (shutdown_) - return; + registered_descriptors_.erase(descriptor); - // Speculative writes are not ok as there will be queued write operations. - descriptor_data.allow_speculative_write = false; - - if (write_op_queue_.enqueue_operation(descriptor, handler)) - { - epoll_event ev = { 0, { 0 } }; - ev.events = EPOLLOUT | EPOLLERR | EPOLLHUP; - if (read_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLIN; - if (except_op_queue_.has_operation(descriptor)) - ev.events |= EPOLLPRI; - ev.data.fd = descriptor; - - int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev); - if (result != 0 && errno == ENOENT) - result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev); - if (result != 0) - { - boost::system::error_code ec(errno, - boost::asio::error::get_system_category()); - write_op_queue_.perform_all_operations(descriptor, ec); - } - } - } + descriptors_lock.unlock(); - // Cancel all operations associated with the given descriptor. The - // handlers associated with the descriptor will be invoked with the - // operation_aborted error. - void cancel_ops(socket_type descriptor, per_descriptor_data&) - { - boost::asio::detail::mutex::scoped_lock lock(mutex_); - cancel_ops_unlocked(descriptor); - } - - // Cancel any operations that are running against the descriptor and remove - // its registration from the reactor. - void close_descriptor(socket_type descriptor, per_descriptor_data&) - { - boost::asio::detail::mutex::scoped_lock lock(mutex_); - - // Remove the descriptor from epoll. - epoll_event ev = { 0, { 0 } }; - epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, descriptor, &ev); - - // Cancel any outstanding operations associated with the descriptor. - cancel_ops_unlocked(descriptor); + io_service_.post_deferred_completions(ops); } // Add a new timer queue to the reactor. template <typename Time_Traits> void add_timer_queue(timer_queue<Time_Traits>& timer_queue) { - boost::asio::detail::mutex::scoped_lock lock(mutex_); - timer_queues_.push_back(&timer_queue); + mutex::scoped_lock lock(mutex_); + timer_queues_.insert(&timer_queue); } // Remove a timer queue from the reactor. template <typename Time_Traits> void remove_timer_queue(timer_queue<Time_Traits>& timer_queue) { - boost::asio::detail::mutex::scoped_lock lock(mutex_); - for (std::size_t i = 0; i < timer_queues_.size(); ++i) - { - if (timer_queues_[i] == &timer_queue) - { - timer_queues_.erase(timer_queues_.begin() + i); - return; - } - } + mutex::scoped_lock lock(mutex_); + timer_queues_.erase(&timer_queue); } - // Schedule a timer in the given timer queue to expire at the specified - // absolute time. The handler object will be invoked when the timer expires. - template <typename Time_Traits, typename Handler> + // Schedule a new operation in the given timer queue to expire at the + // specified absolute time. + template <typename Time_Traits> void schedule_timer(timer_queue<Time_Traits>& timer_queue, - const typename Time_Traits::time_type& time, Handler handler, void* token) + const typename Time_Traits::time_type& time, timer_op* op, void* token) { - boost::asio::detail::mutex::scoped_lock lock(mutex_); + mutex::scoped_lock lock(mutex_); if (!shutdown_) - if (timer_queue.enqueue_timer(time, handler, token)) + { + bool earliest = timer_queue.enqueue_timer(time, op, token); + io_service_.work_started(); + if (earliest) + { +#if defined(BOOST_ASIO_HAS_TIMERFD) + if (timer_fd_ != -1) + { + itimerspec new_timeout; + itimerspec old_timeout; + int flags = get_timeout(new_timeout); + timerfd_settime(timer_fd_, flags, &new_timeout, &old_timeout); + return; + } +#endif // defined(BOOST_ASIO_HAS_TIMERFD) interrupter_.interrupt(); + } + } } - // Cancel the timer associated with the given token. Returns the number of - // handlers that have been posted or dispatched. + // Cancel the timer operations associated with the given token. Returns the + // number of operations that have been posted or dispatched. template <typename Time_Traits> std::size_t cancel_timer(timer_queue<Time_Traits>& timer_queue, void* token) { - boost::asio::detail::mutex::scoped_lock lock(mutex_); - std::size_t n = timer_queue.cancel_timer(token); - if (n > 0) - interrupter_.interrupt(); + mutex::scoped_lock lock(mutex_); + op_queue<operation> ops; + std::size_t n = timer_queue.cancel_timer(token, ops); + lock.unlock(); + io_service_.post_deferred_completions(ops); return n; } -private: - friend class task_io_service<epoll_reactor<Own_Thread> >; - // Run epoll once until interrupted or events are ready to be dispatched. - void run(bool block) + void run(bool block, op_queue<operation>& ops) { - boost::asio::detail::mutex::scoped_lock lock(mutex_); - - // Dispatch any operation cancellations that were made while the select - // loop was not running. - read_op_queue_.perform_cancellations(); - write_op_queue_.perform_cancellations(); - except_op_queue_.perform_cancellations(); - for (std::size_t i = 0; i < timer_queues_.size(); ++i) - timer_queues_[i]->dispatch_cancellations(); - - // Check if the thread is supposed to stop. - if (stop_thread_) - { - complete_operations_and_timers(lock); - return; - } - - // We can return immediately if there's no work to do and the reactor is - // not supposed to block. - if (!block && read_op_queue_.empty() && write_op_queue_.empty() - && except_op_queue_.empty() && all_timer_queues_are_empty()) + // Calculate a timeout only if timerfd is not used. + int timeout; + if (timer_fd_ != -1) + timeout = block ? -1 : 0; + else { - complete_operations_and_timers(lock); - return; + mutex::scoped_lock lock(mutex_); + timeout = block ? get_timeout() : 0; } - int timeout = block ? get_timeout() : 0; - wait_in_progress_ = true; - lock.unlock(); - // Block on the epoll descriptor. epoll_event events[128]; - int num_events = (block || need_epoll_wait_) - ? epoll_wait(epoll_fd_, events, 128, timeout) - : 0; + int num_events = epoll_wait(epoll_fd_, events, 128, timeout); - lock.lock(); - wait_in_progress_ = false; +#if defined(BOOST_ASIO_HAS_TIMERFD) + bool check_timers = (timer_fd_ == -1); +#else // defined(BOOST_ASIO_HAS_TIMERFD) + bool check_timers = true; +#endif // defined(BOOST_ASIO_HAS_TIMERFD) // Dispatch the waiting events. for (int i = 0; i < num_events; ++i) { - int descriptor = events[i].data.fd; - if (descriptor == interrupter_.read_descriptor()) + void* ptr = events[i].data.ptr; + if (ptr == &interrupter_) { - interrupter_.reset(); + // No need to reset the interrupter since we're leaving the descriptor + // in a ready-to-read state and relying on edge-triggered notifications + // to make it so that we only get woken up when the descriptor's epoll + // registration is updated. + +#if defined(BOOST_ASIO_HAS_TIMERFD) + if (timer_fd_ == -1) + check_timers = true; +#else // defined(BOOST_ASIO_HAS_TIMERFD) + check_timers = true; +#endif // defined(BOOST_ASIO_HAS_TIMERFD) } +#if defined(BOOST_ASIO_HAS_TIMERFD) + else if (ptr == &timer_fd_) + { + check_timers = true; + } +#endif // defined(BOOST_ASIO_HAS_TIMERFD) else { - bool more_reads = false; - bool more_writes = false; - bool more_except = false; - boost::system::error_code ec; + descriptor_state* descriptor_data = static_cast<descriptor_state*>(ptr); + mutex::scoped_lock descriptor_lock(descriptor_data->mutex_); // Exception operations must be processed first to ensure that any // out-of-band data is read before normal data. - if (events[i].events & (EPOLLPRI | EPOLLERR | EPOLLHUP)) - more_except = except_op_queue_.perform_operation(descriptor, ec); - else - more_except = except_op_queue_.has_operation(descriptor); - - if (events[i].events & (EPOLLIN | EPOLLERR | EPOLLHUP)) - more_reads = read_op_queue_.perform_operation(descriptor, ec); - else - more_reads = read_op_queue_.has_operation(descriptor); - - if (events[i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP)) - more_writes = write_op_queue_.perform_operation(descriptor, ec); - else - more_writes = write_op_queue_.has_operation(descriptor); - - if ((events[i].events & (EPOLLERR | EPOLLHUP)) != 0 - && (events[i].events & ~(EPOLLERR | EPOLLHUP)) == 0 - && !more_except && !more_reads && !more_writes) + static const int flag[max_ops] = { EPOLLIN, EPOLLOUT, EPOLLPRI }; + for (int j = max_ops - 1; j >= 0; --j) { - // If we have an event and no operations associated with the - // descriptor then we need to delete the descriptor from epoll. The - // epoll_wait system call can produce EPOLLHUP or EPOLLERR events - // when there is no operation pending, so if we do not remove the - // descriptor we can end up in a tight loop of repeated - // calls to epoll_wait. - epoll_event ev = { 0, { 0 } }; - epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, descriptor, &ev); - } - else - { - epoll_event ev = { 0, { 0 } }; - ev.events = EPOLLERR | EPOLLHUP; - if (more_reads) - ev.events |= EPOLLIN; - if (more_writes) - ev.events |= EPOLLOUT; - if (more_except) - ev.events |= EPOLLPRI; - ev.data.fd = descriptor; - int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev); - if (result != 0 && errno == ENOENT) - result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev); - if (result != 0) + if (events[i].events & (flag[j] | EPOLLERR | EPOLLHUP)) { - ec = boost::system::error_code(errno, - boost::asio::error::get_system_category()); - read_op_queue_.perform_all_operations(descriptor, ec); - write_op_queue_.perform_all_operations(descriptor, ec); - except_op_queue_.perform_all_operations(descriptor, ec); + while (reactor_op* op = descriptor_data->op_queue_[j].front()) + { + if (op->perform()) + { + descriptor_data->op_queue_[j].pop(); + ops.push(op); + } + else + break; + } } } } } - read_op_queue_.perform_cancellations(); - write_op_queue_.perform_cancellations(); - except_op_queue_.perform_cancellations(); - for (std::size_t i = 0; i < timer_queues_.size(); ++i) - { - timer_queues_[i]->dispatch_timers(); - timer_queues_[i]->dispatch_cancellations(); - } - - // Issue any pending cancellations. - for (size_t i = 0; i < pending_cancellations_.size(); ++i) - cancel_ops_unlocked(pending_cancellations_[i]); - pending_cancellations_.clear(); - - // Determine whether epoll_wait should be called when the reactor next runs. - need_epoll_wait_ = !read_op_queue_.empty() - || !write_op_queue_.empty() || !except_op_queue_.empty(); - - complete_operations_and_timers(lock); - } - // Run the select loop in the thread. - void run_thread() - { - boost::asio::detail::mutex::scoped_lock lock(mutex_); - while (!stop_thread_) + if (check_timers) { - lock.unlock(); - run(true); - lock.lock(); - } - } + mutex::scoped_lock common_lock(mutex_); + timer_queues_.get_ready_timers(ops); - // Entry point for the select loop thread. - static void call_run_thread(epoll_reactor* reactor) - { - reactor->run_thread(); +#if defined(BOOST_ASIO_HAS_TIMERFD) + if (timer_fd_ != -1) + { + itimerspec new_timeout; + itimerspec old_timeout; + int flags = get_timeout(new_timeout); + timerfd_settime(timer_fd_, flags, &new_timeout, &old_timeout); + } +#endif // defined(BOOST_ASIO_HAS_TIMERFD) + } } // Interrupt the select loop. void interrupt() { - interrupter_.interrupt(); + epoll_event ev = { 0, { 0 } }; + ev.events = EPOLLIN | EPOLLERR | EPOLLET; + ev.data.ptr = &interrupter_; + epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, interrupter_.read_descriptor(), &ev); } +private: // The hint to pass to epoll_create to size its data structures. enum { epoll_size = 20000 }; @@ -606,117 +437,65 @@ private: return fd; } - // Check if all timer queues are empty. - bool all_timer_queues_are_empty() const - { - for (std::size_t i = 0; i < timer_queues_.size(); ++i) - if (!timer_queues_[i]->empty()) - return false; - return true; - } - // Get the timeout value for the epoll_wait call. The timeout value is // returned as a number of milliseconds. A return value of -1 indicates // that epoll_wait should block indefinitely. int get_timeout() { - if (all_timer_queues_are_empty()) - return -1; - // By default we will wait no longer than 5 minutes. This will ensure that // any changes to the system clock are detected after no longer than this. - boost::posix_time::time_duration minimum_wait_duration - = boost::posix_time::minutes(5); - - for (std::size_t i = 0; i < timer_queues_.size(); ++i) - { - boost::posix_time::time_duration wait_duration - = timer_queues_[i]->wait_duration(); - if (wait_duration < minimum_wait_duration) - minimum_wait_duration = wait_duration; - } - - if (minimum_wait_duration > boost::posix_time::time_duration()) - { - int milliseconds = minimum_wait_duration.total_milliseconds(); - return milliseconds > 0 ? milliseconds : 1; - } - else - { - return 0; - } + return timer_queues_.wait_duration_msec(5 * 60 * 1000); } - // Cancel all operations associated with the given descriptor. The do_cancel - // function of the handler objects will be invoked. This function does not - // acquire the epoll_reactor's mutex. - void cancel_ops_unlocked(socket_type descriptor) +#if defined(BOOST_ASIO_HAS_TIMERFD) + // Get the timeout value for the timer descriptor. The return value is the + // flag argument to be used when calling timerfd_settime. + int get_timeout(itimerspec& ts) { - bool interrupt = read_op_queue_.cancel_operations(descriptor); - interrupt = write_op_queue_.cancel_operations(descriptor) || interrupt; - interrupt = except_op_queue_.cancel_operations(descriptor) || interrupt; - if (interrupt) - interrupter_.interrupt(); - } + ts.it_interval.tv_sec = 0; + ts.it_interval.tv_nsec = 0; - // Clean up operations and timers. We must not hold the lock since the - // destructors may make calls back into this reactor. We make a copy of the - // vector of timer queues since the original may be modified while the lock - // is not held. - void complete_operations_and_timers( - boost::asio::detail::mutex::scoped_lock& lock) - { - timer_queues_for_cleanup_ = timer_queues_; - lock.unlock(); - read_op_queue_.complete_operations(); - write_op_queue_.complete_operations(); - except_op_queue_.complete_operations(); - for (std::size_t i = 0; i < timer_queues_for_cleanup_.size(); ++i) - timer_queues_for_cleanup_[i]->complete_timers(); + long usec = timer_queues_.wait_duration_usec(5 * 60 * 1000 * 1000); + ts.it_value.tv_sec = usec / 1000000; + ts.it_value.tv_nsec = usec ? (usec % 1000000) * 1000 : 1; + + return usec ? 0 : TFD_TIMER_ABSTIME; } +#endif // defined(BOOST_ASIO_HAS_TIMERFD) + + // The io_service implementation used to post completions. + io_service_impl& io_service_; // Mutex to protect access to internal data. - boost::asio::detail::mutex mutex_; + mutex mutex_; // The epoll file descriptor. int epoll_fd_; - // Whether the epoll_wait call is currently in progress - bool wait_in_progress_; + // The timer file descriptor. + int timer_fd_; // The interrupter is used to break a blocking epoll_wait call. select_interrupter interrupter_; - // The queue of read operations. - reactor_op_queue<socket_type> read_op_queue_; - - // The queue of write operations. - reactor_op_queue<socket_type> write_op_queue_; - - // The queue of except operations. - reactor_op_queue<socket_type> except_op_queue_; - // The timer queues. - std::vector<timer_queue_base*> timer_queues_; - - // A copy of the timer queues, used when cleaning up timers. The copy is - // stored as a class data member to avoid unnecessary memory allocation. - std::vector<timer_queue_base*> timer_queues_for_cleanup_; - - // The descriptors that are pending cancellation. - std::vector<socket_type> pending_cancellations_; - - // Does the reactor loop thread need to stop. - bool stop_thread_; - - // The thread that is running the reactor loop. - boost::asio::detail::thread* thread_; + timer_queue_set timer_queues_; // Whether the service has been shut down. bool shutdown_; - // Whether we need to call epoll_wait the next time the reactor is run. - bool need_epoll_wait_; + // Mutex to protect access to the registered descriptors. + mutex registered_descriptors_mutex_; + + // Keep track of all registered descriptors. This code relies on the fact that + // the hash_map implementation pools deleted nodes, meaning that we can assume + // our descriptor_state pointer remains valid even after the entry is removed. + // Technically this is not true for C++98, as that standard says that spliced + // elements in a list are invalidated. However, C++0x fixes this shortcoming + // so we'll just assume that C++98 std::list implementations will do the right + // thing anyway. + typedef detail::hash_map<socket_type, descriptor_state> descriptor_map; + descriptor_map registered_descriptors_; }; } // namespace detail |