/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2019, Google Inc. * * event_loop.cpp - cam - Event loop */ #include "event_loop.h" #include <assert.h> #include <event2/event.h> #include <event2/thread.h> #include <iostream> EventLoop *EventLoop::instance_ = nullptr; EventLoop::EventLoop() { assert(!instance_); evthread_use_pthreads(); base_ = event_base_new(); instance_ = this; } EventLoop::~EventLoop() { instance_ = nullptr; events_.clear(); event_base_free(base_); libevent_global_shutdown(); } EventLoop *EventLoop::instance() { return instance_; } int EventLoop::exec() { exitCode_ = -1; event_base_loop(base_, EVLOOP_NO_EXIT_ON_EMPTY); return exitCode_; } void EventLoop::exit(int code) { exitCode_ = code; event_base_loopbreak(base_); } void EventLoop::callLater(const std::function<void()> &func) { { std::unique_lock<std::mutex> locker(lock_); calls_.push_back(func); } event_base_once(base_, -1, EV_TIMEOUT, dispatchCallback, this, nullptr); } void EventLoop::addEvent(int fd, EventType type, const std::function<void()> &callback) { std::unique_ptr<Event> event = std::make_unique<Event>(callback); short events = (type & Read ? EV_READ : 0) | (type & Write ? EV_WRITE : 0) | EV_PERSIST; event->event_ = event_new(base_, fd, events, &EventLoop::Event::dispatch, event.get()); if (!event->event_) { std::cerr << "Failed to create event for fd " << fd << std::endl; return; } int ret = event_add(event->event_, nullptr); if (ret < 0) { std::cerr << "Failed to add event for fd " << fd << std::endl; return; } events_.push_back(std::move(event)); } void EventLoop::dispatchCallback([[maybe_unused]] evutil_socket_t fd, [[maybe_unused]] short flags, void *param) { EventLoop *loop = static_cast<EventLoop *>(param); loop->dispatchCall(); } void EventLoop::dispatchCall() { std::function<void()> call; { std::unique_lock<std::mutex> locker(lock_); if (calls_.empty()) return; call = calls_.front(); calls_.pop_front(); } call(); } EventLoop::Event::Event(const std::function<void()> &callback) : callback_(callback), event_(nullptr) { } EventLoop::Event::~Event() { event_del(event_); event_free(event_); } void EventLoop::Event::dispatch([[maybe_unused]] int fd, [[maybe_unused]] short events, void *arg) { Event *event = static_cast<Event *>(arg); event->callback_(); }