5b60b689c1
Cam uses libevent to deal with threads and idle loop while still implementing its own event queue. This creates issues when the event loop is terminated as it might get stuck in the idle loop if exit() is called while the thread is busy with dispatchCalls(). Solve this by removing the custom event execution and instead injecting the calls as events to the base event loop. Reported-by: Sebastian Fricke <sebastian.fricke@posteo.net> Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
83 lines
1.3 KiB
C++
83 lines
1.3 KiB
C++
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* Copyright (C) 2019, Google Inc.
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*
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* event_loop.cpp - cam - Event loop
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*/
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#include "event_loop.h"
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#include <assert.h>
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#include <event2/event.h>
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#include <event2/thread.h>
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EventLoop *EventLoop::instance_ = nullptr;
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EventLoop::EventLoop()
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{
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assert(!instance_);
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evthread_use_pthreads();
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base_ = event_base_new();
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instance_ = this;
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}
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EventLoop::~EventLoop()
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{
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instance_ = nullptr;
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event_base_free(base_);
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libevent_global_shutdown();
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}
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EventLoop *EventLoop::instance()
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{
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return instance_;
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}
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int EventLoop::exec()
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{
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exitCode_ = -1;
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event_base_loop(base_, EVLOOP_NO_EXIT_ON_EMPTY);
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return exitCode_;
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}
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void EventLoop::exit(int code)
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{
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exitCode_ = code;
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event_base_loopbreak(base_);
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}
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void EventLoop::callLater(const std::function<void()> &func)
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{
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{
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std::unique_lock<std::mutex> locker(lock_);
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calls_.push_back(func);
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}
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event_base_once(base_, -1, EV_TIMEOUT, dispatchCallback, this, nullptr);
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}
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void EventLoop::dispatchCallback([[maybe_unused]] evutil_socket_t fd,
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[[maybe_unused]] short flags, void *param)
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{
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EventLoop *loop = static_cast<EventLoop *>(param);
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loop->dispatchCall();
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}
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void EventLoop::dispatchCall()
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{
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std::function<void()> call;
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{
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std::unique_lock<std::mutex> locker(lock_);
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if (calls_.empty())
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return;
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call = calls_.front();
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calls_.pop_front();
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}
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call();
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}
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