mirror of
https://github.com/encounter/engine.git
synced 2026-03-30 11:09:55 -07:00
Chinmay Garde
ca1d163d45
The number of workers depends on what the platform deem appropriate for the system at runtime.
94 lines
2.3 KiB
C++
94 lines
2.3 KiB
C++
// Copyright 2013 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "flutter/fml/platform/linux/message_loop_linux.h"
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#include <sys/epoll.h>
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#include <unistd.h>
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#include "flutter/fml/eintr_wrapper.h"
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#include "flutter/fml/platform/linux/timerfd.h"
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namespace fml {
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static constexpr int kClockType = CLOCK_MONOTONIC;
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MessageLoopLinux::MessageLoopLinux()
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: epoll_fd_(FML_HANDLE_EINTR(::epoll_create(1 /* unused */))),
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timer_fd_(::timerfd_create(kClockType, TFD_NONBLOCK | TFD_CLOEXEC)),
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running_(false) {
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FML_CHECK(epoll_fd_.is_valid());
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FML_CHECK(timer_fd_.is_valid());
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bool added_source = AddOrRemoveTimerSource(true);
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FML_CHECK(added_source);
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}
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MessageLoopLinux::~MessageLoopLinux() {
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bool removed_source = AddOrRemoveTimerSource(false);
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FML_CHECK(removed_source);
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}
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bool MessageLoopLinux::AddOrRemoveTimerSource(bool add) {
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struct epoll_event event = {};
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event.events = EPOLLIN;
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// The data is just for informational purposes so we know when we were worken
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// by the FD.
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event.data.fd = timer_fd_.get();
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int ctl_result =
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::epoll_ctl(epoll_fd_.get(), add ? EPOLL_CTL_ADD : EPOLL_CTL_DEL,
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timer_fd_.get(), &event);
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return ctl_result == 0;
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}
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// |fml::MessageLoopImpl|
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void MessageLoopLinux::Run() {
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running_ = true;
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while (running_) {
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struct epoll_event event = {};
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int epoll_result = FML_HANDLE_EINTR(
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::epoll_wait(epoll_fd_.get(), &event, 1, -1 /* timeout */));
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// Errors are fatal.
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if (event.events & (EPOLLERR | EPOLLHUP)) {
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running_ = false;
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continue;
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}
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// Timeouts are fatal since we specified an infinite timeout already.
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// Likewise, > 1 is not possible since we waited for one result.
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if (epoll_result != 1) {
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running_ = false;
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continue;
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}
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if (event.data.fd == timer_fd_.get()) {
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OnEventFired();
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}
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}
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}
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// |fml::MessageLoopImpl|
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void MessageLoopLinux::Terminate() {
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running_ = false;
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WakeUp(fml::TimePoint::Now());
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}
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// |fml::MessageLoopImpl|
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void MessageLoopLinux::WakeUp(fml::TimePoint time_point) {
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bool result = TimerRearm(timer_fd_.get(), time_point);
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FML_DCHECK(result);
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}
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void MessageLoopLinux::OnEventFired() {
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if (TimerDrain(timer_fd_.get())) {
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RunExpiredTasksNow();
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}
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}
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} // namespace fml
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