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-rw-r--r--src/apps/cam/event_loop.cpp150
1 files changed, 150 insertions, 0 deletions
diff --git a/src/apps/cam/event_loop.cpp b/src/apps/cam/event_loop.cpp
new file mode 100644
index 00000000..cb83845c
--- /dev/null
+++ b/src/apps/cam/event_loop.cpp
@@ -0,0 +1,150 @@
+/* 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::addFdEvent(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::addTimerEvent(const std::chrono::microseconds period,
+ const std::function<void()> &callback)
+{
+ std::unique_ptr<Event> event = std::make_unique<Event>(callback);
+ event->event_ = event_new(base_, -1, EV_PERSIST, &EventLoop::Event::dispatch,
+ event.get());
+ if (!event->event_) {
+ std::cerr << "Failed to create timer event" << std::endl;
+ return;
+ }
+
+ struct timeval tv;
+ tv.tv_sec = period.count() / 1000000ULL;
+ tv.tv_usec = period.count() % 1000000ULL;
+
+ int ret = event_add(event->event_, &tv);
+ if (ret < 0) {
+ std::cerr << "Failed to add timer event" << 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_();
+}