omxplayer/utils/Mailbox.h

94 lines
3 KiB
C++

#pragma once
// Author: Torarin Hals Bakke (2012)
// Boost Software License - Version 1.0 - August 17th, 2003
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
#include <type_traits>
#include <utility>
#include <deque>
#include <mutex>
#include <condition_variable>
#include "variant.hpp"
#include "LockBlock.h"
#include "FunctorVisitor.h"
template <typename... Ts>
class Mailbox {
public:
template <typename T>
void send(T&& msg) {
LOCK_BLOCK (messages_lock_) {
messages_.push_back(std::forward<T>(msg));
messages_cond_.notify_one();
}
}
template <typename... Funs>
void receive(Funs&&... funs) {
for (;;) {
LOCK_BLOCK (messages_lock_)
if (messages_.empty()) break;
auto extract_message = [&]() {
LOCK_BLOCK (messages_lock_) {
utils::variant<Ts...> msg(std::move(messages_.front()));
messages_.pop_front();
return msg;
}
assert(0);
};
utils::apply_visitor(functor_visitor<Funs&...>(funs...),
extract_message());
}
}
template <typename Rep, typename Period, typename... Funs>
void receive_wait(const std::chrono::duration<Rep, Period>& rel_time,
Funs&&... funs)
{
{
std::unique_lock<std::mutex> lock(messages_lock_);
if (!messages_cond_.wait_for(lock,
rel_time,
[&]{return !messages_.empty();}))
return;
}
receive(std::forward<Funs>(funs)...);
}
void clear() {
LOCK_BLOCK(messages_lock_)
messages_.clear();
}
private:
std::deque<utils::variant<Ts...>> messages_;
std::mutex messages_lock_;
std::condition_variable messages_cond_;
};