133 lines
3.5 KiB
C++
133 lines
3.5 KiB
C++
/* Copyright 2016, Ableton AG, Berlin. All rights reserved.
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
* If you would like to incorporate Link into a proprietary software application,
|
|
* please contact <link-devs@ableton.com>.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <ableton/platforms/asio/AsioWrapper.hpp>
|
|
#include <ableton/util/SafeAsyncHandler.hpp>
|
|
#include <functional>
|
|
|
|
namespace ableton
|
|
{
|
|
namespace platforms
|
|
{
|
|
namespace asio
|
|
{
|
|
|
|
// This implementation is based on the boost::asio::system_timer concept.
|
|
// Since boost::system_timer doesn't support move semantics, we create a wrapper
|
|
// with a unique_ptr to get a movable type. It also handles an inconvenient
|
|
// aspect of asio timers, which is that you must explicitly guard against the
|
|
// handler firing after cancellation. We handle this by use of the SafeAsyncHandler
|
|
// utility. AsioTimer therefore guarantees that a handler will not be called after
|
|
// the destruction of the timer, or after the timer has been canceled.
|
|
|
|
class AsioTimer
|
|
{
|
|
public:
|
|
using ErrorCode = ::asio::error_code;
|
|
using TimePoint = std::chrono::system_clock::time_point;
|
|
|
|
AsioTimer(::asio::io_service& io)
|
|
: mpTimer(new ::asio::system_timer(io))
|
|
, mpAsyncHandler(std::make_shared<AsyncHandler>())
|
|
{
|
|
}
|
|
|
|
~AsioTimer()
|
|
{
|
|
// The timer may not be valid anymore if this instance was moved from
|
|
if (mpTimer != nullptr)
|
|
{
|
|
// Ignore errors during cancellation
|
|
cancel();
|
|
}
|
|
}
|
|
|
|
AsioTimer(const AsioTimer&) = delete;
|
|
AsioTimer& operator=(const AsioTimer&) = delete;
|
|
|
|
// Enable move construction but not move assignment. Move assignment
|
|
// would get weird - would have to handle outstanding handlers
|
|
AsioTimer(AsioTimer&& rhs)
|
|
: mpTimer(std::move(rhs.mpTimer))
|
|
, mpAsyncHandler(std::move(rhs.mpAsyncHandler))
|
|
{
|
|
}
|
|
|
|
void expires_at(std::chrono::system_clock::time_point tp)
|
|
{
|
|
mpTimer->expires_at(std::move(tp));
|
|
}
|
|
|
|
template <typename T>
|
|
void expires_from_now(T duration)
|
|
{
|
|
mpTimer->expires_from_now(std::move(duration));
|
|
}
|
|
|
|
ErrorCode cancel()
|
|
{
|
|
ErrorCode ec;
|
|
mpTimer->cancel(ec);
|
|
mpAsyncHandler->mpHandler = nullptr;
|
|
return ec;
|
|
}
|
|
|
|
template <typename Handler>
|
|
void async_wait(Handler handler)
|
|
{
|
|
*mpAsyncHandler = std::move(handler);
|
|
mpTimer->async_wait(util::makeAsyncSafe(mpAsyncHandler));
|
|
}
|
|
|
|
TimePoint now() const
|
|
{
|
|
return std::chrono::system_clock::now();
|
|
}
|
|
|
|
private:
|
|
struct AsyncHandler
|
|
{
|
|
template <typename Handler>
|
|
AsyncHandler& operator=(Handler handler)
|
|
{
|
|
mpHandler = [handler](ErrorCode ec) { handler(std::move(ec)); };
|
|
return *this;
|
|
}
|
|
|
|
void operator()(ErrorCode ec)
|
|
{
|
|
if (mpHandler)
|
|
{
|
|
mpHandler(std::move(ec));
|
|
}
|
|
}
|
|
|
|
std::function<void(const ErrorCode)> mpHandler;
|
|
};
|
|
|
|
std::unique_ptr<::asio::system_timer> mpTimer;
|
|
std::shared_ptr<AsyncHandler> mpAsyncHandler;
|
|
};
|
|
|
|
} // namespace asio
|
|
} // namespace platforms
|
|
} // namespace ableton
|