Files
mpd/src/client/ThreadBackgroundCommand.hxx
2023-03-06 14:59:48 +01:00

64 lines
1.3 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#ifndef MPD_THREAD_BACKGROUND_COMMAND_HXX
#define MPD_THREAD_BACKGROUND_COMMAND_HXX
#include "BackgroundCommand.hxx"
#include "event/InjectEvent.hxx"
#include "thread/Thread.hxx"
#include <exception>
class Client;
class Response;
/**
* A #BackgroundCommand which defers execution into a new thread.
*/
class ThreadBackgroundCommand : public BackgroundCommand {
Thread thread;
InjectEvent defer_finish;
Client &client;
/**
* The error thrown by Run().
*/
std::exception_ptr error;
public:
explicit ThreadBackgroundCommand(Client &_client) noexcept;
auto &GetEventLoop() const noexcept {
return defer_finish.GetEventLoop();
}
void Start() {
thread.Start();
}
void Cancel() noexcept final;
private:
void _Run() noexcept;
void DeferredFinish() noexcept;
protected:
/**
* If this method throws, the exception will be converted to a
* MPD response, and SendResponse() will not be called.
*/
virtual void Run() = 0;
/**
* Send the response after Run() has finished. Note that you
* must not send errors here; if an error occurs, Run() should
* throw an exception instead.
*/
virtual void SendResponse(Response &response) noexcept = 0;
virtual void CancelThread() noexcept = 0;
};
#endif