ladybird/Libraries/LibThread/BackgroundAction.h

97 lines
3.2 KiB
C++

/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/Function.h>
#include <AK/NonnullRefPtr.h>
#include <AK/Optional.h>
#include <AK/Queue.h>
#include <LibCore/Event.h>
#include <LibCore/EventLoop.h>
#include <LibCore/Object.h>
#include <LibThread/Lock.h>
#include <LibThread/Thread.h>
namespace LibThread {
template<typename Result>
class BackgroundAction;
class BackgroundActionBase {
template<typename Result>
friend class BackgroundAction;
private:
BackgroundActionBase() { }
static Lockable<Queue<Function<void()>>>& all_actions();
static Thread& background_thread();
};
template<typename Result>
class BackgroundAction final : public Core::Object
, private BackgroundActionBase {
C_OBJECT(BackgroundAction);
public:
static NonnullRefPtr<BackgroundAction<Result>> create(
Function<Result()> action,
Function<void(Result)> on_complete = nullptr)
{
return adopt(*new BackgroundAction(move(action), move(on_complete)));
}
virtual ~BackgroundAction() { }
private:
BackgroundAction(Function<Result()> action, Function<void(Result)> on_complete)
: Core::Object(&background_thread())
, m_action(move(action))
, m_on_complete(move(on_complete))
{
LOCKER(all_actions().lock());
all_actions().resource().enqueue([this] {
m_result = m_action();
if (m_on_complete) {
Core::EventLoop::current().post_event(*this, make<Core::DeferredInvocationEvent>([this](auto&) {
m_on_complete(m_result.release_value());
this->remove_from_parent();
}));
Core::EventLoop::wake();
} else {
this->remove_from_parent();
}
});
}
Function<Result()> m_action;
Function<void(Result)> m_on_complete;
Optional<Result> m_result;
};
}