ladybird/Libraries/LibWeb/HTML/Timer.h
Andreas Kling 4d27e9aa5e LibWeb: Make setInterval() reuse the timer to reduce drift
Instead of creating a new single-shot timer every time a setInterval
timer reschedules itself, we now use a repeating Core::Timer internally.

This dramatically reduces timer drift, since the next timeout is now
based on when the timer fired, rather than when the timer callback
completed (which could take arbitrarily long since we run JS).

It's not perfect, but it's a huge improvement and allows us to play
DiabloWeb at full framerate (20 fps).
2025-12-01 19:58:47 +01:00

48 lines
1 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Forward.h>
#include <AK/Function.h>
#include <AK/WeakPtr.h>
#include <LibCore/Forward.h>
#include <LibGC/Function.h>
#include <LibGC/Ptr.h>
#include <LibJS/Heap/Cell.h>
#include <LibWeb/Forward.h>
namespace Web::HTML {
class Timer final : public JS::Cell {
GC_CELL(Timer, JS::Cell);
GC_DECLARE_ALLOCATOR(Timer);
public:
enum class Repeating {
No,
Yes,
};
static GC::Ref<Timer> create(JS::Object&, i32 milliseconds, Function<void()> callback, i32 id, Repeating);
virtual ~Timer() override;
void start();
void stop();
void set_callback(Function<void()>);
private:
Timer(JS::Object& window, i32 milliseconds, Function<void()> callback, i32 id, Repeating);
virtual void visit_edges(Cell::Visitor&) override;
RefPtr<Core::Timer> m_timer;
GC::Ref<JS::Object> m_window_or_worker_global_scope;
i32 m_id { 0 };
};
}