RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-20 12:15:07 +00:00
Code Issues Activity Actions

LibWeb: Improve HTML::EventLoop::spin_until()

Browse source 
This algorithm now saved and restores the JavaScript execution context
stack while performing a microtask checkpoint, as the spec mandates.
This commit is contained in:
Andreas Kling 2021-10-03 14:54:01 +02:00
parent 406d3199d0
commit 6283c098ad
1 changed files with 22 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

44
Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.cpp
View file

@ -48,38 +48,38 @@ EventLoop& main_thread_event_loop()
// https://html.spec.whatwg.org/multipage/webappapis.html#spin-the-event-loop
void EventLoop::spin_until(Function<bool()> goal_condition)
{
// FIXME: This is an ad-hoc hack until we implement the proper mechanism.
Core::EventLoop loop;
loop.spin_until([&]() -> bool {
if (goal_condition())
return true;
perform_a_microtask_checkpoint();
return goal_condition();
});
// Real spec steps:
// FIXME: 1. Let task be the event loop's currently running task.
// FIXME: 2. Let task source be task's source.
// FIXME: 3. Let old stack be a copy of the JavaScript execution context stack.
// 3. Let old stack be a copy of the JavaScript execution context stack.
// 4. Empty the JavaScript execution context stack.
auto& vm = Bindings::main_thread_vm();
vm.save_execution_context_stack();
// FIXME: 4. Empty the JavaScript execution context stack.
// 5. Perform a microtask checkpoint.
perform_a_microtask_checkpoint();
// FIXME: 5. Perform a microtask checkpoint.
// 6. In parallel:
// NOTE: We do these in reverse order here, but it shouldn't matter.
// FIXME: 6. In parallel:
// 2. Queue a task on task source to:
// 1. Replace the JavaScript execution context stack with old stack.
vm.restore_execution_context_stack();
// 2. Perform any steps that appear after this spin the event loop instance in the original algorithm.
// NOTE: This is achieved by returning from the function.
// FIXME: 1. Wait until the condition goal is met.
// 1. Wait until the condition goal is met.
Core::EventLoop loop;
loop.spin_until([&]() -> bool {
if (goal_condition())
return true;
// FIXME: 2. Queue a task on task source to:
return goal_condition();
});
// FIXME: 1. Replace the JavaScript execution context stack with old stack.
// FIXME: 2. Perform any steps that appear after this spin the event loop instance in the original algorithm.
// FIXME: 7. Stop task, allowing whatever algorithm that invoked it to resume.
// 7. Stop task, allowing whatever algorithm that invoked it to resume.
// NOTE: This is achieved by returning from the function.
}
// https://html.spec.whatwg.org/multipage/webappapis.html#event-loop-processing-model