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HTMLParser::the_end() had three spin_until calls that blocked the event loop: step 5 (deferred scripts), step 7 (ASAP scripts), and step 8 (load event delay). This replaces them with an HTMLParserEndState state machine that progresses asynchronously via callbacks. The state machine has three phases matching the three spin_until calls: - WaitingForDeferredScripts: loops executing ready deferred scripts - WaitingForASAPScripts: waits for ASAP script lists to empty - WaitingForLoadEventDelay: waits for nothing to delay the load event Notification triggers re-evaluate the state machine when conditions change: HTMLScriptElement::mark_as_ready, stylesheet unblocking in StyleElementBase/HTMLLinkElement, did_stop_being_active_document, and DocumentLoadEventDelayer decrements. NavigableContainer state changes (session history readiness, content navigable cleared, lazy load flag) also trigger re-evaluation of the load event delay check. Key design decisions and why: 1. Microtask checkpoint in schedule_progress_check(): The old spin_until called perform_a_microtask_checkpoint() before checking conditions. This is critical because HTMLImageElement::update_the_image_data step 8 queues a microtask that creates the DocumentLoadEventDelayer. Without the checkpoint, check_progress() would see zero delayers and complete before images start delaying the load event. 2. deferred_invoke in schedule_progress_check(): I tried Core::Timer (0ms), queue_global_task, and synchronous calls. Timers caused non-deterministic ordering with the HTML event loop's task processing timer, leading to image layout tests failing (wrong subtest pass/fail patterns). Synchronous calls fired too early during image load processing before dimensions were set, causing 0-height images in layout tests. queue_global_task had task ordering issues with the session history traversal queue. deferred_invoke runs after the current callback returns but within the same event loop pump, giving the right balance. 3. Navigation load event guard (m_navigation_load_event_guard): During cross-document navigation, finalize_a_cross_document_navigation step 2 calls set_delaying_load_events(false) before the session history traversal activates the new document. This creates a transient state where the parent's load event delay check sees the about:blank (which has ready_for_post_load_tasks=true) as the active document and completes prematurely. |
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| .. | ||
| Entities.cpp | ||
| Entities.h | ||
| Entities.json | ||
| HTMLEncodingDetection.cpp | ||
| HTMLEncodingDetection.h | ||
| HTMLParser.cpp | ||
| HTMLParser.h | ||
| HTMLToken.cpp | ||
| HTMLToken.h | ||
| HTMLTokenizer.cpp | ||
| HTMLTokenizer.h | ||
| ListOfActiveFormattingElements.cpp | ||
| ListOfActiveFormattingElements.h | ||
| StackOfOpenElements.cpp | ||
| StackOfOpenElements.h | ||