Struct ScriptThread

pub struct ScriptThread {

    last_render_opportunity_time: Cell<Option<Instant>>,
    documents: DomRefCell<DocumentCollection>,
    window_proxies: DomRefCell<HashMapTracedValues<BrowsingContextId, Dom<WindowProxy>>>,
    incomplete_loads: DomRefCell<Vec<InProgressLoad>>,
    incomplete_parser_contexts: IncompleteParserContexts,
    image_cache: Arc<dyn ImageCache>,
    receivers: ScriptThreadReceivers,
    senders: ScriptThreadSenders,
    resource_threads: ResourceThreads,
    task_queue: TaskQueue<MainThreadScriptMsg>,
    background_hang_monitor: Box<dyn BackgroundHangMonitor>,
    closing: Arc<AtomicBool>,
    timer_scheduler: RefCell<TimerScheduler>,
    system_font_service: Arc<SystemFontServiceProxy>,
    js_runtime: Rc<Runtime>,
    closed_pipelines: DomRefCell<HashSet<PipelineId>>,
    microtask_queue: Rc<MicrotaskQueue>,
    mutation_observer_microtask_queued: Cell<bool>,
    mutation_observers: DomRefCell<Vec<Dom<MutationObserver>>>,
    signal_slots: DomRefCell<Vec<Dom<HTMLSlotElement>>>,
    webgl_chan: Option<WebGLPipeline>,
    webxr_registry: Option<Registry>,
    worklet_thread_pool: DomRefCell<Option<Rc<WorkletThreadPool>>>,
    docs_with_no_blocking_loads: DomRefCell<HashSet<Dom<Document>>>,
    custom_element_reaction_stack: CustomElementReactionStack,
    compositor_api: CrossProcessCompositorApi,
    profile_script_events: bool,
    print_pwm: bool,
    unminify_js: bool,
    local_script_source: Option<String>,
    unminify_css: bool,
    user_content_manager: UserContentManager,
    player_context: WindowGLContext,
    pipeline_to_node_ids: DomRefCell<HashMap<PipelineId, HashSet<String>>>,
    is_user_interacting: Cell<bool>,
    gpu_id_hub: Arc<IdentityHub>,
    inherited_secure_context: Option<bool>,
    layout_factory: Arc<dyn LayoutFactory>,
    relative_mouse_down_point: Cell<Point2D<f32, DevicePixel>>,
    scheduled_update_the_rendering: RefCell<Option<TimerId>>,
    needs_rendering_update: Arc<AtomicBool>,
    debugger_global: Dom<DebuggerGlobalScope>,
}

Fields

last_render_opportunity_time: Cell<Option<Instant>>

https://html.spec.whatwg.org/multipage/#last-render-opportunity-time

documents: DomRefCell<DocumentCollection>

The documents for pipelines managed by this thread

window_proxies: DomRefCell<HashMapTracedValues<BrowsingContextId, Dom<WindowProxy>>>

The window proxies known by this thread TODO: this map grows, but never shrinks. Issue #15258.

incomplete_loads: DomRefCell<Vec<InProgressLoad>>

A list of data pertaining to loads that have not yet received a network response

incomplete_parser_contexts: IncompleteParserContexts

A vector containing parser contexts which have not yet been fully processed

image_cache: Arc<dyn ImageCache>

Image cache for this script thread.

receivers: ScriptThreadReceivers

A ScriptThreadReceivers holding all of the incoming Receivers for messages to this ScriptThread.

senders: ScriptThreadSenders

A ScriptThreadSenders that holds all outgoing sending channels necessary to communicate to other parts of Servo.

resource_threads: ResourceThreads

A handle to the resource thread. This is an Arc to avoid running out of file descriptors if there are many iframes.

task_queue: TaskQueue<MainThreadScriptMsg>

A queue of tasks to be executed in this script-thread.

background_hang_monitor: Box<dyn BackgroundHangMonitor>

The dedicated means of communication with the background-hang-monitor for this script-thread.

closing: Arc<AtomicBool>

A flag set to true by the BHM on exit, and checked from within the interrupt handler.

timer_scheduler: RefCell<TimerScheduler>

A TimerScheduler used to schedule timers for this ScriptThread. Timers are handled in the ScriptThread event loop.

system_font_service: Arc<SystemFontServiceProxy>

A proxy to the SystemFontService to use for accessing system font lists.

js_runtime: Rc<Runtime>

The JavaScript runtime.

closed_pipelines: DomRefCell<HashSet<PipelineId>>

List of pipelines that have been owned and closed by this script thread.

microtask_queue: Rc<MicrotaskQueue>

https://html.spec.whatwg.org/multipage/#microtask-queue

mutation_observer_microtask_queued: Cell<bool>

Microtask Queue for adding support for mutation observer microtasks

mutation_observers: DomRefCell<Vec<Dom<MutationObserver>>>

The unit of related similar-origin browsing contexts’ list of MutationObserver objects

signal_slots: DomRefCell<Vec<Dom<HTMLSlotElement>>>

https://dom.spec.whatwg.org/#signal-slot-list

webgl_chan: Option<WebGLPipeline>

A handle to the WebGL thread

webxr_registry: Option<Registry>

The WebXR device registry

worklet_thread_pool: DomRefCell<Option<Rc<WorkletThreadPool>>>

The worklet thread pool

docs_with_no_blocking_loads: DomRefCell<HashSet<Dom<Document>>>

A list of pipelines containing documents that finished loading all their blocking resources during a turn of the event loop.

custom_element_reaction_stack: CustomElementReactionStack

https://html.spec.whatwg.org/multipage/#custom-element-reactions-stack

compositor_api: CrossProcessCompositorApi

Cross-process access to the compositor’s API.

profile_script_events: bool

Periodically print out on which events script threads spend their processing time.

print_pwm: bool

Print Progressive Web Metrics to console.

unminify_js: bool

Unminify Javascript.

local_script_source: Option<String>

Directory with stored unminified scripts

unminify_css: bool

Unminify Css.

user_content_manager: UserContentManager

User content manager

player_context: WindowGLContext

Application window’s GL Context for Media player

pipeline_to_node_ids: DomRefCell<HashMap<PipelineId, HashSet<String>>>

A map from pipelines to all owned nodes ever created in this script thread

is_user_interacting: Cell<bool>

Code is running as a consequence of a user interaction

gpu_id_hub: Arc<IdentityHub>

Identity manager for WebGPU resources

inherited_secure_context: Option<bool>

layout_factory: Arc<dyn LayoutFactory>

A factory for making new layouts. This allows layout to depend on script.

relative_mouse_down_point: Cell<Point2D<f32, DevicePixel>>

The screen coordinates where the primary mouse button was pressed.

scheduled_update_the_rendering: RefCell<Option<TimerId>>

The TimerId of a ScriptThread-scheduled “update the rendering” call, if any. The ScriptThread schedules calls to “update the rendering,” but the renderer can also do this when animating. Renderer-based calls always take precedence.

needs_rendering_update: Arc<AtomicBool>

Whether an animation tick or ScriptThread-triggered rendering update is pending. This might either be because the Servo renderer is managing animations and the ScriptThread has received a ScriptThreadMessage::TickAllAnimations message, because the ScriptThread itself is managing animations the the timer fired triggering a ScriptThread-based animation tick, or if there are no animations running and the ScriptThread has noticed a change that requires a rendering update.

debugger_global: Dom<DebuggerGlobalScope>

Implementations

impl ScriptThread

pub(crate) fn runtime_handle() -> ParentRuntime

pub(crate) fn can_continue_running() -> bool

pub(crate) fn prepare_for_shutdown()

pub(crate) fn set_mutation_observer_microtask_queued(value: bool)

pub(crate) fn is_mutation_observer_microtask_queued() -> bool

pub(crate) fn add_mutation_observer(observer: &MutationObserver)

pub(crate) fn get_mutation_observers() -> Vec<DomRoot<MutationObserver>>

pub(crate) fn add_signal_slot(observer: &HTMLSlotElement)

pub(crate) fn take_signal_slots() -> Vec<DomRoot<HTMLSlotElement>>

pub(crate) fn mark_document_with_no_blocked_loads(doc: &Document)

pub(crate) fn page_headers_available( id: &PipelineId, metadata: Option<Metadata>, can_gc: CanGc, ) -> Option<DomRoot<ServoParser>>

pub(crate) fn process_event(msg: CommonScriptMsg) -> bool

Process a single event as if it were the next event in the queue for this window event-loop. Returns a boolean indicating whether further events should be processed.

pub(crate) fn schedule_timer(&self, request: TimerEventRequest) -> TimerId

Schedule a TimerEventRequest on this ScriptThread’s TimerScheduler.

pub(crate) fn await_stable_state(task: Microtask)

pub(crate) fn check_load_origin( source: &LoadOrigin, target: &ImmutableOrigin, ) -> bool

Check that two origins are “similar enough”, for now only used to prevent cross-origin JS url evaluation.

https://github.com/whatwg/html/issues/2591

pub(crate) fn set_needs_rendering_update(&self)

Inform the ScriptThread that it should make a call to ScriptThread::update_the_rendering as soon as possible, as the rendering update timer has fired or the renderer has asked us for a new rendering update.

pub(crate) fn navigate( pipeline_id: PipelineId, load_data: LoadData, history_handling: NavigationHistoryBehavior, )

Step 13 of https://html.spec.whatwg.org/multipage/#navigate

pub(crate) fn process_attach_layout( new_layout_info: NewLayoutInfo, origin: MutableOrigin, )

pub(crate) fn get_top_level_for_browsing_context( sender_pipeline: PipelineId, browsing_context_id: BrowsingContextId, ) -> Option<WebViewId>

pub(crate) fn find_document(id: PipelineId) -> Option<DomRoot<Document>>

pub(crate) fn set_user_interacting(interacting: bool)

pub(crate) fn is_user_interacting() -> bool

pub(crate) fn get_fully_active_document_ids() -> HashSet<PipelineId>

pub(crate) fn find_window_proxy( id: BrowsingContextId, ) -> Option<DomRoot<WindowProxy>>

pub(crate) fn find_window_proxy_by_name( name: &DOMString, ) -> Option<DomRoot<WindowProxy>>

pub(crate) fn worklet_thread_pool( image_cache: Arc<dyn ImageCache>, ) -> Rc<WorkletThreadPool>

The worklet will use the given ImageCache.

fn handle_register_paint_worklet( &self, pipeline_id: PipelineId, name: Atom, properties: Vec<Atom>, painter: Box<dyn Painter>, )

pub(crate) fn push_new_element_queue()

pub(crate) fn pop_current_element_queue(can_gc: CanGc)

pub(crate) fn enqueue_callback_reaction( element: &Element, reaction: CallbackReaction, definition: Option<Rc<CustomElementDefinition>>, )

pub(crate) fn enqueue_upgrade_reaction( element: &Element, definition: Rc<CustomElementDefinition>, )

pub(crate) fn invoke_backup_element_queue(can_gc: CanGc)

pub(crate) fn save_node_id(pipeline: PipelineId, node_id: String)

pub(crate) fn has_node_id(pipeline: PipelineId, node_id: &str) -> bool

pub(crate) fn new( state: InitialScriptState, layout_factory: Arc<dyn LayoutFactory>, system_font_service: Arc<SystemFontServiceProxy>, ) -> ScriptThread

Creates a new script thread.

pub(crate) fn get_cx(&self) -> JSContext

fn can_continue_running_inner(&self) -> bool

Check if we are closing.

fn prepare_for_shutdown_inner(&self)

We are closing, ensure no script can run and potentially hang.

pub(crate) fn start(&self, can_gc: CanGc)

Starts the script thread. After calling this method, the script thread will loop receiving messages on its port.

fn process_pending_input_events(&self, pipeline_id: PipelineId, can_gc: CanGc)

Process compositor events as part of a “update the rendering task”.

fn cancel_scheduled_update_the_rendering(&self)

fn schedule_update_the_rendering_timer_if_necessary(&self, delay: Duration)

pub(crate) fn update_the_rendering(&self, can_gc: CanGc) -> bool

https://html.spec.whatwg.org/multipage/#update-the-rendering

Attempt to update the rendering and then do a microtask checkpoint if rendering was actually updated.

Returns true if any reflows produced a new display list.

fn maybe_schedule_rendering_opportunity_after_ipc_message( &self, built_any_display_lists: bool, )

Schedule a rendering update (“update the rendering”), if necessary. This can be necessary for a couple reasons. For instance, when the DOM changes a scheduled rendering update becomes necessary if one isn’t scheduled already. Another example is if rAFs are running but no display lists are being produced. In that case the ScriptThread is responsible for scheduling animation ticks.

fn maybe_fulfill_font_ready_promises(&self, can_gc: CanGc)

Fulfill the possibly-pending pending document.fonts.ready promise if all web fonts have loaded.

fn maybe_send_idle_document_state_to_constellation(&self)

If waiting for an idle Pipeline state in order to dump a screenshot at the right time, inform the Constellation this Pipeline has entered the idle state when applicable.

fn handle_msgs(&self, can_gc: CanGc) -> bool

Handle incoming messages from other tasks and the task queue.

fn categorize_msg(&self, msg: &MixedMessage) -> ScriptThreadEventCategory

fn profile_event<F, R>( &self, category: ScriptThreadEventCategory, pipeline_id: Option<PipelineId>, f: F, ) -> R

where F: FnOnce() -> R,

fn handle_msg_from_constellation(&self, msg: ScriptThreadMessage, can_gc: CanGc)

fn handle_set_scroll_states( &self, pipeline_id: PipelineId, scroll_states: HashMap<ExternalScrollId, LayoutVector2D>, )

fn handle_msg_from_webgpu_server(&self, msg: WebGPUMsg, can_gc: CanGc)

fn handle_msg_from_script(&self, msg: MainThreadScriptMsg)

fn handle_msg_from_devtools(&self, msg: DevtoolScriptControlMsg, can_gc: CanGc)

fn handle_msg_from_image_cache(&self, response: ImageCacheResponseMessage)

fn handle_webdriver_msg( &self, pipeline_id: PipelineId, msg: WebDriverScriptCommand, can_gc: CanGc, )

pub(crate) fn handle_resize_message( &self, id: PipelineId, viewport_details: ViewportDetails, size_type: WindowSizeType, )

Batch window resize operations into a single “update the rendering” task, or, if a load is in progress, set the window size directly.

fn handle_theme_change_msg(&self, theme: Theme)

Handle changes to the theme, triggering reflow if the theme actually changed.

fn handle_exit_fullscreen(&self, id: PipelineId, can_gc: CanGc)

fn handle_viewport(&self, id: PipelineId, rect: Rect<f32>)

fn handle_new_layout( &self, new_layout_info: NewLayoutInfo, origin: MutableOrigin, )

fn collect_reports(&self, reports_chan: ReportsChan)

fn handle_set_throttled_in_containing_iframe_msg( &self, parent_pipeline_id: PipelineId, browsing_context_id: BrowsingContextId, throttled: bool, )

Updates iframe element after a change in visibility

fn handle_set_throttled_msg(&self, id: PipelineId, throttled: bool)

fn handle_set_document_activity_msg( &self, id: PipelineId, activity: DocumentActivity, can_gc: CanGc, )

Handles activity change message

fn handle_focus_iframe_msg( &self, parent_pipeline_id: PipelineId, browsing_context_id: BrowsingContextId, sequence: FocusSequenceNumber, can_gc: CanGc, )

fn handle_focus_document_msg( &self, pipeline_id: PipelineId, sequence: FocusSequenceNumber, can_gc: CanGc, )

fn handle_unfocus_msg( &self, pipeline_id: PipelineId, sequence: FocusSequenceNumber, can_gc: CanGc, )

fn handle_post_message_msg( &self, pipeline_id: PipelineId, source_pipeline_id: PipelineId, source_browsing_context: WebViewId, origin: Option<ImmutableOrigin>, source_origin: ImmutableOrigin, data: StructuredSerializedData, )

fn handle_stop_delaying_load_events_mode(&self, pipeline_id: PipelineId)

fn handle_unload_document(&self, pipeline_id: PipelineId, can_gc: CanGc)

fn handle_update_pipeline_id( &self, parent_pipeline_id: PipelineId, browsing_context_id: BrowsingContextId, webview_id: WebViewId, new_pipeline_id: PipelineId, reason: UpdatePipelineIdReason, can_gc: CanGc, )

fn handle_update_history_state_msg( &self, pipeline_id: PipelineId, history_state_id: Option<HistoryStateId>, url: ServoUrl, can_gc: CanGc, )

fn handle_remove_history_states( &self, pipeline_id: PipelineId, history_states: Vec<HistoryStateId>, )

fn handle_resize_inactive_msg( &self, id: PipelineId, new_viewport_details: ViewportDetails, )

Window was resized, but this script was not active, so don’t reflow yet

fn handle_page_headers_available( &self, id: &PipelineId, metadata: Option<Metadata>, can_gc: CanGc, ) -> Option<DomRoot<ServoParser>>

We have received notification that the response associated with a load has completed. Kick off the document and frame tree creation process using the result.

fn handle_get_title_msg(&self, pipeline_id: PipelineId)

Handles a request for the window title.

fn handle_exit_pipeline_msg( &self, webview_id: WebViewId, id: PipelineId, discard_bc: DiscardBrowsingContext, can_gc: CanGc, )

Handles a request to exit a pipeline and shut down layout.

fn handle_exit_script_thread_msg(&self, can_gc: CanGc)

Handles a request to exit the script thread and shut down layout.

pub(crate) fn handle_tick_all_animations_for_testing(id: PipelineId)

Handles animation tick requested during testing.

fn handle_web_font_loaded(&self, pipeline_id: PipelineId, _success: bool)

Handles a Web font being loaded. Does nothing if the page no longer exists.

fn handle_worklet_loaded(&self, pipeline_id: PipelineId)

Handles a worklet being loaded by triggering a relayout of the page. Does nothing if the page no longer exists.

fn handle_storage_event( &self, pipeline_id: PipelineId, storage_type: StorageType, url: ServoUrl, key: Option<String>, old_value: Option<String>, new_value: Option<String>, )

Notify a window of a storage event

fn handle_iframe_load_event( &self, parent_id: PipelineId, browsing_context_id: BrowsingContextId, child_id: PipelineId, can_gc: CanGc, )

Notify the containing document of a child iframe that has completed loading.

fn ask_constellation_for_browsing_context_info( &self, pipeline_id: PipelineId, ) -> Option<(BrowsingContextId, Option<PipelineId>)>

fn ask_constellation_for_top_level_info( &self, sender_pipeline: PipelineId, browsing_context_id: BrowsingContextId, ) -> Option<WebViewId>

fn remote_window_proxy( &self, global_to_clone: &GlobalScope, webview_id: WebViewId, pipeline_id: PipelineId, opener: Option<BrowsingContextId>, ) -> Option<DomRoot<WindowProxy>>

fn local_window_proxy( &self, window: &Window, browsing_context_id: BrowsingContextId, webview_id: WebViewId, parent_info: Option<PipelineId>, opener: Option<BrowsingContextId>, ) -> DomRoot<WindowProxy>

fn load( &self, metadata: Metadata, incomplete: InProgressLoad, can_gc: CanGc, ) -> DomRoot<ServoParser>

The entry point to document loading. Defines bindings, sets up the window and document objects, parses HTML and CSS, and kicks off initial layout.

fn notify_devtools( &self, title: DOMString, url: ServoUrl, is_top_level_global: bool, (browsing_context_id, pipeline_id, worker_id, webview_id): (BrowsingContextId, PipelineId, Option<WorkerId>, WebViewId), )

fn handle_input_event( &self, pipeline_id: PipelineId, event: ConstellationInputEvent, )

Queue compositor events for later dispatching as part of a update_the_rendering task.

fn handle_navigate_iframe( &self, parent_pipeline_id: PipelineId, browsing_context_id: BrowsingContextId, load_data: LoadData, history_handling: NavigationHistoryBehavior, can_gc: CanGc, )

Handle a “navigate an iframe” message from the constellation.

pub(crate) fn eval_js_url( global_scope: &GlobalScope, load_data: &mut LoadData, can_gc: CanGc, )

Turn javascript: URL into JS code to eval, according to the steps in https://html.spec.whatwg.org/multipage/#javascript-protocol

fn pre_page_load(&self, incomplete: InProgressLoad)

Instructs the constellation to fetch the document that will be loaded. Stores the InProgressLoad argument until a notification is received that the fetch is complete.

fn handle_navigation_response( &self, pipeline_id: PipelineId, message: FetchResponseMsg, )

fn handle_fetch_metadata( &self, id: PipelineId, request_id: RequestId, fetch_metadata: Result<FetchMetadata, NetworkError>, )

fn handle_fetch_chunk( &self, pipeline_id: PipelineId, request_id: RequestId, chunk: Vec<u8>, )

fn handle_fetch_eof( &self, id: PipelineId, request_id: RequestId, eof: Result<ResourceFetchTiming, NetworkError>, )

fn handle_csp_violations( &self, id: PipelineId, _: RequestId, violations: Vec<Violation>, )

fn handle_navigation_redirect(&self, id: PipelineId, metadata: &Metadata)

fn start_page_load_about_blank(&self, incomplete: InProgressLoad)

Synchronously fetch about:blank. Stores the InProgressLoad argument until a notification is received that the fetch is complete.

fn page_load_about_srcdoc(&self, incomplete: InProgressLoad)

Synchronously parse a srcdoc document from a giving HTML string.

fn handle_css_error_reporting( &self, pipeline_id: PipelineId, filename: String, line: u32, column: u32, msg: String, )

fn handle_reload(&self, pipeline_id: PipelineId, can_gc: CanGc)

fn handle_paint_metric( &self, pipeline_id: PipelineId, metric_type: ProgressiveWebMetricType, metric_value: CrossProcessInstant, first_reflow: bool, can_gc: CanGc, )

fn handle_media_session_action( &self, pipeline_id: PipelineId, action: MediaSessionActionType, can_gc: CanGc, )

pub(crate) fn enqueue_microtask(job: Microtask)

fn perform_a_microtask_checkpoint(&self, can_gc: CanGc)

fn handle_evaluate_javascript( &self, pipeline_id: PipelineId, evaluation_id: JavaScriptEvaluationId, script: String, can_gc: CanGc, )

fn handle_refresh_cursor( &self, pipeline_id: PipelineId, cursor_position: Point2D<f32, CSSPixel>, )

Trait Implementations

impl Drop for ScriptThread

fn drop(&mut self)

Executes the destructor for this type.

impl ScriptThreadFactory for ScriptThread

fn create( state: InitialScriptState, layout_factory: Arc<dyn LayoutFactory>, system_font_service: Arc<SystemFontServiceProxy>, load_data: LoadData, ) -> JoinHandle<()>

Create a ScriptThread.

impl Traceable for ScriptThread

unsafe fn trace(&self, tracer: *mut JSTracer)

Trace self.