script/
messaging.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use core::fmt;
6#[cfg(feature = "webgpu")]
7use std::cell::RefCell;
8use std::option::Option;
9use std::result::Result;
10
11use base::generic_channel::{GenericSender, RoutedReceiver};
12use base::id::PipelineId;
13#[cfg(feature = "bluetooth")]
14use bluetooth_traits::BluetoothRequest;
15use constellation_traits::ScriptToConstellationMessage;
16use crossbeam_channel::{Receiver, SendError, Sender, select};
17use devtools_traits::{DevtoolScriptControlMsg, ScriptToDevtoolsControlMsg};
18use embedder_traits::ScriptToEmbedderChan;
19use ipc_channel::ipc::IpcSender;
20use net_traits::FetchResponseMsg;
21use net_traits::image_cache::ImageCacheResponseMessage;
22use profile_traits::mem::{self as profile_mem, OpaqueSender, ReportsChan};
23use profile_traits::time::{self as profile_time};
24use rustc_hash::FxHashSet;
25use script_traits::{Painter, ScriptThreadMessage};
26use stylo_atoms::Atom;
27use timers::TimerScheduler;
28#[cfg(feature = "webgpu")]
29use webgpu_traits::WebGPUMsg;
30
31use crate::dom::abstractworker::WorkerScriptMsg;
32use crate::dom::bindings::trace::CustomTraceable;
33use crate::dom::csp::Violation;
34use crate::dom::dedicatedworkerglobalscope::DedicatedWorkerScriptMsg;
35use crate::dom::serviceworkerglobalscope::ServiceWorkerScriptMsg;
36use crate::dom::worker::TrustedWorkerAddress;
37use crate::script_runtime::ScriptThreadEventCategory;
38use crate::task::TaskBox;
39use crate::task_queue::{QueuedTask, QueuedTaskConversion, TaskQueue};
40use crate::task_source::TaskSourceName;
41
42#[allow(clippy::large_enum_variant)]
43#[derive(Debug)]
44pub(crate) enum MixedMessage {
45    FromConstellation(ScriptThreadMessage),
46    FromScript(MainThreadScriptMsg),
47    FromDevtools(DevtoolScriptControlMsg),
48    FromImageCache(ImageCacheResponseMessage),
49    #[cfg(feature = "webgpu")]
50    FromWebGPUServer(WebGPUMsg),
51    TimerFired,
52}
53
54impl MixedMessage {
55    pub(crate) fn pipeline_id(&self) -> Option<PipelineId> {
56        match self {
57            MixedMessage::FromConstellation(inner_msg) => match inner_msg {
58                ScriptThreadMessage::StopDelayingLoadEventsMode(id) => Some(*id),
59                ScriptThreadMessage::AttachLayout(new_layout_info) => new_layout_info
60                    .parent_info
61                    .or(Some(new_layout_info.new_pipeline_id)),
62                ScriptThreadMessage::Resize(id, ..) => Some(*id),
63                ScriptThreadMessage::ThemeChange(id, ..) => Some(*id),
64                ScriptThreadMessage::ResizeInactive(id, ..) => Some(*id),
65                ScriptThreadMessage::UnloadDocument(id) => Some(*id),
66                ScriptThreadMessage::ExitPipeline(_webview_id, id, ..) => Some(*id),
67                ScriptThreadMessage::ExitScriptThread => None,
68                ScriptThreadMessage::SendInputEvent(id, ..) => Some(*id),
69                ScriptThreadMessage::RefreshCursor(id, ..) => Some(*id),
70                ScriptThreadMessage::Viewport(id, ..) => Some(*id),
71                ScriptThreadMessage::GetTitle(id) => Some(*id),
72                ScriptThreadMessage::SetDocumentActivity(id, ..) => Some(*id),
73                ScriptThreadMessage::SetThrottled(id, ..) => Some(*id),
74                ScriptThreadMessage::SetThrottledInContainingIframe(id, ..) => Some(*id),
75                ScriptThreadMessage::NavigateIframe(id, ..) => Some(*id),
76                ScriptThreadMessage::PostMessage { target: id, .. } => Some(*id),
77                ScriptThreadMessage::UpdatePipelineId(_, _, _, id, _) => Some(*id),
78                ScriptThreadMessage::UpdateHistoryState(id, ..) => Some(*id),
79                ScriptThreadMessage::RemoveHistoryStates(id, ..) => Some(*id),
80                ScriptThreadMessage::FocusIFrame(id, ..) => Some(*id),
81                ScriptThreadMessage::FocusDocument(id, ..) => Some(*id),
82                ScriptThreadMessage::Unfocus(id, ..) => Some(*id),
83                ScriptThreadMessage::WebDriverScriptCommand(id, ..) => Some(*id),
84                ScriptThreadMessage::TickAllAnimations(..) => None,
85                ScriptThreadMessage::WebFontLoaded(id, ..) => Some(*id),
86                ScriptThreadMessage::DispatchIFrameLoadEvent {
87                    target: _,
88                    parent: id,
89                    child: _,
90                } => Some(*id),
91                ScriptThreadMessage::DispatchStorageEvent(id, ..) => Some(*id),
92                ScriptThreadMessage::ReportCSSError(id, ..) => Some(*id),
93                ScriptThreadMessage::Reload(id, ..) => Some(*id),
94                ScriptThreadMessage::PaintMetric(id, ..) => Some(*id),
95                ScriptThreadMessage::ExitFullScreen(id, ..) => Some(*id),
96                ScriptThreadMessage::MediaSessionAction(..) => None,
97                #[cfg(feature = "webgpu")]
98                ScriptThreadMessage::SetWebGPUPort(..) => None,
99                ScriptThreadMessage::SetScrollStates(id, ..) => Some(*id),
100                ScriptThreadMessage::EvaluateJavaScript(id, _, _) => Some(*id),
101                ScriptThreadMessage::SendImageKeysBatch(..) => None,
102                ScriptThreadMessage::PreferencesUpdated(..) => None,
103                ScriptThreadMessage::NoLongerWaitingOnAsychronousImageUpdates(_) => None,
104            },
105            MixedMessage::FromScript(inner_msg) => match inner_msg {
106                MainThreadScriptMsg::Common(CommonScriptMsg::Task(_, _, pipeline_id, _)) => {
107                    *pipeline_id
108                },
109                MainThreadScriptMsg::Common(CommonScriptMsg::CollectReports(_)) => None,
110                MainThreadScriptMsg::Common(CommonScriptMsg::ReportCspViolations(
111                    pipeline_id,
112                    _,
113                )) => Some(*pipeline_id),
114                MainThreadScriptMsg::NavigationResponse { pipeline_id, .. } => Some(*pipeline_id),
115                MainThreadScriptMsg::WorkletLoaded(pipeline_id) => Some(*pipeline_id),
116                MainThreadScriptMsg::RegisterPaintWorklet { pipeline_id, .. } => Some(*pipeline_id),
117                MainThreadScriptMsg::Inactive => None,
118                MainThreadScriptMsg::WakeUp => None,
119            },
120            MixedMessage::FromImageCache(response) => match response {
121                ImageCacheResponseMessage::NotifyPendingImageLoadStatus(response) => {
122                    Some(response.pipeline_id)
123                },
124                ImageCacheResponseMessage::VectorImageRasterizationComplete(response) => {
125                    Some(response.pipeline_id)
126                },
127            },
128            MixedMessage::FromDevtools(_) | MixedMessage::TimerFired => None,
129            #[cfg(feature = "webgpu")]
130            MixedMessage::FromWebGPUServer(..) => None,
131        }
132    }
133}
134
135/// Messages used to control the script event loop.
136#[derive(Debug)]
137pub(crate) enum MainThreadScriptMsg {
138    /// Common variants associated with the script messages
139    Common(CommonScriptMsg),
140    /// Notifies the script thread that a new worklet has been loaded, and thus the page should be
141    /// reflowed.
142    WorkletLoaded(PipelineId),
143    NavigationResponse {
144        pipeline_id: PipelineId,
145        message: Box<FetchResponseMsg>,
146    },
147    /// Notifies the script thread that a new paint worklet has been registered.
148    RegisterPaintWorklet {
149        pipeline_id: PipelineId,
150        name: Atom,
151        properties: Vec<Atom>,
152        painter: Box<dyn Painter>,
153    },
154    /// A task related to a not fully-active document has been throttled.
155    Inactive,
156    /// Wake-up call from the task queue.
157    WakeUp,
158}
159
160/// Common messages used to control the event loops in both the script and the worker
161pub(crate) enum CommonScriptMsg {
162    /// Requests that the script thread measure its memory usage. The results are sent back via the
163    /// supplied channel.
164    CollectReports(ReportsChan),
165    /// Generic message that encapsulates event handling.
166    Task(
167        ScriptThreadEventCategory,
168        Box<dyn TaskBox>,
169        Option<PipelineId>,
170        TaskSourceName,
171    ),
172    /// Report CSP violations in the script
173    ReportCspViolations(PipelineId, Vec<Violation>),
174}
175
176impl fmt::Debug for CommonScriptMsg {
177    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
178        match *self {
179            CommonScriptMsg::CollectReports(_) => write!(f, "CollectReports(...)"),
180            CommonScriptMsg::Task(ref category, ref task, _, _) => {
181                f.debug_tuple("Task").field(category).field(task).finish()
182            },
183            CommonScriptMsg::ReportCspViolations(..) => write!(f, "ReportCspViolations(...)"),
184        }
185    }
186}
187
188/// A wrapper around various types of `Sender`s that send messages back to the event loop
189/// of a script context event loop. This will either target the main `ScriptThread` event
190/// loop or that of a worker.
191#[derive(Clone, JSTraceable, MallocSizeOf)]
192pub(crate) enum ScriptEventLoopSender {
193    /// A sender that sends to the main `ScriptThread` event loop.
194    MainThread(Sender<MainThreadScriptMsg>),
195    /// A sender that sends to a `ServiceWorker` event loop.
196    ServiceWorker(Sender<ServiceWorkerScriptMsg>),
197    /// A sender that sends to a dedicated worker (such as a generic Web Worker) event loop.
198    /// Note that this sender keeps the main thread Worker DOM object alive as long as it or
199    /// or any message it sends is not dropped.
200    DedicatedWorker {
201        sender: Sender<DedicatedWorkerScriptMsg>,
202        main_thread_worker: TrustedWorkerAddress,
203    },
204}
205
206impl ScriptEventLoopSender {
207    /// Send a message to the event loop, which might be a main thread event loop or a worker event loop.
208    pub(crate) fn send(&self, message: CommonScriptMsg) -> Result<(), SendError<()>> {
209        match self {
210            Self::MainThread(sender) => sender
211                .send(MainThreadScriptMsg::Common(message))
212                .map_err(|_| SendError(())),
213            Self::ServiceWorker(sender) => sender
214                .send(ServiceWorkerScriptMsg::CommonWorker(
215                    WorkerScriptMsg::Common(message),
216                ))
217                .map_err(|_| SendError(())),
218            Self::DedicatedWorker {
219                sender,
220                main_thread_worker,
221            } => {
222                let common_message = WorkerScriptMsg::Common(message);
223                sender
224                    .send(DedicatedWorkerScriptMsg::CommonWorker(
225                        main_thread_worker.clone(),
226                        common_message,
227                    ))
228                    .map_err(|_| SendError(()))
229            },
230        }
231    }
232}
233
234/// A wrapper around various types of `Receiver`s that receive event loop messages. Used for
235/// synchronous DOM APIs that need to abstract over multiple kinds of event loops (worker/main
236/// thread) with different Receiver interfaces.
237pub(crate) enum ScriptEventLoopReceiver {
238    /// A receiver that receives messages to the main `ScriptThread` event loop.
239    MainThread(Receiver<MainThreadScriptMsg>),
240    /// A receiver that receives messages to dedicated workers (such as a generic Web Worker) event loop.
241    DedicatedWorker(Receiver<DedicatedWorkerScriptMsg>),
242}
243
244impl ScriptEventLoopReceiver {
245    pub(crate) fn recv(&self) -> Result<CommonScriptMsg, ()> {
246        match self {
247            Self::MainThread(receiver) => match receiver.recv() {
248                Ok(MainThreadScriptMsg::Common(script_msg)) => Ok(script_msg),
249                Ok(_) => panic!("unexpected main thread event message!"),
250                Err(_) => Err(()),
251            },
252            Self::DedicatedWorker(receiver) => match receiver.recv() {
253                Ok(DedicatedWorkerScriptMsg::CommonWorker(_, WorkerScriptMsg::Common(message))) => {
254                    Ok(message)
255                },
256                Ok(_) => panic!("unexpected worker event message!"),
257                Err(_) => Err(()),
258            },
259        }
260    }
261}
262
263impl QueuedTaskConversion for MainThreadScriptMsg {
264    fn task_source_name(&self) -> Option<&TaskSourceName> {
265        let script_msg = match self {
266            MainThreadScriptMsg::Common(script_msg) => script_msg,
267            _ => return None,
268        };
269        match script_msg {
270            CommonScriptMsg::Task(_category, _boxed, _pipeline_id, task_source) => {
271                Some(task_source)
272            },
273            _ => None,
274        }
275    }
276
277    fn pipeline_id(&self) -> Option<PipelineId> {
278        let script_msg = match self {
279            MainThreadScriptMsg::Common(script_msg) => script_msg,
280            _ => return None,
281        };
282        match script_msg {
283            CommonScriptMsg::Task(_category, _boxed, pipeline_id, _task_source) => *pipeline_id,
284            _ => None,
285        }
286    }
287
288    fn into_queued_task(self) -> Option<QueuedTask> {
289        let script_msg = match self {
290            MainThreadScriptMsg::Common(script_msg) => script_msg,
291            _ => return None,
292        };
293        let (category, boxed, pipeline_id, task_source) = match script_msg {
294            CommonScriptMsg::Task(category, boxed, pipeline_id, task_source) => {
295                (category, boxed, pipeline_id, task_source)
296            },
297            _ => return None,
298        };
299        Some((None, category, boxed, pipeline_id, task_source))
300    }
301
302    fn from_queued_task(queued_task: QueuedTask) -> Self {
303        let (_worker, category, boxed, pipeline_id, task_source) = queued_task;
304        let script_msg = CommonScriptMsg::Task(category, boxed, pipeline_id, task_source);
305        MainThreadScriptMsg::Common(script_msg)
306    }
307
308    fn inactive_msg() -> Self {
309        MainThreadScriptMsg::Inactive
310    }
311
312    fn wake_up_msg() -> Self {
313        MainThreadScriptMsg::WakeUp
314    }
315
316    fn is_wake_up(&self) -> bool {
317        matches!(self, MainThreadScriptMsg::WakeUp)
318    }
319}
320
321impl OpaqueSender<CommonScriptMsg> for ScriptEventLoopSender {
322    fn send(&self, message: CommonScriptMsg) {
323        self.send(message).unwrap()
324    }
325}
326
327#[derive(Clone, JSTraceable)]
328pub(crate) struct ScriptThreadSenders {
329    /// A channel to hand out to script thread-based entities that need to be able to enqueue
330    /// events in the event queue.
331    pub(crate) self_sender: Sender<MainThreadScriptMsg>,
332
333    /// A handle to the bluetooth thread.
334    #[no_trace]
335    #[cfg(feature = "bluetooth")]
336    pub(crate) bluetooth_sender: IpcSender<BluetoothRequest>,
337
338    /// A [`Sender`] that sends messages to the `Constellation`.
339    #[no_trace]
340    pub(crate) constellation_sender: GenericSender<ScriptThreadMessage>,
341
342    /// A [`Sender`] that sends messages to the `Constellation` associated with
343    /// particular pipelines.
344    #[no_trace]
345    pub(crate) pipeline_to_constellation_sender:
346        GenericSender<(PipelineId, ScriptToConstellationMessage)>,
347
348    /// A channel to send messages to the Embedder.
349    #[no_trace]
350    pub(crate) pipeline_to_embedder_sender: ScriptToEmbedderChan,
351
352    /// The shared [`IpcSender`] which is sent to the `ImageCache` when requesting an image. The
353    /// messages on this channel are routed to crossbeam [`Sender`] on the router thread, which
354    /// in turn sends messages to [`ScriptThreadReceivers::image_cache_receiver`].
355    #[no_trace]
356    pub(crate) image_cache_sender: IpcSender<ImageCacheResponseMessage>,
357
358    /// For providing contact with the time profiler.
359    #[no_trace]
360    pub(crate) time_profiler_sender: profile_time::ProfilerChan,
361
362    /// For providing contact with the memory profiler.
363    #[no_trace]
364    pub(crate) memory_profiler_sender: profile_mem::ProfilerChan,
365
366    /// For providing instructions to an optional devtools server.
367    #[no_trace]
368    pub(crate) devtools_server_sender: Option<IpcSender<ScriptToDevtoolsControlMsg>>,
369
370    #[no_trace]
371    pub(crate) devtools_client_to_script_thread_sender: IpcSender<DevtoolScriptControlMsg>,
372
373    #[no_trace]
374    pub(crate) content_process_shutdown_sender: Sender<()>,
375}
376
377#[derive(JSTraceable)]
378pub(crate) struct ScriptThreadReceivers {
379    /// A [`Receiver`] that receives messages from the constellation.
380    #[no_trace]
381    pub(crate) constellation_receiver: RoutedReceiver<ScriptThreadMessage>,
382
383    /// The [`Receiver`] which receives incoming messages from the `ImageCache`.
384    #[no_trace]
385    pub(crate) image_cache_receiver: Receiver<ImageCacheResponseMessage>,
386
387    /// For receiving commands from an optional devtools server. Will be ignored if no such server
388    /// exists. When devtools are not active this will be [`crossbeam_channel::never()`].
389    #[no_trace]
390    pub(crate) devtools_server_receiver: Receiver<DevtoolScriptControlMsg>,
391
392    /// Receiver to receive commands from optional WebGPU server. When there is no active
393    /// WebGPU context, this will be [`crossbeam_channel::never()`].
394    #[no_trace]
395    #[cfg(feature = "webgpu")]
396    pub(crate) webgpu_receiver: RefCell<Receiver<WebGPUMsg>>,
397}
398
399impl ScriptThreadReceivers {
400    /// Block until a message is received by any of the receivers of this [`ScriptThreadReceivers`]
401    /// or the given [`TaskQueue`] or [`TimerScheduler`]. Return the first message received.
402    pub(crate) fn recv(
403        &self,
404        task_queue: &TaskQueue<MainThreadScriptMsg>,
405        timer_scheduler: &TimerScheduler,
406        fully_active: &FxHashSet<PipelineId>,
407    ) -> MixedMessage {
408        select! {
409            recv(task_queue.select()) -> msg => {
410                task_queue.take_tasks(msg.unwrap(), fully_active);
411                let event = task_queue
412                    .recv()
413                    .expect("Spurious wake-up of the event-loop, task-queue has no tasks available");
414                MixedMessage::FromScript(event)
415            },
416            recv(self.constellation_receiver) -> msg => MixedMessage::FromConstellation(msg.unwrap().unwrap()),
417            recv(self.devtools_server_receiver) -> msg => MixedMessage::FromDevtools(msg.unwrap()),
418            recv(self.image_cache_receiver) -> msg => MixedMessage::FromImageCache(msg.unwrap()),
419            recv(timer_scheduler.wait_channel()) -> _ => MixedMessage::TimerFired,
420            recv({
421                #[cfg(feature = "webgpu")]
422                {
423                    self.webgpu_receiver.borrow()
424                }
425                #[cfg(not(feature = "webgpu"))]
426                {
427                    crossbeam_channel::never::<()>()
428                }
429            }) -> msg => {
430                #[cfg(feature = "webgpu")]
431                {
432                    MixedMessage::FromWebGPUServer(msg.unwrap())
433                }
434                #[cfg(not(feature = "webgpu"))]
435                {
436                    unreachable!("This should never be hit when webgpu is disabled ({msg:?})");
437                }
438            }
439        }
440    }
441
442    /// Try to receive a from any of the receivers of this [`ScriptThreadReceivers`] or the given
443    /// [`TaskQueue`]. Return `None` if no messages are ready to be received.
444    pub(crate) fn try_recv(
445        &self,
446        task_queue: &TaskQueue<MainThreadScriptMsg>,
447        fully_active: &FxHashSet<PipelineId>,
448    ) -> Option<MixedMessage> {
449        if let Ok(message) = self.constellation_receiver.try_recv() {
450            let message = message
451                .inspect_err(|e| {
452                    log::warn!(
453                        "ScriptThreadReceivers IPC error on constellation_receiver: {:?}",
454                        e
455                    );
456                })
457                .ok()?;
458            return MixedMessage::FromConstellation(message).into();
459        }
460        if let Ok(message) = task_queue.take_tasks_and_recv(fully_active) {
461            return MixedMessage::FromScript(message).into();
462        }
463        if let Ok(message) = self.devtools_server_receiver.try_recv() {
464            return MixedMessage::FromDevtools(message).into();
465        }
466        if let Ok(message) = self.image_cache_receiver.try_recv() {
467            return MixedMessage::FromImageCache(message).into();
468        }
469        #[cfg(feature = "webgpu")]
470        if let Ok(message) = self.webgpu_receiver.borrow().try_recv() {
471            return MixedMessage::FromWebGPUServer(message).into();
472        }
473        None
474    }
475}
script/messaging.rs

script/
messaging.rs
