script/dom/workers/
worker.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 std::cell::Cell;
6use std::sync::Arc;
7use std::sync::atomic::{AtomicBool, Ordering};
8
9use crossbeam_channel::{Sender, unbounded};
10use devtools_traits::{DevtoolsPageInfo, ScriptToDevtoolsControlMsg, WorkerId};
11use dom_struct::dom_struct;
12use js::context::JSContext;
13use js::jsapi::{Heap, JSObject};
14use js::jsval::UndefinedValue;
15use js::rust::{CustomAutoRooter, CustomAutoRooterGuard, HandleObject, HandleValue};
16use net_traits::request::Referrer;
17use servo_base::generic_channel;
18use servo_constellation_traits::{StructuredSerializedData, WorkerScriptLoadOrigin};
19use uuid::Uuid;
20
21use crate::dom::abstractworker::{MessageData, SimpleWorkerErrorHandler, WorkerScriptMsg};
22use crate::dom::bindings::cell::DomRefCell;
23use crate::dom::bindings::codegen::Bindings::MessagePortBinding::StructuredSerializeOptions;
24use crate::dom::bindings::codegen::Bindings::WorkerBinding::{WorkerMethods, WorkerOptions};
25use crate::dom::bindings::codegen::UnionTypes::TrustedScriptURLOrUSVString;
26use crate::dom::bindings::error::{Error, ErrorResult, Fallible};
27use crate::dom::bindings::inheritance::Castable;
28use crate::dom::bindings::refcounted::Trusted;
29use crate::dom::bindings::reflector::{DomGlobal, reflect_dom_object_with_proto};
30use crate::dom::bindings::root::DomRoot;
31use crate::dom::bindings::structuredclone;
32use crate::dom::bindings::trace::{CustomTraceable, RootedTraceableBox};
33use crate::dom::dedicatedworkerglobalscope::{
34    DedicatedWorkerGlobalScope, DedicatedWorkerScriptMsg,
35};
36use crate::dom::eventtarget::EventTarget;
37use crate::dom::globalscope::GlobalScope;
38use crate::dom::messageevent::MessageEvent;
39use crate::dom::trustedtypes::trustedscripturl::TrustedScriptURL;
40use crate::dom::window::Window;
41use crate::dom::workerglobalscope::prepare_workerscope_init;
42use crate::realms::enter_auto_realm;
43use crate::script_runtime::{CanGc, ThreadSafeJSContext};
44use crate::task::TaskOnce;
45use crate::url::ensure_blob_referenced_by_url_is_kept_alive;
46
47pub(crate) type TrustedWorkerAddress = Trusted<Worker>;
48
49// https://html.spec.whatwg.org/multipage/#worker
50#[dom_struct]
51pub(crate) struct Worker {
52    eventtarget: EventTarget,
53    /// Sender to the Receiver associated with the DedicatedWorkerGlobalScope
54    /// this Worker created.
55    sender: Sender<DedicatedWorkerScriptMsg>,
56    #[conditional_malloc_size_of]
57    closing: Arc<AtomicBool>,
58    terminated: Cell<bool>,
59    #[ignore_malloc_size_of = "mozjs"]
60    #[no_trace]
61    context_for_interrupt: DomRefCell<Option<ThreadSafeJSContext>>,
62}
63
64impl Worker {
65    fn new_inherited(sender: Sender<DedicatedWorkerScriptMsg>, closing: Arc<AtomicBool>) -> Worker {
66        Worker {
67            eventtarget: EventTarget::new_inherited(),
68            sender,
69            closing,
70            terminated: Cell::new(false),
71            context_for_interrupt: Default::default(),
72        }
73    }
74
75    fn new(
76        global: &GlobalScope,
77        proto: Option<HandleObject>,
78        sender: Sender<DedicatedWorkerScriptMsg>,
79        closing: Arc<AtomicBool>,
80        can_gc: CanGc,
81    ) -> DomRoot<Worker> {
82        reflect_dom_object_with_proto(
83            Box::new(Worker::new_inherited(sender, closing)),
84            global,
85            proto,
86            can_gc,
87        )
88    }
89
90    pub(crate) fn is_terminated(&self) -> bool {
91        self.terminated.get()
92    }
93
94    pub(crate) fn set_context_for_interrupt(&self, cx: ThreadSafeJSContext) {
95        assert!(
96            self.context_for_interrupt.borrow().is_none(),
97            "Context for interrupt must be set only once"
98        );
99        *self.context_for_interrupt.borrow_mut() = Some(cx);
100    }
101
102    pub(crate) fn handle_message(
103        address: TrustedWorkerAddress,
104        data: StructuredSerializedData,
105        cx: &mut JSContext,
106    ) {
107        let worker = address.root();
108
109        if worker.is_terminated() {
110            return;
111        }
112
113        let global = worker.global();
114        let target = worker.upcast();
115        let mut realm = enter_auto_realm(cx, target);
116        let cx = &mut realm.current_realm();
117        rooted!(&in(cx) let mut message = UndefinedValue());
118        if let Ok(ports) =
119            structuredclone::read(&global, data, message.handle_mut(), CanGc::from_cx(cx))
120        {
121            MessageEvent::dispatch_jsval(
122                target,
123                &global,
124                message.handle(),
125                None,
126                None,
127                ports,
128                CanGc::from_cx(cx),
129            );
130        } else {
131            // Step 4 of the "port post message steps" of the implicit messageport, fire messageerror.
132            MessageEvent::dispatch_error(cx, target, &global);
133        }
134    }
135
136    pub(crate) fn dispatch_simple_error(
137        cx: &mut js::context::JSContext,
138        address: TrustedWorkerAddress,
139    ) {
140        let worker = address.root();
141        worker.upcast().fire_event(cx, atom!("error"));
142    }
143
144    /// <https://html.spec.whatwg.org/multipage/#dom-dedicatedworkerglobalscope-postmessage>
145    fn post_message_impl(
146        &self,
147        cx: &mut JSContext,
148        message: HandleValue,
149        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
150    ) -> ErrorResult {
151        let data = structuredclone::write(cx.into(), message, Some(transfer))?;
152        let address = Trusted::new(self);
153
154        // NOTE: step 9 of https://html.spec.whatwg.org/multipage/#dom-messageport-postmessage
155        // indicates that a nonexistent communication channel should result in a silent error.
156        let _ = self.sender.send(DedicatedWorkerScriptMsg::CommonWorker(
157            address,
158            WorkerScriptMsg::DOMMessage(MessageData {
159                origin: self.global().origin().immutable().clone(),
160                data: Box::new(data),
161            }),
162        ));
163        Ok(())
164    }
165}
166
167impl WorkerMethods<crate::DomTypeHolder> for Worker {
168    /// <https://html.spec.whatwg.org/multipage/#dom-worker>
169    fn Constructor(
170        cx: &mut JSContext,
171        global: &GlobalScope,
172        proto: Option<HandleObject>,
173        script_url: TrustedScriptURLOrUSVString,
174        worker_options: &WorkerOptions,
175    ) -> Fallible<DomRoot<Worker>> {
176        // Step 1: Let compliantScriptURL be the result of invoking the
177        // Get Trusted Type compliant string algorithm with TrustedScriptURL,
178        // this's relevant global object, scriptURL, "Worker constructor", and "script".
179        let compliant_script_url = TrustedScriptURL::get_trusted_type_compliant_string(
180            cx,
181            global,
182            script_url,
183            "Worker constructor",
184        )?;
185        // Step 2. Let outsideSettings be this's relevant settings object.
186        // Step 3. Let workerURL be the result of encoding-parsing a URL given compliantScriptURL,
187        // relative to outsideSettings.
188        // TODO: Locking the URL should eventually happen inside encoding_parse_a_url, since most callers
189        // will expect their blobs to be kept alive...
190        let Ok(worker_url) = global
191            .encoding_parse_a_url(&compliant_script_url.str())
192            .map(|url| ensure_blob_referenced_by_url_is_kept_alive(global, url))
193        else {
194            // Step 4. If workerURL is failure, then throw a "SyntaxError" DOMException.
195            return Err(Error::Syntax(None));
196        };
197
198        let (sender, receiver) = unbounded();
199        let closing = Arc::new(AtomicBool::new(false));
200        let worker = Worker::new(
201            global,
202            proto,
203            sender.clone(),
204            closing.clone(),
205            CanGc::from_cx(cx),
206        );
207        let worker_ref = Trusted::new(&*worker);
208
209        let worker_load_origin = WorkerScriptLoadOrigin {
210            referrer_url: match global.get_referrer() {
211                Referrer::Client(url) => Some(url),
212                Referrer::ReferrerUrl(url) => Some(url),
213                _ => None,
214            },
215            referrer_policy: global.get_referrer_policy(),
216            pipeline_id: global.pipeline_id(),
217        };
218
219        let webview_id = global
220            .webview_id()
221            .expect("Global object must have a WebViewId");
222        let browsing_context = global
223            .downcast::<Window>()
224            .map(|w| w.window_proxy().browsing_context_id())
225            .or_else(|| {
226                global
227                    .downcast::<DedicatedWorkerGlobalScope>()
228                    .and_then(|w| w.browsing_context())
229            });
230
231        let (devtools_sender, devtools_receiver) = generic_channel::channel().unwrap();
232        let worker_id = WorkerId(Uuid::new_v4());
233        if let Some(chan) = global.devtools_chan() {
234            let pipeline_id = global.pipeline_id();
235            let title = format!("Worker for {}", worker_url.url());
236            if let Some(browsing_context) = browsing_context {
237                let page_info = DevtoolsPageInfo {
238                    title,
239                    url: worker_url.url(),
240                    is_top_level_global: false,
241                    is_service_worker: false,
242                };
243                let _ = chan.send(ScriptToDevtoolsControlMsg::NewGlobal(
244                    (browsing_context, pipeline_id, Some(worker_id), webview_id),
245                    devtools_sender.clone(),
246                    page_info,
247                ));
248            }
249        }
250
251        let webgl_chan = global
252            .downcast::<Window>()
253            .and_then(|window| window.webgl_chan_value());
254        let init =
255            prepare_workerscope_init(global, Some(devtools_sender), Some(worker_id), webgl_chan);
256
257        let (control_sender, control_receiver) = unbounded();
258        let (context_sender, context_receiver) = unbounded();
259
260        let event_loop_sender = global
261            .event_loop_sender()
262            .expect("Tried to create a worker in a worker while not handling a message?");
263        let join_handle = DedicatedWorkerGlobalScope::run_worker_scope(
264            init,
265            webview_id,
266            worker_url,
267            devtools_receiver,
268            worker_ref,
269            event_loop_sender,
270            sender,
271            receiver,
272            worker_load_origin,
273            worker_options,
274            closing.clone(),
275            global.image_cache(),
276            browsing_context,
277            #[cfg(feature = "webgpu")]
278            global.wgpu_id_hub(),
279            control_receiver,
280            context_sender,
281            global.insecure_requests_policy(),
282            global.policy_container(),
283            global.font_context().cloned(),
284        );
285
286        let context = context_receiver
287            .recv()
288            .expect("Couldn't receive a context for worker.");
289
290        worker.set_context_for_interrupt(context.clone());
291        global.track_worker(closing, join_handle, control_sender, context);
292
293        Ok(worker)
294    }
295
296    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
297    fn PostMessage(
298        &self,
299        cx: &mut JSContext,
300        message: HandleValue,
301        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
302    ) -> ErrorResult {
303        self.post_message_impl(cx, message, transfer)
304    }
305
306    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
307    fn PostMessage_(
308        &self,
309        cx: &mut JSContext,
310        message: HandleValue,
311        options: RootedTraceableBox<StructuredSerializeOptions>,
312    ) -> ErrorResult {
313        let mut rooted = CustomAutoRooter::new(
314            options
315                .transfer
316                .iter()
317                .map(|js: &RootedTraceableBox<Heap<*mut JSObject>>| js.get())
318                .collect(),
319        );
320        #[expect(unsafe_code)]
321        let guard = unsafe { CustomAutoRooterGuard::new(cx.raw_cx(), &mut rooted) };
322        self.post_message_impl(cx, message, guard)
323    }
324
325    /// <https://html.spec.whatwg.org/multipage/#terminate-a-worker>
326    fn Terminate(&self) {
327        // Step 1
328        if self.closing.swap(true, Ordering::SeqCst) {
329            return;
330        }
331
332        // Step 2
333        self.terminated.set(true);
334
335        // Step 3
336        if let Some(cx) = self.context_for_interrupt.borrow().as_ref() {
337            cx.request_interrupt_callback()
338        }
339    }
340
341    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessage
342    event_handler!(message, GetOnmessage, SetOnmessage);
343
344    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessageerror
345    event_handler!(messageerror, GetOnmessageerror, SetOnmessageerror);
346
347    // https://html.spec.whatwg.org/multipage/#handler-workerglobalscope-onerror
348    event_handler!(error, GetOnerror, SetOnerror);
349}
350
351impl TaskOnce for SimpleWorkerErrorHandler<Worker> {
352    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
353    fn run_once(self, cx: &mut JSContext) {
354        Worker::dispatch_simple_error(cx, self.addr);
355    }
356}
script/dom/workers/worker.rs

script/dom/workers/
worker.rs
