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(target, &global, CanGc::from_cx(cx));
133        }
134    }
135
136    pub(crate) fn dispatch_simple_error(address: TrustedWorkerAddress, can_gc: CanGc) {
137        let worker = address.root();
138        worker.upcast().fire_event(atom!("error"), can_gc);
139    }
140
141    /// <https://html.spec.whatwg.org/multipage/#dom-dedicatedworkerglobalscope-postmessage>
142    fn post_message_impl(
143        &self,
144        cx: &mut JSContext,
145        message: HandleValue,
146        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
147    ) -> ErrorResult {
148        let data = structuredclone::write(cx.into(), message, Some(transfer))?;
149        let address = Trusted::new(self);
150
151        // NOTE: step 9 of https://html.spec.whatwg.org/multipage/#dom-messageport-postmessage
152        // indicates that a nonexistent communication channel should result in a silent error.
153        let _ = self.sender.send(DedicatedWorkerScriptMsg::CommonWorker(
154            address,
155            WorkerScriptMsg::DOMMessage(MessageData {
156                origin: self.global().origin().immutable().clone(),
157                data: Box::new(data),
158            }),
159        ));
160        Ok(())
161    }
162}
163
164impl WorkerMethods<crate::DomTypeHolder> for Worker {
165    /// <https://html.spec.whatwg.org/multipage/#dom-worker>
166    fn Constructor(
167        cx: &mut JSContext,
168        global: &GlobalScope,
169        proto: Option<HandleObject>,
170        script_url: TrustedScriptURLOrUSVString,
171        worker_options: &WorkerOptions,
172    ) -> Fallible<DomRoot<Worker>> {
173        // Step 1: Let compliantScriptURL be the result of invoking the
174        // Get Trusted Type compliant string algorithm with TrustedScriptURL,
175        // this's relevant global object, scriptURL, "Worker constructor", and "script".
176        let compliant_script_url = TrustedScriptURL::get_trusted_type_compliant_string(
177            cx,
178            global,
179            script_url,
180            "Worker constructor",
181        )?;
182        // Step 2. Let outsideSettings be this's relevant settings object.
183        // Step 3. Let workerURL be the result of encoding-parsing a URL given compliantScriptURL,
184        // relative to outsideSettings.
185        // TODO: Locking the URL should eventually happen inside encoding_parse_a_url, since most callers
186        // will expect their blobs to be kept alive...
187        let Ok(worker_url) = global
188            .encoding_parse_a_url(&compliant_script_url.str())
189            .map(|url| ensure_blob_referenced_by_url_is_kept_alive(global, url))
190        else {
191            // Step 4. If workerURL is failure, then throw a "SyntaxError" DOMException.
192            return Err(Error::Syntax(None));
193        };
194
195        let (sender, receiver) = unbounded();
196        let closing = Arc::new(AtomicBool::new(false));
197        let worker = Worker::new(
198            global,
199            proto,
200            sender.clone(),
201            closing.clone(),
202            CanGc::from_cx(cx),
203        );
204        let worker_ref = Trusted::new(&*worker);
205
206        let worker_load_origin = WorkerScriptLoadOrigin {
207            referrer_url: match global.get_referrer() {
208                Referrer::Client(url) => Some(url),
209                Referrer::ReferrerUrl(url) => Some(url),
210                _ => None,
211            },
212            referrer_policy: global.get_referrer_policy(),
213            pipeline_id: global.pipeline_id(),
214        };
215
216        let webview_id = global
217            .webview_id()
218            .expect("Global object must have a WebViewId");
219        let browsing_context = global
220            .downcast::<Window>()
221            .map(|w| w.window_proxy().browsing_context_id())
222            .or_else(|| {
223                global
224                    .downcast::<DedicatedWorkerGlobalScope>()
225                    .and_then(|w| w.browsing_context())
226            });
227
228        let (devtools_sender, devtools_receiver) = generic_channel::channel().unwrap();
229        let worker_id = WorkerId(Uuid::new_v4());
230        if let Some(chan) = global.devtools_chan() {
231            let pipeline_id = global.pipeline_id();
232            let title = format!("Worker for {}", worker_url.url());
233            if let Some(browsing_context) = browsing_context {
234                let page_info = DevtoolsPageInfo {
235                    title,
236                    url: worker_url.url(),
237                    is_top_level_global: false,
238                    is_service_worker: false,
239                };
240                let _ = chan.send(ScriptToDevtoolsControlMsg::NewGlobal(
241                    (browsing_context, pipeline_id, Some(worker_id), webview_id),
242                    devtools_sender.clone(),
243                    page_info,
244                ));
245            }
246        }
247
248        let init = prepare_workerscope_init(global, Some(devtools_sender), Some(worker_id));
249
250        let (control_sender, control_receiver) = unbounded();
251        let (context_sender, context_receiver) = unbounded();
252
253        let event_loop_sender = global
254            .event_loop_sender()
255            .expect("Tried to create a worker in a worker while not handling a message?");
256        let join_handle = DedicatedWorkerGlobalScope::run_worker_scope(
257            init,
258            webview_id,
259            worker_url,
260            devtools_receiver,
261            worker_ref,
262            event_loop_sender,
263            sender,
264            receiver,
265            worker_load_origin,
266            worker_options,
267            closing.clone(),
268            global.image_cache(),
269            browsing_context,
270            #[cfg(feature = "webgpu")]
271            global.wgpu_id_hub(),
272            control_receiver,
273            context_sender,
274            global.insecure_requests_policy(),
275            global.policy_container(),
276            global.font_context().cloned(),
277        );
278
279        let context = context_receiver
280            .recv()
281            .expect("Couldn't receive a context for worker.");
282
283        worker.set_context_for_interrupt(context.clone());
284        global.track_worker(closing, join_handle, control_sender, context);
285
286        Ok(worker)
287    }
288
289    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
290    fn PostMessage(
291        &self,
292        cx: &mut JSContext,
293        message: HandleValue,
294        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
295    ) -> ErrorResult {
296        self.post_message_impl(cx, message, transfer)
297    }
298
299    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
300    fn PostMessage_(
301        &self,
302        cx: &mut JSContext,
303        message: HandleValue,
304        options: RootedTraceableBox<StructuredSerializeOptions>,
305    ) -> ErrorResult {
306        let mut rooted = CustomAutoRooter::new(
307            options
308                .transfer
309                .iter()
310                .map(|js: &RootedTraceableBox<Heap<*mut JSObject>>| js.get())
311                .collect(),
312        );
313        #[expect(unsafe_code)]
314        let guard = unsafe { CustomAutoRooterGuard::new(cx.raw_cx(), &mut rooted) };
315        self.post_message_impl(cx, message, guard)
316    }
317
318    /// <https://html.spec.whatwg.org/multipage/#terminate-a-worker>
319    fn Terminate(&self) {
320        // Step 1
321        if self.closing.swap(true, Ordering::SeqCst) {
322            return;
323        }
324
325        // Step 2
326        self.terminated.set(true);
327
328        // Step 3
329        if let Some(cx) = self.context_for_interrupt.borrow().as_ref() {
330            cx.request_interrupt_callback()
331        }
332    }
333
334    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessage
335    event_handler!(message, GetOnmessage, SetOnmessage);
336
337    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessageerror
338    event_handler!(messageerror, GetOnmessageerror, SetOnmessageerror);
339
340    // https://html.spec.whatwg.org/multipage/#handler-workerglobalscope-onerror
341    event_handler!(error, GetOnerror, SetOnerror);
342}
343
344impl TaskOnce for SimpleWorkerErrorHandler<Worker> {
345    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
346    fn run_once(self, cx: &mut JSContext) {
347        Worker::dispatch_simple_error(self.addr, CanGc::from_cx(cx));
348    }
349}
script/dom/workers/worker.rs

script/dom/workers/
worker.rs
