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

script/dom/workers/
worker.rs
