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

script/dom/workers/
worker.rs
