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
5#![cfg_attr(crown, allow(crown::jscontext_first_arg))]
6
7use std::cell::Cell;
8use std::sync::Arc;
9use std::sync::atomic::{AtomicBool, Ordering};
10
11use crossbeam_channel::{Sender, unbounded};
12#[cfg(feature = "devtools")]
13use devtools_traits::{DevtoolsPageInfo, ScriptToDevtoolsControlMsg};
14use dom_struct::dom_struct;
15use js::context::JSContext;
16use js::jsapi::{Heap, JSObject};
17use js::jsval::UndefinedValue;
18use js::rust::{CustomAutoRooterGuard, HandleObject, HandleValue};
19use net_traits::request::Referrer;
20use script_bindings::cell::DomRefCell;
21use script_bindings::reflector::reflect_dom_object_with_proto;
22use servo_base::generic_channel;
23use servo_base::id::WorkerId;
24use servo_constellation_traits::{StructuredSerializedData, WorkerScriptLoadOrigin};
25use uuid::Uuid;
26
27use crate::dom::abstractworker::{MessageData, SimpleWorkerErrorHandler, WorkerScriptMsg};
28use crate::dom::bindings::codegen::Bindings::MessagePortBinding::StructuredSerializeOptions;
29use crate::dom::bindings::codegen::Bindings::WorkerBinding::{WorkerMethods, WorkerOptions};
30use crate::dom::bindings::codegen::UnionTypes::TrustedScriptURLOrUSVString;
31use crate::dom::bindings::error::{Error, ErrorResult, Fallible};
32use crate::dom::bindings::inheritance::Castable;
33use crate::dom::bindings::refcounted::Trusted;
34use crate::dom::bindings::reflector::DomGlobal;
35use crate::dom::bindings::root::DomRoot;
36use crate::dom::bindings::structuredclone;
37use crate::dom::bindings::trace::{CustomTraceable, RootedTraceableBox};
38use crate::dom::dedicatedworkerglobalscope::{
39    DedicatedWorkerGlobalScope, DedicatedWorkerScriptMsg,
40};
41use crate::dom::eventtarget::EventTarget;
42use crate::dom::globalscope::GlobalScope;
43use crate::dom::messageevent::MessageEvent;
44use crate::dom::sharedworkerglobalscope::SharedWorkerGlobalScope;
45use crate::dom::trustedtypes::trustedscripturl::TrustedScriptURL;
46use crate::dom::window::Window;
47use crate::dom::workerglobalscope::prepare_workerscope_init;
48use crate::realms::enter_auto_realm;
49use crate::runtime::script_runtime::ThreadSafeJSContext;
50use crate::tasks::task::TaskOnce;
51use crate::url::ensure_blob_referenced_by_url_is_kept_alive;
52
53pub(crate) type TrustedWorkerAddress = Trusted<Worker>;
54
55/// <https://html.spec.whatwg.org/multipage/#worker>
56#[dom_struct]
57pub(crate) struct Worker {
58    eventtarget: EventTarget,
59    /// Sender to the Receiver associated with the DedicatedWorkerGlobalScope
60    /// this Worker created.
61    sender: Sender<DedicatedWorkerScriptMsg>,
62    #[conditional_malloc_size_of]
63    closing: Arc<AtomicBool>,
64    terminated: Cell<bool>,
65    #[ignore_malloc_size_of = "mozjs"]
66    #[no_trace]
67    context_for_interrupt: DomRefCell<Option<ThreadSafeJSContext>>,
68}
69
70impl Worker {
71    fn new_inherited(sender: Sender<DedicatedWorkerScriptMsg>, closing: Arc<AtomicBool>) -> Worker {
72        Worker {
73            eventtarget: EventTarget::new_inherited(),
74            sender,
75            closing,
76            terminated: Cell::new(false),
77            context_for_interrupt: Default::default(),
78        }
79    }
80
81    fn new(
82        cx: &mut JSContext,
83        global: &GlobalScope,
84        proto: Option<HandleObject>,
85        sender: Sender<DedicatedWorkerScriptMsg>,
86        closing: Arc<AtomicBool>,
87    ) -> DomRoot<Worker> {
88        reflect_dom_object_with_proto(
89            cx,
90            Box::new(Worker::new_inherited(sender, closing)),
91            global,
92            proto,
93        )
94    }
95
96    pub(crate) fn is_terminated(&self) -> bool {
97        self.terminated.get()
98    }
99
100    pub(crate) fn set_context_for_interrupt(&self, cx: ThreadSafeJSContext) {
101        assert!(
102            self.context_for_interrupt.borrow().is_none(),
103            "Context for interrupt must be set only once"
104        );
105        *self.context_for_interrupt.borrow_mut() = Some(cx);
106    }
107
108    pub(crate) fn handle_message(
109        address: TrustedWorkerAddress,
110        data: StructuredSerializedData,
111        cx: &mut JSContext,
112    ) {
113        let worker = address.root();
114
115        if worker.is_terminated() {
116            return;
117        }
118
119        let global = worker.global();
120        let target = worker.upcast();
121        let mut realm = enter_auto_realm(cx, target);
122        let cx = &mut realm.current_realm();
123        rooted!(&in(cx) let mut message = UndefinedValue());
124        if let Ok(ports) = structuredclone::read(cx, &global, data, message.handle_mut()) {
125            MessageEvent::dispatch_jsval(cx, target, &global, message.handle(), None, None, ports);
126        } else {
127            // Step 4 of the "port post message steps" of the implicit messageport, fire messageerror.
128            MessageEvent::dispatch_error(cx, target, &global);
129        }
130    }
131
132    pub(crate) fn dispatch_simple_error(
133        cx: &mut js::context::JSContext,
134        address: TrustedWorkerAddress,
135    ) {
136        let worker = address.root();
137        worker.upcast().fire_event(cx, atom!("error"));
138    }
139
140    /// <https://html.spec.whatwg.org/multipage/#dom-dedicatedworkerglobalscope-postmessage>
141    fn post_message_impl(
142        &self,
143        cx: &mut JSContext,
144        message: HandleValue,
145        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
146    ) -> ErrorResult {
147        let data = structuredclone::write(cx, message, Some(transfer))?;
148        let address = Trusted::new(self);
149
150        // NOTE: step 9 of https://html.spec.whatwg.org/multipage/#dom-messageport-postmessage
151        // indicates that a nonexistent communication channel should result in a silent error.
152        let _ = self.sender.send(DedicatedWorkerScriptMsg::CommonWorker(
153            address,
154            WorkerScriptMsg::DOMMessage(MessageData {
155                origin: self.global().origin().immutable().clone(),
156                pipeline_id: self.global().pipeline_id(),
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(cx, global, proto, sender.clone(), closing.clone());
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                    .or_else(|| {
221                        global
222                            .downcast::<SharedWorkerGlobalScope>()
223                            .and_then(|w| w.browsing_context())
224                    })
225            });
226
227        #[cfg(feature = "devtools")]
228        let (devtools_sender, devtools_receiver) = generic_channel::channel().unwrap();
229        let worker_id = WorkerId(Uuid::new_v4());
230        #[cfg(feature = "devtools")]
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        #[cfg(feature = "webgl")]
250        let webgl_chan = global
251            .downcast::<Window>()
252            .and_then(|window| window.webgl_chan_value());
253        let init = prepare_workerscope_init(
254            global,
255            #[cfg(feature = "devtools")]
256            Some(devtools_sender),
257            Some(worker_id),
258            #[cfg(feature = "webgl")]
259            webgl_chan,
260        );
261        let animation_frame_provider_supported = global
262            .downcast::<DedicatedWorkerGlobalScope>()
263            .map(|worker| worker.animation_frame_provider_supported_flag())
264            .unwrap_or_else(|| Arc::new(AtomicBool::new(init.animation_frame_provider_supported)));
265
266        let (control_sender, control_receiver) = unbounded();
267        let (context_sender, context_receiver) = unbounded();
268
269        let event_loop_sender = global
270            .event_loop_sender()
271            .expect("Tried to create a worker in a worker while not handling a message?");
272        let join_handle = DedicatedWorkerGlobalScope::run_worker_scope(
273            init,
274            webview_id,
275            worker_url,
276            #[cfg(feature = "devtools")]
277            devtools_receiver,
278            worker_ref,
279            event_loop_sender,
280            sender,
281            receiver,
282            worker_load_origin,
283            worker_options,
284            closing.clone(),
285            animation_frame_provider_supported.clone(),
286            global.image_cache(),
287            browsing_context,
288            #[cfg(feature = "webgpu")]
289            global.wgpu_id_hub(),
290            control_receiver,
291            context_sender,
292            global.insecure_requests_policy(),
293            global.policy_container(),
294            global.font_context(),
295        );
296
297        let context = context_receiver
298            .recv()
299            .expect("Couldn't receive a context for worker.");
300
301        worker.set_context_for_interrupt(context.clone());
302        global.track_worker(
303            closing,
304            animation_frame_provider_supported,
305            join_handle,
306            control_sender,
307            context,
308        );
309
310        Ok(worker)
311    }
312
313    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
314    fn PostMessage(
315        &self,
316        cx: &mut JSContext,
317        message: HandleValue,
318        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
319    ) -> ErrorResult {
320        self.post_message_impl(cx, message, transfer)
321    }
322
323    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
324    fn PostMessage_(
325        &self,
326        cx: &mut JSContext,
327        message: HandleValue,
328        options: &StructuredSerializeOptions,
329    ) -> ErrorResult {
330        auto_root!(&in(cx) let guard =
331            options
332                .transfer
333                .iter()
334                .map(|js: &RootedTraceableBox<Heap<*mut JSObject>>| js.get())
335                .collect::<Vec<_>>());
336        self.post_message_impl(cx, message, guard)
337    }
338
339    /// <https://html.spec.whatwg.org/multipage/#terminate-a-worker>
340    fn Terminate(&self) {
341        // Step 1
342        if self.closing.swap(true, Ordering::SeqCst) {
343            return;
344        }
345
346        // Step 2
347        self.terminated.set(true);
348
349        // Step 3
350        if let Some(cx) = self.context_for_interrupt.borrow().as_ref() {
351            cx.request_interrupt_callback()
352        }
353    }
354
355    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessage
356    event_handler!(message, GetOnmessage, SetOnmessage);
357
358    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessageerror
359    event_handler!(messageerror, GetOnmessageerror, SetOnmessageerror);
360
361    // https://html.spec.whatwg.org/multipage/#handler-workerglobalscope-onerror
362    event_handler!(error, GetOnerror, SetOnerror);
363}
364
365impl TaskOnce for SimpleWorkerErrorHandler<Worker> {
366    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
367    fn run_once(self, cx: &mut JSContext) {
368        Worker::dispatch_simple_error(cx, self.addr);
369    }
370}
script/dom/workers/worker.rs

script/dom/workers/
worker.rs
