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};
12use devtools_traits::{DevtoolsPageInfo, ScriptToDevtoolsControlMsg, WorkerId};
13use dom_struct::dom_struct;
14use js::context::JSContext;
15use js::jsapi::{Heap, JSObject};
16use js::jsval::UndefinedValue;
17use js::rust::{CustomAutoRooterGuard, HandleObject, HandleValue};
18use net_traits::request::Referrer;
19use script_bindings::cell::DomRefCell;
20use script_bindings::reflector::reflect_dom_object_with_proto;
21use servo_base::generic_channel;
22use servo_constellation_traits::{StructuredSerializedData, WorkerScriptLoadOrigin};
23use uuid::Uuid;
24
25use crate::dom::abstractworker::{MessageData, SimpleWorkerErrorHandler, WorkerScriptMsg};
26use crate::dom::bindings::codegen::Bindings::MessagePortBinding::StructuredSerializeOptions;
27use crate::dom::bindings::codegen::Bindings::WorkerBinding::{WorkerMethods, WorkerOptions};
28use crate::dom::bindings::codegen::UnionTypes::TrustedScriptURLOrUSVString;
29use crate::dom::bindings::error::{Error, ErrorResult, Fallible};
30use crate::dom::bindings::inheritance::Castable;
31use crate::dom::bindings::refcounted::Trusted;
32use crate::dom::bindings::reflector::DomGlobal;
33use crate::dom::bindings::root::DomRoot;
34use crate::dom::bindings::structuredclone;
35use crate::dom::bindings::trace::{CustomTraceable, RootedTraceableBox};
36use crate::dom::dedicatedworkerglobalscope::{
37    DedicatedWorkerGlobalScope, DedicatedWorkerScriptMsg,
38};
39use crate::dom::eventtarget::EventTarget;
40use crate::dom::globalscope::GlobalScope;
41use crate::dom::messageevent::MessageEvent;
42use crate::dom::sharedworkerglobalscope::SharedWorkerGlobalScope;
43use crate::dom::trustedtypes::trustedscripturl::TrustedScriptURL;
44use crate::dom::window::Window;
45use crate::dom::workerglobalscope::prepare_workerscope_init;
46use crate::realms::enter_auto_realm;
47use crate::runtime::script_runtime::ThreadSafeJSContext;
48use crate::tasks::task::TaskOnce;
49use crate::url::ensure_blob_referenced_by_url_is_kept_alive;
50
51pub(crate) type TrustedWorkerAddress = Trusted<Worker>;
52
53// https://html.spec.whatwg.org/multipage/#worker
54#[dom_struct]
55pub(crate) struct Worker {
56    eventtarget: EventTarget,
57    /// Sender to the Receiver associated with the DedicatedWorkerGlobalScope
58    /// this Worker created.
59    sender: Sender<DedicatedWorkerScriptMsg>,
60    #[conditional_malloc_size_of]
61    closing: Arc<AtomicBool>,
62    terminated: Cell<bool>,
63    #[ignore_malloc_size_of = "mozjs"]
64    #[no_trace]
65    context_for_interrupt: DomRefCell<Option<ThreadSafeJSContext>>,
66}
67
68impl Worker {
69    fn new_inherited(sender: Sender<DedicatedWorkerScriptMsg>, closing: Arc<AtomicBool>) -> Worker {
70        Worker {
71            eventtarget: EventTarget::new_inherited(),
72            sender,
73            closing,
74            terminated: Cell::new(false),
75            context_for_interrupt: Default::default(),
76        }
77    }
78
79    fn new(
80        cx: &mut JSContext,
81        global: &GlobalScope,
82        proto: Option<HandleObject>,
83        sender: Sender<DedicatedWorkerScriptMsg>,
84        closing: Arc<AtomicBool>,
85    ) -> DomRoot<Worker> {
86        reflect_dom_object_with_proto(
87            cx,
88            Box::new(Worker::new_inherited(sender, closing)),
89            global,
90            proto,
91        )
92    }
93
94    pub(crate) fn is_terminated(&self) -> bool {
95        self.terminated.get()
96    }
97
98    pub(crate) fn set_context_for_interrupt(&self, cx: ThreadSafeJSContext) {
99        assert!(
100            self.context_for_interrupt.borrow().is_none(),
101            "Context for interrupt must be set only once"
102        );
103        *self.context_for_interrupt.borrow_mut() = Some(cx);
104    }
105
106    pub(crate) fn handle_message(
107        address: TrustedWorkerAddress,
108        data: StructuredSerializedData,
109        cx: &mut JSContext,
110    ) {
111        let worker = address.root();
112
113        if worker.is_terminated() {
114            return;
115        }
116
117        let global = worker.global();
118        let target = worker.upcast();
119        let mut realm = enter_auto_realm(cx, target);
120        let cx = &mut realm.current_realm();
121        rooted!(&in(cx) let mut message = UndefinedValue());
122        if let Ok(ports) = structuredclone::read(cx, &global, data, message.handle_mut()) {
123            MessageEvent::dispatch_jsval(cx, target, &global, message.handle(), None, None, ports);
124        } else {
125            // Step 4 of the "port post message steps" of the implicit messageport, fire messageerror.
126            MessageEvent::dispatch_error(cx, target, &global);
127        }
128    }
129
130    pub(crate) fn dispatch_simple_error(
131        cx: &mut js::context::JSContext,
132        address: TrustedWorkerAddress,
133    ) {
134        let worker = address.root();
135        worker.upcast().fire_event(cx, atom!("error"));
136    }
137
138    /// <https://html.spec.whatwg.org/multipage/#dom-dedicatedworkerglobalscope-postmessage>
139    fn post_message_impl(
140        &self,
141        cx: &mut JSContext,
142        message: HandleValue,
143        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
144    ) -> ErrorResult {
145        let data = structuredclone::write(cx, message, Some(transfer))?;
146        let address = Trusted::new(self);
147
148        // NOTE: step 9 of https://html.spec.whatwg.org/multipage/#dom-messageport-postmessage
149        // indicates that a nonexistent communication channel should result in a silent error.
150        let _ = self.sender.send(DedicatedWorkerScriptMsg::CommonWorker(
151            address,
152            WorkerScriptMsg::DOMMessage(MessageData {
153                origin: self.global().origin().immutable().clone(),
154                pipeline_id: self.global().pipeline_id(),
155                data: Box::new(data),
156            }),
157        ));
158        Ok(())
159    }
160}
161
162impl WorkerMethods<crate::DomTypeHolder> for Worker {
163    /// <https://html.spec.whatwg.org/multipage/#dom-worker>
164    fn Constructor(
165        cx: &mut JSContext,
166        global: &GlobalScope,
167        proto: Option<HandleObject>,
168        script_url: TrustedScriptURLOrUSVString,
169        worker_options: &WorkerOptions,
170    ) -> Fallible<DomRoot<Worker>> {
171        // Step 1: Let compliantScriptURL be the result of invoking the
172        // Get Trusted Type compliant string algorithm with TrustedScriptURL,
173        // this's relevant global object, scriptURL, "Worker constructor", and "script".
174        let compliant_script_url = TrustedScriptURL::get_trusted_type_compliant_string(
175            cx,
176            global,
177            script_url,
178            "Worker constructor",
179        )?;
180        // Step 2. Let outsideSettings be this's relevant settings object.
181        // Step 3. Let workerURL be the result of encoding-parsing a URL given compliantScriptURL,
182        // relative to outsideSettings.
183        // TODO: Locking the URL should eventually happen inside encoding_parse_a_url, since most callers
184        // will expect their blobs to be kept alive...
185        let Ok(worker_url) = global
186            .encoding_parse_a_url(&compliant_script_url.str())
187            .map(|url| ensure_blob_referenced_by_url_is_kept_alive(global, url))
188        else {
189            // Step 4. If workerURL is failure, then throw a "SyntaxError" DOMException.
190            return Err(Error::Syntax(None));
191        };
192
193        let (sender, receiver) = unbounded();
194        let closing = Arc::new(AtomicBool::new(false));
195        let worker = Worker::new(cx, global, proto, sender.clone(), closing.clone());
196        let worker_ref = Trusted::new(&*worker);
197
198        let worker_load_origin = WorkerScriptLoadOrigin {
199            referrer_url: match global.get_referrer() {
200                Referrer::Client(url) => Some(url),
201                Referrer::ReferrerUrl(url) => Some(url),
202                _ => None,
203            },
204            referrer_policy: global.get_referrer_policy(),
205            pipeline_id: global.pipeline_id(),
206        };
207
208        let webview_id = global
209            .webview_id()
210            .expect("Global object must have a WebViewId");
211        let browsing_context = global
212            .downcast::<Window>()
213            .map(|w| w.window_proxy().browsing_context_id())
214            .or_else(|| {
215                global
216                    .downcast::<DedicatedWorkerGlobalScope>()
217                    .and_then(|w| w.browsing_context())
218                    .or_else(|| {
219                        global
220                            .downcast::<SharedWorkerGlobalScope>()
221                            .and_then(|w| w.browsing_context())
222                    })
223            });
224
225        let (devtools_sender, devtools_receiver) = generic_channel::channel().unwrap();
226        let worker_id = WorkerId(Uuid::new_v4());
227        if let Some(chan) = global.devtools_chan() {
228            let pipeline_id = global.pipeline_id();
229            let title = format!("Worker for {}", worker_url.url());
230            if let Some(browsing_context) = browsing_context {
231                let page_info = DevtoolsPageInfo {
232                    title,
233                    url: worker_url.url(),
234                    is_top_level_global: false,
235                    is_service_worker: false,
236                };
237                let _ = chan.send(ScriptToDevtoolsControlMsg::NewGlobal(
238                    (browsing_context, pipeline_id, Some(worker_id), webview_id),
239                    devtools_sender.clone(),
240                    page_info,
241                ));
242            }
243        }
244
245        #[cfg(feature = "webgl")]
246        let webgl_chan = global
247            .downcast::<Window>()
248            .and_then(|window| window.webgl_chan_value());
249        let init = prepare_workerscope_init(
250            global,
251            Some(devtools_sender),
252            Some(worker_id),
253            #[cfg(feature = "webgl")]
254            webgl_chan,
255        );
256        let animation_frame_provider_supported = global
257            .downcast::<DedicatedWorkerGlobalScope>()
258            .map(|worker| worker.animation_frame_provider_supported_flag())
259            .unwrap_or_else(|| Arc::new(AtomicBool::new(init.animation_frame_provider_supported)));
260
261        let (control_sender, control_receiver) = unbounded();
262        let (context_sender, context_receiver) = unbounded();
263
264        let event_loop_sender = global
265            .event_loop_sender()
266            .expect("Tried to create a worker in a worker while not handling a message?");
267        let join_handle = DedicatedWorkerGlobalScope::run_worker_scope(
268            init,
269            webview_id,
270            worker_url,
271            devtools_receiver,
272            worker_ref,
273            event_loop_sender,
274            sender,
275            receiver,
276            worker_load_origin,
277            worker_options,
278            closing.clone(),
279            animation_frame_provider_supported.clone(),
280            global.image_cache(),
281            browsing_context,
282            #[cfg(feature = "webgpu")]
283            global.wgpu_id_hub(),
284            control_receiver,
285            context_sender,
286            global.insecure_requests_policy(),
287            global.policy_container(),
288            global.font_context(),
289        );
290
291        let context = context_receiver
292            .recv()
293            .expect("Couldn't receive a context for worker.");
294
295        worker.set_context_for_interrupt(context.clone());
296        global.track_worker(
297            closing,
298            animation_frame_provider_supported,
299            join_handle,
300            control_sender,
301            context,
302        );
303
304        Ok(worker)
305    }
306
307    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
308    fn PostMessage(
309        &self,
310        cx: &mut JSContext,
311        message: HandleValue,
312        transfer: CustomAutoRooterGuard<Vec<*mut JSObject>>,
313    ) -> ErrorResult {
314        self.post_message_impl(cx, message, transfer)
315    }
316
317    /// <https://html.spec.whatwg.org/multipage/#dom-worker-postmessage>
318    fn PostMessage_(
319        &self,
320        cx: &mut JSContext,
321        message: HandleValue,
322        options: RootedTraceableBox<StructuredSerializeOptions>,
323    ) -> ErrorResult {
324        auto_root!(&in(cx) let guard =
325            options
326                .transfer
327                .iter()
328                .map(|js: &RootedTraceableBox<Heap<*mut JSObject>>| js.get())
329                .collect::<Vec<_>>());
330        self.post_message_impl(cx, message, guard)
331    }
332
333    /// <https://html.spec.whatwg.org/multipage/#terminate-a-worker>
334    fn Terminate(&self) {
335        // Step 1
336        if self.closing.swap(true, Ordering::SeqCst) {
337            return;
338        }
339
340        // Step 2
341        self.terminated.set(true);
342
343        // Step 3
344        if let Some(cx) = self.context_for_interrupt.borrow().as_ref() {
345            cx.request_interrupt_callback()
346        }
347    }
348
349    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessage
350    event_handler!(message, GetOnmessage, SetOnmessage);
351
352    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessageerror
353    event_handler!(messageerror, GetOnmessageerror, SetOnmessageerror);
354
355    // https://html.spec.whatwg.org/multipage/#handler-workerglobalscope-onerror
356    event_handler!(error, GetOnerror, SetOnerror);
357}
358
359impl TaskOnce for SimpleWorkerErrorHandler<Worker> {
360    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
361    fn run_once(self, cx: &mut JSContext) {
362        Worker::dispatch_simple_error(cx, self.addr);
363    }
364}
script/dom/workers/worker.rs

script/dom/workers/
worker.rs
