diff options
| -rw-r--r-- | components/script/docs/JS-Servos-only-GC.md | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/components/script/docs/JS-Servos-only-GC.md b/components/script/docs/JS-Servos-only-GC.md index 4f67bade28a..d7611fc7336 100644 --- a/components/script/docs/JS-Servos-only-GC.md +++ b/components/script/docs/JS-Servos-only-GC.md @@ -171,21 +171,35 @@ is where we actually call the SpiderMonkey trace hooks: [dom]: https://doc.servo.org/script/dom/bindings/root/struct.Dom.html ```rust +/// Trace the `JSObject` held by `reflector`. +#[allow(unrooted_must_root)] pub fn trace_reflector(tracer: *mut JSTracer, description: &str, reflector: &Reflector) { + trace!("tracing reflector {}", description); + trace_object(tracer, description, reflector.rootable()) +} + +/// Trace a `JSObject`. +pub fn trace_object(tracer: *mut JSTracer, description: &str, obj: &Heap<*mut JSObject>) { unsafe { - let name = CString::new(description).unwrap(); - (*tracer).debugPrinter_ = None; - (*tracer).debugPrintIndex_ = !0; - (*tracer).debugPrintArg_ = name.as_ptr() as *const libc::c_void; - debug!("tracing reflector {}", description); - JS_CallUnbarrieredObjectTracer(tracer, reflector.rootable(), - GCTraceKindToAscii(JSGCTraceKind::JSTRACE_OBJECT)); + trace!("tracing {}", description); + CallObjectTracer( + tracer, + obj.ptr.get() as *mut _, + GCTraceKindToAscii(TraceKind::Object), + ); } } -impl<T: DomObject> JSTraceable for Dom<T> { +unsafe impl<T: DomObject> JSTraceable for Dom<T> { unsafe fn trace(&self, trc: *mut JSTracer) { - trace_reflector(trc, "", unsafe { (**self.ptr).reflector() }); + let trace_string; + let trace_info = if cfg!(debug_assertions) { + trace_string = format!("for {} on heap", ::std::any::type_name::<T>()); + &trace_string[..] + } else { + "for DOM object on heap" + }; + trace_reflector(trc, trace_info, (*self.ptr.as_ptr()).reflector()); } } ``` @@ -232,10 +246,10 @@ In some cases, we need to use a DOM object longer than the reference we received allows us to; the [`DomRoot::from_ref` associated function][from-ref] allows creating a new `DomRoot<T>` struct in that case. -[root]: https://doc.servo.org/script/dom/bindings/root/struct.DomRoot.html +[root]: https://doc.servo.org/script/dom/bindings/root/type.DomRoot.html [raii]: https://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization [new]: https://doc.servo.org/script/dom/index.html#construction -[from-ref]: https://doc.servo.org/script/dom/bindings/root/struct.DomRoot.html#method.from_ref +[from-ref]: https://doc.servo.org/script/dom/bindings/root/struct.Root.html#method.from_ref We can then obtain a reference from the `DomRoot<T>` through Rust's built-in [`Deref` trait][deref], which exposes a method `deref` with the following @@ -320,7 +334,7 @@ the usual [warnings infrastructure][warnings], we can use the `allow` attribute in places where it's okay to use `Dom<T>`, like DOM struct definitions and the implementation of `Dom<T>` itself. -[js-lint]: https://doc.servo.org/plugins/lints/unrooted_must_root/struct.UnrootedPass.html +[js-lint]: https://doc.servo.org/script_plugins/struct.UnrootedPass.html [stack]: https://en.wikipedia.org/wiki/Stack-based_memory_allocation [warnings]: https://doc.rust-lang.org/book/compiler-plugins.html#lint-plugins |