Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-06-21 15:49:04 +01:00
Code Issues Projects Releases Packages Wiki Activity

Update doc links and code snippet for trace implementation

Browse source
This commit is contained in:
Utsav Oza 2020-05-03 19:03:33 +05:30
parent 0b05b5ed87
commit 494ff6b66a
1 changed files with 26 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

38
components/script/docs/JS-Servos-only-GC.md
View file

@ -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