mirror of
https://github.com/servo/servo.git
synced 2025-06-13 19:04:30 +00:00
266 lines
7.8 KiB
Rust
266 lines
7.8 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#![deny(missing_docs)]
|
|
|
|
//! Utilities for tracing JS-managed values.
|
|
//!
|
|
//! The lifetime of DOM objects is managed by the SpiderMonkey Garbage
|
|
//! Collector. A rooted DOM object implementing the interface `Foo` is traced
|
|
//! as follows:
|
|
//!
|
|
//! 1. The GC calls `_trace` defined in `FooBinding` during the marking
|
|
//! phase. (This happens through `JSClass.trace` for non-proxy bindings, and
|
|
//! through `ProxyTraps.trace` otherwise.)
|
|
//! 2. `_trace` calls `Foo::trace()` (an implementation of `JSTraceable`).
|
|
//! This is typically derived via a #[jstraceable] annotation
|
|
//! 3. For all fields, `Foo::trace()`
|
|
//! calls `trace()` on the field.
|
|
//! For example, for fields of type `JS<T>`, `JS<T>::trace()` calls
|
|
//! `trace_reflector()`.
|
|
//! 4. `trace_reflector()` calls `trace_object()` with the `JSObject` for the
|
|
//! reflector.
|
|
//! 5. `trace_object()` calls `JS_CallTracer()` to notify the GC, which will
|
|
//! add the object to the graph, and will trace that object as well.
|
|
//!
|
|
//! The no_jsmanaged_fields!() macro adds an empty implementation of JSTraceable to
|
|
//! a datatype.
|
|
|
|
use dom::bindings::js::JS;
|
|
use dom::bindings::refcounted::Trusted;
|
|
use dom::bindings::utils::{Reflectable, Reflector, WindowProxyHandler};
|
|
use dom::node::{Node, TrustedNodeAddress};
|
|
use script_task::ScriptChan;
|
|
|
|
use collections::hash::{Hash, Hasher};
|
|
use cssparser::RGBA;
|
|
use geom::rect::Rect;
|
|
use html5ever::tree_builder::QuirksMode;
|
|
use hyper::header::Headers;
|
|
use hyper::method::Method;
|
|
use js::jsapi::{JSObject, JSTracer, JS_CallTracer, JSGCTraceKind};
|
|
use js::jsval::JSVal;
|
|
use js::rust::Cx;
|
|
use layout_interface::{LayoutRPC, LayoutChan};
|
|
use libc;
|
|
use msg::constellation_msg::{PipelineId, SubpageId, WindowSizeData};
|
|
use net::image_cache_task::ImageCacheTask;
|
|
use script_traits::ScriptControlChan;
|
|
use script_traits::UntrustedNodeAddress;
|
|
use servo_msg::compositor_msg::ScriptListener;
|
|
use servo_msg::constellation_msg::ConstellationChan;
|
|
use servo_util::smallvec::{SmallVec1, SmallVec};
|
|
use servo_util::str::{LengthOrPercentageOrAuto};
|
|
use std::cell::{Cell, RefCell};
|
|
use std::collections::HashMap;
|
|
use std::comm::{Receiver, Sender};
|
|
use std::io::timer::Timer;
|
|
use std::rc::Rc;
|
|
use string_cache::{Atom, Namespace};
|
|
use style::PropertyDeclarationBlock;
|
|
use url::Url;
|
|
|
|
|
|
/// A trait to allow tracing (only) DOM objects.
|
|
pub trait JSTraceable {
|
|
/// Trace `self`.
|
|
fn trace(&self, trc: *mut JSTracer);
|
|
}
|
|
|
|
impl<T: Reflectable> JSTraceable for JS<T> {
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
trace_reflector(trc, "", self.reflector());
|
|
}
|
|
}
|
|
|
|
no_jsmanaged_fields!(Reflector)
|
|
|
|
/// Trace a `JSVal`.
|
|
pub fn trace_jsval(tracer: *mut JSTracer, description: &str, val: JSVal) {
|
|
if !val.is_markable() {
|
|
return;
|
|
}
|
|
|
|
unsafe {
|
|
let name = description.to_c_str();
|
|
(*tracer).debugPrinter = None;
|
|
(*tracer).debugPrintIndex = -1;
|
|
(*tracer).debugPrintArg = name.as_ptr() as *const libc::c_void;
|
|
debug!("tracing value {}", description);
|
|
JS_CallTracer(tracer, val.to_gcthing(), val.trace_kind());
|
|
}
|
|
}
|
|
|
|
/// Trace the `JSObject` held by `reflector`.
|
|
#[allow(unrooted_must_root)]
|
|
pub fn trace_reflector(tracer: *mut JSTracer, description: &str, reflector: &Reflector) {
|
|
trace_object(tracer, description, reflector.get_jsobject())
|
|
}
|
|
|
|
/// Trace a `JSObject`.
|
|
pub fn trace_object(tracer: *mut JSTracer, description: &str, obj: *mut JSObject) {
|
|
unsafe {
|
|
let name = description.to_c_str();
|
|
(*tracer).debugPrinter = None;
|
|
(*tracer).debugPrintIndex = -1;
|
|
(*tracer).debugPrintArg = name.as_ptr() as *const libc::c_void;
|
|
debug!("tracing {}", description);
|
|
JS_CallTracer(tracer, obj as *mut libc::c_void, JSGCTraceKind::JSTRACE_OBJECT);
|
|
}
|
|
}
|
|
|
|
impl<T: JSTraceable> JSTraceable for RefCell<T> {
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
self.borrow().trace(trc)
|
|
}
|
|
}
|
|
|
|
impl<T: JSTraceable> JSTraceable for Rc<T> {
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
(**self).trace(trc)
|
|
}
|
|
}
|
|
|
|
impl<T: JSTraceable> JSTraceable for Box<T> {
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
(**self).trace(trc)
|
|
}
|
|
}
|
|
|
|
impl<T: JSTraceable+Copy> JSTraceable for Cell<T> {
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
self.get().trace(trc)
|
|
}
|
|
}
|
|
|
|
impl JSTraceable for *mut JSObject {
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
trace_object(trc, "object", *self);
|
|
}
|
|
}
|
|
|
|
impl JSTraceable for JSVal {
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
trace_jsval(trc, "val", *self);
|
|
}
|
|
}
|
|
|
|
// XXXManishearth Check if the following three are optimized to no-ops
|
|
// if e.trace() is a no-op (e.g it is an no_jsmanaged_fields type)
|
|
impl<T: JSTraceable> JSTraceable for Vec<T> {
|
|
#[inline]
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
for e in self.iter() {
|
|
e.trace(trc);
|
|
}
|
|
}
|
|
}
|
|
|
|
// XXXManishearth Check if the following three are optimized to no-ops
|
|
// if e.trace() is a no-op (e.g it is an no_jsmanaged_fields type)
|
|
impl<T: JSTraceable + 'static> JSTraceable for SmallVec1<T> {
|
|
#[inline]
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
for e in self.iter() {
|
|
e.trace(trc);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T: JSTraceable> JSTraceable for Option<T> {
|
|
#[inline]
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
self.as_ref().map(|e| e.trace(trc));
|
|
}
|
|
}
|
|
|
|
impl<K,V,S,H> JSTraceable for HashMap<K, V, H> where K: Eq + Hash<S> + JSTraceable,
|
|
V: JSTraceable,
|
|
H: Hasher<S> {
|
|
#[inline]
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
for e in self.iter() {
|
|
e.val0().trace(trc);
|
|
e.val1().trace(trc);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<A: JSTraceable, B: JSTraceable> JSTraceable for (A, B) {
|
|
#[inline]
|
|
fn trace(&self, trc: *mut JSTracer) {
|
|
let (ref a, ref b) = *self;
|
|
a.trace(trc);
|
|
b.trace(trc);
|
|
}
|
|
}
|
|
|
|
|
|
no_jsmanaged_fields!(bool, f32, f64, String, Url)
|
|
no_jsmanaged_fields!(uint, u8, u16, u32, u64)
|
|
no_jsmanaged_fields!(int, i8, i16, i32, i64)
|
|
no_jsmanaged_fields!(Sender<T>)
|
|
no_jsmanaged_fields!(Receiver<T>)
|
|
no_jsmanaged_fields!(Rect<T>)
|
|
no_jsmanaged_fields!(ImageCacheTask, ScriptControlChan)
|
|
no_jsmanaged_fields!(Atom, Namespace, Timer)
|
|
no_jsmanaged_fields!(Trusted<T>)
|
|
no_jsmanaged_fields!(PropertyDeclarationBlock)
|
|
// These three are interdependent, if you plan to put jsmanaged data
|
|
// in one of these make sure it is propagated properly to containing structs
|
|
no_jsmanaged_fields!(SubpageId, WindowSizeData, PipelineId)
|
|
no_jsmanaged_fields!(QuirksMode)
|
|
no_jsmanaged_fields!(Cx)
|
|
no_jsmanaged_fields!(Headers, Method)
|
|
no_jsmanaged_fields!(ConstellationChan)
|
|
no_jsmanaged_fields!(LayoutChan)
|
|
no_jsmanaged_fields!(WindowProxyHandler)
|
|
no_jsmanaged_fields!(UntrustedNodeAddress)
|
|
no_jsmanaged_fields!(LengthOrPercentageOrAuto)
|
|
no_jsmanaged_fields!(RGBA)
|
|
|
|
impl JSTraceable for Box<ScriptChan+Send> {
|
|
#[inline]
|
|
fn trace(&self, _trc: *mut JSTracer) {
|
|
// Do nothing
|
|
}
|
|
}
|
|
|
|
impl<'a> JSTraceable for &'a str {
|
|
#[inline]
|
|
fn trace(&self, _: *mut JSTracer) {
|
|
// Do nothing
|
|
}
|
|
}
|
|
|
|
impl<A,B> JSTraceable for fn(A) -> B {
|
|
#[inline]
|
|
fn trace(&self, _: *mut JSTracer) {
|
|
// Do nothing
|
|
}
|
|
}
|
|
|
|
impl JSTraceable for Box<ScriptListener+'static> {
|
|
#[inline]
|
|
fn trace(&self, _: *mut JSTracer) {
|
|
// Do nothing
|
|
}
|
|
}
|
|
|
|
impl JSTraceable for Box<LayoutRPC+'static> {
|
|
#[inline]
|
|
fn trace(&self, _: *mut JSTracer) {
|
|
// Do nothing
|
|
}
|
|
}
|
|
|
|
impl JSTraceable for TrustedNodeAddress {
|
|
fn trace(&self, s: *mut JSTracer) {
|
|
let TrustedNodeAddress(addr) = *self;
|
|
let node = addr as *const Node;
|
|
unsafe {
|
|
JS::from_raw(node).trace(s)
|
|
}
|
|
}
|
|
}
|