forked from mirrors/gecko-dev
33a9e6d050
<!-- Please describe your changes on the following line: --> Before this PR, every object reflected in CSSOM is in `Arc<RwLock<_>>` to enable safe (synchronized) mutable aliasing. Acquiring all these locks has significant cost during selector matching: * https://bugzilla.mozilla.org/show_bug.cgi?id=1311469 * https://bugzilla.mozilla.org/show_bug.cgi?id=1335941 * https://bugzilla.mozilla.org/show_bug.cgi?id=1339703 This PR introduce a mechanism to protect many objects with the same `RwLock` that only needs to be acquired once. In Stylo, there is one such lock per process (in a `lazy_static`), used for everything. I non-Stylo Servo, I originally intended to have one such lock per document (for author-origin stylesheets, and one per process for user-agent and user sytlesheets since they’re shared across documents, and never mutated anyway). However I failed to have the same document-specific (or pipeline-specific) `Arc` reachable from both `Document` nodes and `LayoutThread`. Recursively following callers lead me to include this `Arc` in `UnprivilegedPipelineContent`, but that needs to be serializable. So there is a second process-wide lock. This was previously #15998, closed accidentally. --- <!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: --> - [x] `./mach build -d` does not report any errors - [x] `./mach test-tidy` does not report any errors - [ ] These changes fix #__ (github issue number if applicable). <!-- Either: --> - [ ] There are tests for these changes OR - [ ] These changes do not require tests because _____ <!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. --> Source-Repo: https://github.com/servo/servo Source-Revision: bb54f0a429de0e8b8861f8071b6cf82f73622664 --HG-- extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear extra : subtree_revision : 851230e57ac8775707df5f0f103be5feac81fc41
74 lines
2.6 KiB
Rust
74 lines
2.6 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/. */
|
|
|
|
use dom::bindings::codegen::Bindings::CSSStyleRuleBinding::{self, CSSStyleRuleMethods};
|
|
use dom::bindings::inheritance::Castable;
|
|
use dom::bindings::js::{JS, MutNullableJS, Root};
|
|
use dom::bindings::reflector::{DomObject, reflect_dom_object};
|
|
use dom::bindings::str::DOMString;
|
|
use dom::cssrule::{CSSRule, SpecificCSSRule};
|
|
use dom::cssstyledeclaration::{CSSModificationAccess, CSSStyleDeclaration, CSSStyleOwner};
|
|
use dom::cssstylesheet::CSSStyleSheet;
|
|
use dom::window::Window;
|
|
use dom_struct::dom_struct;
|
|
use std::sync::Arc;
|
|
use style::shared_lock::{Locked, ToCssWithGuard};
|
|
use style::stylesheets::StyleRule;
|
|
|
|
#[dom_struct]
|
|
pub struct CSSStyleRule {
|
|
cssrule: CSSRule,
|
|
#[ignore_heap_size_of = "Arc"]
|
|
stylerule: Arc<Locked<StyleRule>>,
|
|
style_decl: MutNullableJS<CSSStyleDeclaration>,
|
|
}
|
|
|
|
impl CSSStyleRule {
|
|
fn new_inherited(parent_stylesheet: &CSSStyleSheet, stylerule: Arc<Locked<StyleRule>>)
|
|
-> CSSStyleRule {
|
|
CSSStyleRule {
|
|
cssrule: CSSRule::new_inherited(parent_stylesheet),
|
|
stylerule: stylerule,
|
|
style_decl: Default::default(),
|
|
}
|
|
}
|
|
|
|
#[allow(unrooted_must_root)]
|
|
pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
|
|
stylerule: Arc<Locked<StyleRule>>) -> Root<CSSStyleRule> {
|
|
reflect_dom_object(box CSSStyleRule::new_inherited(parent_stylesheet, stylerule),
|
|
window,
|
|
CSSStyleRuleBinding::Wrap)
|
|
}
|
|
}
|
|
|
|
impl SpecificCSSRule for CSSStyleRule {
|
|
fn ty(&self) -> u16 {
|
|
use dom::bindings::codegen::Bindings::CSSRuleBinding::CSSRuleConstants;
|
|
CSSRuleConstants::STYLE_RULE
|
|
}
|
|
|
|
fn get_css(&self) -> DOMString {
|
|
let guard = self.cssrule.shared_lock().read();
|
|
self.stylerule.read_with(&guard).to_css_string(&guard).into()
|
|
}
|
|
}
|
|
|
|
impl CSSStyleRuleMethods for CSSStyleRule {
|
|
// https://drafts.csswg.org/cssom/#dom-cssstylerule-style
|
|
fn Style(&self) -> Root<CSSStyleDeclaration> {
|
|
self.style_decl.or_init(|| {
|
|
let guard = self.cssrule.shared_lock().read();
|
|
CSSStyleDeclaration::new(
|
|
self.global().as_window(),
|
|
CSSStyleOwner::CSSRule(
|
|
JS::from_ref(self.upcast()),
|
|
self.stylerule.read_with(&guard).block.clone()
|
|
),
|
|
None,
|
|
CSSModificationAccess::ReadWrite
|
|
)
|
|
})
|
|
}
|
|
}
|