Replace RwLock<MediaList> with shared_lock::Locked<MediaList>

components/layout_thread/lib.rs

@@ -115,6 +115,7 @@ use style::logical_geometry::LogicalPoint;
 use style::media_queries::{Device, MediaType};
 use style::parser::ParserContextExtraData;
 use style::servo::restyle_damage::{REFLOW, REFLOW_OUT_OF_FLOW, REPAINT, REPOSITION, STORE_OVERFLOW};
+use style::shared_lock::SharedRwLock;
 use style::stylesheets::{Origin, Stylesheet, UserAgentStylesheets};
 use style::stylist::Stylist;
 use style::thread_state;
@@ -934,6 +935,7 @@ impl LayoutThread {
                              possibly_locked_rw_data: &mut RwData<'a, 'b>) {
         let document = unsafe { ServoLayoutNode::new(&data.document) };
         let document = document.as_document().unwrap();
+        let style_guard = document.style_shared_lock().read();
         self.quirks_mode = Some(document.quirks_mode());
 
         // FIXME(pcwalton): Combine `ReflowGoal` and `ReflowQueryType`. Then remove this assert.
@@ -1010,7 +1012,8 @@ impl LayoutThread {
 
         // Calculate the actual viewport as per DEVICE-ADAPT § 6
         let device = Device::new(MediaType::Screen, initial_viewport);
-        Arc::get_mut(&mut rw_data.stylist).unwrap().set_device(device, &data.document_stylesheets);
+        Arc::get_mut(&mut rw_data.stylist).unwrap()
+            .set_device(device, &style_guard, &data.document_stylesheets);
 
         self.viewport_size =
             rw_data.stylist.viewport_constraints().map_or(current_screen_size, |constraints| {
@@ -1528,7 +1531,8 @@ fn get_root_flow_background_color(flow: &mut Flow) -> webrender_traits::ColorF {
 }
 
 fn get_ua_stylesheets() -> Result<UserAgentStylesheets, &'static str> {
-    fn parse_ua_stylesheet(filename: &'static str) -> Result<Stylesheet, &'static str> {
+    fn parse_ua_stylesheet(shared_lock: &SharedRwLock, filename: &'static str)
+                           -> Result<Stylesheet, &'static str> {
         let res = try!(read_resource_file(filename).map_err(|_| filename));
         Ok(Stylesheet::from_bytes(
             &res,
@@ -1537,26 +1541,29 @@ fn get_ua_stylesheets() -> Result<UserAgentStylesheets, &'static str> {
             None,
             Origin::UserAgent,
             Default::default(),
+            shared_lock.clone(),
             None,
             &StdoutErrorReporter,
             ParserContextExtraData::default()))
     }
 
+    let shared_lock = SharedRwLock::new();
     let mut user_or_user_agent_stylesheets = vec!();
     // FIXME: presentational-hints.css should be at author origin with zero specificity.
     //        (Does it make a difference?)
     for &filename in &["user-agent.css", "servo.css", "presentational-hints.css"] {
-        user_or_user_agent_stylesheets.push(try!(parse_ua_stylesheet(filename)));
+        user_or_user_agent_stylesheets.push(try!(parse_ua_stylesheet(&shared_lock, filename)));
     }
     for &(ref contents, ref url) in &opts::get().user_stylesheets {
         user_or_user_agent_stylesheets.push(Stylesheet::from_bytes(
             &contents, url.clone(), None, None, Origin::User, Default::default(),
-            None, &StdoutErrorReporter, ParserContextExtraData::default()));
+            shared_lock.clone(), None, &StdoutErrorReporter, ParserContextExtraData::default()));
     }
 
-    let quirks_mode_stylesheet = try!(parse_ua_stylesheet("quirks-mode.css"));
+    let quirks_mode_stylesheet = try!(parse_ua_stylesheet(&shared_lock, "quirks-mode.css"));
 
     Ok(UserAgentStylesheets {
+        shared_lock: shared_lock,
         user_or_user_agent_stylesheets: user_or_user_agent_stylesheets,
         quirks_mode_stylesheet: quirks_mode_stylesheet,
     })

components/script/dom/bindings/trace.rs

@@ -99,6 +99,7 @@ use style::keyframes::Keyframe;
 use style::media_queries::MediaList;
 use style::properties::PropertyDeclarationBlock;
 use style::selector_parser::{PseudoElement, Snapshot};
+use style::shared_lock::SharedRwLock as StyleSharedRwLock;
 use style::stylesheets::{CssRules, KeyframesRule, MediaRule, NamespaceRule, StyleRule, ImportRule};
 use style::stylesheets::SupportsRule;
 use style::values::specified::Length;
@@ -360,6 +361,7 @@ unsafe_no_jsmanaged_fields!(HttpsState);
 unsafe_no_jsmanaged_fields!(Request);
 unsafe_no_jsmanaged_fields!(RequestInit);
 unsafe_no_jsmanaged_fields!(SharedRt);
+unsafe_no_jsmanaged_fields!(StyleSharedRwLock);
 unsafe_no_jsmanaged_fields!(TouchpadPressurePhase);
 unsafe_no_jsmanaged_fields!(USVString);
 unsafe_no_jsmanaged_fields!(ReferrerPolicy);

components/script/dom/document.rs

@@ -134,6 +134,7 @@ use style::attr::AttrValue;
 use style::context::{QuirksMode, ReflowGoal};
 use style::restyle_hints::{RestyleHint, RESTYLE_STYLE_ATTRIBUTE};
 use style::selector_parser::{RestyleDamage, Snapshot};
+use style::shared_lock::SharedRwLock as StyleSharedRwLock;
 use style::str::{HTML_SPACE_CHARACTERS, split_html_space_chars, str_join};
 use style::stylesheets::Stylesheet;
 use task_source::TaskSource;
@@ -220,6 +221,9 @@ pub struct Document {
     scripts: MutNullableJS<HTMLCollection>,
     anchors: MutNullableJS<HTMLCollection>,
     applets: MutNullableJS<HTMLCollection>,
+    /// Lock use for style attributes and author-origin stylesheet objects in this document.
+    /// Can be acquired once for accessing many objects.
+    style_shared_lock: StyleSharedRwLock,
     /// List of stylesheets associated with nodes in this document. |None| if the list needs to be refreshed.
     stylesheets: DOMRefCell<Option<Vec<StylesheetInDocument>>>,
     /// Whether the list of stylesheets has changed since the last reflow was triggered.
@@ -1964,6 +1968,7 @@ pub trait LayoutDocumentHelpers {
     unsafe fn needs_paint_from_layout(&self);
     unsafe fn will_paint(&self);
     unsafe fn quirks_mode(&self) -> QuirksMode;
+    unsafe fn style_shared_lock(&self) -> &StyleSharedRwLock;
 }
 
 #[allow(unsafe_code)]
@@ -2000,6 +2005,11 @@ impl LayoutDocumentHelpers for LayoutJS<Document> {
     unsafe fn quirks_mode(&self) -> QuirksMode {
         (*self.unsafe_get()).quirks_mode()
     }
+
+    #[inline]
+    unsafe fn style_shared_lock(&self) -> &StyleSharedRwLock {
+        (*self.unsafe_get()).style_shared_lock()
+    }
 }
 
 // https://html.spec.whatwg.org/multipage/#is-a-registrable-domain-suffix-of-or-is-equal-to
@@ -2121,6 +2131,7 @@ impl Document {
             scripts: Default::default(),
             anchors: Default::default(),
             applets: Default::default(),
+            style_shared_lock: StyleSharedRwLock::new(),
             stylesheets: DOMRefCell::new(None),
             stylesheets_changed_since_reflow: Cell::new(false),
             stylesheet_list: MutNullableJS::new(None),
@@ -2250,6 +2261,11 @@ impl Document {
         };
     }
 
+    /// Return a reference to the per-document shared lock used in stylesheets.
+    pub fn style_shared_lock(&self) -> &StyleSharedRwLock {
+        &self.style_shared_lock
+    }
+
     /// Returns the list of stylesheets associated with nodes in the document.
     pub fn stylesheets(&self) -> Vec<Arc<Stylesheet>> {
         self.ensure_stylesheets();

components/script/dom/htmlmetaelement.rs

@@ -99,12 +99,15 @@ impl HTMLMetaElement {
             let content = content.value();
             if !content.is_empty() {
                 if let Some(translated_rule) = ViewportRule::from_meta(&**content) {
+                    let document = self.upcast::<Node>().owner_doc();
+                    let shared_lock = document.style_shared_lock();
                     *self.stylesheet.borrow_mut() = Some(Arc::new(Stylesheet {
                         rules: CssRules::new(vec![CssRule::Viewport(Arc::new(RwLock::new(translated_rule)))]),
                         origin: Origin::Author,
+                        shared_lock: shared_lock.clone(),
                         base_url: window_from_node(self).get_url(),
                         namespaces: Default::default(),
-                        media: Default::default(),
+                        media: Arc::new(shared_lock.wrap(Default::default())),
                         // Viewport constraints are always recomputed on resize; they don't need to
                         // force all styles to be recomputed.
                         dirty_on_viewport_size_change: AtomicBool::new(false),

components/script/dom/htmlstyleelement.rs

@@ -84,9 +84,10 @@ impl HTMLStyleElement {
 
         let data = node.GetTextContent().expect("Element.textContent must be a string");
         let mq = parse_media_query_list(&mut CssParser::new(&mq_str));
+        let shared_lock = node.owner_doc().style_shared_lock().clone();
         let loader = StylesheetLoader::for_element(self.upcast());
         let sheet = Stylesheet::from_str(&data, url, Origin::Author, mq,
-                                         Some(&loader),
+                                         shared_lock, Some(&loader),
                                          win.css_error_reporter(),
                                          ParserContextExtraData::default());
 

components/script/layout_wrapper.rs

@@ -69,6 +69,7 @@ use style::dom::UnsafeNode;
 use style::element_state::*;
 use style::properties::{ComputedValues, PropertyDeclarationBlock};
 use style::selector_parser::{NonTSPseudoClass, PseudoElement, SelectorImpl};
+use style::shared_lock::SharedRwLock as StyleSharedRwLock;
 use style::sink::Push;
 use style::str::is_whitespace;
 use style::stylist::ApplicableDeclarationBlock;
@@ -330,6 +331,10 @@ impl<'ld> ServoLayoutDocument<'ld> {
         unsafe { self.document.quirks_mode() }
     }
 
+    pub fn style_shared_lock(&self) -> &StyleSharedRwLock {
+        unsafe { self.document.style_shared_lock() }
+    }
+
     pub fn from_layout_js(doc: LayoutJS<Document>) -> ServoLayoutDocument<'ld> {
         ServoLayoutDocument {
             document: doc,

components/script/stylesheet_loader.rs

@@ -152,12 +152,14 @@ impl FetchResponseListener for StylesheetContext {
                     let is_stylesheet_load_applicable =
                         self.request_generation_id.map_or(true, |gen| gen == link.get_request_generation_id());
                     if is_stylesheet_load_applicable {
+                        let shared_lock = document.style_shared_lock().clone();
                         let sheet =
                             Arc::new(Stylesheet::from_bytes(&data, final_url,
                                                             protocol_encoding_label,
                                                             Some(environment_encoding),
                                                             Origin::Author,
                                                             media.take().unwrap(),
+                                                            shared_lock,
                                                             Some(&loader),
                                                             win.css_error_reporter(),
                                                             ParserContextExtraData::default()));

components/style/encoding_support.rs

@@ -12,6 +12,7 @@ use media_queries::MediaList;
 use parser::ParserContextExtraData;
 use self::encoding::{EncodingRef, DecoderTrap};
 use servo_url::ServoUrl;
+use shared_lock::SharedRwLock;
 use std::str;
 use stylesheets::{Stylesheet, StylesheetLoader, Origin};
 
@@ -54,6 +55,7 @@ impl Stylesheet {
                       environment_encoding: Option<EncodingRef>,
                       origin: Origin,
                       media: MediaList,
+                      shared_lock: SharedRwLock,
                       stylesheet_loader: Option<&StylesheetLoader>,
                       error_reporter: &ParseErrorReporter,
                       extra_data: ParserContextExtraData)
@@ -64,6 +66,7 @@ impl Stylesheet {
                              base_url,
                              origin,
                              media,
+                             shared_lock,
                              stylesheet_loader,
                              error_reporter,
                              extra_data)

components/style/stylesheets.rs

@@ -21,6 +21,7 @@ use selector_parser::{SelectorImpl, SelectorParser};
 use selectors::parser::SelectorList;
 use servo_config::prefs::PREFS;
 use servo_url::ServoUrl;
+use shared_lock::{SharedRwLock, Locked, SharedRwLockReadGuard};
 use std::cell::Cell;
 use std::fmt;
 use std::sync::Arc;
@@ -175,11 +176,13 @@ pub struct Stylesheet {
     /// cascading order)
     pub rules: Arc<RwLock<CssRules>>,
     /// List of media associated with the Stylesheet.
-    pub media: Arc<RwLock<MediaList>>,
+    pub media: Arc<Locked<MediaList>>,
     /// The origin of this stylesheet.
     pub origin: Origin,
     /// The base url this stylesheet should use.
     pub base_url: ServoUrl,
+    /// The lock used for objects inside this stylesheet
+    pub shared_lock: SharedRwLock,
     /// The namespaces that apply to this stylesheet.
     pub namespaces: RwLock<Namespaces>,
     /// Whether this stylesheet would be dirty when the viewport size changes.
@@ -191,6 +194,8 @@ pub struct Stylesheet {
 
 /// This structure holds the user-agent and user stylesheets.
 pub struct UserAgentStylesheets {
+    /// The lock used for user-agent stylesheets.
+    pub shared_lock: SharedRwLock,
     /// The user or user agent stylesheets.
     pub user_or_user_agent_stylesheets: Vec<Stylesheet>,
     /// The quirks mode stylesheet.
@@ -291,12 +296,12 @@ impl CssRule {
     /// used for others.
     ///
     /// This will not recurse down unsupported @supports rules
-    pub fn with_nested_rules_and_mq<F, R>(&self, mut f: F) -> R
+    pub fn with_nested_rules_and_mq<F, R>(&self, guard: &SharedRwLockReadGuard, mut f: F) -> R
     where F: FnMut(&[CssRule], Option<&MediaList>) -> R {
         match *self {
             CssRule::Import(ref lock) => {
                 let rule = lock.read();
-                let media = rule.stylesheet.media.read();
+                let media = rule.stylesheet.media.read_with(guard);
                 let rules = rule.stylesheet.rules.read();
                 // FIXME(emilio): Include the nested rules if the stylesheet is
                 // loaded.
@@ -349,6 +354,7 @@ impl CssRule {
         let mut rule_parser = TopLevelRuleParser {
             stylesheet_origin: parent_stylesheet.origin,
             context: context,
+            shared_lock: &parent_stylesheet.shared_lock,
             loader: None,
             state: Cell::new(state),
             namespaces: &mut namespaces,
@@ -424,7 +430,8 @@ impl ToCss for ImportRule {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
         try!(dest.write_str("@import "));
         try!(self.url.to_css(dest));
-        let media = self.stylesheet.media.read();
+        let guard = self.stylesheet.shared_lock.read();  // FIXME: have the caller pass this?
+        let media = self.stylesheet.media.read_with(&guard);
         if !media.is_empty() {
             try!(dest.write_str(" "));
             try!(media.to_css(dest));
@@ -554,6 +561,7 @@ impl Stylesheet {
         let rule_parser = TopLevelRuleParser {
             stylesheet_origin: existing.origin,
             namespaces: &mut namespaces,
+            shared_lock: &existing.shared_lock,
             loader: stylesheet_loader,
             context: ParserContext::new_with_extra_data(existing.origin,
                                                         &existing.base_url,
@@ -591,6 +599,7 @@ impl Stylesheet {
                     base_url: ServoUrl,
                     origin: Origin,
                     media: MediaList,
+                    shared_lock: SharedRwLock,
                     stylesheet_loader: Option<&StylesheetLoader>,
                     error_reporter: &ParseErrorReporter,
                     extra_data: ParserContextExtraData) -> Stylesheet {
@@ -599,7 +608,8 @@ impl Stylesheet {
             base_url: base_url,
             namespaces: RwLock::new(Namespaces::default()),
             rules: CssRules::new(vec![]),
-            media: Arc::new(RwLock::new(media)),
+            media: Arc::new(shared_lock.wrap(media)),
+            shared_lock: shared_lock.clone(),
             dirty_on_viewport_size_change: AtomicBool::new(false),
             disabled: AtomicBool::new(false),
         };
@@ -638,7 +648,8 @@ impl Stylesheet {
     ///
     /// Always true if no associated MediaList exists.
     pub fn is_effective_for_device(&self, device: &Device) -> bool {
-        self.media.read().evaluate(device)
+        let guard = self.shared_lock.read();  // FIXME: have the caller pass this?
+        self.media.read_with(&guard).evaluate(device)
     }
 
     /// Return an iterator over the effective rules within the style-sheet, as
@@ -649,7 +660,8 @@ impl Stylesheet {
     /// examined.
     #[inline]
     pub fn effective_rules<F>(&self, device: &Device, mut f: F) where F: FnMut(&CssRule) {
-        effective_rules(&self.rules.read().0, device, &mut f);
+        let guard = self.shared_lock.read();  // FIXME: have the caller pass this?
+        effective_rules(&self.rules.read().0, device, &guard, &mut f);
     }
 
     /// Returns whether the stylesheet has been explicitly disabled through the
@@ -670,16 +682,17 @@ impl Stylesheet {
     }
 }
 
-fn effective_rules<F>(rules: &[CssRule], device: &Device, f: &mut F) where F: FnMut(&CssRule) {
+fn effective_rules<F>(rules: &[CssRule], device: &Device, guard: &SharedRwLockReadGuard, f: &mut F)
+where F: FnMut(&CssRule) {
     for rule in rules {
         f(rule);
-        rule.with_nested_rules_and_mq(|rules, mq| {
+        rule.with_nested_rules_and_mq(guard, |rules, mq| {
             if let Some(media_queries) = mq {
                 if !media_queries.evaluate(device) {
                     return
                 }
             }
-            effective_rules(rules, device, f)
+            effective_rules(rules, device, guard, f)
         })
     }
 }
@@ -724,6 +737,7 @@ pub trait StylesheetLoader {
 struct TopLevelRuleParser<'a> {
     stylesheet_origin: Origin,
     namespaces: &'a mut Namespaces,
+    shared_lock: &'a SharedRwLock,
     loader: Option<&'a StylesheetLoader>,
     context: ParserContext<'a>,
     state: Cell<State>,
@@ -780,7 +794,7 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
                                                              &self.context));
 
                     let media =
-                        Arc::new(RwLock::new(parse_media_query_list(input)));
+                        Arc::new(self.shared_lock.wrap(parse_media_query_list(input)));
 
                     let is_valid_url = url.url().is_some();
 
@@ -790,6 +804,7 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
                             stylesheet: Arc::new(Stylesheet {
                                 rules: Arc::new(RwLock::new(CssRules(vec![]))),
                                 media: media,
+                                shared_lock: self.shared_lock.clone(),
                                 origin: self.context.stylesheet_origin,
                                 base_url: self.context.base_url.clone(),
                                 namespaces: RwLock::new(Namespaces::default()),