mirror of
https://github.com/servo/servo.git
synced 2025-06-20 23:28:59 +01:00
251 lines
8.2 KiB
Rust
251 lines
8.2 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/. */
|
|
|
|
//! Implements parallel traversals over the DOM and flow trees.
|
|
//!
|
|
//! This code is highly unsafe. Keep this file small and easy to audit.
|
|
|
|
use css::matching::MatchMethods;
|
|
use layout::context::LayoutContext;
|
|
use layout::extra::LayoutAuxMethods;
|
|
use layout::flow::{Flow, FlowLeafSet, PostorderFlowTraversal};
|
|
use layout::flow;
|
|
use layout::layout_task::{AssignHeightsAndStoreOverflowTraversal, BubbleWidthsTraversal};
|
|
use layout::util::{LayoutDataAccess, OpaqueNode};
|
|
use layout::wrapper::{layout_node_to_unsafe_layout_node, LayoutNode, UnsafeLayoutNode};
|
|
|
|
use extra::arc::MutexArc;
|
|
use servo_util::time::{ProfilerChan, profile};
|
|
use servo_util::time;
|
|
use servo_util::workqueue::{WorkQueue, WorkUnit, WorkerProxy};
|
|
use std::cast;
|
|
use std::ptr;
|
|
use std::sync::atomics::{AtomicInt, Relaxed, SeqCst};
|
|
use style::{Stylist, TNode};
|
|
|
|
pub enum TraversalKind {
|
|
BubbleWidthsTraversalKind,
|
|
AssignHeightsAndStoreOverflowTraversalKind,
|
|
}
|
|
|
|
pub type UnsafeFlow = (uint, uint);
|
|
|
|
fn null_unsafe_flow() -> UnsafeFlow {
|
|
(0, 0)
|
|
}
|
|
|
|
pub fn owned_flow_to_unsafe_flow(flow: *~Flow) -> UnsafeFlow {
|
|
unsafe {
|
|
cast::transmute_copy(&*flow)
|
|
}
|
|
}
|
|
|
|
pub fn mut_owned_flow_to_unsafe_flow(flow: *mut ~Flow) -> UnsafeFlow {
|
|
unsafe {
|
|
cast::transmute_copy(&*flow)
|
|
}
|
|
}
|
|
|
|
/// Information that we need stored in each DOM node.
|
|
pub struct DomParallelInfo {
|
|
/// The number of children that still need work done.
|
|
children_count: AtomicInt,
|
|
}
|
|
|
|
impl DomParallelInfo {
|
|
pub fn new() -> DomParallelInfo {
|
|
DomParallelInfo {
|
|
children_count: AtomicInt::new(0),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Information that we need stored in each flow.
|
|
pub struct FlowParallelInfo {
|
|
/// The number of children that still need work done.
|
|
children_count: AtomicInt,
|
|
/// The address of the parent flow.
|
|
parent: UnsafeFlow,
|
|
}
|
|
|
|
impl FlowParallelInfo {
|
|
pub fn new() -> FlowParallelInfo {
|
|
FlowParallelInfo {
|
|
children_count: AtomicInt::new(0),
|
|
parent: null_unsafe_flow(),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A parallel bottom-up flow traversal.
|
|
trait ParallelPostorderFlowTraversal : PostorderFlowTraversal {
|
|
fn run_parallel(&mut self, mut unsafe_flow: UnsafeFlow) {
|
|
loop {
|
|
unsafe {
|
|
// Get a real flow.
|
|
let flow: &mut ~Flow = cast::transmute(&unsafe_flow);
|
|
|
|
// Perform the appropriate traversal.
|
|
if self.should_process(*flow) {
|
|
self.process(*flow);
|
|
}
|
|
|
|
let base = flow::mut_base(*flow);
|
|
|
|
// Reset the count of children for the next layout traversal.
|
|
base.parallel.children_count.store(base.children.len() as int, Relaxed);
|
|
|
|
// Possibly enqueue the parent.
|
|
let unsafe_parent = base.parallel.parent;
|
|
if unsafe_parent == null_unsafe_flow() {
|
|
// We're done!
|
|
break
|
|
}
|
|
|
|
// No, we're not at the root yet. Then are we the last sibling of our parent? If
|
|
// so, we can continue on with our parent; otherwise, we've gotta wait.
|
|
let parent: &mut ~Flow = cast::transmute(&unsafe_parent);
|
|
let parent_base = flow::mut_base(*parent);
|
|
if parent_base.parallel.children_count.fetch_sub(1, SeqCst) == 1 {
|
|
// We were the last child of our parent. Reflow our parent.
|
|
unsafe_flow = unsafe_parent
|
|
} else {
|
|
// Stop.
|
|
break
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a> ParallelPostorderFlowTraversal for BubbleWidthsTraversal<'a> {}
|
|
|
|
impl<'a> ParallelPostorderFlowTraversal for AssignHeightsAndStoreOverflowTraversal<'a> {}
|
|
|
|
fn match_and_cascade_node(unsafe_layout_node: UnsafeLayoutNode,
|
|
proxy: &mut WorkerProxy<*mut LayoutContext,UnsafeLayoutNode>) {
|
|
unsafe {
|
|
let layout_context: &mut LayoutContext = cast::transmute(*proxy.user_data());
|
|
|
|
// Get a real layout node.
|
|
let node: LayoutNode = cast::transmute(unsafe_layout_node);
|
|
|
|
// Initialize layout data.
|
|
//
|
|
// FIXME(pcwalton): Stop allocating here. Ideally this should just be done by the HTML
|
|
// parser.
|
|
node.initialize_layout_data(layout_context.layout_chan.clone());
|
|
|
|
if node.is_element() {
|
|
// Perform the CSS selector matching.
|
|
let stylist: &Stylist = cast::transmute(layout_context.stylist);
|
|
node.match_node(stylist);
|
|
|
|
// Perform the CSS cascade.
|
|
let parent_opt = if OpaqueNode::from_layout_node(&node) == layout_context.reflow_root {
|
|
None
|
|
} else {
|
|
node.parent_node()
|
|
};
|
|
node.cascade_node(parent_opt);
|
|
}
|
|
|
|
// Enqueue kids.
|
|
let mut child_count = 0;
|
|
for kid in node.children() {
|
|
child_count += 1;
|
|
|
|
proxy.push(WorkUnit {
|
|
fun: match_and_cascade_node,
|
|
data: layout_node_to_unsafe_layout_node(&kid),
|
|
});
|
|
}
|
|
|
|
// Prepare for flow construction by adding this node to the leaf set or counting its
|
|
// children.
|
|
if child_count == 0 {
|
|
// We don't need set the `child_count` field here since that's only used by kids during
|
|
// bottom-up traversals, and since this node is a leaf it has no kids.
|
|
layout_context.dom_leaf_set.access(|dom_leaf_set| dom_leaf_set.insert(&node));
|
|
} else {
|
|
let mut layout_data_ref = node.mutate_layout_data();
|
|
match *layout_data_ref.get() {
|
|
Some(ref mut layout_data) => {
|
|
layout_data.data.parallel.children_count.store(child_count as int, Relaxed)
|
|
}
|
|
None => fail!("no layout data"),
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
fn bubble_widths(unsafe_flow: UnsafeFlow, proxy: &mut WorkerProxy<*mut LayoutContext,UnsafeFlow>) {
|
|
let layout_context: &mut LayoutContext = unsafe {
|
|
cast::transmute(*proxy.user_data())
|
|
};
|
|
let mut bubble_widths_traversal = BubbleWidthsTraversal {
|
|
layout_context: layout_context,
|
|
};
|
|
bubble_widths_traversal.run_parallel(unsafe_flow)
|
|
}
|
|
|
|
fn assign_heights_and_store_overflow(unsafe_flow: UnsafeFlow,
|
|
proxy: &mut WorkerProxy<*mut LayoutContext,UnsafeFlow>) {
|
|
let layout_context: &mut LayoutContext = unsafe {
|
|
cast::transmute(*proxy.user_data())
|
|
};
|
|
let mut assign_heights_traversal = AssignHeightsAndStoreOverflowTraversal {
|
|
layout_context: layout_context,
|
|
};
|
|
assign_heights_traversal.run_parallel(unsafe_flow)
|
|
}
|
|
|
|
pub fn match_and_cascade_subtree(root_node: &LayoutNode,
|
|
layout_context: &mut LayoutContext,
|
|
queue: &mut WorkQueue<*mut LayoutContext,UnsafeLayoutNode>) {
|
|
unsafe {
|
|
queue.data = cast::transmute(layout_context)
|
|
}
|
|
|
|
// Enqueue the root node.
|
|
queue.push(WorkUnit {
|
|
fun: match_and_cascade_node,
|
|
data: layout_node_to_unsafe_layout_node(root_node),
|
|
});
|
|
|
|
queue.run();
|
|
|
|
queue.data = ptr::mut_null()
|
|
}
|
|
|
|
pub fn traverse_flow_tree(kind: TraversalKind,
|
|
leaf_set: &MutexArc<FlowLeafSet>,
|
|
profiler_chan: ProfilerChan,
|
|
layout_context: &mut LayoutContext,
|
|
queue: &mut WorkQueue<*mut LayoutContext,UnsafeFlow>) {
|
|
unsafe {
|
|
queue.data = cast::transmute(layout_context)
|
|
}
|
|
|
|
let fun = match kind {
|
|
BubbleWidthsTraversalKind => bubble_widths,
|
|
AssignHeightsAndStoreOverflowTraversalKind => assign_heights_and_store_overflow,
|
|
};
|
|
|
|
profile(time::LayoutParallelWarmupCategory, profiler_chan, || {
|
|
leaf_set.access(|leaf_set| {
|
|
for &flow in leaf_set.iter() {
|
|
queue.push(WorkUnit {
|
|
fun: fun,
|
|
data: flow,
|
|
})
|
|
}
|
|
})
|
|
});
|
|
|
|
queue.run();
|
|
|
|
queue.data = ptr::mut_null()
|
|
}
|
|
|