Auto merge of #15535 - froydnj:global-style-thread-pool, r=bholley

geckolib: use a global thread pool for styling

By having a single thread pool, rather than one per document, we use less memory.  This addresses https://bugzilla.mozilla.org/show_bug.cgi?id=1324250.

This may be obvious to an experienced Rust programmer, but I went with raw pointers because trying to use `Option` global variables resulted in complaints about turning on feature flags in nightly Rust.  Since this is for stylo, nightly features are not appropriate here.

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- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] These changes do not require tests because _____

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This commit is contained in:
bors-servo 2017-02-23 10:15:41 -08:00 committed by GitHub
commit 56a99577b3
9 changed files with 60 additions and 47 deletions

View file

@ -13,7 +13,7 @@ path = "lib.rs"
doctest = false
[features]
gecko = ["nsstring_vendor", "num_cpus", "rayon/unstable"]
gecko = ["nsstring_vendor", "rayon/unstable"]
use_bindgen = ["bindgen", "regex"]
servo = ["serde/unstable", "serde", "serde_derive", "heapsize_derive",
"style_traits/servo", "servo_atoms", "html5ever-atoms",
@ -57,10 +57,6 @@ servo_url = {path = "../url"}
time = "0.1"
unicode-segmentation = "1.0"
[dependencies.num_cpus]
optional = true
version = "1.0"
[target.'cfg(windows)'.dependencies]
kernel32-sys = "0.2"

View file

@ -11,13 +11,9 @@ use gecko_bindings::bindings::RawServoStyleSet;
use gecko_bindings::structs::RawGeckoPresContextOwned;
use gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
use media_queries::Device;
use num_cpus;
use parking_lot::RwLock;
use properties::ComputedValues;
use rayon;
use std::cmp;
use std::collections::HashMap;
use std::env;
use std::sync::Arc;
use std::sync::mpsc::{Receiver, Sender, channel};
use stylesheets::Stylesheet;
@ -48,29 +44,12 @@ pub struct PerDocumentStyleDataImpl {
/// Unused. Will go away when we actually implement transitions and
/// animations properly.
pub expired_animations: Arc<RwLock<HashMap<OpaqueNode, Vec<Animation>>>>,
/// The worker thread pool.
/// FIXME(bholley): This shouldn't be per-document.
pub work_queue: Option<rayon::ThreadPool>,
/// The number of threads of the work queue.
pub num_threads: usize,
}
/// The data itself is an `AtomicRefCell`, which guarantees the proper semantics
/// and unexpected races while trying to mutate it.
pub struct PerDocumentStyleData(AtomicRefCell<PerDocumentStyleDataImpl>);
lazy_static! {
/// The number of layout threads, computed statically.
pub static ref NUM_THREADS: usize = {
match env::var("STYLO_THREADS").map(|s| s.parse::<usize>().expect("invalid STYLO_THREADS")) {
Ok(num) => num,
_ => cmp::max(num_cpus::get() * 3 / 4, 1),
}
};
}
impl PerDocumentStyleData {
/// Create a dummy `PerDocumentStyleData`.
pub fn new(pres_context: RawGeckoPresContextOwned) -> Self {
@ -86,14 +65,6 @@ impl PerDocumentStyleData {
new_animations_receiver: new_anims_receiver,
running_animations: Arc::new(RwLock::new(HashMap::new())),
expired_animations: Arc::new(RwLock::new(HashMap::new())),
work_queue: if *NUM_THREADS <= 1 {
None
} else {
let configuration =
rayon::Configuration::new().set_num_threads(*NUM_THREADS);
rayon::ThreadPool::new(configuration).ok()
},
num_threads: *NUM_THREADS,
}))
}
@ -141,9 +112,3 @@ unsafe impl HasFFI for PerDocumentStyleData {
}
unsafe impl HasSimpleFFI for PerDocumentStyleData {}
unsafe impl HasBoxFFI for PerDocumentStyleData {}
impl Drop for PerDocumentStyleDataImpl {
fn drop(&mut self) {
let _ = self.work_queue.take();
}
}

View file

@ -61,7 +61,6 @@ extern crate matches;
#[cfg(feature = "gecko")] extern crate nsstring_vendor as nsstring;
extern crate num_integer;
extern crate num_traits;
#[cfg(feature = "gecko")] extern crate num_cpus;
extern crate ordered_float;
extern crate owning_ref;
extern crate parking_lot;