introduce a generic worker event-loop

This commit is contained in:
Gregory Terzian 2018-08-18 20:28:42 +02:00
parent ca6306c430
commit 029715aba6
3 changed files with 175 additions and 131 deletions

View file

@ -6,6 +6,7 @@ use devtools;
use devtools_traits::DevtoolScriptControlMsg;
use dom::abstractworker::{SimpleWorkerErrorHandler, WorkerScriptMsg};
use dom::abstractworkerglobalscope::{SendableWorkerScriptChan, WorkerThreadWorkerChan};
use dom::abstractworkerglobalscope::{WorkerEventLoopMethods, run_worker_event_loop};
use dom::bindings::cell::DomRefCell;
use dom::bindings::codegen::Bindings::DedicatedWorkerGlobalScopeBinding;
use dom::bindings::codegen::Bindings::DedicatedWorkerGlobalScopeBinding::DedicatedWorkerGlobalScopeMethods;
@ -40,7 +41,7 @@ use servo_url::ServoUrl;
use std::mem::replace;
use std::sync::Arc;
use std::sync::atomic::AtomicBool;
use std::sync::mpsc::{Receiver, Select, Sender, channel};
use std::sync::mpsc::{Receiver, Sender, channel};
use std::thread;
use style::thread_state::{self, ThreadState};
use task_queue::{QueuedTask, QueuedTaskConversion, TaskQueue};
@ -49,7 +50,7 @@ use task_queue::{QueuedTask, QueuedTaskConversion, TaskQueue};
/// value for the duration of this object's lifetime. This ensures that the related Worker
/// object only lives as long as necessary (ie. while events are being executed), while
/// providing a reference that can be cloned freely.
struct AutoWorkerReset<'a> {
pub struct AutoWorkerReset<'a> {
workerscope: &'a DedicatedWorkerGlobalScope,
old_worker: Option<TrustedWorkerAddress>,
}
@ -78,7 +79,7 @@ pub enum DedicatedWorkerScriptMsg {
WakeUp,
}
enum MixedMessage {
pub enum MixedMessage {
FromWorker(DedicatedWorkerScriptMsg),
FromScheduler((TrustedWorkerAddress, TimerEvent)),
FromDevtools(DevtoolScriptControlMsg)
@ -155,6 +156,41 @@ pub struct DedicatedWorkerGlobalScope {
parent_sender: Box<ScriptChan + Send>,
}
impl WorkerEventLoopMethods for DedicatedWorkerGlobalScope {
type TimerMsg = (TrustedWorkerAddress, TimerEvent);
type WorkerMsg = DedicatedWorkerScriptMsg;
type Event = MixedMessage;
fn timer_event_port(&self) -> &Receiver<(TrustedWorkerAddress, TimerEvent)> {
&self.timer_event_port
}
fn task_queue(&self) -> &TaskQueue<DedicatedWorkerScriptMsg> {
&self.task_queue
}
fn handle_event(&self, event: MixedMessage) {
self.handle_mixed_message(event);
}
fn handle_worker_post_event(&self, worker: &TrustedWorkerAddress) -> Option<AutoWorkerReset> {
let ar = AutoWorkerReset::new(&self, worker.clone());
Some(ar)
}
fn from_worker_msg(&self, msg: DedicatedWorkerScriptMsg) -> MixedMessage {
MixedMessage::FromWorker(msg)
}
fn from_timer_msg(&self, msg: (TrustedWorkerAddress, TimerEvent)) -> MixedMessage {
MixedMessage::FromScheduler(msg)
}
fn from_devtools_msg(&self, msg: DevtoolScriptControlMsg) -> MixedMessage {
MixedMessage::FromDevtools(msg)
}
}
impl DedicatedWorkerGlobalScope {
fn new_inherited(init: WorkerGlobalScopeInit,
worker_url: ServoUrl,
@ -309,7 +345,7 @@ impl DedicatedWorkerGlobalScope {
// The worker processing model remains on this step until the event loop is destroyed,
// which happens after the closing flag is set to true.
while !scope.is_closing() {
global.run_event_loop(worker.clone());
run_worker_event_loop(&*global, Some(&worker));
}
}, reporter_name, parent_sender, CommonScriptMsg::CollectReports);
}).expect("Thread spawning failed");
@ -331,65 +367,6 @@ impl DedicatedWorkerGlobalScope {
(chan, Box::new(rx))
}
#[allow(unsafe_code)]
fn run_event_loop(&self, worker: TrustedWorkerAddress) {
let scope = self.upcast::<WorkerGlobalScope>();
let timer_event_port = &self.timer_event_port;
let devtools_port = scope.from_devtools_receiver();
let sel = Select::new();
let mut worker_handle = sel.handle(self.task_queue.select());
let mut timer_event_handle = sel.handle(timer_event_port);
let mut devtools_handle = sel.handle(devtools_port);
unsafe {
worker_handle.add();
timer_event_handle.add();
if scope.from_devtools_sender().is_some() {
devtools_handle.add();
}
}
let ret = sel.wait();
let event = {
if ret == worker_handle.id() {
MixedMessage::FromWorker(self.task_queue.take_tasks().recv().unwrap())
} else if ret == timer_event_handle.id() {
MixedMessage::FromScheduler(timer_event_port.recv().unwrap())
} else if ret == devtools_handle.id() {
MixedMessage::FromDevtools(devtools_port.recv().unwrap())
} else {
panic!("unexpected select result!")
}
};
let mut sequential = vec![];
sequential.push(event);
// https://html.spec.whatwg.org/multipage/#worker-event-loop
// Once the WorkerGlobalScope's closing flag is set to true,
// the event loop's task queues must discard any further tasks
// that would be added to them
// (tasks already on the queue are unaffected except where otherwise specified).
while !scope.is_closing() {
// Batch all events that are ready.
// The task queue will throttle non-priority tasks if necessary.
match self.task_queue.take_tasks().try_recv() {
Err(_) => match timer_event_port.try_recv() {
Err(_) => match devtools_port.try_recv() {
Err(_) => break,
Ok(ev) => sequential.push(MixedMessage::FromDevtools(ev)),
},
Ok(ev) => sequential.push(MixedMessage::FromScheduler(ev)),
},
Ok(ev) => sequential.push(MixedMessage::FromWorker(ev)),
}
}
// Step 3
for event in sequential {
self.handle_event(event);
// Step 6
let _ar = AutoWorkerReset::new(&self, worker.clone());
self.upcast::<GlobalScope>().perform_a_microtask_checkpoint();
}
}
fn handle_script_event(&self, msg: WorkerScriptMsg) {
match msg {
WorkerScriptMsg::DOMMessage(data) => {
@ -407,8 +384,8 @@ impl DedicatedWorkerGlobalScope {
}
}
fn handle_event(&self, event: MixedMessage) {
match event {
fn handle_mixed_message(&self, msg: MixedMessage) {
match msg {
MixedMessage::FromDevtools(msg) => {
match msg {
DevtoolScriptControlMsg::EvaluateJS(_pipe_id, string, sender) =>