deno/cli/web_worker.rs

353 lines
9.7 KiB
Rust

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
use crate::ops;
use crate::state::State;
use crate::worker::Worker;
use crate::worker::WorkerEvent;
use crate::worker::WorkerHandle;
use deno_core::v8;
use deno_core::ErrBox;
use deno_core::StartupData;
use futures::channel::mpsc;
use futures::future::FutureExt;
use futures::stream::StreamExt;
use std::future::Future;
use std::ops::Deref;
use std::ops::DerefMut;
use std::pin::Pin;
use std::sync::atomic::AtomicBool;
use std::sync::atomic::Ordering;
use std::sync::Arc;
use std::task::Context;
use std::task::Poll;
/// Wrapper for `WorkerHandle` that adds functionality
/// for terminating workers.
///
/// This struct is used by host as well as worker itself.
///
/// Host uses it to communicate with worker and terminate it,
/// while worker uses it only to finish execution on `self.close()`.
#[derive(Clone)]
pub struct WebWorkerHandle {
worker_handle: WorkerHandle,
terminate_tx: mpsc::Sender<()>,
terminated: Arc<AtomicBool>,
isolate_handle: v8::IsolateHandle,
}
impl Deref for WebWorkerHandle {
type Target = WorkerHandle;
fn deref(&self) -> &Self::Target {
&self.worker_handle
}
}
impl DerefMut for WebWorkerHandle {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.worker_handle
}
}
impl WebWorkerHandle {
pub fn terminate(&self) {
// This function can be called multiple times by whomever holds
// the handle. However only a single "termination" should occur so
// we need a guard here.
let already_terminated = self.terminated.swap(true, Ordering::Relaxed);
if !already_terminated {
self.isolate_handle.terminate_execution();
let mut sender = self.terminate_tx.clone();
// This call should be infallible hence the `expect`.
// This might change in the future.
sender.try_send(()).expect("Failed to terminate");
}
}
}
/// This worker is implementation of `Worker` Web API
///
/// At the moment this type of worker supports only
/// communication with parent and creating new workers.
///
/// Each `WebWorker` is either a child of `MainWorker` or other
/// `WebWorker`.
pub struct WebWorker {
worker: Worker,
event_loop_idle: bool,
terminate_rx: mpsc::Receiver<()>,
handle: WebWorkerHandle,
pub has_deno_namespace: bool,
}
impl WebWorker {
pub fn new(
name: String,
startup_data: StartupData,
state: State,
has_deno_namespace: bool,
) -> Self {
let state_ = state.clone();
let mut worker = Worker::new(name, startup_data, state_);
let terminated = Arc::new(AtomicBool::new(false));
let isolate_handle = worker.isolate.thread_safe_handle();
let (terminate_tx, terminate_rx) = mpsc::channel::<()>(1);
let handle = WebWorkerHandle {
worker_handle: worker.thread_safe_handle(),
terminated,
isolate_handle,
terminate_tx,
};
let mut web_worker = Self {
worker,
event_loop_idle: false,
terminate_rx,
handle,
has_deno_namespace,
};
let handle = web_worker.thread_safe_handle();
{
let isolate = &mut web_worker.worker.isolate;
ops::runtime::init(isolate, &state);
ops::web_worker::init(
isolate,
&state,
&web_worker.worker.internal_channels.sender,
handle,
);
ops::worker_host::init(isolate, &state);
ops::idna::init(isolate, &state);
ops::io::init(isolate, &state);
ops::resources::init(isolate, &state);
ops::errors::init(isolate, &state);
ops::timers::init(isolate, &state);
ops::fetch::init(isolate, &state);
if has_deno_namespace {
ops::runtime_compiler::init(isolate, &state);
ops::fs::init(isolate, &state);
ops::fs_events::init(isolate, &state);
ops::plugin::init(isolate, &state);
ops::net::init(isolate, &state);
ops::tls::init(isolate, &state);
ops::os::init(isolate, &state);
ops::permissions::init(isolate, &state);
ops::process::init(isolate, &state);
ops::random::init(isolate, &state);
ops::signal::init(isolate, &state);
ops::tty::init(isolate, &state);
}
}
web_worker
}
}
impl WebWorker {
/// Returns a way to communicate with the Worker from other threads.
pub fn thread_safe_handle(&self) -> WebWorkerHandle {
self.handle.clone()
}
}
impl Deref for WebWorker {
type Target = Worker;
fn deref(&self) -> &Self::Target {
&self.worker
}
}
impl DerefMut for WebWorker {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.worker
}
}
impl Future for WebWorker {
type Output = Result<(), ErrBox>;
fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
let inner = self.get_mut();
let worker = &mut inner.worker;
let terminated = inner.handle.terminated.load(Ordering::Relaxed);
if terminated {
return Poll::Ready(Ok(()));
}
if !inner.event_loop_idle {
match worker.poll_unpin(cx) {
Poll::Ready(r) => {
let terminated = inner.handle.terminated.load(Ordering::Relaxed);
if terminated {
return Poll::Ready(Ok(()));
}
if let Err(e) = r {
let mut sender = worker.internal_channels.sender.clone();
sender
.try_send(WorkerEvent::Error(e))
.expect("Failed to post message to host");
}
inner.event_loop_idle = true;
}
Poll::Pending => {}
}
}
if let Poll::Ready(r) = inner.terminate_rx.poll_next_unpin(cx) {
// terminate_rx should never be closed
assert!(r.is_some());
return Poll::Ready(Ok(()));
}
if let Poll::Ready(r) =
worker.internal_channels.receiver.poll_next_unpin(cx)
{
match r {
Some(msg) => {
let msg = String::from_utf8(msg.to_vec()).unwrap();
let script = format!("workerMessageRecvCallback({})", msg);
if let Err(e) = worker.execute(&script) {
// If execution was terminated during message callback then
// just ignore it
if inner.handle.terminated.load(Ordering::Relaxed) {
return Poll::Ready(Ok(()));
}
// Otherwise forward error to host
let mut sender = worker.internal_channels.sender.clone();
sender
.try_send(WorkerEvent::Error(e))
.expect("Failed to post message to host");
}
// Let event loop be polled again
inner.event_loop_idle = false;
worker.waker.wake();
}
None => unreachable!(),
}
}
Poll::Pending
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::startup_data;
use crate::state::State;
use crate::tokio_util;
use crate::worker::WorkerEvent;
fn create_test_worker() -> WebWorker {
let state = State::mock("./hello.js");
let mut worker = WebWorker::new(
"TEST".to_string(),
startup_data::deno_isolate_init(),
state,
false,
);
worker
.execute("bootstrap.workerRuntime(\"TEST\", false)")
.unwrap();
worker
}
#[test]
fn test_worker_messages() {
let (handle_sender, handle_receiver) =
std::sync::mpsc::sync_channel::<WebWorkerHandle>(1);
let join_handle = std::thread::spawn(move || {
let mut worker = create_test_worker();
let source = r#"
onmessage = function(e) {
console.log("msg from main script", e.data);
if (e.data == "exit") {
return close();
} else {
console.assert(e.data === "hi");
}
postMessage([1, 2, 3]);
console.log("after postMessage");
}
"#;
worker.execute(source).unwrap();
let handle = worker.thread_safe_handle();
handle_sender.send(handle).unwrap();
let r = tokio_util::run_basic(worker);
assert!(r.is_ok())
});
let mut handle = handle_receiver.recv().unwrap();
tokio_util::run_basic(async move {
let msg = json!("hi").to_string().into_boxed_str().into_boxed_bytes();
let r = handle.post_message(msg.clone());
assert!(r.is_ok());
let maybe_msg = handle.get_event().await.unwrap();
assert!(maybe_msg.is_some());
let r = handle.post_message(msg.clone());
assert!(r.is_ok());
let maybe_msg = handle.get_event().await.unwrap();
assert!(maybe_msg.is_some());
match maybe_msg {
Some(WorkerEvent::Message(buf)) => {
assert_eq!(*buf, *b"[1,2,3]");
}
_ => unreachable!(),
}
let msg = json!("exit")
.to_string()
.into_boxed_str()
.into_boxed_bytes();
let r = handle.post_message(msg);
assert!(r.is_ok());
let event = handle.get_event().await.unwrap();
assert!(event.is_none());
handle.sender.close_channel();
});
join_handle.join().expect("Failed to join worker thread");
}
#[test]
fn removed_from_resource_table_on_close() {
let (handle_sender, handle_receiver) =
std::sync::mpsc::sync_channel::<WebWorkerHandle>(1);
let join_handle = std::thread::spawn(move || {
let mut worker = create_test_worker();
worker.execute("onmessage = () => { close(); }").unwrap();
let handle = worker.thread_safe_handle();
handle_sender.send(handle).unwrap();
let r = tokio_util::run_basic(worker);
assert!(r.is_ok())
});
let mut handle = handle_receiver.recv().unwrap();
tokio_util::run_basic(async move {
let msg = json!("hi").to_string().into_boxed_str().into_boxed_bytes();
let r = handle.post_message(msg.clone());
assert!(r.is_ok());
let event = handle.get_event().await.unwrap();
assert!(event.is_none());
handle.sender.close_channel();
});
join_handle.join().expect("Failed to join worker thread");
}
}