1 files changed, 454 insertions, 0 deletions
diff --git a/cli/web_worker.rs b/cli/web_worker.rs
new file mode 100644
index 000000000..97db42279
--- /dev/null
+++ b/cli/web_worker.rs
@@ -0,0 +1,454 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+use crate::colors;
+use crate::fmt_errors::PrettyJsError;
+use crate::inspector::DenoInspector;
+use crate::js;
+use crate::metrics::Metrics;
+use crate::module_loader::CliModuleLoader;
+use crate::ops;
+use crate::permissions::Permissions;
+use crate::program_state::ProgramState;
+use crate::source_maps::apply_source_map;
+use deno_core::error::AnyError;
+use deno_core::futures::channel::mpsc;
+use deno_core::futures::future::poll_fn;
+use deno_core::futures::future::FutureExt;
+use deno_core::futures::stream::StreamExt;
+use deno_core::futures::task::AtomicWaker;
+use deno_core::url::Url;
+use deno_core::v8;
+use deno_core::JsRuntime;
+use deno_core::ModuleSpecifier;
+use deno_core::RuntimeOptions;
+use std::env;
+use std::sync::atomic::AtomicBool;
+use std::sync::atomic::Ordering;
+use std::sync::Arc;
+use std::task::Context;
+use std::task::Poll;
+use tokio::sync::Mutex as AsyncMutex;
+
+/// Events that are sent to host from child
+/// worker.
+pub enum WorkerEvent {
+  Message(Box<[u8]>),
+  Error(AnyError),
+  TerminalError(AnyError),
+}
+
+pub struct WorkerChannelsInternal {
+  pub sender: mpsc::Sender<WorkerEvent>,
+  pub receiver: mpsc::Receiver<Box<[u8]>>,
+}
+
+/// 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 {
+  pub sender: mpsc::Sender<Box<[u8]>>,
+  pub receiver: Arc<AsyncMutex<mpsc::Receiver<WorkerEvent>>>,
+  terminate_tx: mpsc::Sender<()>,
+  terminated: Arc<AtomicBool>,
+  isolate_handle: v8::IsolateHandle,
+}
+
+impl WebWorkerHandle {
+  /// Post message to worker as a host.
+  pub fn post_message(&self, buf: Box<[u8]>) -> Result<(), AnyError> {
+    let mut sender = self.sender.clone();
+    sender.try_send(buf)?;
+    Ok(())
+  }
+
+  /// Get the event with lock.
+  /// Return error if more than one listener tries to get event
+  pub async fn get_event(&self) -> Result<Option<WorkerEvent>, AnyError> {
+    let mut receiver = self.receiver.try_lock()?;
+    Ok(receiver.next().await)
+  }
+
+  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");
+    }
+  }
+}
+
+fn create_channels(
+  isolate_handle: v8::IsolateHandle,
+  terminate_tx: mpsc::Sender<()>,
+) -> (WorkerChannelsInternal, WebWorkerHandle) {
+  let (in_tx, in_rx) = mpsc::channel::<Box<[u8]>>(1);
+  let (out_tx, out_rx) = mpsc::channel::<WorkerEvent>(1);
+  let internal_channels = WorkerChannelsInternal {
+    sender: out_tx,
+    receiver: in_rx,
+  };
+  let external_channels = WebWorkerHandle {
+    sender: in_tx,
+    receiver: Arc::new(AsyncMutex::new(out_rx)),
+    terminated: Arc::new(AtomicBool::new(false)),
+    terminate_tx,
+    isolate_handle,
+  };
+  (internal_channels, external_channels)
+}
+
+/// This struct is an implementation of `Worker` Web API
+///
+/// Each `WebWorker` is either a child of `MainWorker` or other
+/// `WebWorker`.
+pub struct WebWorker {
+  inspector: Option<Box<DenoInspector>>,
+  // Following fields are pub because they are accessed
+  // when creating a new WebWorker instance.
+  pub(crate) internal_channels: WorkerChannelsInternal,
+  pub(crate) js_runtime: JsRuntime,
+  pub(crate) name: String,
+  waker: AtomicWaker,
+  event_loop_idle: bool,
+  terminate_rx: mpsc::Receiver<()>,
+  handle: WebWorkerHandle,
+  pub has_deno_namespace: bool,
+}
+
+impl WebWorker {
+  pub fn new(
+    name: String,
+    permissions: Permissions,
+    main_module: ModuleSpecifier,
+    program_state: Arc<ProgramState>,
+    has_deno_namespace: bool,
+  ) -> Self {
+    let module_loader = CliModuleLoader::new_for_worker();
+    let global_state_ = program_state.clone();
+
+    let js_error_create_fn = Box::new(move |core_js_error| {
+      let source_mapped_error =
+        apply_source_map(&core_js_error, global_state_.clone());
+      PrettyJsError::create(source_mapped_error)
+    });
+
+    let mut js_runtime = JsRuntime::new(RuntimeOptions {
+      module_loader: Some(module_loader),
+      startup_snapshot: Some(js::deno_isolate_init()),
+      js_error_create_fn: Some(js_error_create_fn),
+      get_error_class_fn: Some(&crate::errors::get_error_class_name),
+      ..Default::default()
+    });
+
+    let inspector =
+      if let Some(inspector_server) = &program_state.maybe_inspector_server {
+        Some(DenoInspector::new(
+          &mut js_runtime,
+          Some(inspector_server.clone()),
+        ))
+      } else if program_state.flags.coverage || program_state.flags.repl {
+        Some(DenoInspector::new(&mut js_runtime, None))
+      } else {
+        None
+      };
+
+    let (terminate_tx, terminate_rx) = mpsc::channel::<()>(1);
+    let isolate_handle = js_runtime.v8_isolate().thread_safe_handle();
+    let (internal_channels, handle) =
+      create_channels(isolate_handle, terminate_tx);
+
+    let mut worker = Self {
+      inspector,
+      internal_channels,
+      js_runtime,
+      name,
+      waker: AtomicWaker::new(),
+      event_loop_idle: false,
+      terminate_rx,
+      handle,
+      has_deno_namespace,
+    };
+
+    {
+      let handle = worker.thread_safe_handle();
+      let sender = worker.internal_channels.sender.clone();
+      let js_runtime = &mut worker.js_runtime;
+      // All ops registered in this function depend on these
+      {
+        let op_state = js_runtime.op_state();
+        let mut op_state = op_state.borrow_mut();
+        op_state.put::<Metrics>(Default::default());
+        op_state.put::<Arc<ProgramState>>(program_state.clone());
+        op_state.put::<Permissions>(permissions);
+      }
+
+      ops::web_worker::init(js_runtime, sender.clone(), handle);
+      ops::runtime::init(js_runtime, main_module);
+      ops::fetch::init(js_runtime, program_state.flags.ca_file.as_deref());
+      ops::timers::init(js_runtime);
+      ops::worker_host::init(js_runtime, Some(sender));
+      ops::reg_json_sync(js_runtime, "op_close", deno_core::op_close);
+      ops::reg_json_sync(js_runtime, "op_resources", deno_core::op_resources);
+      ops::reg_json_sync(
+        js_runtime,
+        "op_domain_to_ascii",
+        deno_web::op_domain_to_ascii,
+      );
+      ops::errors::init(js_runtime);
+      ops::io::init(js_runtime);
+      ops::websocket::init(js_runtime);
+
+      if has_deno_namespace {
+        ops::fs_events::init(js_runtime);
+        ops::fs::init(js_runtime);
+        ops::net::init(js_runtime);
+        ops::os::init(js_runtime);
+        ops::permissions::init(js_runtime);
+        ops::plugin::init(js_runtime);
+        ops::process::init(js_runtime);
+        ops::crypto::init(js_runtime, program_state.flags.seed);
+        ops::runtime_compiler::init(js_runtime);
+        ops::signal::init(js_runtime);
+        ops::tls::init(js_runtime);
+        ops::tty::init(js_runtime);
+      }
+    }
+
+    worker
+  }
+
+  /// Same as execute2() but the filename defaults to "$CWD/__anonymous__".
+  pub fn execute(&mut self, js_source: &str) -> Result<(), AnyError> {
+    let path = env::current_dir().unwrap().join("__anonymous__");
+    let url = Url::from_file_path(path).unwrap();
+    self.js_runtime.execute(url.as_str(), js_source)
+  }
+
+  /// Loads, instantiates and executes specified JavaScript module.
+  pub async fn execute_module(
+    &mut self,
+    module_specifier: &ModuleSpecifier,
+  ) -> Result<(), AnyError> {
+    let id = self.js_runtime.load_module(module_specifier, None).await?;
+    self.js_runtime.mod_evaluate(id).await
+  }
+
+  /// Returns a way to communicate with the Worker from other threads.
+  pub fn thread_safe_handle(&self) -> WebWorkerHandle {
+    self.handle.clone()
+  }
+
+  pub fn poll_event_loop(
+    &mut self,
+    cx: &mut Context,
+  ) -> Poll<Result<(), AnyError>> {
+    let terminated = self.handle.terminated.load(Ordering::Relaxed);
+
+    if terminated {
+      return Poll::Ready(Ok(()));
+    }
+
+    if !self.event_loop_idle {
+      let poll_result = {
+        // We always poll the inspector if it exists.
+        let _ = self.inspector.as_mut().map(|i| i.poll_unpin(cx));
+        self.waker.register(cx.waker());
+        self.js_runtime.poll_event_loop(cx)
+      };
+      match poll_result {
+        Poll::Ready(r) => {
+          let terminated = self.handle.terminated.load(Ordering::Relaxed);
+          if terminated {
+            return Poll::Ready(Ok(()));
+          }
+
+          if let Err(e) = r {
+            eprintln!(
+              "{}: Uncaught (in worker \"{}\") {}",
+              colors::red_bold("error"),
+              self.name.to_string(),
+              e.to_string().trim_start_matches("Uncaught "),
+            );
+            let mut sender = self.internal_channels.sender.clone();
+            sender
+              .try_send(WorkerEvent::Error(e))
+              .expect("Failed to post message to host");
+          }
+          self.event_loop_idle = true;
+        }
+        Poll::Pending => {}
+      }
+    }
+
+    if let Poll::Ready(r) = self.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) = self.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) = self.execute(&script) {
+            // If execution was terminated during message callback then
+            // just ignore it
+            if self.handle.terminated.load(Ordering::Relaxed) {
+              return Poll::Ready(Ok(()));
+            }
+
+            // Otherwise forward error to host
+            let mut sender = self.internal_channels.sender.clone();
+            sender
+              .try_send(WorkerEvent::Error(e))
+              .expect("Failed to post message to host");
+          }
+
+          // Let event loop be polled again
+          self.event_loop_idle = false;
+          self.waker.wake();
+        }
+        None => unreachable!(),
+      }
+    }
+
+    Poll::Pending
+  }
+
+  pub async fn run_event_loop(&mut self) -> Result<(), AnyError> {
+    poll_fn(|cx| self.poll_event_loop(cx)).await
+  }
+}
+
+impl Drop for WebWorker {
+  fn drop(&mut self) {
+    // The Isolate object must outlive the Inspector object, but this is
+    // currently not enforced by the type system.
+    self.inspector.take();
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use crate::program_state::ProgramState;
+  use crate::tokio_util;
+  use deno_core::serde_json::json;
+
+  fn create_test_web_worker() -> WebWorker {
+    let main_module =
+      ModuleSpecifier::resolve_url_or_path("./hello.js").unwrap();
+    let program_state = ProgramState::mock(vec!["deno".to_string()], None);
+    let mut worker = WebWorker::new(
+      "TEST".to_string(),
+      Permissions::allow_all(),
+      main_module,
+      program_state,
+      false,
+    );
+    worker
+      .execute("bootstrap.workerRuntime(\"TEST\", false)")
+      .unwrap();
+    worker
+  }
+
+  #[tokio::test]
+  async 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_web_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.run_event_loop());
+      assert!(r.is_ok())
+    });
+
+    let mut handle = handle_receiver.recv().unwrap();
+
+    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");
+  }
+
+  #[tokio::test]
+  async 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_web_worker();
+      worker.execute("onmessage = () => { close(); }").unwrap();
+      let handle = worker.thread_safe_handle();
+      handle_sender.send(handle).unwrap();
+      let r = tokio_util::run_basic(worker.run_event_loop());
+      assert!(r.is_ok())
+    });
+
+    let mut handle = handle_receiver.recv().unwrap();
+
+    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");
+  }
+}