Make --inspect-brk pause on the first line of _user_ code (#5250)

cli/inspector.rs

@@ -374,7 +374,6 @@ impl DenoInspector {
  pub fn new(
  isolate: &mut deno_core::CoreIsolate,
  host: SocketAddr,
- wait_for_debugger: bool,
  ) -> Box<Self> {
  let deno_core::CoreIsolate {
  v8_isolate,
@@ -406,7 +405,7 @@ impl DenoInspector {
  v8::inspector::V8Inspector::create(scope, unsafe { &mut *self_ptr });
 
  let sessions = InspectorSessions::new(self_ptr, new_websocket_rx);
- let flags = InspectorFlags::new(wait_for_debugger);
+ let flags = InspectorFlags::new();
  let waker = InspectorWaker::new(scope.isolate().thread_safe_handle());
 
  Self {
@@ -426,9 +425,6 @@ impl DenoInspector {
  self_.context_created(context, Self::CONTEXT_GROUP_ID, context_name);
 
  // Register this inspector with the server thread.
- // Note: poll_sessions() might block if we need to wait for a
- // debugger front-end to connect. Therefore the server thread must to be
- // nofified *before* polling.
  InspectorServer::register_inspector(info);
 
  // Poll the session handler so we will get notified whenever there is
@@ -469,14 +465,9 @@ impl DenoInspector {
  replace(&mut self.flags.borrow_mut().session_handshake_done, false);
  match poll_result {
  Poll::Pending if handshake_done => {
- let mut session = sessions.handshake.take().unwrap();
- if replace(
- &mut self.flags.borrow_mut().waiting_for_session,
- false,
- ) {
- session.break_on_first_statement();
- }
+ let session = sessions.handshake.take().unwrap();
  sessions.established.push(session);
+ take(&mut self.flags.borrow_mut().waiting_for_session);
  }
  Poll::Ready(_) => sessions.handshake = None,
  Poll::Pending => break,
@@ -547,6 +538,21 @@ impl DenoInspector {
  };
  }
  }
+
+ /// This function blocks the thread until at least one inspector client has
+ /// established a websocket connection and successfully completed the
+ /// handshake. After that, it instructs V8 to pause at the next statement.
+ pub fn wait_for_session_and_break_on_next_statement(&mut self) {
+ loop {
+ match self.sessions.get_mut().established.iter_mut().next() {
+ Some(session) => break session.break_on_next_statement(),
+ None => {
+ self.flags.get_mut().waiting_for_session = true;
+ let _ = self.poll_sessions(None).unwrap();
+ }
+ };
+ }
+ }
 }
 
 #[derive(Default)]
@@ -557,11 +563,8 @@ struct InspectorFlags {
 }
 
 impl InspectorFlags {
- fn new(waiting_for_session: bool) -> RefCell<Self> {
- let self_ = Self {
- waiting_for_session,
- ..Default::default()
- };
+ fn new() -> RefCell<Self> {
+ let self_ = Self::default();
  RefCell::new(self_)
  }
 }
@@ -753,7 +756,7 @@ impl DenoInspectorSession {
  let _ = self.websocket_tx.unbounded_send(msg);
  }
 
- pub fn break_on_first_statement(&mut self) {
+ pub fn break_on_next_statement(&mut self) {
  let reason = v8::inspector::StringView::from(&b"debugCommand"[..]);
  let detail = v8::inspector::StringView::empty();
  self.schedule_pause_on_next_statement(reason, detail);

cli/main.rs

@@ -74,7 +74,6 @@ use crate::msg::MediaType;
 use crate::op_error::OpError;
 use crate::ops::io::get_stdio;
 use crate::permissions::Permissions;
-use crate::state::DebugType;
 use crate::state::State;
 use crate::tsc::TargetLib;
 use crate::worker::MainWorker;
@@ -140,7 +139,7 @@ fn create_main_worker(
  global_state: GlobalState,
  main_module: ModuleSpecifier,
 ) -> Result<MainWorker, ErrBox> {
- let state = State::new(global_state, None, main_module, DebugType::Main)?;
+ let state = State::new(global_state, None, main_module, false)?;
 
  let mut worker = MainWorker::new(
  "main".to_string(),

cli/state.rs

@@ -3,6 +3,7 @@ use crate::file_fetcher::SourceFileFetcher;
 use crate::global_state::GlobalState;
 use crate::global_timer::GlobalTimer;
 use crate::import_map::ImportMap;
+use crate::inspector::DenoInspector;
 use crate::metrics::Metrics;
 use crate::op_error::OpError;
 use crate::ops::JsonOp;
@@ -11,6 +12,7 @@ use crate::permissions::Permissions;
 use crate::tsc::TargetLib;
 use crate::web_worker::WebWorkerHandle;
 use deno_core::Buf;
+use deno_core::CoreIsolate;
 use deno_core::ErrBox;
 use deno_core::ModuleLoadId;
 use deno_core::ModuleLoader;
@@ -31,15 +33,6 @@ use std::rc::Rc;
 use std::str;
 use std::thread::JoinHandle;
 use std::time::Instant;
-#[derive(Copy, Clone, Eq, PartialEq)]
-pub enum DebugType {
- /// Can be debugged, will wait for debugger when --inspect-brk given.
- Main,
- /// Can be debugged, never waits for debugger.
- Dependent,
- /// No inspector instance is created.
- Internal,
-}
 
 #[derive(Clone)]
 pub struct State(Rc<RefCell<StateInner>>);
@@ -66,8 +59,9 @@ pub struct StateInner {
  pub start_time: Instant,
  pub seeded_rng: Option<StdRng>,
  pub target_lib: TargetLib,
- pub debug_type: DebugType,
  pub is_main: bool,
+ pub is_internal: bool,
+ pub inspector: Option<Box<DenoInspector>>,
 }
 
 impl State {
@@ -370,7 +364,7 @@ impl State {
  global_state: GlobalState,
  shared_permissions: Option<Permissions>,
  main_module: ModuleSpecifier,
- debug_type: DebugType,
+ is_internal: bool,
  ) -> Result<Self, ErrBox> {
  let import_map: Option<ImportMap> =
  match global_state.flags.import_map_path.as_ref() {
@@ -406,8 +400,9 @@ impl State {
  start_time: Instant::now(),
  seeded_rng,
  target_lib: TargetLib::Main,
- debug_type,
  is_main: true,
+ is_internal,
+ inspector: None,
  }));
 
  Ok(Self(state))
@@ -442,8 +437,9 @@ impl State {
  start_time: Instant::now(),
  seeded_rng,
  target_lib: TargetLib::Worker,
- debug_type: DebugType::Dependent,
  is_main: false,
+ is_internal: false,
+ inspector: None,
  }));
 
  Ok(Self(state))
@@ -512,6 +508,35 @@ impl State {
  }
  }
 
+ pub fn maybe_init_inspector(&self, isolate: &mut CoreIsolate) {
+ let mut state = self.borrow_mut();
+
+ if state.is_internal {
+ return;
+ };
+
+ let inspector_host = {
+ let global_state = &state.global_state;
+ match global_state
+ .flags
+ .inspect
+ .or(global_state.flags.inspect_brk)
+ {
+ Some(host) => host,
+ None => return,
+ }
+ };
+
+ let inspector = DenoInspector::new(isolate, inspector_host);
+ state.inspector.replace(inspector);
+ }
+
+ #[inline]
+ pub fn should_inspector_break_on_first_statement(&self) -> bool {
+ let state = self.borrow();
+ state.inspector.is_some() && state.is_main
+ }
+
  #[cfg(test)]
  pub fn mock(main_module: &str) -> State {
  let module_specifier = ModuleSpecifier::resolve_url_or_path(main_module)
@@ -520,7 +545,7 @@ impl State {
  GlobalState::mock(vec!["deno".to_string()]),
  None,
  module_specifier,
- DebugType::Main,
+ false,
  )
  .unwrap()
  }

cli/tsc.rs

@@ -15,7 +15,6 @@ use crate::permissions::Permissions;
 use crate::source_maps::SourceMapGetter;
 use crate::startup_data;
 use crate::state::State;
-use crate::state::*;
 use crate::tokio_util;
 use crate::version;
 use crate::web_worker::WebWorker;
@@ -351,13 +350,9 @@ impl TsCompiler {
  ) -> CompilerWorker {
  let entry_point =
  ModuleSpecifier::resolve_url_or_path("./__$deno$ts_compiler.ts").unwrap();
- let worker_state = State::new(
- global_state.clone(),
- Some(permissions),
- entry_point,
- DebugType::Internal,
- )
- .expect("Unable to create worker state");
+ let worker_state =
+ State::new(global_state.clone(), Some(permissions), entry_point, true)
+ .expect("Unable to create worker state");
 
  // Count how many times we start the compiler worker.
  global_state.compiler_starts.fetch_add(1, Ordering::SeqCst);