[nextest-runner] remove cancellation AtomicBool

We've changed things such that the executor always checks in with the
dispatcher before starting a unit. This makes the bool unnecessary.

The cancel receiver is currently necessary for the
handle_delay_between_attempts step, which should cancel the run no matter what.
We'll remove this shortly by moving this functionality into req_rx.

Author: sunshowers

nextest-runner/src/runner/dispatcher.rs

@@ -23,11 +23,7 @@ use crate::{
 use chrono::Local;
 use debug_ignore::DebugIgnore;
 use quick_junit::ReportUuid;
-use std::{
-    collections::BTreeMap,
-    sync::atomic::{AtomicBool, Ordering},
-    time::Duration,
-};
+use std::{collections::BTreeMap, time::Duration};
 use tokio::sync::{
     broadcast,
     mpsc::{unbounded_channel, UnboundedReceiver, UnboundedSender},
@@ -102,7 +98,6 @@ where
         signal_handler: &mut SignalHandler,
         input_handler: &mut InputHandler,
         report_cancel_rx: oneshot::Receiver<()>,
-        cancelled_ref: &AtomicBool,
         cancellation_sender: broadcast::Sender<()>,
     ) -> RunnerTaskState {
         let mut report_cancel_rx = std::pin::pin!(report_cancel_rx);
@@ -275,10 +270,7 @@ where
                     self.info_finished(total.saturating_sub(index + 1));
                 }
                 HandleEventResponse::Cancel(cancel) => {
-                    // A cancellation notice was received. Note the ordering here:
-                    // cancelled_ref is set *before* notifications are broadcast. This
-                    // prevents race conditions.
-                    cancelled_ref.store(true, Ordering::Release);
+                    // A cancellation notice was received.
                     let _ = cancellation_sender.send(());
                     match cancel {
                         // Some of the branches here don't do anything, but are specified

nextest-runner/src/runner/executor.rs

@@ -39,10 +39,7 @@ use std::{
     num::NonZeroUsize,
     pin::Pin,
     process::{ExitStatus, Stdio},
-    sync::{
-        atomic::{AtomicBool, Ordering},
-        Arc,
-    },
+    sync::Arc,
     time::Duration,
 };
 use tokio::{
@@ -92,7 +89,6 @@ impl<'a> ExecutorContext<'a> {
     pub(super) async fn run_setup_scripts(
         &self,
         resp_tx: UnboundedSender<ExecutorEvent<'a>>,
-        cancelled_ref: &AtomicBool,
     ) -> SetupScriptExecuteData<'a> {
         let setup_scripts = self.profile.setup_scripts(self.test_list);
         let total = setup_scripts.len();
@@ -108,11 +104,6 @@ impl<'a> ExecutorContext<'a> {
             let config = script.config;
 
             let script_fut = async move {
-                if cancelled_ref.load(Ordering::Acquire) {
-                    // Check for test cancellation.
-                    return None;
-                }
-
                 let (req_rx_tx, req_rx_rx) = oneshot::channel();
                 let _ = this_resp_tx.send(ExecutorEvent::SetupScriptStarted {
                     script_id: script_id.clone(),
@@ -172,15 +163,9 @@ impl<'a> ExecutorContext<'a> {
         test_instance: TestInstance<'a>,
         settings: TestSettings<'a>,
         resp_tx: UnboundedSender<ExecutorEvent<'a>>,
-        cancelled_ref: &AtomicBool,
         mut cancel_receiver: broadcast::Receiver<()>,
         setup_script_data: Arc<SetupScriptExecuteData<'a>>,
     ) {
-        if cancelled_ref.load(Ordering::Acquire) {
-            // Check for test cancellation.
-            return;
-        }
-
         debug!(test_name = test_instance.name, "running test");
 
         let settings = Arc::new(settings);
@@ -224,14 +209,10 @@ impl<'a> ExecutorContext<'a> {
                 total_attempts,
             };
 
-            // Note: do not check for cancellation here.
-            // Only check for cancellation after the first
-            // run, to avoid a situation where run_statuses
-            // is empty.
-
             if retry_data.attempt > 1 {
-                // Ensure that the dispatcher believes the run is still ongoing. If the run is
-                // cancelled, the dispatcher will let us know.
+                // Ensure that the dispatcher believes the run is still ongoing.
+                // If the run is cancelled, the dispatcher will let us know by
+                // dropping the receiver.
                 let (tx, rx) = oneshot::channel();
                 _ = resp_tx.send(ExecutorEvent::RetryStarted {
                     test_instance,
@@ -242,8 +223,8 @@ impl<'a> ExecutorContext<'a> {
                 match rx.await {
                     Ok(()) => {}
                     Err(_) => {
-                        // The receiver was dropped -- the dispatcher has signaled that this unit
-                        // should exit.
+                        // The receiver was dropped -- the dispatcher has
+                        // signaled that this unit should exit.
                         return;
                     }
                 }
@@ -265,9 +246,6 @@ impl<'a> ExecutorContext<'a> {
             if run_status.result.is_success() {
                 // The test succeeded.
                 break run_status;
-            } else if cancelled_ref.load(Ordering::Acquire) {
-                // The test was cancelled.
-                break run_status;
             } else if retry_data.attempt < retry_data.total_attempts {
                 // Retry this test: send a retry event, then retry the loop.
                 delay = backoff_iter

nextest-runner/src/runner/imp.rs

@@ -20,11 +20,7 @@ use async_scoped::TokioScope;
 use future_queue::StreamExt;
 use futures::prelude::*;
 use quick_junit::ReportUuid;
-use std::{
-    convert::Infallible,
-    fmt,
-    sync::{atomic::AtomicBool, Arc},
-};
+use std::{convert::Infallible, fmt, sync::Arc};
 use tokio::{
     runtime::Runtime,
     sync::{broadcast, mpsc::unbounded_channel, oneshot},
@@ -178,7 +174,6 @@ impl<'a> TestRunner<'a> {
         F: FnMut(TestEvent<'a>) -> Result<(), E> + Send,
         E: fmt::Debug + Send,
     {
-        let cancelled = AtomicBool::new(false);
         let (report_cancel_tx, report_cancel_rx) = oneshot::channel();
 
         // If report_cancel_tx is None, at least one error has occurred and the
@@ -190,7 +185,6 @@ impl<'a> TestRunner<'a> {
         let res = self.inner.execute(
             &mut self.signal_handler,
             &mut self.input_handler,
-            &cancelled,
             report_cancel_rx,
             |event| {
                 match callback(event) {
@@ -247,7 +241,6 @@ impl<'a> TestRunnerInner<'a> {
         &self,
         signal_handler: &mut SignalHandler,
         input_handler: &mut InputHandler,
-        cancelled_ref: &AtomicBool,
         report_cancel_rx: oneshot::Receiver<()>,
         callback: F,
     ) -> Result<RunStats, Vec<JoinError>>
@@ -295,7 +288,6 @@ impl<'a> TestRunnerInner<'a> {
                 signal_handler,
                 input_handler,
                 report_cancel_rx,
-                cancelled_ref,
                 cancellation_sender.clone(),
             );
             scope.spawn_cancellable(dispatcher_fut, || RunnerTaskState::Cancelled);
@@ -305,9 +297,7 @@ impl<'a> TestRunnerInner<'a> {
             let run_scripts_fut = async move {
                 // Since script tasks are run serially, we just reuse the one
                 // script task.
-                let script_data = executor_cx_ref
-                    .run_setup_scripts(script_resp_tx, cancelled_ref)
-                    .await;
+                let script_data = executor_cx_ref.run_setup_scripts(script_resp_tx).await;
                 if script_tx.send(script_data).is_err() {
                     // The dispatcher has shut down, so we should too.
                     debug!("script_tx.send failed, shutting down");
@@ -369,7 +359,6 @@ impl<'a> TestRunnerInner<'a> {
                                     test_instance,
                                     settings,
                                     resp_tx.clone(),
-                                    cancelled_ref,
                                     cancel_rx,
                                     setup_script_data,
                                 ))