runtime: model wakeableSleep.lock in the race detector

Currently the flight recorder tests are failing in race mode because the
race detector doesn't see s.lock, leading to false positives. This has
also appeared in the trace tests. Model the lock in the race detector.

Fixes #65207.
Fixes #65283.

Change-Id: I1e9a5c9606536f55fdfc46b5f8443e9c7213c23d
Reviewed-on: https://go-review.googlesource.com/c/go/+/560215
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>

diff --git a/src/runtime/trace2.go b/src/runtime/trace2.go
index 3639adaa1571dab8066435f462376b6a5c0ca7c0..d40596f39be985e7c726f57252872852fd2cd02c 100644 (file)
--- a/src/runtime/trace2.go
+++ b/src/runtime/trace2.go
@@ -932,7 +932,13 @@ func newWakeableSleep() *wakeableSleep {
 func (s *wakeableSleep) sleep(ns int64) {
        resetTimer(s.timer, nanotime()+ns)
        lock(&s.lock)
+       if raceenabled {
+               raceacquire(unsafe.Pointer(&s.lock))
+       }
        wakeup := s.wakeup
+       if raceenabled {
+               racerelease(unsafe.Pointer(&s.lock))
+       }
        unlock(&s.lock)
        <-wakeup
        stopTimer(s.timer)
@@ -945,6 +951,9 @@ func (s *wakeableSleep) wake() {
        // Grab the wakeup channel, which may be nil if we're
        // racing with close.
        lock(&s.lock)
+       if raceenabled {
+               raceacquire(unsafe.Pointer(&s.lock))
+       }
        if s.wakeup != nil {
                // Non-blocking send.
                //
@@ -956,6 +965,9 @@ func (s *wakeableSleep) wake() {
                default:
                }
        }
+       if raceenabled {
+               racerelease(unsafe.Pointer(&s.lock))
+       }
        unlock(&s.lock)
 }
 
@@ -969,11 +981,18 @@ func (s *wakeableSleep) wake() {
 func (s *wakeableSleep) close() {
        // Set wakeup to nil so that a late timer ends up being a no-op.
        lock(&s.lock)
+       if raceenabled {
+               raceacquire(unsafe.Pointer(&s.lock))
+       }
        wakeup := s.wakeup
        s.wakeup = nil
 
        // Close the channel.
        close(wakeup)
+
+       if raceenabled {
+               racerelease(unsafe.Pointer(&s.lock))
+       }
        unlock(&s.lock)
        return
 }