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| author | Damien Neil <dneil@google.com> | 2025-08-26 13:26:57 -0700 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2025-09-11 10:49:57 -0700 |
| commit | 879e3cb5f787ed56bee2f5f4d92fd013a9b47b21 (patch) | |
| tree | cac3960b5e77ea77c5c14b691f42b7f20795a448 | |
| parent | 56ebf80e57db9f61981fc0636fc6419dc6f68eda (diff) | |
| download | go-879e3cb5f787ed56bee2f5f4d92fd013a9b47b21.tar.xz | |
[release-branch.go1.25] runtime: lock mheap_.speciallock when allocating synctest specials
Avoid racing use of mheap_.specialBubbleAlloc.
For #75134
Fixes #75347
Change-Id: I0c9140c18d2bca1e1c3387cd81230f0e8c9ac23e
Reviewed-on: https://go-review.googlesource.com/c/go/+/699255
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
(cherry picked from commit 5dcedd65504cc9cadc9a5ea8bc3af51a26eec704)
Reviewed-on: https://go-review.googlesource.com/c/go/+/701797
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Mark Freeman <markfreeman@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
| -rw-r--r-- | src/internal/synctest/synctest_test.go | 22 | ||||
| -rw-r--r-- | src/runtime/synctest.go | 2 |
2 files changed, 24 insertions, 0 deletions
diff --git a/src/internal/synctest/synctest_test.go b/src/internal/synctest/synctest_test.go index 307eee62e2..73a0a1c453 100644 --- a/src/internal/synctest/synctest_test.go +++ b/src/internal/synctest/synctest_test.go @@ -779,6 +779,28 @@ func TestWaitGroupHeapAllocated(t *testing.T) { }) } +// Issue #75134: Many racing bubble associations. +func TestWaitGroupManyBubbles(t *testing.T) { + var wg sync.WaitGroup + for range 100 { + wg.Go(func() { + synctest.Run(func() { + cancelc := make(chan struct{}) + var wg2 sync.WaitGroup + for range 100 { + wg2.Go(func() { + <-cancelc + }) + } + synctest.Wait() + close(cancelc) + wg2.Wait() + }) + }) + } + wg.Wait() +} + func TestHappensBefore(t *testing.T) { // Use two parallel goroutines accessing different vars to ensure that // we correctly account for multiple goroutines in the bubble. diff --git a/src/runtime/synctest.go b/src/runtime/synctest.go index 16af1209b4..529f69fd93 100644 --- a/src/runtime/synctest.go +++ b/src/runtime/synctest.go @@ -410,7 +410,9 @@ func getOrSetBubbleSpecial(p unsafe.Pointer, bubbleid uint64, add bool) (assoc i } else if add { // p is not associated with a bubble, // and we've been asked to add an association. + lock(&mheap_.speciallock) s := (*specialBubble)(mheap_.specialBubbleAlloc.alloc()) + unlock(&mheap_.speciallock) s.bubbleid = bubbleid s.special.kind = _KindSpecialBubble s.special.offset = offset |