From 5912f4fc376013897998747bd81602dce962072b Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 12 Feb 2020 20:17:16 -0800 Subject: [PATCH] runtime: really wait for goroutines in testSemaHandoff The code has a comment saying that it waited for the goroutines, but it didn't actually do so. Change-Id: Icaeb40613711053a9f443cc34143835560427dda Reviewed-on: https://go-review.googlesource.com/c/go/+/219277 Run-TryBot: Ian Lance Taylor TryBot-Result: Gobot Gobot Reviewed-by: Brad Fitzpatrick --- src/runtime/sema_test.go | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/runtime/sema_test.go b/src/runtime/sema_test.go index 8bd5d4ce57..cf3de0a190 100644 --- a/src/runtime/sema_test.go +++ b/src/runtime/sema_test.go @@ -6,6 +6,7 @@ package runtime_test import ( . "runtime" + "sync" "sync/atomic" "testing" ) @@ -61,8 +62,11 @@ func testSemaHandoff() bool { // to another goroutine. Stop the current goroutine from migrating to // another CPU where it can win the race (and appear to have not yielded) by // keeping the CPUs slightly busy. + var wg sync.WaitGroup for i := 0; i < GOMAXPROCS(-1); i++ { + wg.Add(1) go func() { + defer wg.Done() for { select { case <-done: @@ -74,7 +78,9 @@ func testSemaHandoff() bool { }() } + wg.Add(1) go func() { + defer wg.Done() Semacquire(&sema) atomic.CompareAndSwapUint32(&res, 0, 1) @@ -91,7 +97,7 @@ func testSemaHandoff() bool { Semrelease1(&sema, true, 0) atomic.CompareAndSwapUint32(&res, 0, 2) - <-done // wait for goroutines to finish to avoid data races + wg.Wait() // wait for goroutines to finish to avoid data races return res == 1 // did the waiter run first? } -- 2.50.0