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Diffstat (limited to 'libgo/go/sync/waitgroup.go')
| -rw-r--r-- | libgo/go/sync/waitgroup.go | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/libgo/go/sync/waitgroup.go b/libgo/go/sync/waitgroup.go index 9b0ffec58b3..ca38837833e 100644 --- a/libgo/go/sync/waitgroup.go +++ b/libgo/go/sync/waitgroup.go @@ -34,10 +34,16 @@ type WaitGroup struct { // G3: Wait() // G1 still hasn't run, G3 finds sema == 1, unblocked! Bug. // Add adds delta, which may be negative, to the WaitGroup counter. -// If the counter becomes zero, all goroutines blocked on Wait() are released. +// If the counter becomes zero, all goroutines blocked on Wait are released. // If the counter goes negative, Add panics. +// +// Note that calls with positive delta must happen before the call to Wait, +// or else Wait may wait for too small a group. Typically this means the calls +// to Add should execute before the statement creating the goroutine or +// other event to be waited for. See the WaitGroup example. func (wg *WaitGroup) Add(delta int) { if raceenabled { + _ = wg.m.state raceReleaseMerge(unsafe.Pointer(wg)) raceDisable() defer raceEnable() @@ -66,6 +72,7 @@ func (wg *WaitGroup) Done() { // Wait blocks until the WaitGroup counter is zero. func (wg *WaitGroup) Wait() { if raceenabled { + _ = wg.m.state raceDisable() } if atomic.LoadInt32(&wg.counter) == 0 { |