avoid race condition

core/executors/periodicalexecutor.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"zero/core/proc"
+	"zero/core/syncx"
 	"zero/core/threading"
 	"zero/core/timex"
 )
@@ -30,6 +31,8 @@ type (
 		interval  time.Duration
 		container TaskContainer
 		waitGroup sync.WaitGroup
+		// avoid race condition on waitGroup when calling wg.Add/Done/Wait(...)
+		wgBarrier syncx.Barrier
 		guarded   bool
 		newTicker func(duration time.Duration) timex.Ticker
 		lock      sync.Mutex
@@ -74,7 +77,9 @@ func (pe *PeriodicalExecutor) Sync(fn func()) {
 }
 
 func (pe *PeriodicalExecutor) Wait() {
-	pe.waitGroup.Wait()
+	pe.wgBarrier.Guard(func() {
+		pe.waitGroup.Wait()
+	})
 }
 
 func (pe *PeriodicalExecutor) addAndCheck(task interface{}) (interface{}, bool) {
@@ -131,8 +136,12 @@ func (pe *PeriodicalExecutor) backgroundFlush() {
 }
 
 func (pe *PeriodicalExecutor) executeTasks(tasks interface{}) bool {
-	pe.waitGroup.Add(1)
-	defer pe.waitGroup.Done()
+	pe.wgBarrier.Guard(func() {
+		pe.waitGroup.Add(1)
+	})
+	defer pe.wgBarrier.Guard(func() {
+		pe.waitGroup.Done()
+	})
 
 	ok := pe.hasTasks(tasks)
 	if ok {