fix deadlock #57

pool.go

@@ -364,10 +364,7 @@ func (pool *ObjectPool) ensureIdle(ctx context.Context, idleCount int, always bo
 
 // IsClosed return this pool is closed
 func (pool *ObjectPool) IsClosed() bool {
-	pool.closeLock.Lock()
-	defer pool.closeLock.Unlock()
-	// in java commons pool, closed is volatile, golang has not volatile, so use mutex to avoid data race
-	return pool.closed
+	return pool.getClose()
 }
 
 // ReturnObject return an instance to the pool. By contract, object
@@ -483,17 +480,16 @@ func (pool *ObjectPool) Close(ctx context.Context) {
 	if pool.IsClosed() {
 		return
 	}
-	pool.closeLock.Lock()
-	defer pool.closeLock.Unlock()
-	if pool.closed {
+
+	if pool.getClose() {
 		return
 	}
 
 	// Stop the evictor before the pool is closed since evict() calls
 	// assertOpen()
 	pool.startEvictor(-1)
 
-	pool.closed = true
+	pool.setClose(true)
 	// This clear removes any idle objects
 	pool.Clear(ctx)
 
@@ -668,6 +664,19 @@ func (pool *ObjectPool) evict(ctx context.Context) {
 	}
 }
 
+func (pool *ObjectPool) getClose() bool {
+	pool.closeLock.Lock()
+	defer pool.closeLock.Unlock()
+	// in java commons pool, closed is volatile, golang has not volatile, so use mutex to avoid data race
+	return pool.closed
+}
+
+func (pool *ObjectPool) setClose(closed bool) {
+	pool.closeLock.Lock()
+	defer pool.closeLock.Unlock()
+	pool.closed = closed
+}
+
 func (pool *ObjectPool) ensureMinIdle(ctx context.Context) {
 	pool.ensureIdle(ctx, pool.getMinIdle(), true)
 }

pool_test.go

@@ -2059,6 +2059,32 @@ func (suit *PoolTestSuite) TestPreparePool() {
 	suit.Equal(1, suit.pool.GetNumIdle())
 }
 
+func (suit *PoolTestSuite) TestConcurrentCloseAndEvict() {
+	ctx := context.Background()
+	suit.pool.Config.MinIdle = 1
+	suit.pool.Config.SoftMinEvictableIdleTime = time.Millisecond * 100
+	suit.pool.Config.TimeBetweenEvictionRuns = time.Millisecond * 500
+	suit.factory.destroyLatency = time.Millisecond * 1000 // Destroy takes 1000 ms
+	suit.pool.PreparePool(ctx)
+	suit.pool.StartEvictor()
+	suit.Equal(1, suit.pool.GetNumIdle())
+	ticker := time.NewTicker(time.Millisecond * 1000)
+	testTimeoutTicker := time.NewTicker(time.Millisecond * 5000) // if time exceeds test fails
+	defer ticker.Stop()
+	defer testTimeoutTicker.Stop()
+	go func() {
+		select {
+		case <-testTimeoutTicker.C:
+			// Time-out
+			suit.FailNow("Time is exceeds on pool close")
+		}
+	}()
+	select {
+	case <-ticker.C:
+		suit.pool.Close(ctx)
+	}
+}
+
 func (suit *PoolTestSuite) TestValueFactory() {
 	suit.pool.factory = NewPooledObjectFactorySimple(func(context.Context) (interface{}, error) {
 		return "string value", nil