optimization for default pool

ants.go

@@ -36,7 +36,26 @@ const (
 )
 
 // Init a instance pool when importing ants
-var defaultAntsPool, _ = NewPool(DefaultAntsPoolSize)
+var (
+	defaultAntsPool *Pool
+	err             error
+)
+
+func init() {
+	defaultAntsPool, err = NewPool(DefaultAntsPoolSize)
+	if err != nil {
+		panic(err)
+	}
+}
+
+// Release Closed the default pool
+func Release() {
+	defaultAntsPool.Release()
+	defaultAntsPool, err = NewPool(DefaultAntsPoolSize)
+	if err != nil {
+		panic(err)
+	}
+}
 
 // Submit submit a task to pool
 func Submit(task f) error {
@@ -58,12 +77,6 @@ func Free() int {
 	return defaultAntsPool.Free()
 }
 
-// Release Closed the default pool
-func Release() {
-	defaultAntsPool.Release()
-
-}
-
 // Errors for the Ants API
 var (
 	ErrInvalidPoolSize   = errors.New("invalid size for pool")