avoid possible race condition...
avoid possible race condition...

pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/pfl,pscedu/slash2-stable,pscedu/pfl,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/pfl,pscedu/pfl