| V V
| ============= ============
| SEPARATED/ DROPPING/
- | old->fd>=0 old->fd>=0
+ | flsh->fd>=0 flsh->fd>=0
| [Separated] [Dropping]
| main F idle main none
| old D tail old D tail
| V V
| =============== ===============
| SEPARATED/ DROPPING/
- | old->fd==-1 old->fd==-1
+ | flsh->fd==-1 flsh->fd==-1
| [Finishing] [Dropping]
| main F tail main none
| old D closed old D closed