=== step 1 ===
/proc/self/fdinfo/91:lock:	1: FLOCK  ADVISORY  WRITE 
lock-1 locked
=== step 2 ===
lock-1 unlocked
=== step 3 ===
/proc/self/fdinfo/91:lock:	1: FLOCK  ADVISORY  READ 
lock-1 locked
rc=0
