use_file: replace mutex with nanosleep-based loop
#25
| Job | Run time |
|---|---|
| 12s | |
| 20s | |
| 2m 38s | |
| 3m 10s |
nanosleep-based loop
#25
| Job | Run time |
|---|---|
| 12s | |
| 20s | |
| 2m 38s | |
| 3m 10s |