Allow ThreadPool to run jobs in both modes, and improve scheduling
#1365
| Job | Run time |
|---|---|
| 51s | |
| 39s | |
| 2m 52s | |
| 25m 49s | |
| 4m 3s | |
| 1m 17s | |
| 3m 31s | |
| 13m 0s | |
| 15m 54s | |
| 3m 15s | |
| 53m 34s | |
| 15m 30s | |
| 2m 12s | |
| 45s | |
| 15s | |
| 42s | |
| 2m 15s | |
| 47s | |
| 45s | |
| 19s | |
| 1m 41s | |
| 19s | |
| 1m 39s | |
| 50s | |
| 43s | |
| 0s | |
| 2h 33m 27s |