The maximum time (in msecs) to sleep when a thread is idle, yet others are not, so may eventually generate work that the current thread can steal. This value reflects the maximum time that a thread may sleep when it possibly should not, because there are other active threads that might generate work. In practice, designs in which some threads become stalled because others are running yet not generating tasks are not likely to work well in this framework anyway, so the exact value does not matter too much. However, keeping it in the sub-second range does help smooth out startup and shutdown effects.
Referenced by checkActive().