The status field holds run control status bits packed into a
single int to ensure atomicity. Status is initially zero, and
takes on nonnegative values until completed, upon which it
holds (sign bit) DONE, possibly with ABNORMAL (cancelled or
exceptional) and THROWN (in which case an exception has been
stored). Tasks with dependent blocked waiting joiners have the
SIGNAL bit set. Completion of a task with SIGNAL set awakens
any waiters via notifyAll. (Waiters also help signal others
upon completion.)
These control bits occupy only (some of) the upper half (16
bits) of status field. The lower bits are used for user-defined
tags.
The status field holds run control status bits packed into a single int to ensure atomicity. Status is initially zero, and takes on nonnegative values until completed, upon which it holds (sign bit) DONE, possibly with ABNORMAL (cancelled or exceptional) and THROWN (in which case an exception has been stored). Tasks with dependent blocked waiting joiners have the SIGNAL bit set. Completion of a task with SIGNAL set awakens any waiters via notifyAll. (Waiters also help signal others upon completion.)
These control bits occupy only (some of) the upper half (16 bits) of status field. The lower bits are used for user-defined tags.