Atomically conditionally sets the tag value for this task.
Among other applications, tags can be used as visit markers
in tasks operating on graphs, as in methods that check: {@code
if (task.compareAndSetForkJoinTaskTag((short)0, (short)1))}
before processing, otherwise exiting because the node has
already been visited.
@param expect the expected tag value
@param update the new tag value
@return {@code true} if successful; i.e., the current value was
equal to {@code expect} and was changed to {@code update}.
Atomically conditionally sets the tag value for this task. Among other applications, tags can be used as visit markers in tasks operating on graphs, as in methods that check: {@code if (task.compareAndSetForkJoinTaskTag((short)0, (short)1))} before processing, otherwise exiting because the node has already been visited.
@param expect the expected tag value @param update the new tag value @return {@code true} if successful; i.e., the current value was equal to {@code expect} and was changed to {@code update}.