Current top of DEQ. Generally acts just like a stack pointer in an array-based stack, except that it circularly wraps around the array, as in an array-based queue. The value is NOT always kept within
0 ... deq.length though. The current top element is always at
top & (deq.length-1). To avoid integer overflow, top is reset down within bounds whenever it is noticed to be out out bounds; at worst when it is at
2 * deq.length.
Definition at line 300 of file FJTaskRunner.java.
Referenced by checkOverflow(), coInvoke(), confirmPop(), confirmTake(), pop(), push(), put(), and take().