A shared counter resource, such as a register, is disclosed in the hardware, where the register representing how much free space there is in the command queue is accessible to one or more processing elements. When a processing element reads the “reservation” register, the hardware automatically decrements the available free space by a preconfigured amount (e.g., 1) and returns the value of the free space immediately prior to the read/reservation. If the read returns 0 (or a number less than the preconfigured amount), there was insufficient free space to satisfy the request. In the event there was insufficient space to satisfy the request the reservation register may be configured to reserve however much space was available or to not reserve any space at all. Any number of processing elements may read these registers and various scenarios are described where the input and output queues are accessible via various processing elements.
