Abstract: A system and method for interprocess communication between concurrently executing, cooperating sequential processes in a digital computer system uses a shared memory queue as a mechanism for message passing and process synchronization. Data to be transferred from a sending process to a receiving process is stored in a queue entry which is visible in the virtual address space of the first process. The queue entry is added to a queue by the sending process directing the processor to execute an enqueue instruction. The receiving process removes the queue entry from the queue by directing the processor to execute a dequeue instruction. The receiving process then has direct access and visibility to the contents of the queue entry without having to copy the data into its virtual address space. Instead of sending data in a queue entry, a sending process may send an event indicator and no data.

Abstract: A portable security wall for isolating an area on the ground includes an enclosure wall comprised of a plurality of sections, a plurality of post members for mounting the wall on the ground, and a plurality of weighted post support members for supporting the post members. The wall can be made of separate rigid sections or, alternatively, a continuous flexible band with a plurality of longitudinally-spaced pockets for receiving the post members. The pockets define the sections of the wall. The wall can also be made of separate flexible sections which may be wound on or unwound from elongated shaft members by applying a rotary force, e.g., through use of a motor. The wall may be made tall to block the public's view of the area and two tall walls may be connected together to form a canopy.