1. A computing system, comprising: one or more processors configured for multithreaded operation; a memory comprising program instructions executable by the one or more processors to implement: a lock-free shared queue; and coordination of accesses to the queue that employs only pointer-sized single-target synchronizations; and wherein the program instructions further comprise a functional sequence executable to select, using a first one of the pointer-sized single-target synchronizations, a previously unselected one of two alternative end node identifying pointers, the two alternative pointers identifying different respective nodes as the end node of one end of the shared queue.