1. A computer readable storage medium encoding program code executable on one or more processors to implement: instantiating a data structure implementation in a memory comprising a double-ended array; executing a plurality of opposing-end access operations that, when executed on the one or more processors, access the memory, and provide concurrent push-type and pop-type access to at least one of the opposing ends and concurrent, opposing-end accesses that are non-interfering for at least some states of the array; and mediating concurrent execution of the access operations using a single-target synchronization primitive; wherein the data structure implementation is linearizable and non-blocking, and wherein the single-target of the single-target synchronization primitive includes a value encoding for an element of the array and a version number encoded integrally therewith.