Escrow-locking multithreaded process-pair resource manager dictionary

Abstract

A dictionary in a distributed transaction processing system. The dictionary is implemented as an escrow-locking multithreaded process-pair resource manager (PPRM) dictionary which is produced as an escrow-locking object implemented in the context of a PPRM and inheriting its functionality. A process pair in the PPRM is responsive to multiple concurrent transactions and including a concurrent aspect, a serial aspect and an escrow-locking dictionary. The concurrent aspect is a front-end multithreaded process of the process pair for concurrently servicing the multiple concurrent transactions. The serial aspect is a single-threaded process of the process pair for serializing the multiple concurrent transaction. Each of the concurrent aspect and the serial aspect includes an instance of the escrow-locking dictionary. That is, each of the concurrent aspect and the serial aspect has it own copy of the escrow-locking dictionary and, combined, the two copies maintains an appearance of a single virtual dictionary. The escrow-locking dictionary has a dictionary resource and uses escrow-locking for allowing the multiple concurrent transactions to share the dictionary resource. As a result, the dictionary performs operations on behalf of the multiple concurrent transactions without compromising their atomic, consistent, isolated and durable (ACID) properties. Additionally, a method and a computer program product, including a computer useable medium having computer readable code embodied therein, are for providing access to the dictionary in the data processing system.