Towards scalable and transparent parallelization of multiplayer games using transactional memory support

Abstract

This work addresses the problem of parallelizing multiplayer games using software Transactional Memory (STM) support. Using a realistic high impact application, we show that STM provides not only ease of programming, but also better performance than that achievable with state-of-the-art lock-based programming. Towards this goal, we use SynQuake, a game benchmark which extracts the main data structures and the essential features of the popular multiplayer game Quake, but can be driven with a synthetic workload generator that flexibly emulates client game actions and various hot-spot scenarios in the game world. We implement, evaluate and compare the STM version of SynQuake with a state-of-the-art lock-based parallelization of Quake, which we ported to SynQuake. While in STM-SynQuake support for maintaining the consistency of each potentially complex game action is automatic, conservative locking of surrounding objects within a bounding box for the duration of the game action is inherently needed in lock-based SynQuake. This leads to a higher scalability factor of STM-SynQuake versus lock-based SynQuake, due to a higher degree of false sharing in the latter.