A CONCURRENT GARBAGE COLLECTOR STRATEGY FOR REAL TIME

to the importance of garbage collection mechanism, especially in real-time systems, a lot

of effort had been done. Meanwhile, concurrent garbage collection based on sporadic or

deferrable server may be considered as the significant topic in this area. In such topics, the

garbage collection task is assumed to be the single aperiodic task in the system. When there

are other different types of traffic, with short deadlines and long deadlines, the single server

provides poor performance. The garbage collection task may have to wait till a less urgent or

a higher deadline request finishes its execution which leads to an increase in the system

memory requirement and perhaps a deadline miss of the garbage collection thread.

This paper concentrates on minimizing the system memory requirement when there are

multiple sources of events by introducing a new concurrent garbage collector. In this new

collector, the system will have multiple servers; rather than one in other garbage collectors.

These servers can either share or not share their capacities, i.e. a server can use the unused

capacity of other servers in case of sharing. The two schemes give preference to higher

priority servers. However, after investigating both strategies, the capacity sharing scheme

gives lower response times for jobs with short deadlines, like GC task, than without capacity

sharing scheme. The simulation results show that multiple servers with capacity sharing based

garbage collection scheduling strategy with all its variations exhibits a better performance in

terms of reducing the system memory requirement and meeting most of deadlines than the

single server and multiple servers without capacity sharing based garbage collectors.