High-Performance Embedded Computing

3.3 Memory-Oriented Optimizations 175

the standard identified three major features of Java that limit programmers’ abil-

ity to determine a program’s real-time properties: scheduling, memory manage-

ment, and synchronization.

Java did not provide detailed specifications about scheduling. RTSJ requires

a fixed-priority preemptive scheduler with at least 28 unique priorities. A

Real-

timeThread

class defines threads that can be controlled by this scheduler.

Java uses garbage collection to simplify memory management for the general-

purpose programmer but at the price of reduced predictability of memory sys-

tems. To improve the predictability of memory ...