chapter  1
5 Real-Time Operating Systems and Real-Time Kernels
Pages 4

The architecture of a real-time system determines how and when threads are processed. Two common architectures are the

control loop with polling

approach and the

preemptive scheduling

model. In the control loop with polling

approach, the kernel executes an infinite loop, which polls the threads in a predetermined pattern. If a thread needs service, then it is processed. There are several variants to this approach, including


to ensure that each thread is guaranteed access to the processor. Figure 1.3 contains an illustration of the control loop with polling approach.