Using Multiple Synchronized Schedulers

Using Multiple Synchronized Schedulers

When the activities of one frame cannot be completed by one CPU, you need to recruit additional CPUs and execute some activities concurrently. However, it is important that each of the CPUs have the same time base, so that each starts and ends frames at the same time.

You can create one master Frame Scheduler, which owns the time base and one CPU, and as many synchronized Frame Schedulers as you need, each managing an additional CPU. The synchronized schedulers take their time base from the master, so that all start minor frames at the same instant.

Each Frame Scheduler has its own queues of processes. A given process can be enqueued to only one CPU. (However, you could create multiple processes based on the same code, and enqueue each to a different CPU.) All synchronized Frame Schedulers use the same number of minor frames per major frame, which is taken from the definition of the master FRS.

A process can have the FRS control relationship to only one Frame Scheduler. In order to create multiple, synchronized Frame Schedulers, you must create a process to be the FRS controller of each one. Typically these will be lightweight processes created with sproc().