coroutines scheduling

kirbyc wrote on Wednesday, March 07, 2007:


I’ve been looking at either using multitasking or coroutines from the FreeRTOS package.

I developed a test package with a task to blink the LEDs, and also a coroutine to blink the LEDs.

Everything works, but as part of my comparison I wanted to remove everything to do with tasking, and just use the coroutines module and its scheduler.  I was not able to totally remove the "tasks.c" file.

Has anyone managed to use the coroutines file and scheduler separately?

Other than that the package is sweet. 

Kirby W. Cartwright
Sr. Firmware Design Engineer
Invensys Climate Controls
8115 US 42 N
Plain City, OH 43064
PH:  (xxx)xxx-xxxx
FAX:  (xxx)xxx-xxxx

embeddedc wrote on Thursday, March 08, 2007:

Coroutines run in the idle task so you need at least the parts of the task code to create the idle task.  The tick interrupt will still try to save and restore the task context during the interrupt, this might be the only reason why.

I’m not vary familiar with the coroutine functionality, but I think it should be possible to alter the code a bit so the task code is not required.  In particular the preemptive tick should not be used, the cooperative tick is just a normal interrupt and does nothing with the context.

You could just set the idle task stack size to be very large and not create any other tasks.  Then the only disadvantage would be the build would include some code that was not required.  Removing unused symbols would help.