Stop pre-emption

QNX USERS QNX6 - OS
#1

Hi there.

I have a system critical function that i want to protect from being stopped by the qnx system scheduled. I guess one was to do this would be to temperarily raise the priority to 255 and set to FIFO? But I don’t think this would stop interrupts being handled, and also this in not a very nice method in my eyes.

Does anyone know if there is a QNX function call to deal with this sort of thing? for example:

QNX_stop_scheduling();
// Do some critical stuff
QNX_start_scheduling();

Cheers

#2

InterruptEnable(),InterruptDisable(), InterruptLock(), InterruptUnlock() are your friends.

#3

That’s exactly right. Just be aware that all kernel calls turn interrupts back on again, so you have to be careful what code goes between the Disable/Enable pair. For example, printf() will re-enable interrupts.