How to detect when no RAM left for a malloc? It seems to just keep going (Teensy 3.1)

[pjakobs]

Pull request for fix:
https://github.com/PaulStoffregen/cores/pull/219

The linker scripts have a marker for the beginning of the stack: "_estack".

I did see _estack, but I only found it in a static context, not the actual value at run time, the cpu holds that in r13.

true on the ENOMEM

pj

 

[tni]

estack is static, the very top of the RAM. IMO, basing the amount of reserved stack on the current stack size (stack pointer) doesn't make sense.

 

[pjakobs]

thinking about it, you're probably correct that a static stack frame is good enough, expecially if it is, as in your patch, configurable.
I was wondering if there's a way to include "-fstack-usage" in the Arduino build process to actually be able to make an informed decision on stack frame size.
Over the last two weeks, I was working with the Teensy audio library a bit and I have run into quite a few crashes that probably were just memory overrunning the stack...

Thanks

pj

 

[tni]

I was wondering if there's a way to include "-fstack-usage" in the Arduino build process to actually be able to make an informed decision on stack frame size.

You can set STACK_MARGIN.

E.g. change "arduino/hardware/teensy/avr/boards.txt" and add "-DSTACK_MARGIN=..." to the build flags for your Teensy.