[SOLVED] Determine if function is called from Timer or interrupt

spiff · Oct 25th 2022, 11:24am

Hello.

I am using EmbOS CortexM GCC V5.02 on an ATSAM4E8C.

I have a function which I would like to take different code paths if called from a thread or from a timer or interrupt handler.

Basically my function is normally called from a task, but because it uses a MUTEX, this will fail with OS Error 161 if called from a timer handler or 160 if called from an ISR.

Is it possible to determine if my function is called from a timer or interrupt handler, so I can take a different code path, avoiding trying to acquire the mutex?

I would like to do something like the following:

C Source Code

if (OS_InTimerHandler() || OS_In_ISR()) {
do_something_special();
} else {
if (0==OS_MUTEX_LockTimed(&my_mutex, 100)) {
error_mutex_timeout();
} else {
do_something_that_requires_mutex();
OS_MUTEX_Unlock(&my_mutex);
}
}

Note: The function also performs a number of other things before and after the mutex, so replacing all calls from within timer and interrupt handlers with a special version is not desirable.

Best regards
Mikkel Holm Olsen

SEGGER - Til · Oct 25th 2022, 11:52am

Hello Mikkel,

with the most recent embOS version you can use OS_TIMER_GetCurrent() and OS_INT_InInterrupt().
With older embOS versions the return value of OS_TIMER_GetCurrent() was valid during the execution of a timer callback function only.

segger.com/doc/UM01001_embOS.html#OS_TIMER_GetCurrent
segger.com/doc/UM01001_embOS.html#OS_INT_InInterrupt

Would it be possible for you to update to the latest embOS Cortex-M GCC V5.18.0.1?
That would be the easiest solution.

Best regards,
Til

spiff · Oct 27th 2022, 10:47am

Thank you Til.

I will look into the option of upgrading.

Best regards
Mikkel Holm Olsen

[SOLVED] Determine if function is called from Timer or interrupt

[SOLVED] Determine if function is called from Timer or interrupt

C Source Code

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