Long timer expires immediately

[jlangballeswift]

Hi,

I'm having an issue with timers. They work fine for shorter timeout values (<8hours) but after trying with a timeout value of 24 hours, my timers expired immediately. After a bit more digging, I found that how I declare my timer variables seems to matter. This smells like some sort of memory issue but the application code I've written so far looks fine to me.

The following code works as expected

void expiry_fn( struct k_timer* timer )
{
  printk("Timer expired!\n");
}
void main(void) {
  s32_t period = K_HOURS( 24 );
  struct k_timer timer1;
  k_timer_init( &timer1, expiry_fn, NULL );
  k_timer_start( &timer1, period, period );
  struct k_timer timer2;
  k_timer_init( &timer2, expiry_fn, NULL );
  k_timer_start( &timer2, period, period );
}

But this next snippet (declaring the timers all at once) causes both timers to expire immediately

void main(void) {
  s32_t period = K_HOURS( 24 );
  struct k_timer timer1;
  struct k_timer timer2;  // declaring both here causes both timers to expire immediately
  k_timer_init( &timer1, expiry_fn, NULL );
  k_timer_start( &timer1, period, period );
  k_timer_init( &timer2, expiry_fn, NULL );
  k_timer_start( &timer2, period, period );
}

Also noteworthy is if I use a shorter period, the timers work as expected

void main(void) {
  s32_t period = K_HOURS( 12 );
  struct k_timer timer1;
  struct k_timer timer2;  // works fine
  k_timer_init( &timer1, expiry_fn, NULL );
  k_timer_start( &timer1, period, period );
  k_timer_init( &timer2, expiry_fn, NULL );
  k_timer_start( &timer2, period, period );
}

I also tried the following snippet to see if variable scoping was the cause but this also has the issue of both timers expiring immediately.

static struct k_timer timer1;
static struct k_timer timer2;
void main(void) {
  s32_t period = K_HOURS( 24 );
  k_timer_init( &timer1, expiry_fn, NULL );
  k_timer_start( &timer1, period, period );
  k_timer_init( &timer2, expiry_fn, NULL );
  k_timer_start( &timer2, period, period );
  while (1) {
    k_sleep( 1000 );
  }
}

I'm using a nRF9160-based board and the nRF SDK v1.1.

Any ideas on what might be going on?

Thanks,

Jeff

[Heidi-Irene Harvey Sollie]

Hi!

I'm sorry but as of now, DevZone does not provide support for Zephyr with nRF52840, only nRF9160.

Nordic Semiconductor is part of the Zephyr Project and contributes with misc. components/software, but we do not give support for Zephyr running on nRF52840.  

Thanks for your understanding. 

Best regards,

Heidi

[jlangballeswift]

Hi Heidi,

I am using the nRF9160 though...

[Heidi-Irene Harvey Sollie]

Hi! So sorry about that, I misread your post. 

I will get back to you with an answer tomorrow.

[Heidi-Irene Harvey Sollie]

Hi again! Can I ask why you don't want to do it the way you presented in your first example - which you said worked as expected?

[jlangballeswift]

What I'm actually trying to accomplish is having multiple software timers to monitor the health of my different threads. I declare them as an array at compile-time and initialize them later at runtime.

static struct k_timer timers[NUM_MODULES];

...

for (int i = 0; i < NUM_MODULES; ++i)
{
    // Do init for each timer
}

The example I posted is just a stripped down version of this basically

[Heidi-Irene Harvey Sollie]

Okay, thank you for the information.

I will ask around but since it's the holidays here in Norway we are very low on staff. Worst case you will hear back during the beginning of week 2. 

Best regards,

Heidi

[Heidi-Irene Harvey Sollie]

Hi again, you could try to do something like what was done here, instead of delaying x ms you delay max_timeout_length, and then keep doing this until the sum of delays has become x.

Best regards,

Heidi