bool core_util_atomic_cas_u8(uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue)
{
uint8_t currentValue = __LDREXB((volatile uint8_t*)ptr);
if (currentValue != *expectedCurrentValue) {
*expectedCurrentValue = currentValue;
__CLREX();
return false;
}
return !__STREXB(desiredValue, (volatile uint8_t*)ptr);
}
bool atomic_cas<uint32_t>(uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
{
uint32_t currentValue = __LDREXW(ptr);
if (currentValue != *expectedCurrentValue) {
*expectedCurrentValue = currentValue;
__CLREX();
return false;
}
return !__STREXW(desiredValue, ptr);
}
bool core_util_atomic_cas_u32(volatile uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
{
do {
uint32_t currentValue = __LDREXW(ptr);
if (currentValue != *expectedCurrentValue) {
*expectedCurrentValue = currentValue;
__CLREX();
return false;
}
} while (__STREXW(desiredValue, ptr));
return true;
}
/**
\fn int32_t Set_Channel_active_flag (uint8_t ch)
\brief Protected set of channel active flag
\param[in] ch Channel number (0..7)
\returns
- \b 0: function succeeded
- \b -1: function failed
*/
static int32_t Set_Channel_active_flag (uint8_t ch) {
uint32_t val;
do {
val = __LDREXW (&Channel_active);
if (val & (1 << ch)) {
__CLREX ();
return -1;
}
} while (__STREXW (val | (1 << ch), &Channel_active));
return 0;
}
int atomic_cas(atomic_int_t *var, int old, int now)
{
int tmp;
int status;
/* Load exclusive */
tmp = __LDREXW((volatile uint32_t *)(&ATOMIC_VALUE(*var)));
if (tmp != old) {
/* Clear memory exclusivity */
__CLREX();
return 0;
}
/* Try to write the new value */
status = __STREXW(now, (volatile uint32_t *)(&ATOMIC_VALUE(*var)));
return (status == 0);
}
/**
* @brief Triggered by systen timer interrupt every millisecond.
* @param None
* @retval None
*/
void timer_interrupt_fn(void)
{
boot_time_ms++;
/* we do it like this to have correct roll-over behaviour */
boot_time_us_base += 1000u;
/* each timer decrements every millisecond if > 0 */
for (unsigned i = 0; i < NTIMERS; i++) {
/* dont need exclusive access for reading the enabled flag because it will not be changed very often */
if (timer[i].flags & TIMER_FLAG_ENABLED) {
if (timer[i].countdown > 0) {
timer[i].countdown--;
} else {
timer[i].countdown = timer[i].period - 1;
/* set the flag: */
timer[i].flags |= TIMER_FLAG_TRIGGERED;
/* force a fail of the flags access instructions: */
__CLREX();
}
}
}
}
