Change interrupt from rising to falling edge inside interrupt service routine

Projects General Guidance
1

In my code I change interrupt from rising to falling edge inside interrupt service routine.
It seems to be working, but is it safe the way I do it?

This is the ISR I use :

/* Interrupt routines  */

void Isr_SensorRising()
{
    detachInterrupt(0);
    attachInterrupt(0, Isr_SensorFalling, FALLING);
    start = mmTaktCount;    
    frontDetected = true;
}

void Isr_SensorFalling()
{
    detachInterrupt(0);
    attachInterrupt(0, Isr_SensorRising, RISING);
    length = mmTaktCount - start    
    endDetected = true;
}

void Isr_mmTaktPulse()
{
    mmTaktCount ++;
}
2

You don't need detach/attach. All you need to do is change the value in the external interrupt control register EICRA, which has four bits controlling whether interrupt 0/1 is triggered on low, change, rising or falling. You can do that within the ISR.

e.g.

EICRA = 1; //any logical change on INT0 triggers interrupt.

See the ATmega328 data sheet, section 12.2.1

3

Why not use CHANGE? In the ISR, you can determine the current state of the interrupt pin, to know whether it was a RISING edge (now HIGH) or a FALLING edge (now LOW) that triggered the interrupt service routine.