The following code typically loops one more time than times e.g. with 0, it loops once, with 1, it loops twice.

#define PTIME 30
void pulse(int pin, int times) {
 do {
 digitalWrite(pin, HIGH);
 delay(PTIME);
 digitalWrite(pin, LOW);
 delay(PTIME);
 } while (times--);
}

ADDITIONAL SUGGESTION#1: Decide whether it should loop 0 times or once, when times is set to 0; looping almost forever is probably not desired.
ADDITIONAL SUGGESTION#2: Add optional additional parameter int duration that defaults to PTIME or 30.