al_add_timer_count - Man Page

#include <allegro5/allegro.h>

void al_add_timer_count(ALLEGRO_TIMER *timer, int64_t diff)

Add diff to the timer’s counter value. This is similar to writing:

al_set_timer_count(timer, al_get_timer_count(timer) + diff);

except that the addition is performed atomically, so no ticks will be lost.

al_set_timer_count(3)

al_set_timer_count(3).