al_create_timer man page
al_create_timer — Allegro 5 API
#include <allegro5/allegro.h> ALLEGRO_TIMER *al_create_timer(double speed_secs)
Allocates and initializes a timer. If successful, a pointer to a new timer object is returned, otherwise NULL is returned. speed_secs is in seconds per "tick", and must be positive. The new timer is initially stopped.
Usage note: typical granularity is on the order of microseconds, but with some drivers might only be milliseconds.
al_destroy_timer(3), al_get_timer_speed(3), al_set_timer_speed(3).