The interval timer APIs allow a process to set up and query a timer that can be programmed to auto-recur at a fixed time interval. The relevant system calls are these:
#include <sys/time.h>int getitimer(int which, struct itimerval *curr_value);int setitimer(int which, const struct itimerval *new_value, struct itimerval *old_value);
Quite obviously, the setitimer(2) is used to set up a new timer; the getitimer(2) can be used to query it, and returns the time remaining.
The first parameter to both is which—it specifies the type of timer to use. Linux allows us to use three types of interval timer:
- ITIMER_REAL: Use this timer type to count down in real-time, which is also called wall clock time. Upon timer expiry, the kernel ...
