timerfdsettime

timerfdsettime is a function in Linux that sets or resets the time until the next expiration of a timer that is associated with a timerfd file descriptor. The timerfd file descriptor is created by the timerfd_create function. The timerfdsettime function takes two arguments: the timerfd file descriptor and a pointer to a struct itimerspec. The struct itimerspec contains two members, it_interval and it_value, which specify the interval between timer expirations and the initial expiration time, respectively.

The it_value member specifies the time until the next timer expiration. If it_value is zero, the timer is disabled. If it_value is non-zero, it specifies the time until the next expiration. The it_interval member specifies the interval between timer expirations. If it_interval is zero, the timer will expire only once. If it_interval is non-zero, the timer will be reloaded with this interval after each expiration.

The timerfdsettime function can be used to set or reset the time until the next expiration of a timer. This can be useful for a variety of purposes, such as scheduling events, implementing timeouts, and creating periodic tasks. The function returns 0 on success, or -1 on error. The error code is set in the errno variable.