Set clock source for event waiting
# DESCRIPTION
The [io_uring_register_clock] function registers which clock source
should be used by io_uring, when an application waits for event
completions. The *ring* argument should point to the ring in question,
and the *arg* argument should be a pointer to a **struct
io_uring_clock_register .**
The *arg* argument must be filled in with the appropriate information.
It looks as follows:
``` c
struct io_uring_clock_register {
__u32 clockid;
__u32 __resv[3];
};
```
The *clockid* field must contain the clock source, with valid sources
being:
**CLOCK_MONOTONIC**\
a nonsettable system-wide clock that represents monotonic time.
**CLOCK_BOOTTIME**\
A nonsettable system-wide clock that is identical to **CLOCK_MONOTONIC
,** except that is also icnludes any time that the system is suspended.
See [clock_gettime](https://man7.org/linux/man-pages/man2/clock_gettime.2.html) for more details.
The *\_\_resv* fields must be filled with zeroes.
Available since 6.12.
# RETURN VALUE
On success [io_uring_register_clock] returns 0. On failure it
returns **-errno**.
# SEE ALSO
[clock_gettime](https://man7.org/linux/man-pages/man2/clock_gettime.2.html), [io_uring_register],
[io_uring_wait_cqe], [io_uring_wait_cqe_timeout],