sd_event_now(3) - Linux manual page (original) (raw)
SDEVENTNOW(3) sd_event_now SDEVENTNOW(3)
NAME top
sd_event_now - Retrieve current event loop iteration timestampSYNOPSIS top
**#include <systemd/sd-event.h>**
**int sd_event_now(sd_event ***_event_**, clockid_t** _clock_**, uint64_t ***_ret_**);**DESCRIPTION top
**sd_event_now()** returns the time when the most recent event loop
iteration began. A timestamp is taken right after returning from
the event sleep, and before dispatching any event sources. The
_event_ parameter specifies the event loop object to retrieve the
timestamp from. The _clock_ parameter specifies the clock to
retrieve the timestamp for, and is one of **CLOCK_REALTIME** (or
equivalently **CLOCK_REALTIME_ALARM**), **CLOCK_MONOTONIC**, or
**CLOCK_BOOTTIME** (or equivalently **CLOCK_BOOTTIME_ALARM**), see
[clock_gettime(2)](../man2/clock%5Fgettime.2.html) for more information on the various clocks. The
retrieved timestamp is stored in the _ret_ parameter, in μs since
the clock's epoch. If this function is invoked before the first
event loop iteration, the current time is returned, as reported by
**clock_gettime()**. To distinguish this case from a regular
invocation the return value will be positive, and zero when the
returned timestamp refers to an actual event loop iteration.RETURN VALUE top
If the first event loop iteration has not run yet **sd_event_now()**
writes current time to _ret_ and returns a positive return value.
Otherwise, it will write the requested timestamp to _ret_ and return
0. On failure, the call returns a negative errno-style error code.Errors Returned values may indicate the following problems:
**-EINVAL**
An invalid parameter was passed.
**-EOPNOTSUPP**
Unsupported clock type.
**-ECHILD**
The event loop object was created in a different process,
library or module instance.NOTES top
Functions described here are available as a shared library, which
can be compiled against and linked to with the
**libsystemd pkg-config**(1) file.
The code described here uses [getenv(3)](../man3/getenv.3.html), which is declared to be
not multi-thread-safe. This means that the code calling the
functions described here must not call [setenv(3)](../man3/setenv.3.html) from a parallel
thread. It is recommended to only do calls to **setenv()** from an
early phase of the program when no other threads have been
started.HISTORY top
**sd_event_now()** was added in version 229.SEE ALSO top
[systemd(1)](../man1/systemd.1.html), [sd-event(3)](../man3/sd-event.3.html), [sd_event_new(3)](../man3/sd%5Fevent%5Fnew.3.html), [sd_event_add_time(3)](../man3/sd%5Fevent%5Fadd%5Ftime.3.html),
[clock_gettime(2)](../man2/clock%5Fgettime.2.html)COLOPHON top
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(which is _not_ part of the original manual page), send a mail to
man-pages@man7.orgsystemd 258~devel SDEVENTNOW(3)
Pages that refer to this page:sd-event(3), sd_event_add_child(3), sd_event_add_defer(3), sd_event_add_inotify(3), sd_event_add_io(3), sd_event_add_signal(3), sd_event_add_time(3), systemd.directives(7), systemd.index(7)