NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON
SD_EVENT_NOW(3) sd_event_now SD_EVENT_NOW(3)
sd_event_now - Retrieve current event loop iteration timestamp
#include <systemd/sd-event.h> int sd_event_now(sd_event *event, clockid_t clock, uint64_t *usec);
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) for more information on the various clocks. The retrieved timestamp is stored in the usec 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.
If the first event loop iteration has not run yet sd_event_now() writes current time to usec and returns a positive return value. Otherwise, it will write the requested timestamp to usec 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.
These APIs are implemented as a shared library, which can be compiled and linked to with the libsystemd pkg-config(1) file.
systemd(1), sd-event(3), sd_event_new(3), sd_event_add_time(3), clock_gettime(2)
This page is part of the systemd (systemd system and service manager) project. Information about the project can be found at ⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug report for this manual page, see ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This page was obtained from the project's upstream Git repository ⟨https://github.com/systemd/systemd.git⟩ on 2022-12-17. (At that time, the date of the most recent commit that was found in the repository was 2022-12-16.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to email@example.com systemd 252 SD_EVENT_NOW(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)