NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | NOTES | SEE ALSO | NOTES | COLOPHON

SD_EVENT_RUN(3)                 sd_event_run                 SD_EVENT_RUN(3)

NAME         top

       sd_event_run, sd_event_loop - Run an event loop

SYNOPSIS         top

       #include <systemd/sd-event.h>

       int sd_event_run(sd_event *event, uint64_t usec);

       int sd_event_loop(sd_event *event);

DESCRIPTION         top

       sd_event_run() may be used to run a single iteration of the event
       loop specified in the event parameter. The function waits until an
       event to process is available, and dispatches the registered handler
       for it. The usec parameter specifies the maximum time (in
       microseconds) to wait for an event. Use (uint64_t) -1 to specify an
       infinite timeout.

       sd_event_loop() invokes sd_event_run() in a loop, thus implementing
       the actual event loop. The call returns as soon as exiting was
       requested using sd_event_exit(3).

       The event loop object event is created with sd_event_new(3). Events
       sources to wait for and their handlers may be registered with
       sd_event_add_io(3), sd_event_add_time(3), sd_event_add_signal(3),
       sd_event_add_child(3), sd_event_add_defer(3), sd_event_add_post(3)
       and sd_event_add_exit(3).

       For low-level control of event loop execution, use
       sd_event_prepare(3), sd_event_wait(3) and sd_event_dispatch(3) which
       are wrapped by sd_event_run(). Along with sd_event_get_fd(3), these
       functions allow integration of an sd-event(3) event loop into foreign
       event loop implementations.

RETURN VALUE         top

       On failure, these functions return a negative errno-style error code.
       sd_event_run() returns a positive, non-zero integer if an event
       source was dispatched, and zero when the specified timeout hit before
       an event source has seen any event, and hence no event source was
       dispatched.  sd_event_loop() returns the exit code specified when
       invoking sd_event_exit().

ERRORS         top

       Returned errors may indicate the following problems:

       -EINVAL
           The event parameter is invalid or NULL.

       -EBUSY
           The event loop object is not in the right state (see
           sd_event_prepare(3) for an explanation of possible states).

       -ESTALE
           The event loop is already terminated.

       -ECHILD
           The event loop has been created in a different process.

       Other errors are possible, too.

NOTES         top

       These APIs are implemented as a shared library, which can be compiled
       and linked to with the libsystemd pkg-config(1) file.

SEE ALSO         top

       systemd(1), sd_event_new(3), sd_event_add_io(3),
       sd_event_add_time(3), sd_event_add_signal(3), sd_event_add_defer(3),
       sd_event_add_exit(3), sd_event_add_post(3), sd_event_exit(3),
       sd_event_get_fd(3), sd_event_wait(3), GLib Main Event Loop[1].

NOTES         top

        1. GLib Main Event Loop
           https://developer.gnome.org/glib/unstable/glib-The-Main-Event-Loop.html

COLOPHON         top

       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 2017-05-03.  If you dis‐
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       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 man-pages@man7.org

systemd 233                                                  SD_EVENT_RUN(3)

Pages that refer to this page: sd-event(3)sd_event_exit(3)sd_event_new(3)sd_event_wait(3)systemd.directives(7)systemd.index(7)