SD_EVENT_SOURCE_SET_ENABLEsd_event_source_set_enSD_EVENT_SOURCE_SET_ENABLED(3)

NAME
       sd_event_source_set_enabled, sd_event_source_get_enabled, SD_EVENT_ON,
       SD_EVENT_OFF, SD_EVENT_ONESHOT - Enable or disable event sources

SYNOPSIS
       #include <systemd/sd-event.h>

       enum {
               SD_EVENT_OFF = 0,
               SD_EVENT_ON = 1,
               SD_EVENT_ONESHOT = -1,
       };

       int sd_event_source_set_enabled(sd_event_source *source, int enabled);

       int sd_event_source_get_enabled(sd_event_source *source, int *enabled);

DESCRIPTION
       sd_event_source_set_enabled() may be used to enable or disable the
       event source object specified as source. The enabled parameter takes
       one of SD_EVENT_ON (to enable), SD_EVENT_OFF (to disable) or
       SD_EVENT_ONESHOT. If invoked with SD_EVENT_ONESHOT the event source
       will be enabled but automatically reset to SD_EVENT_OFF after one
       dispatch. For SD_EVENT_OFF, the event source source may be NULL, in
       which case the function does nothing. Otherwise, source must be a valid
       pointer to an sd_event_source object.

       Event sources that are disabled will not result in event loop wakeups
       and will not be dispatched, until they are enabled again.

       sd_event_source_get_enabled() may be used to query whether the event
       source object source is currently enabled or not. If both the source
       and the output parameter enabled are NULL, this function returns false.
       Otherwise, source must be a valid pointer to an sd_event_source object.
       If the output parameter enabled is not NULL, it is set to the
       enablement state (one of SD_EVENT_ON, SD_EVENT_OFF, SD_EVENT_ONESHOT).
       The function also returns true if the event source is not disabled.

       Event source objects are enabled when they are first created with calls
       such as sd_event_add_io(3), sd_event_add_time(3). However, depending on
       the event source type they are enabled continuously (SD_EVENT_ON) or
       only for a single invocation of the event source handler
       (SD_EVENT_ONESHOT). For details see the respective manual pages.

       As event source objects stay active and may be dispatched as long as
       there is at least one reference to them, in many cases it is a good
       idea to combine a call to sd_event_source_unref(3) with a prior call to
       sd_event_source_set_enabled() with SD_EVENT_OFF, to ensure the event
       source is not dispatched again until all other remaining references are
       dropped.

RETURN VALUE
       On success, sd_event_source_set_enabled() returns a non-negative
       integer.  sd_event_source_get_enabled() returns zero if the source is
       disabled (SD_EVENT_OFF) and a positive integer otherwise. On failure,
       they return a negative errno-style error code.

   Errors
       Returned errors may indicate the following problems:

       -EINVAL
           source is not a valid pointer to an sd_event_source object.

       -ENOMEM
           Not enough memory.

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

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

SEE ALSO
       sd-event(3), sd_event_add_io(3), sd_event_add_time(3),
       sd_event_add_signal(3), sd_event_add_child(3), sd_event_add_inotify(3),
       sd_event_add_defer(3), sd_event_source_unref(3),
       sd_event_source_set_ratelimit(3)

systemd 252                                     SD_EVENT_SOURCE_SET_ENABLED(3)

Czas wygenerowania: 0.00029 sek.

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