mirror of
https://git.proxmox.com/git/systemd
synced 2025-08-03 17:32:17 +00:00
103 lines
3.9 KiB
Groff
103 lines
3.9 KiB
Groff
'\" t
|
|
.TH "SD_EVENT_ADD_DEFER" "3" "" "systemd 219" "sd_event_add_defer"
|
|
.\" -----------------------------------------------------------------
|
|
.\" * Define some portability stuff
|
|
.\" -----------------------------------------------------------------
|
|
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
.\" http://bugs.debian.org/507673
|
|
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
|
|
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
.ie \n(.g .ds Aq \(aq
|
|
.el .ds Aq '
|
|
.\" -----------------------------------------------------------------
|
|
.\" * set default formatting
|
|
.\" -----------------------------------------------------------------
|
|
.\" disable hyphenation
|
|
.nh
|
|
.\" disable justification (adjust text to left margin only)
|
|
.ad l
|
|
.\" -----------------------------------------------------------------
|
|
.\" * MAIN CONTENT STARTS HERE *
|
|
.\" -----------------------------------------------------------------
|
|
.SH "NAME"
|
|
sd_event_add_defer, sd_event_add_post, sd_event_add_exit \- Add static event sources to an event loop
|
|
.SH "SYNOPSIS"
|
|
.sp
|
|
.ft B
|
|
.nf
|
|
#include <systemd/sd\-bus\&.h>
|
|
.fi
|
|
.ft
|
|
.HP \w'int\ sd_event_add_defer('u
|
|
.BI "int sd_event_add_defer(sd_event\ *" "event" ", sd_event_source\ **" "source" ", sd_event_handler_t\ " "handler" ", void\ *" "userdata" ");"
|
|
.HP \w'int\ sd_event_add_post('u
|
|
.BI "int sd_event_add_post(sd_event\ *" "event" ", sd_event_source\ **" "source" ", sd_event_handler_t\ " "handler" ", void\ *" "userdata" ");"
|
|
.HP \w'int\ sd_event_add_exit('u
|
|
.BI "int sd_event_add_exit(sd_event\ *" "event" ", sd_event_source\ **" "source" ", sd_event_handler_t\ " "handler" ", void\ *" "userdata" ");"
|
|
.HP \w'typedef\ int\ (*sd_event_handler_t)('u
|
|
.BI "typedef int (*sd_event_handler_t)(sd_event_source\ *" "s" ", void\ *" "userdata" ");"
|
|
.SH "DESCRIPTION"
|
|
.PP
|
|
Those three functions add new event sources to an event loop object\&. The event loop is specified in
|
|
\fIevent\fR, the event source is returned in the
|
|
\fIsource\fR
|
|
parameter\&. The event sources are enabled statically and will "fire" when the event loop is run and the conditions described below are met\&. The handler function will be passed the
|
|
\fIuserdata\fR
|
|
pointer, which may be chosen freely by the caller\&.
|
|
.PP
|
|
\fBsd_event_add_defer()\fR
|
|
adds a new event source that will "fire" the next time the event loop is run\&. By default, the handler will be called once (\fBSD_EVENT_ONESHOT\fR)\&.
|
|
.PP
|
|
\fBsd_event_add_post()\fR
|
|
adds a new event source that will "fire" if any event handlers are invoked whenever the event loop is run\&. By default, the source is enabled permanently (\fBSD_EVENT_ON\fR)\&.
|
|
.PP
|
|
\fBsd_event_add_exit()\fR
|
|
adds a new event source that will "fire" when the event loop is terminated with
|
|
\fBsd_event_exit()\fR\&.
|
|
.PP
|
|
The
|
|
\fBsd_event_source_set_enabled\fR(3)
|
|
function may be used to enable the event source permanently (\fBSD_EVENT_ON\fR) or to make it fire just once (\fBSD_EVENT_ONESHOT\fR)\&. If the handler function returns a negative error code, it will be disabled after the invocation, even if
|
|
\fBSD_EVENT_ON\fR
|
|
mode is set\&.
|
|
.SH "RETURN VALUE"
|
|
.PP
|
|
On success, this functions return 0 or a positive integer\&. On failure, they return a negative errno\-style error code\&.
|
|
.SH "ERRORS"
|
|
.PP
|
|
Returned errors may indicate the following problems:
|
|
.PP
|
|
\fB\-ENOMEM\fR
|
|
.RS 4
|
|
Not enough memory to allocate an object\&.
|
|
.RE
|
|
.PP
|
|
\fB\-EINVAL\fR
|
|
.RS 4
|
|
An invalid argument has been passed\&.
|
|
.RE
|
|
.PP
|
|
\fB\-ESTALE\fR
|
|
.RS 4
|
|
The event loop is already terminated\&.
|
|
.RE
|
|
.PP
|
|
\fB\-ECHILD\fR
|
|
.RS 4
|
|
The event loop has been created in a different process\&.
|
|
.RE
|
|
.SH "NOTES"
|
|
.PP
|
|
Functions described here are available as a shared library, which can be compiled and linked to with the
|
|
\fBlibsystemd\fR\ \&\fBpkg-config\fR(1)
|
|
file\&.
|
|
.SH "SEE ALSO"
|
|
.PP
|
|
\fBsystemd\fR(1),
|
|
\fBsd-event\fR(3),
|
|
\fBsd_event_new\fR(3),
|
|
\fBsd_event_add_time\fR(3),
|
|
\fBsd_event_add_signal\fR(3),
|
|
\fBsd_event_add_child\fR(3),
|
|
\fBsd_event_source_set_enabled\fR(3)
|