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Diffstat (limited to 'upstream/opensuse-tumbleweed/man3/sd_event_wait.3')
| -rw-r--r-- | upstream/opensuse-tumbleweed/man3/sd_event_wait.3 | 284 |
1 files changed, 0 insertions, 284 deletions
diff --git a/upstream/opensuse-tumbleweed/man3/sd_event_wait.3 b/upstream/opensuse-tumbleweed/man3/sd_event_wait.3 deleted file mode 100644 index fe376311..00000000 --- a/upstream/opensuse-tumbleweed/man3/sd_event_wait.3 +++ /dev/null @@ -1,284 +0,0 @@ -'\" t -.TH "SD_EVENT_WAIT" "3" "" "systemd 254" "sd_event_wait" -.\" ----------------------------------------------------------------- -.\" * 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_wait, sd_event_prepare, sd_event_dispatch, sd_event_get_state, sd_event_get_iteration, SD_EVENT_INITIAL, SD_EVENT_PREPARING, SD_EVENT_ARMED, SD_EVENT_PENDING, SD_EVENT_RUNNING, SD_EVENT_EXITING, SD_EVENT_FINISHED \- Low\-level event loop operations -.SH "SYNOPSIS" -.sp -.ft B -.nf -#include <systemd/sd\-event\&.h> -.fi -.ft -.sp -.ft B -.nf -enum { - \fBSD_EVENT_INITIAL\fR, - \fBSD_EVENT_PREPARING\fR, - \fBSD_EVENT_ARMED\fR, - \fBSD_EVENT_PENDING\fR, - \fBSD_EVENT_RUNNING\fR, - \fBSD_EVENT_EXITING\fR, - \fBSD_EVENT_FINISHED\fR, -}; -.fi -.ft -.HP \w'int\ sd_event_prepare('u -.BI "int sd_event_prepare(sd_event\ *" "event" ");" -.HP \w'int\ sd_event_wait('u -.BI "int sd_event_wait(sd_event\ *" "event" ", uint64_t\ " "usec" ");" -.HP \w'int\ sd_event_dispatch('u -.BI "int sd_event_dispatch(sd_event\ *" "event" ");" -.HP \w'int\ sd_event_get_state('u -.BI "int sd_event_get_state(sd_event\ *" "event" ");" -.HP \w'int\ sd_event_get_iteration('u -.BI "int sd_event_get_iteration(sd_event\ *" "event" ", uint64_t\ *" "ret" ");" -.SH "DESCRIPTION" -.PP -The low\-level -\fBsd_event_prepare()\fR, -\fBsd_event_wait()\fR -and -\fBsd_event_dispatch()\fR -functions may be used to execute specific phases of an event loop\&. See -\fBsd_event_run\fR(3) -and -\fBsd_event_loop\fR(3) -for higher\-level functions that execute individual but complete iterations of an event loop or run it continuously\&. -.PP -\fBsd_event_prepare()\fR -checks for pending events and arms necessary timers\&. If any events are ready to be processed ("pending"), it returns a positive, non\-zero value, and the caller should process these events with -\fBsd_event_dispatch()\fR\&. -.PP -\fBsd_event_dispatch()\fR -dispatches the highest priority event source that has a pending event\&. On success, -\fBsd_event_dispatch()\fR -returns either zero, which indicates that no further event sources may be dispatched and exiting of the event loop was requested via -\fBsd_event_exit\fR(3); or a positive non\-zero value, which means that an event source was dispatched and the loop returned to its initial state, and the caller should initiate the next event loop iteration by invoking -\fBsd_event_prepare()\fR -again\&. -.PP -In case -\fBsd_event_prepare()\fR -returned zero, -\fBsd_event_wait()\fR -should be called to wait for further events or a timeout\&. If any events are ready to be processed, it returns a positive, non\-zero value, and the events should be dispatched with -\fBsd_event_dispatch()\fR\&. Otherwise, the event loop returned to its initial state and the next event loop iteration should be initiated by invoking -\fBsd_event_prepare()\fR -again\&. -.PP -\fBsd_event_get_state()\fR -may be used to determine the state the event loop is currently in\&. It returns one of the states described below\&. -.PP -\fBsd_event_get_iteration()\fR -may be used to determine the current iteration of the event loop\&. It returns an unsigned 64\-bit integer containing a counter that increases monotonically with each iteration of the event loop, starting with 0\&. The counter is increased at the time of the -\fBsd_event_prepare()\fR -invocation\&. -.PP -All five functions take, as the first argument, the event loop object -\fIevent\fR -that has been created with -\fBsd_event_new()\fR\&. The timeout for -\fBsd_event_wait()\fR -is specified in -\fIusec\fR -in microseconds\&. -\fB(uint64_t) \-1\fR -may be used to specify an infinite timeout\&. -.SH "STATE MACHINE" -.PP -The event loop knows the following states, that may be queried with -\fBsd_event_get_state()\fR\&. -.PP -\fBSD_EVENT_INITIAL\fR -.RS 4 -The initial state the event loop is in, before each event loop iteration\&. Use -\fBsd_event_prepare()\fR -to transition the event loop into the -\fBSD_EVENT_ARMED\fR -or -\fBSD_EVENT_PENDING\fR -states\&. -.RE -.PP -\fBSD_EVENT_PREPARING\fR -.RS 4 -An event source is currently being prepared, i\&.e\&. the preparation handler is currently being executed, as set with -\fBsd_event_source_set_prepare\fR(3)\&. This state is only seen in the event source preparation handler that is invoked from the -\fBsd_event_prepare()\fR -call and is immediately followed by -\fBSD_EVENT_ARMED\fR -or -\fBSD_EVENT_PENDING\fR\&. -.RE -.PP -\fBSD_EVENT_ARMED\fR -.RS 4 -\fBsd_event_prepare()\fR -has been called and no event sources were ready to be dispatched\&. Use -\fBsd_event_wait()\fR -to wait for new events, and transition into -\fBSD_EVENT_PENDING\fR -or back into -\fBSD_EVENT_INITIAL\fR\&. -.RE -.PP -\fBSD_EVENT_PENDING\fR -.RS 4 -\fBsd_event_prepare()\fR -or -\fBsd_event_wait()\fR -have been called and there were event sources with events pending\&. Use -\fBsd_event_dispatch()\fR -to dispatch the highest priority event source and transition back to -\fBSD_EVENT_INITIAL\fR, or -\fBSD_EVENT_FINISHED\fR\&. -.RE -.PP -\fBSD_EVENT_RUNNING\fR -.RS 4 -A regular event source is currently being dispatched\&. This state is only seen in the event source handler that is invoked from the -\fBsd_event_dispatch()\fR -call, and is immediately followed by -\fBSD_EVENT_INITIAL\fR -or -\fBSD_EVENT_FINISHED\fR -as soon the event source handler returns\&. Note that during dispatching of exit event sources the -\fBSD_EVENT_EXITING\fR -state is seen instead\&. -.RE -.PP -\fBSD_EVENT_EXITING\fR -.RS 4 -Similar to -\fBSD_EVENT_RUNNING\fR -but is the state in effect while dispatching exit event sources\&. It is followed by -\fBSD_EVENT_INITIAL\fR -or -\fBSD_EVENT_FINISHED\fR -as soon as the event handler returns\&. -.RE -.PP -\fBSD_EVENT_FINISHED\fR -.RS 4 -The event loop has exited\&. All exit event sources have run\&. If the event loop is in this state it serves no purpose anymore, and should be freed\&. -.RE -.PP -A simplified flow chart of the states and the calls to transition between them is shown below\&. Note that -\fBSD_EVENT_PREPARING\fR, -\fBSD_EVENT_RUNNING\fR -and -\fBSD_EVENT_EXITING\fR -are not shown here\&. -.sp -.if n \{\ -.RS 4 -.\} -.nf - INITIAL \-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-\e - | | - | ^ - | | - v ret == 0 | - sd_event_prepare() >\-\-\->\-\-\->\-\-\->\-\-\->\- ARMED | - | | ^ - | ret > 0 | | - | | | - v v ret == 0 | - PENDING <\-\-\-<\-\-\-<\-\-\-<\-\-\-<\-\-\-< sd_event_wait() >\-\-\->\-\-\->\-\-+ - | ret > 0 ^ - | | - | | - v | - sd_event_dispatch() >\-\-\->\-\-\->\-\-\->\-\-\->\-\-\->\-\-\->\-\-\->\-\-\->\-\-\->\-\-\->/ - | ret > 0 - | ret == 0 - | - v - FINISHED - -.fi -.if n \{\ -.RE -.\} -.SH "RETURN VALUE" -.PP -On success, these functions return 0 or a positive integer\&. On failure, they return a negative errno\-style error code\&. In case of -\fBsd_event_prepare()\fR -and -\fBsd_event_wait()\fR, a positive, non\-zero return code indicates that events are ready to be processed and zero indicates that no events are ready\&. In case of -\fBsd_event_dispatch()\fR, a positive, non\-zero return code indicates that the event loop returned to its initial state and zero indicates the event loop has exited\&. -\fBsd_event_get_state()\fR -returns a positive or zero state on success\&. -.SS "Errors" -.PP -Returned errors may indicate the following problems: -.PP -\fB\-EINVAL\fR -.RS 4 -The -\fIevent\fR -parameter is invalid or -\fBNULL\fR\&. -.RE -.PP -\fB\-EBUSY\fR -.RS 4 -The event loop object is not in the right state\&. -.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, library or module instance\&. -.RE -.PP -Other errors are possible, too\&. -.SH "NOTES" -.PP -Functions described here are available as a shared library, which can be compiled against and linked to with the -\fBlibsystemd\fR\ \&\fBpkg-config\fR(1) -file\&. -.PP -The code described here uses -\fBgetenv\fR(3), which is declared to be not multi\-thread\-safe\&. This means that the code calling the functions described here must not call -\fBsetenv\fR(3) -from a parallel thread\&. It is recommended to only do calls to -\fBsetenv()\fR -from an early phase of the program when no other threads have been started\&. -.SH "SEE ALSO" -.PP -\fBsystemd\fR(1), -\fBsd_event_new\fR(3), -\fBsd_event_add_io\fR(3), -\fBsd_event_add_time\fR(3), -\fBsd_event_add_signal\fR(3), -\fBsd_event_add_child\fR(3), -\fBsd_event_add_inotify\fR(3), -\fBsd_event_add_defer\fR(3), -\fBsd_event_run\fR(3), -\fBsd_event_get_fd\fR(3), -\fBsd_event_source_set_prepare\fR(3) |