запустить цикл событий (Run an event loop)
Имя (Name)
sd_event_run, sd_event_loop - Run an event loop
Синопсис (Synopsis)
#include <systemd/sd-event.h>
int sd_event_run(sd_event *event, uint64_t usec);
int sd_event_loop(sd_event *event);
Описание (Description)
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.
Возвращаемое значение (Return value)
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
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.
Примечание (Note)
These APIs are implemented as a shared library, which can be
compiled and linked to with the libsystemd pkg-config(1) file.
Смотри также (See also)
systemd(1), sd-event(3), sd_event_new(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_exit(3), sd_event_get_fd(3),
sd_event_wait(3), GLib Main Event Loop
Примечание (Note)
1. GLib Main Event Loop
https://developer.gnome.org/glib/unstable/glib-The-Main-Event-Loop.html
