Systemd/src/systemd/sd-event.h
Nathaniel McCallum ab93297cd0 Add fd close support to sd_event_source
It is often the case that a file descriptor and its corresponding IO
sd_event_source share a life span. When this is the case, developers will
have to unref the event source and close the file descriptor. Instead, we
can just have the event source take ownership of the file descriptor and
close it when the event source is freed. This is especially useful when
combined with cleanup attributes and sd_event_source_unrefp().

This patch adds two new public functions:

    sd_event_source_get_io_fd_own()
    sd_event_source_set_io_fd_own()
2018-01-24 17:57:27 +01:00

150 lines
6 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#ifndef foosdeventhfoo
#define foosdeventhfoo
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <inttypes.h>
#include <signal.h>
#include <sys/epoll.h>
#include <sys/signalfd.h>
#include <sys/types.h>
#include <time.h>
#include "_sd-common.h"
/*
Why is this better than pure epoll?
- Supports event source prioritization
- Scales better with a large number of time events because it does not require one timerfd each
- Automatically tries to coalesce timer events system-wide
- Handles signals and child PIDs
*/
_SD_BEGIN_DECLARATIONS;
#define SD_EVENT_DEFAULT ((sd_event *) 1)
typedef struct sd_event sd_event;
typedef struct sd_event_source sd_event_source;
enum {
SD_EVENT_OFF = 0,
SD_EVENT_ON = 1,
SD_EVENT_ONESHOT = -1
};
enum {
SD_EVENT_INITIAL,
SD_EVENT_ARMED,
SD_EVENT_PENDING,
SD_EVENT_RUNNING,
SD_EVENT_EXITING,
SD_EVENT_FINISHED,
SD_EVENT_PREPARING
};
enum {
/* And everything in-between and outside is good too */
SD_EVENT_PRIORITY_IMPORTANT = -100,
SD_EVENT_PRIORITY_NORMAL = 0,
SD_EVENT_PRIORITY_IDLE = 100
};
typedef int (*sd_event_handler_t)(sd_event_source *s, void *userdata);
typedef int (*sd_event_io_handler_t)(sd_event_source *s, int fd, uint32_t revents, void *userdata);
typedef int (*sd_event_time_handler_t)(sd_event_source *s, uint64_t usec, void *userdata);
typedef int (*sd_event_signal_handler_t)(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata);
#if defined _GNU_SOURCE || _POSIX_C_SOURCE >= 199309L
typedef int (*sd_event_child_handler_t)(sd_event_source *s, const siginfo_t *si, void *userdata);
#else
typedef void* sd_event_child_handler_t;
#endif
int sd_event_default(sd_event **e);
int sd_event_new(sd_event **e);
sd_event* sd_event_ref(sd_event *e);
sd_event* sd_event_unref(sd_event *e);
int sd_event_add_io(sd_event *e, sd_event_source **s, int fd, uint32_t events, sd_event_io_handler_t callback, void *userdata);
int sd_event_add_time(sd_event *e, sd_event_source **s, clockid_t clock, uint64_t usec, uint64_t accuracy, sd_event_time_handler_t callback, void *userdata);
int sd_event_add_signal(sd_event *e, sd_event_source **s, int sig, sd_event_signal_handler_t callback, void *userdata);
int sd_event_add_child(sd_event *e, sd_event_source **s, pid_t pid, int options, sd_event_child_handler_t callback, void *userdata);
int sd_event_add_defer(sd_event *e, sd_event_source **s, sd_event_handler_t callback, void *userdata);
int sd_event_add_post(sd_event *e, sd_event_source **s, sd_event_handler_t callback, void *userdata);
int sd_event_add_exit(sd_event *e, sd_event_source **s, sd_event_handler_t callback, void *userdata);
int sd_event_prepare(sd_event *e);
int sd_event_wait(sd_event *e, uint64_t usec);
int sd_event_dispatch(sd_event *e);
int sd_event_run(sd_event *e, uint64_t usec);
int sd_event_loop(sd_event *e);
int sd_event_exit(sd_event *e, int code);
int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec);
int sd_event_get_fd(sd_event *e);
int sd_event_get_state(sd_event *e);
int sd_event_get_tid(sd_event *e, pid_t *tid);
int sd_event_get_exit_code(sd_event *e, int *code);
int sd_event_set_watchdog(sd_event *e, int b);
int sd_event_get_watchdog(sd_event *e);
int sd_event_get_iteration(sd_event *e, uint64_t *ret);
sd_event_source* sd_event_source_ref(sd_event_source *s);
sd_event_source* sd_event_source_unref(sd_event_source *s);
sd_event *sd_event_source_get_event(sd_event_source *s);
void* sd_event_source_get_userdata(sd_event_source *s);
void* sd_event_source_set_userdata(sd_event_source *s, void *userdata);
int sd_event_source_set_description(sd_event_source *s, const char *description);
int sd_event_source_get_description(sd_event_source *s, const char **description);
int sd_event_source_set_prepare(sd_event_source *s, sd_event_handler_t callback);
int sd_event_source_get_pending(sd_event_source *s);
int sd_event_source_get_priority(sd_event_source *s, int64_t *priority);
int sd_event_source_set_priority(sd_event_source *s, int64_t priority);
int sd_event_source_get_enabled(sd_event_source *s, int *enabled);
int sd_event_source_set_enabled(sd_event_source *s, int enabled);
int sd_event_source_get_io_fd(sd_event_source *s);
int sd_event_source_set_io_fd(sd_event_source *s, int fd);
int sd_event_source_get_io_fd_own(sd_event_source *s);
int sd_event_source_set_io_fd_own(sd_event_source *s, int own);
int sd_event_source_get_io_events(sd_event_source *s, uint32_t* events);
int sd_event_source_set_io_events(sd_event_source *s, uint32_t events);
int sd_event_source_get_io_revents(sd_event_source *s, uint32_t* revents);
int sd_event_source_get_time(sd_event_source *s, uint64_t *usec);
int sd_event_source_set_time(sd_event_source *s, uint64_t usec);
int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *usec);
int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec);
int sd_event_source_get_time_clock(sd_event_source *s, clockid_t *clock);
int sd_event_source_get_signal(sd_event_source *s);
int sd_event_source_get_child_pid(sd_event_source *s, pid_t *pid);
/* Define helpers so that __attribute__((cleanup(sd_event_unrefp))) and similar may be used. */
_SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event, sd_event_unref);
_SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event_source, sd_event_source_unref);
_SD_END_DECLARATIONS;
#endif