src/systemd/sd-event.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #ifndef foosdeventhfoo
   3 #define foosdeventhfoo
   4
   5 /***
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <inttypes.h>
  21 #include <signal.h>
  22 #include <sys/epoll.h>
  23 #include <sys/inotify.h>
  24 #include <sys/signalfd.h>
  25 #include <sys/types.h>
  26 #include <sys/wait.h>
  27 #include <time.h>
  28
  29 #include "_sd-common.h"
  30
  31 /*
  32   Why is this better than pure epoll?
  33
  34   - Supports event source prioritization
  35   - Scales better with a large number of time events because it does not require one timerfd each
  36   - Automatically tries to coalesce timer events system-wide
  37   - Handles signals, child PIDs, inotify events
  38   - Supports systemd-style automatic watchdog event generation
  39 */
  40
  41 _SD_BEGIN_DECLARATIONS;
  42
  43 #define SD_EVENT_DEFAULT ((sd_event *) 1)
  44
  45 typedef struct sd_event sd_event;
  46 typedef struct sd_event_source sd_event_source;
  47
  48 enum {
  49         SD_EVENT_OFF = 0,
  50         SD_EVENT_ON = 1,
  51         SD_EVENT_ONESHOT = -1
  52 };
  53
  54 enum {
  55         SD_EVENT_INITIAL,
  56         SD_EVENT_ARMED,
  57         SD_EVENT_PENDING,
  58         SD_EVENT_RUNNING,
  59         SD_EVENT_EXITING,
  60         SD_EVENT_FINISHED,
  61         SD_EVENT_PREPARING
  62 };
  63
  64 enum {
  65         /* And everything in-between and outside is good too */
  66         SD_EVENT_PRIORITY_IMPORTANT = -100,
  67         SD_EVENT_PRIORITY_NORMAL = 0,
  68         SD_EVENT_PRIORITY_IDLE = 100
  69 };
  70
  71 typedef int (*sd_event_handler_t)(sd_event_source *s, void *userdata);
  72 typedef int (*sd_event_io_handler_t)(sd_event_source *s, int fd, uint32_t revents, void *userdata);
  73 typedef int (*sd_event_time_handler_t)(sd_event_source *s, uint64_t usec, void *userdata);
  74 typedef int (*sd_event_signal_handler_t)(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata);
  75 #if defined _GNU_SOURCE || (defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 199309L)
  76 typedef int (*sd_event_child_handler_t)(sd_event_source *s, const siginfo_t *si, void *userdata);
  77 #else
  78 typedef void* sd_event_child_handler_t;
  79 #endif
  80 typedef int (*sd_event_inotify_handler_t)(sd_event_source *s, const struct inotify_event *event, void *userdata);
  81 typedef _sd_destroy_t sd_event_destroy_t;
  82
  83 int sd_event_default(sd_event **e);
  84
  85 int sd_event_new(sd_event **e);
  86 sd_event* sd_event_ref(sd_event *e);
  87 sd_event* sd_event_unref(sd_event *e);
  88
  89 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);
  90 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);
  91 int sd_event_add_time_relative(sd_event *e, sd_event_source **s, clockid_t clock, uint64_t usec, uint64_t accuracy, sd_event_time_handler_t callback, void *userdata);
  92 int sd_event_add_signal(sd_event *e, sd_event_source **s, int sig, sd_event_signal_handler_t callback, void *userdata);
  93 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);
  94 int sd_event_add_child_pidfd(sd_event *e, sd_event_source **s, int pidfd, int options, sd_event_child_handler_t callback, void *userdata);
  95 int sd_event_add_inotify(sd_event *e, sd_event_source **s, const char *path, uint32_t mask, sd_event_inotify_handler_t callback, void *userdata);
  96 int sd_event_add_defer(sd_event *e, sd_event_source **s, sd_event_handler_t callback, void *userdata);
  97 int sd_event_add_post(sd_event *e, sd_event_source **s, sd_event_handler_t callback, void *userdata);
  98 int sd_event_add_exit(sd_event *e, sd_event_source **s, sd_event_handler_t callback, void *userdata);
  99
 100 int sd_event_prepare(sd_event *e);
 101 int sd_event_wait(sd_event *e, uint64_t usec);
 102 int sd_event_dispatch(sd_event *e);
 103 int sd_event_run(sd_event *e, uint64_t usec);
 104 int sd_event_loop(sd_event *e);
 105 int sd_event_exit(sd_event *e, int code);
 106
 107 int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec);
 108
 109 int sd_event_get_fd(sd_event *e);
 110 int sd_event_get_state(sd_event *e);
 111 int sd_event_get_tid(sd_event *e, pid_t *tid);
 112 int sd_event_get_exit_code(sd_event *e, int *code);
 113 int sd_event_set_watchdog(sd_event *e, int b);
 114 int sd_event_get_watchdog(sd_event *e);
 115 int sd_event_get_iteration(sd_event *e, uint64_t *ret);
 116
 117 sd_event_source* sd_event_source_ref(sd_event_source *s);
 118 sd_event_source* sd_event_source_unref(sd_event_source *s);
 119 sd_event_source* sd_event_source_disable_unref(sd_event_source *s);
 120
 121 sd_event *sd_event_source_get_event(sd_event_source *s);
 122 void* sd_event_source_get_userdata(sd_event_source *s);
 123 void* sd_event_source_set_userdata(sd_event_source *s, void *userdata);
 124
 125 int sd_event_source_set_description(sd_event_source *s, const char *description);
 126 int sd_event_source_get_description(sd_event_source *s, const char **description);
 127 int sd_event_source_set_prepare(sd_event_source *s, sd_event_handler_t callback);
 128 int sd_event_source_get_pending(sd_event_source *s);
 129 int sd_event_source_get_priority(sd_event_source *s, int64_t *priority);
 130 int sd_event_source_set_priority(sd_event_source *s, int64_t priority);
 131 int sd_event_source_get_enabled(sd_event_source *s, int *enabled);
 132 int sd_event_source_set_enabled(sd_event_source *s, int enabled);
 133 int sd_event_source_get_io_fd(sd_event_source *s);
 134 int sd_event_source_set_io_fd(sd_event_source *s, int fd);
 135 int sd_event_source_get_io_fd_own(sd_event_source *s);
 136 int sd_event_source_set_io_fd_own(sd_event_source *s, int own);
 137 int sd_event_source_get_io_events(sd_event_source *s, uint32_t* events);
 138 int sd_event_source_set_io_events(sd_event_source *s, uint32_t events);
 139 int sd_event_source_get_io_revents(sd_event_source *s, uint32_t* revents);
 140 int sd_event_source_get_time(sd_event_source *s, uint64_t *usec);
 141 int sd_event_source_set_time(sd_event_source *s, uint64_t usec);
 142 int sd_event_source_set_time_relative(sd_event_source *s, uint64_t usec);
 143 int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *usec);
 144 int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec);
 145 int sd_event_source_get_time_clock(sd_event_source *s, clockid_t *clock);
 146 int sd_event_source_get_signal(sd_event_source *s);
 147 int sd_event_source_get_child_pid(sd_event_source *s, pid_t *pid);
 148 int sd_event_source_get_child_pidfd(sd_event_source *s);
 149 int sd_event_source_get_child_pidfd_own(sd_event_source *s);
 150 int sd_event_source_set_child_pidfd_own(sd_event_source *s, int own);
 151 int sd_event_source_get_child_process_own(sd_event_source *s);
 152 int sd_event_source_set_child_process_own(sd_event_source *s, int own);
 153 #if defined _GNU_SOURCE || (defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 199309L)
 154 int sd_event_source_send_child_signal(sd_event_source *s, int sig, const siginfo_t *si, unsigned flags);
 155 #else
 156 int sd_event_source_send_child_signal(sd_event_source *s, int sig, const void *si, unsigned flags);
 157 #endif
 158 int sd_event_source_get_inotify_mask(sd_event_source *s, uint32_t *ret);
 159 int sd_event_source_set_destroy_callback(sd_event_source *s, sd_event_destroy_t callback);
 160 int sd_event_source_get_destroy_callback(sd_event_source *s, sd_event_destroy_t *ret);
 161 int sd_event_source_get_floating(sd_event_source *s);
 162 int sd_event_source_set_floating(sd_event_source *s, int b);
 163
 164 /* Define helpers so that __attribute__((cleanup(sd_event_unrefp))) and similar may be used. */
 165 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event, sd_event_unref);
 166 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event_source, sd_event_source_unref);
 167 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event_source, sd_event_source_disable_unref);
 168
 169 _SD_END_DECLARATIONS;
 170
 171 #endif