src/systemd/sd-event.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   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 <https://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <signal.h>
  21 #include <sys/epoll.h>
  22 #include <sys/inotify.h>
  23 #include <sys/signalfd.h>
  24 #include <sys/wait.h>
  25 #include <time.h>
  26
  27 #include "_sd-common.h"
  28
  29 /*
  30   Why is this better than pure epoll?
  31
  32   - Supports event source prioritization
  33   - Scales better with a large number of time events because it does not require one timerfd each
  34   - Automatically tries to coalesce timer events system-wide
  35   - Handles signals, child PIDs, inotify events
  36   - Supports systemd-style automatic watchdog event generation
  37 */
  38
  39 _SD_BEGIN_DECLARATIONS;
  40
  41 #define SD_EVENT_DEFAULT ((sd_event *) 1)
  42
  43 typedef struct sd_event sd_event;
  44 typedef struct sd_event_source sd_event_source;
  45
  46 enum {
  47         SD_EVENT_OFF = 0,
  48         SD_EVENT_ON = 1,
  49         SD_EVENT_ONESHOT = -1
  50 };
  51
  52 enum {
  53         SD_EVENT_INITIAL,
  54         SD_EVENT_ARMED,
  55         SD_EVENT_PENDING,
  56         SD_EVENT_RUNNING,
  57         SD_EVENT_EXITING,
  58         SD_EVENT_FINISHED,
  59         SD_EVENT_PREPARING
  60 };
  61
  62 enum {
  63         /* And everything in-between and outside is good too */
  64         SD_EVENT_PRIORITY_IMPORTANT = -100,
  65         SD_EVENT_PRIORITY_NORMAL = 0,
  66         SD_EVENT_PRIORITY_IDLE = 100
  67 };
  68
  69 #define SD_EVENT_SIGNAL_PROCMASK (1 << 30)
  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 **ret, 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 **ret, 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 **ret, 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 **ret, int sig, sd_event_signal_handler_t callback, void *userdata);
  93 int sd_event_add_child(sd_event *e, sd_event_source **ret, 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 **ret, int pidfd, int options, sd_event_child_handler_t callback, void *userdata);
  95 int sd_event_add_inotify(sd_event *e, sd_event_source **ret, const char *path, uint32_t mask, sd_event_inotify_handler_t callback, void *userdata);
  96 int sd_event_add_inotify_fd(sd_event *e, sd_event_source **ret, int fd, uint32_t mask, sd_event_inotify_handler_t callback, void *userdata);
  97 int sd_event_add_defer(sd_event *e, sd_event_source **ret, sd_event_handler_t callback, void *userdata);
  98 int sd_event_add_post(sd_event *e, sd_event_source **ret, sd_event_handler_t callback, void *userdata);
  99 int sd_event_add_exit(sd_event *e, sd_event_source **ret, sd_event_handler_t callback, void *userdata);
 100 int sd_event_add_memory_pressure(sd_event *e, sd_event_source **ret, sd_event_handler_t callback, void *userdata);
 101
 102 int sd_event_prepare(sd_event *e);
 103 int sd_event_wait(sd_event *e, uint64_t usec);
 104 int sd_event_dispatch(sd_event *e);
 105 int sd_event_run(sd_event *e, uint64_t usec);
 106 int sd_event_loop(sd_event *e);
 107 int sd_event_exit(sd_event *e, int code);
 108
 109 int sd_event_now(sd_event *e, clockid_t clock, uint64_t *ret);
 110
 111 int sd_event_get_fd(sd_event *e);
 112 int sd_event_get_state(sd_event *e);
 113 int sd_event_get_tid(sd_event *e, pid_t *ret);
 114 int sd_event_get_exit_code(sd_event *e, int *ret);
 115 int sd_event_set_watchdog(sd_event *e, int b);
 116 int sd_event_get_watchdog(sd_event *e);
 117 int sd_event_get_iteration(sd_event *e, uint64_t *ret);
 118 int sd_event_set_signal_exit(sd_event *e, int b);
 119
 120 sd_event_source* sd_event_source_ref(sd_event_source *s);
 121 sd_event_source* sd_event_source_unref(sd_event_source *s);
 122 sd_event_source* sd_event_source_disable_unref(sd_event_source *s);
 123
 124 sd_event* sd_event_source_get_event(sd_event_source *s);
 125 void* sd_event_source_get_userdata(sd_event_source *s);
 126 void* sd_event_source_set_userdata(sd_event_source *s, void *userdata);
 127
 128 int sd_event_source_set_description(sd_event_source *s, const char *description);
 129 int sd_event_source_get_description(sd_event_source *s, const char **ret);
 130 int sd_event_source_set_prepare(sd_event_source *s, sd_event_handler_t callback);
 131 int sd_event_source_get_pending(sd_event_source *s);
 132 int sd_event_source_get_priority(sd_event_source *s, int64_t *ret);
 133 int sd_event_source_set_priority(sd_event_source *s, int64_t priority);
 134 int sd_event_source_get_enabled(sd_event_source *s, int *ret);
 135 int sd_event_source_set_enabled(sd_event_source *s, int enabled);
 136 int sd_event_source_get_io_fd(sd_event_source *s);
 137 int sd_event_source_set_io_fd(sd_event_source *s, int fd);
 138 int sd_event_source_get_io_fd_own(sd_event_source *s);
 139 int sd_event_source_set_io_fd_own(sd_event_source *s, int own);
 140 int sd_event_source_get_io_events(sd_event_source *s, uint32_t *ret);
 141 int sd_event_source_set_io_events(sd_event_source *s, uint32_t events);
 142 int sd_event_source_get_io_revents(sd_event_source *s, uint32_t *ret);
 143 int sd_event_source_get_time(sd_event_source *s, uint64_t *ret);
 144 int sd_event_source_set_time(sd_event_source *s, uint64_t usec);
 145 int sd_event_source_set_time_relative(sd_event_source *s, uint64_t usec);
 146 int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *ret);
 147 int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec);
 148 int sd_event_source_get_time_clock(sd_event_source *s, clockid_t *ret);
 149 int sd_event_source_get_signal(sd_event_source *s);
 150 int sd_event_source_get_child_pid(sd_event_source *s, pid_t *ret);
 151 int sd_event_source_get_child_pidfd(sd_event_source *s);
 152 int sd_event_source_get_child_pidfd_own(sd_event_source *s);
 153 int sd_event_source_set_child_pidfd_own(sd_event_source *s, int own);
 154 int sd_event_source_get_child_process_own(sd_event_source *s);
 155 int sd_event_source_set_child_process_own(sd_event_source *s, int own);
 156 #if defined _GNU_SOURCE || (defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 199309L)
 157 int sd_event_source_send_child_signal(sd_event_source *s, int sig, const siginfo_t *si, unsigned flags);
 158 #else
 159 int sd_event_source_send_child_signal(sd_event_source *s, int sig, const void *si, unsigned flags);
 160 #endif
 161 int sd_event_source_get_inotify_mask(sd_event_source *s, uint32_t *ret);
 162 int sd_event_source_get_inotify_path(sd_event_source *s, const char **ret);
 163 int sd_event_source_set_memory_pressure_type(sd_event_source *e, const char *ty);
 164 int sd_event_source_set_memory_pressure_period(sd_event_source *s, uint64_t threshold_usec, uint64_t window_usec);
 165 int sd_event_source_set_destroy_callback(sd_event_source *s, sd_event_destroy_t callback);
 166 int sd_event_source_get_destroy_callback(sd_event_source *s, sd_event_destroy_t *ret);
 167 int sd_event_source_get_floating(sd_event_source *s);
 168 int sd_event_source_set_floating(sd_event_source *s, int b);
 169 int sd_event_source_get_exit_on_failure(sd_event_source *s);
 170 int sd_event_source_set_exit_on_failure(sd_event_source *s, int b);
 171 int sd_event_source_set_ratelimit(sd_event_source *s, uint64_t interval_usec, unsigned burst);
 172 int sd_event_source_get_ratelimit(sd_event_source *s, uint64_t *ret_interval_usec, unsigned *ret_burst);
 173 int sd_event_source_is_ratelimited(sd_event_source *s);
 174 int sd_event_source_set_ratelimit_expire_callback(sd_event_source *s, sd_event_handler_t callback);
 175 int sd_event_source_leave_ratelimit(sd_event_source *s);
 176
 177 int sd_event_trim_memory(void);
 178
 179 /* Define helpers so that __attribute__((cleanup(sd_event_unrefp))) and similar may be used. */
 180 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event, sd_event_unref);
 181 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event_source, sd_event_source_unref);
 182 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_event_source, sd_event_source_disable_unref);
 183
 184 _SD_END_DECLARATIONS;
 185
 186 #endif