unit.h

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #ifndef foounithfoo
   4 #define foounithfoo
   5
   6 #include <stdbool.h>
   7 #include <stdlib.h>
   8
   9 typedef union Unit Unit;
  10 typedef struct Meta Meta;
  11 typedef struct UnitVTable UnitVTable;
  12 typedef enum UnitType UnitType;
  13 typedef enum UnitLoadState UnitLoadState;
  14 typedef enum UnitActiveState UnitActiveState;
  15 typedef enum UnitDependency UnitDependency;
  16
  17 #include "set.h"
  18 #include "util.h"
  19 #include "list.h"
  20 #include "socket-util.h"
  21 #include "execute.h"
  22
  23 #define UNIT_NAME_MAX 128
  24 #define DEFAULT_TIMEOUT_USEC (20*USEC_PER_SEC)
  25 #define DEFAULT_RESTART_USEC (100*USEC_PER_MSEC)
  26
  27 enum UnitType {
  28         UNIT_SERVICE = 0,
  29         UNIT_TIMER,
  30         UNIT_SOCKET,
  31         UNIT_TARGET,
  32         UNIT_DEVICE,
  33         UNIT_MOUNT,
  34         UNIT_AUTOMOUNT,
  35         UNIT_SNAPSHOT,
  36         _UNIT_TYPE_MAX,
  37         _UNIT_TYPE_INVALID = -1,
  38 };
  39
  40 enum UnitLoadState {
  41         UNIT_STUB,
  42         UNIT_LOADED,
  43         UNIT_FAILED,
  44         _UNIT_LOAD_STATE_MAX,
  45         _UNIT_LOAD_STATE_INVALID = -1
  46 };
  47
  48 enum UnitActiveState {
  49         UNIT_ACTIVE,
  50         UNIT_ACTIVE_RELOADING,
  51         UNIT_INACTIVE,
  52         UNIT_ACTIVATING,
  53         UNIT_DEACTIVATING,
  54         _UNIT_ACTIVE_STATE_MAX,
  55         _UNIT_ACTIVE_STATE_INVALID = -1
  56 };
  57
  58 static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
  59         return t == UNIT_ACTIVE || t == UNIT_ACTIVE_RELOADING;
  60 }
  61
  62 static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
  63         return t == UNIT_ACTIVE || t == UNIT_ACTIVATING || t == UNIT_ACTIVE_RELOADING;
  64 }
  65
  66 static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
  67         return t == UNIT_INACTIVE || t == UNIT_DEACTIVATING;
  68 }
  69
  70 enum UnitDependency {
  71         /* Positive dependencies */
  72         UNIT_REQUIRES,
  73         UNIT_SOFT_REQUIRES,
  74         UNIT_WANTS,
  75         UNIT_REQUISITE,
  76         UNIT_SOFT_REQUISITE,
  77
  78         /* Inverse of the above */
  79         UNIT_REQUIRED_BY,       /* inverse of 'requires' and 'requisite' is 'required_by' */
  80         UNIT_SOFT_REQUIRED_BY,  /* inverse of 'soft_requires' and 'soft_requisite' is 'soft_required_by' */
  81         UNIT_WANTED_BY,         /* inverse of 'wants' */
  82
  83         /* Negative dependencies */
  84         UNIT_CONFLICTS,         /* inverse of 'conflicts' is 'conflicts' */
  85
  86         /* Order */
  87         UNIT_BEFORE,            /* inverse of before is after and vice versa */
  88         UNIT_AFTER,
  89
  90         _UNIT_DEPENDENCY_MAX,
  91         _UNIT_DEPENDENCY_INVALID = -1
  92 };
  93
  94 #include "manager.h"
  95 #include "job.h"
  96
  97 struct Meta {
  98         Manager *manager;
  99         UnitType type;
 100         UnitLoadState load_state;
 101
 102         char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
 103
 104         Set *names;
 105         Set *dependencies[_UNIT_DEPENDENCY_MAX];
 106
 107         char *description;
 108         char *load_path; /* if loaded from a config file this is the primary path to it */
 109
 110         /* If there is something to do with this unit, then this is
 111          * the job for it */
 112         Job *job;
 113
 114         bool in_load_queue:1;
 115
 116         /* If we go down, pull down everything that depends on us, too */
 117         bool recursive_stop;
 118
 119         /* Garbage collect us we nobody wants or requires us anymore */
 120         bool stop_when_unneeded;
 121
 122         usec_t active_enter_timestamp;
 123         usec_t active_exit_timestamp;
 124
 125         /* Load queue */
 126         LIST_FIELDS(Meta, load_queue);
 127
 128         /* Per type list */
 129         LIST_FIELDS(Meta, units_per_type);
 130 };
 131
 132 #include "service.h"
 133 #include "timer.h"
 134 #include "socket.h"
 135 #include "target.h"
 136 #include "device.h"
 137 #include "mount.h"
 138 #include "automount.h"
 139 #include "snapshot.h"
 140
 141 union Unit {
 142         Meta meta;
 143         Service service;
 144         Timer timer;
 145         Socket socket;
 146         Target target;
 147         Device device;
 148         Mount mount;
 149         Automount automount;
 150         Snapshot snapshot;
 151 };
 152
 153 struct UnitVTable {
 154         const char *suffix;
 155
 156         int (*init)(Unit *u);
 157         void (*done)(Unit *u);
 158         int (*coldplug)(Unit *u);
 159
 160         void (*dump)(Unit *u, FILE *f, const char *prefix);
 161
 162         int (*start)(Unit *u);
 163         int (*stop)(Unit *u);
 164         int (*reload)(Unit *u);
 165
 166         bool (*can_reload)(Unit *u);
 167
 168         /* Boils down the more complex internal state of this unit to
 169          * a simpler one that the engine can understand */
 170         UnitActiveState (*active_state)(Unit *u);
 171
 172         void (*fd_event)(Unit *u, int fd, uint32_t events, Watch *w);
 173         void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
 174         void (*timer_event)(Unit *u, uint64_t n_elapsed, Watch *w);
 175
 176         /* This is called for each unit type and should be used to
 177          * enumerate existing devices and load them. However,
 178          * everything that is loaded here should still stay in
 179          * inactive state. It is the job of the coldplug() call above
 180          * to put the units into the initial state.  */
 181         int (*enumerate)(Manager *m);
 182
 183         /* Type specific cleanups. */
 184         void (*shutdown)(Manager *m);
 185 };
 186
 187 extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
 188
 189 #define UNIT_VTABLE(u) unit_vtable[(u)->meta.type]
 190
 191 /* For casting a unit into the various unit types */
 192 #define DEFINE_CAST(UPPERCASE, MixedCase)                               \
 193         static inline MixedCase* UPPERCASE(Unit *u) {                   \
 194                 if (!u || u->meta.type != UNIT_##UPPERCASE)             \
 195                         return NULL;                                    \
 196                                                                         \
 197                 return (MixedCase*) u;                                  \
 198         }
 199
 200 /* For casting the various unit types into a unit */
 201 #define UNIT(u) ((Unit*) (u))
 202
 203 DEFINE_CAST(SOCKET, Socket);
 204 DEFINE_CAST(TIMER, Timer);
 205 DEFINE_CAST(SERVICE, Service);
 206 DEFINE_CAST(TARGET, Target);
 207 DEFINE_CAST(DEVICE, Device);
 208 DEFINE_CAST(MOUNT, Mount);
 209 DEFINE_CAST(AUTOMOUNT, Automount);
 210 DEFINE_CAST(SNAPSHOT, Snapshot);
 211
 212 UnitType unit_name_to_type(const char *n);
 213 bool unit_name_is_valid(const char *n);
 214 char *unit_name_change_suffix(const char *n, const char *suffix);
 215
 216 Unit *unit_new(Manager *m);
 217 void unit_free(Unit *u);
 218
 219 int unit_add_name(Unit *u, const char *name);
 220 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other);
 221 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name);
 222
 223 int unit_choose_id(Unit *u, const char *name);
 224 int unit_set_description(Unit *u, const char *description);
 225
 226 void unit_add_to_load_queue(Unit *u);
 227
 228 int unit_merge(Unit *u, Unit *other);
 229
 230 int unit_load_fragment_and_dropin(Unit *u);
 231 int unit_load(Unit *unit);
 232
 233 const char* unit_id(Unit *u);
 234 const char *unit_description(Unit *u);
 235
 236 UnitActiveState unit_active_state(Unit *u);
 237
 238 void unit_dump(Unit *u, FILE *f, const char *prefix);
 239
 240 bool unit_can_reload(Unit *u);
 241 bool unit_can_start(Unit *u);
 242
 243 int unit_start(Unit *u);
 244 int unit_stop(Unit *u);
 245 int unit_reload(Unit *u);
 246
 247 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns);
 248
 249 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w);
 250 void unit_unwatch_fd(Unit *u, Watch *w);
 251
 252 int unit_watch_pid(Unit *u, pid_t pid);
 253 void unit_unwatch_pid(Unit *u, pid_t pid);
 254
 255 int unit_watch_timer(Unit *u, usec_t delay, Watch *w);
 256 void unit_unwatch_timer(Unit *u, Watch *w);
 257
 258 bool unit_job_is_applicable(Unit *u, JobType j);
 259
 260 const char *unit_path(void);
 261 int set_unit_path(const char *p);
 262
 263 char *unit_name_escape_path(const char *prefix, const char *path, const char *suffix);
 264
 265 const char *unit_type_to_string(UnitType i);
 266 UnitType unit_type_from_string(const char *s);
 267
 268 const char *unit_load_state_to_string(UnitLoadState i);
 269 UnitLoadState unit_load_state_from_string(const char *s);
 270
 271 const char *unit_active_state_to_string(UnitActiveState i);
 272 UnitActiveState unit_active_state_from_string(const char *s);
 273
 274 const char *unit_dependency_to_string(UnitDependency i);
 275 UnitDependency unit_dependency_from_string(const char *s);
 276
 277 char *unit_dbus_path(Unit *u);
 278
 279 #endif