unit.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #include <assert.h>
   4 #include <errno.h>
   5 #include <string.h>
   6 #include <sys/epoll.h>
   7 #include <sys/timerfd.h>
   8 #include <sys/poll.h>
   9
  10 #include "set.h"
  11 #include "unit.h"
  12 #include "macro.h"
  13 #include "strv.h"
  14 #include "load-fragment.h"
  15 #include "load-dropin.h"
  16 #include "log.h"
  17
  18 const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
  19         [UNIT_SERVICE] = &service_vtable,
  20         [UNIT_TIMER] = &timer_vtable,
  21         [UNIT_SOCKET] = &socket_vtable,
  22         [UNIT_TARGET] = &target_vtable,
  23         [UNIT_DEVICE] = &device_vtable,
  24         [UNIT_MOUNT] = &mount_vtable,
  25         [UNIT_AUTOMOUNT] = &automount_vtable,
  26         [UNIT_SNAPSHOT] = &snapshot_vtable
  27 };
  28
  29 UnitType unit_name_to_type(const char *n) {
  30         UnitType t;
  31
  32         assert(n);
  33
  34         for (t = 0; t < _UNIT_TYPE_MAX; t++)
  35                 if (endswith(n, unit_vtable[t]->suffix))
  36                         return t;
  37
  38         return _UNIT_TYPE_INVALID;
  39 }
  40
  41 #define VALID_CHARS                             \
  42         "0123456789"                            \
  43         "abcdefghijklmnopqrstuvwxyz"            \
  44         "ABCDEFGHIJKLMNOPQRSTUVWXYZ"            \
  45         "-_"
  46
  47 bool unit_name_is_valid(const char *n) {
  48         UnitType t;
  49         const char *e, *i;
  50
  51         assert(n);
  52
  53         if (strlen(n) >= UNIT_NAME_MAX)
  54                 return false;
  55
  56         t = unit_name_to_type(n);
  57         if (t < 0 || t >= _UNIT_TYPE_MAX)
  58                 return false;
  59
  60         if (!(e = strrchr(n, '.')))
  61                 return false;
  62
  63         for (i = n; i < e; i++)
  64                 if (!strchr(VALID_CHARS, *i))
  65                         return false;
  66
  67         return true;
  68 }
  69
  70 char *unit_name_change_suffix(const char *n, const char *suffix) {
  71         char *e, *r;
  72         size_t a, b;
  73
  74         assert(n);
  75         assert(unit_name_is_valid(n));
  76         assert(suffix);
  77
  78         assert_se(e = strrchr(n, '.'));
  79         a = e - n;
  80         b = strlen(suffix);
  81
  82         if (!(r = new(char, a + b + 1)))
  83                 return NULL;
  84
  85         memcpy(r, n, a);
  86         memcpy(r+a, suffix, b+1);
  87
  88         return r;
  89 }
  90
  91 Unit *unit_new(Manager *m) {
  92         Unit *u;
  93
  94         assert(m);
  95
  96         if (!(u = new0(Unit, 1)))
  97                 return NULL;
  98
  99         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
 100                 free(u);
 101                 return NULL;
 102         }
 103
 104         u->meta.manager = m;
 105         u->meta.type = _UNIT_TYPE_INVALID;
 106
 107         return u;
 108 }
 109
 110 int unit_add_name(Unit *u, const char *text) {
 111         UnitType t;
 112         char *s;
 113         int r;
 114
 115         assert(u);
 116         assert(text);
 117
 118         if (!unit_name_is_valid(text))
 119                 return -EINVAL;
 120
 121         if ((t = unit_name_to_type(text)) == _UNIT_TYPE_INVALID)
 122                 return -EINVAL;
 123
 124         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type)
 125                 return -EINVAL;
 126
 127         if (!(s = strdup(text)))
 128                 return -ENOMEM;
 129
 130         if ((r = set_put(u->meta.names, s)) < 0) {
 131                 free(s);
 132
 133                 if (r == -EEXIST)
 134                         return 0;
 135
 136                 return r;
 137         }
 138
 139         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 140                 set_remove(u->meta.names, s);
 141                 free(s);
 142                 return r;
 143         }
 144
 145         u->meta.type = t;
 146
 147         if (!u->meta.id)
 148                 u->meta.id = s;
 149
 150         return 0;
 151 }
 152
 153 void unit_add_to_load_queue(Unit *u) {
 154         assert(u);
 155
 156         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 157                 return;
 158
 159         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 160         u->meta.in_load_queue = true;
 161 }
 162
 163 static void bidi_set_free(Unit *u, Set *s) {
 164         Iterator i;
 165         Unit *other;
 166
 167         assert(u);
 168
 169         /* Frees the set and makes sure we are dropped from the
 170          * inverse pointers */
 171
 172         SET_FOREACH(other, s, i) {
 173                 UnitDependency d;
 174
 175                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 176                         set_remove(other->meta.dependencies[d], u);
 177         }
 178
 179         set_free(s);
 180 }
 181
 182 void unit_free(Unit *u) {
 183         UnitDependency d;
 184         Iterator i;
 185         char *t;
 186
 187         assert(u);
 188
 189         /* Detach from next 'bigger' objects */
 190
 191         SET_FOREACH(t, u->meta.names, i)
 192                 hashmap_remove_value(u->meta.manager->units, t, u);
 193
 194         if (u->meta.in_load_queue)
 195                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 196
 197         if (u->meta.load_state == UNIT_LOADED)
 198                 if (UNIT_VTABLE(u)->done)
 199                         UNIT_VTABLE(u)->done(u);
 200
 201         /* Free data and next 'smaller' objects */
 202         if (u->meta.job)
 203                 job_free(u->meta.job);
 204
 205         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 206                 bidi_set_free(u, u->meta.dependencies[d]);
 207
 208         free(u->meta.description);
 209
 210         while ((t = set_steal_first(u->meta.names)))
 211                 free(t);
 212         set_free(u->meta.names);
 213
 214         free(u);
 215 }
 216
 217 UnitActiveState unit_active_state(Unit *u) {
 218         assert(u);
 219
 220         if (u->meta.load_state != UNIT_LOADED)
 221                 return UNIT_INACTIVE;
 222
 223         return UNIT_VTABLE(u)->active_state(u);
 224 }
 225
 226 static int ensure_merge(Set **s, Set *other) {
 227
 228         if (!other)
 229                 return 0;
 230
 231         if (*s)
 232                 return set_merge(*s, other);
 233
 234         if (!(*s = set_copy(other)))
 235                 return -ENOMEM;
 236
 237         return 0;
 238 }
 239
 240 /* FIXME: Does not rollback on failure! */
 241 int unit_merge(Unit *u, Unit *other) {
 242         int r;
 243         UnitDependency d;
 244
 245         assert(u);
 246         assert(other);
 247         assert(u->meta.manager == other->meta.manager);
 248
 249         /* This merges 'other' into 'unit'. FIXME: This does not
 250          * rollback on failure. */
 251
 252         if (u->meta.type != u->meta.type)
 253                 return -EINVAL;
 254
 255         if (u->meta.load_state != UNIT_STUB)
 256                 return -EINVAL;
 257
 258         /* Merge names */
 259         if ((r = ensure_merge(&u->meta.names, other->meta.names)) < 0)
 260                 return r;
 261
 262         /* Merge dependencies */
 263         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 264                 /* fixme, the inverse mapping is missing */
 265                 if ((r = ensure_merge(&u->meta.dependencies[d], other->meta.dependencies[d])) < 0)
 266                         return r;
 267
 268         return 0;
 269 }
 270
 271 const char* unit_id(Unit *u) {
 272         assert(u);
 273
 274         if (u->meta.id)
 275                 return u->meta.id;
 276
 277         return set_first(u->meta.names);
 278 }
 279
 280 const char *unit_description(Unit *u) {
 281         assert(u);
 282
 283         if (u->meta.description)
 284                 return u->meta.description;
 285
 286         return unit_id(u);
 287 }
 288
 289 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 290
 291         static const char* const load_state_table[_UNIT_LOAD_STATE_MAX] = {
 292                 [UNIT_STUB] = "stub",
 293                 [UNIT_LOADED] = "loaded",
 294                 [UNIT_FAILED] = "failed"
 295         };
 296
 297         static const char* const active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
 298                 [UNIT_ACTIVE] = "active",
 299                 [UNIT_INACTIVE] = "inactive",
 300                 [UNIT_ACTIVATING] = "activating",
 301                 [UNIT_DEACTIVATING] = "deactivating"
 302         };
 303
 304         static const char* const dependency_table[_UNIT_DEPENDENCY_MAX] = {
 305                 [UNIT_REQUIRES] = "Requires",
 306                 [UNIT_SOFT_REQUIRES] = "SoftRequires",
 307                 [UNIT_WANTS] = "Wants",
 308                 [UNIT_REQUISITE] = "Requisite",
 309                 [UNIT_SOFT_REQUISITE] = "SoftRequisite",
 310                 [UNIT_REQUIRED_BY] = "RequiredBy",
 311                 [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy",
 312                 [UNIT_WANTED_BY] = "WantedBy",
 313                 [UNIT_CONFLICTS] = "Conflicts",
 314                 [UNIT_BEFORE] = "Before",
 315                 [UNIT_AFTER] = "After",
 316         };
 317
 318         char *t;
 319         UnitDependency d;
 320         Iterator i;
 321         char *prefix2;
 322
 323         assert(u);
 324
 325         if (!prefix)
 326                 prefix = "";
 327         prefix2 = strappend(prefix, "\t");
 328         if (!prefix2)
 329                 prefix2 = "";
 330
 331         fprintf(f,
 332                 "%s→ Unit %s:\n"
 333                 "%s\tDescription: %s\n"
 334                 "%s\tUnit Load State: %s\n"
 335                 "%s\tUnit Active State: %s\n",
 336                 prefix, unit_id(u),
 337                 prefix, unit_description(u),
 338                 prefix, load_state_table[u->meta.load_state],
 339                 prefix, active_state_table[unit_active_state(u)]);
 340
 341         SET_FOREACH(t, u->meta.names, i)
 342                 fprintf(f, "%s\tName: %s\n", prefix, t);
 343
 344         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 345                 Unit *other;
 346
 347                 if (set_isempty(u->meta.dependencies[d]))
 348                         continue;
 349
 350                 SET_FOREACH(other, u->meta.dependencies[d], i)
 351                         fprintf(f, "%s\t%s: %s\n", prefix, dependency_table[d], unit_id(other));
 352         }
 353
 354         if (UNIT_VTABLE(u)->dump)
 355                 UNIT_VTABLE(u)->dump(u, f, prefix2);
 356
 357         if (u->meta.job)
 358                 job_dump(u->meta.job, f, prefix2);
 359
 360         free(prefix2);
 361 }
 362
 363 /* Common implementation for multiple backends */
 364 int unit_load_fragment_and_dropin(Unit *u) {
 365         int r;
 366
 367         assert(u);
 368
 369         /* Load a .socket file */
 370         if ((r = unit_load_fragment(u)) < 0)
 371                 return r;
 372
 373         /* Load drop-in directory data */
 374         if ((r = unit_load_dropin(u)) < 0)
 375                 return r;
 376
 377         return 0;
 378 }
 379
 380 int unit_load(Unit *u) {
 381         int r;
 382
 383         assert(u);
 384
 385         if (u->meta.in_load_queue) {
 386                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 387                 u->meta.in_load_queue = false;
 388         }
 389
 390         if (u->meta.load_state != UNIT_STUB)
 391                 return 0;
 392
 393         if (UNIT_VTABLE(u)->init)
 394                 if ((r = UNIT_VTABLE(u)->init(u)) < 0)
 395                         goto fail;
 396
 397         u->meta.load_state = UNIT_LOADED;
 398         return 0;
 399
 400 fail:
 401         u->meta.load_state = UNIT_FAILED;
 402         return r;
 403 }
 404
 405 /* Errors:
 406  *         -EBADR:    This unit type does not support starting.
 407  *         -EALREADY: Unit is already started.
 408  *         -EAGAIN:   An operation is already in progress. Retry later.
 409  */
 410 int unit_start(Unit *u) {
 411         UnitActiveState state;
 412
 413         assert(u);
 414
 415         if (!UNIT_VTABLE(u)->start)
 416                 return -EBADR;
 417
 418         state = unit_active_state(u);
 419         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 420                 return -EALREADY;
 421
 422         /* We don't suppress calls to ->start() here when we are
 423          * already starting, to allow this request to be used as a
 424          * "hurry up" call, for example when the unit is in some "auto
 425          * restart" state where it waits for a holdoff timer to elapse
 426          * before it will start again. */
 427
 428         return UNIT_VTABLE(u)->start(u);
 429 }
 430
 431 bool unit_can_start(Unit *u) {
 432         assert(u);
 433
 434         return !!UNIT_VTABLE(u)->start;
 435 }
 436
 437 /* Errors:
 438  *         -EBADR:    This unit type does not support stopping.
 439  *         -EALREADY: Unit is already stopped.
 440  *         -EAGAIN:   An operation is already in progress. Retry later.
 441  */
 442 int unit_stop(Unit *u) {
 443         UnitActiveState state;
 444
 445         assert(u);
 446
 447         if (!UNIT_VTABLE(u)->stop)
 448                 return -EBADR;
 449
 450         state = unit_active_state(u);
 451         if (state == UNIT_INACTIVE)
 452                 return -EALREADY;
 453
 454         if (state == UNIT_DEACTIVATING)
 455                 return 0;
 456
 457         return UNIT_VTABLE(u)->stop(u);
 458 }
 459
 460 /* Errors:
 461  *         -EBADR:    This unit type does not support reloading.
 462  *         -ENOEXEC:  Unit is not started.
 463  *         -EAGAIN:   An operation is already in progress. Retry later.
 464  */
 465 int unit_reload(Unit *u) {
 466         UnitActiveState state;
 467
 468         assert(u);
 469
 470         if (!unit_can_reload(u))
 471                 return -EBADR;
 472
 473         state = unit_active_state(u);
 474         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 475                 return -EALREADY;
 476
 477         if (unit_active_state(u) != UNIT_ACTIVE)
 478                 return -ENOEXEC;
 479
 480         return UNIT_VTABLE(u)->reload(u);
 481 }
 482
 483 bool unit_can_reload(Unit *u) {
 484         assert(u);
 485
 486         if (!UNIT_VTABLE(u)->reload)
 487                 return false;
 488
 489         if (!UNIT_VTABLE(u)->can_reload)
 490                 return true;
 491
 492         return UNIT_VTABLE(u)->can_reload(u);
 493 }
 494
 495 static void retroactively_start_dependencies(Unit *u) {
 496         Iterator i;
 497         Unit *other;
 498
 499         assert(u);
 500         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 501
 502         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 503                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 504                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 505
 506         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 507                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 508                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 509
 510         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 511                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 512                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 513
 514         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 515                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 516                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 517
 518         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 519                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 520                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 521 }
 522
 523 static void retroactively_stop_dependencies(Unit *u) {
 524         Iterator i;
 525         Unit *other;
 526
 527         assert(u);
 528         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 529
 530         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 531                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 532                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 533 }
 534
 535 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 536         assert(u);
 537         assert(os < _UNIT_ACTIVE_STATE_MAX);
 538         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 539         assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING));
 540         assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING));
 541
 542         if (os == ns)
 543                 return;
 544
 545         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 546                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 547         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 548                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 549
 550         if (u->meta.job) {
 551
 552                 if (u->meta.job->state == JOB_WAITING)
 553
 554                         /* So we reached a different state for this
 555                          * job. Let's see if we can run it now if it
 556                          * failed previously due to EAGAIN. */
 557                         job_schedule_run(u->meta.job);
 558
 559                 else {
 560                         assert(u->meta.job->state == JOB_RUNNING);
 561
 562                         /* Let's check of this state change
 563                          * constitutes a finished job, or maybe
 564                          * cotradicts a running job and hence needs to
 565                          * invalidate jobs. */
 566
 567                         switch (u->meta.job->type) {
 568
 569                         case JOB_START:
 570                         case JOB_VERIFY_ACTIVE:
 571
 572                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
 573                                         job_finish_and_invalidate(u->meta.job, true);
 574                                         return;
 575                                 } else if (ns == UNIT_ACTIVATING)
 576                                         return;
 577                                 else
 578                                         job_finish_and_invalidate(u->meta.job, false);
 579
 580                                 break;
 581
 582                         case JOB_RELOAD:
 583                         case JOB_RELOAD_OR_START:
 584
 585                                 if (ns == UNIT_ACTIVE) {
 586                                         job_finish_and_invalidate(u->meta.job, true);
 587                                         return;
 588                                 } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING)
 589                                         return;
 590                                 else
 591                                         job_finish_and_invalidate(u->meta.job, false);
 592
 593                                 break;
 594
 595                         case JOB_STOP:
 596                         case JOB_RESTART:
 597                         case JOB_TRY_RESTART:
 598
 599                                 if (ns == UNIT_INACTIVE) {
 600                                         job_finish_and_invalidate(u->meta.job, true);
 601                                         return;
 602                                 } else if (ns == UNIT_DEACTIVATING)
 603                                         return;
 604                                 else
 605                                         job_finish_and_invalidate(u->meta.job, false);
 606
 607                                 break;
 608
 609                         default:
 610                                 assert_not_reached("Job type unknown");
 611                         }
 612                 }
 613         }
 614
 615         /* If this state change happened without being requested by a
 616          * job, then let's retroactively start or stop dependencies */
 617
 618         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 619                 retroactively_start_dependencies(u);
 620         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 621                 retroactively_stop_dependencies(u);
 622 }
 623
 624 int unit_watch_fd(Unit *u, int fd, uint32_t events) {
 625         struct epoll_event ev;
 626
 627         assert(u);
 628         assert(fd >= 0);
 629
 630         zero(ev);
 631         ev.data.fd = fd;
 632         ev.data.ptr = u;
 633         ev.data.u32 = MANAGER_FD;
 634         ev.events = events;
 635
 636         if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) >= 0)
 637                 return 0;
 638
 639         if (errno == EEXIST)
 640                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_MOD, fd, &ev) >= 0)
 641                         return 0;
 642
 643         return -errno;
 644 }
 645
 646 void unit_unwatch_fd(Unit *u, int fd) {
 647         assert(u);
 648         assert(fd >= 0);
 649
 650         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, fd, NULL) >= 0 || errno == ENOENT);
 651 }
 652
 653 int unit_watch_pid(Unit *u, pid_t pid) {
 654         assert(u);
 655         assert(pid >= 1);
 656
 657         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
 658 }
 659
 660 void unit_unwatch_pid(Unit *u, pid_t pid) {
 661         assert(u);
 662         assert(pid >= 1);
 663
 664         hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid));
 665 }
 666
 667 int unit_watch_timer(Unit *u, usec_t delay, int *id) {
 668         struct epoll_event ev;
 669         int fd;
 670         struct itimerspec its;
 671         int flags;
 672         bool ours;
 673
 674         assert(u);
 675         assert(id);
 676
 677         /* This will try to reuse the old timer if there is one */
 678
 679         if (*id >= 0) {
 680                 ours = false;
 681                 fd = *id;
 682
 683         } else {
 684                 ours = true;
 685
 686                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 687                         return -errno;
 688         }
 689
 690         zero(its);
 691
 692         if (delay <= 0) {
 693                 /* Set absolute time in the past, but not 0, since we
 694                  * don't want to disarm the timer */
 695                 its.it_value.tv_sec = 0;
 696                 its.it_value.tv_nsec = 1;
 697
 698                 flags = TFD_TIMER_ABSTIME;
 699         } else {
 700                 timespec_store(&its.it_value, delay);
 701                 flags = 0;
 702         }
 703
 704         /* This will also flush the elapse counter */
 705         if (timerfd_settime(fd, flags, &its, NULL) < 0)
 706                 goto fail;
 707
 708         zero(ev);
 709         ev.data.fd = fd;
 710         ev.data.ptr = u;
 711         ev.data.u32 = MANAGER_TIMER;
 712         ev.events = POLLIN;
 713
 714         if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
 715                 goto fail;
 716
 717         *id = fd;
 718         return 0;
 719
 720 fail:
 721         if (ours)
 722                 assert_se(close_nointr(fd) == 0);
 723
 724         return -errno;
 725 }
 726
 727 void unit_unwatch_timer(Unit *u, int *id) {
 728         assert(u);
 729         assert(id);
 730
 731         if (*id < 0)
 732                 return;
 733
 734         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, *id, NULL) >= 0);
 735         assert_se(close_nointr(*id) == 0);
 736         *id = -1;
 737 }
 738
 739 bool unit_job_is_applicable(Unit *u, JobType j) {
 740         assert(u);
 741         assert(j >= 0 && j < _JOB_TYPE_MAX);
 742
 743         switch (j) {
 744
 745         case JOB_VERIFY_ACTIVE:
 746         case JOB_START:
 747                 return true;
 748
 749         case JOB_STOP:
 750         case JOB_RESTART:
 751         case JOB_TRY_RESTART:
 752                 return unit_can_start(u);
 753
 754         case JOB_RELOAD:
 755                 return unit_can_reload(u);
 756
 757         case JOB_RELOAD_OR_START:
 758                 return unit_can_reload(u) && unit_can_start(u);
 759
 760         default:
 761                 assert_not_reached("Invalid job type");
 762         }
 763 }
 764
 765 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) {
 766
 767         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
 768                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
 769                 [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY,
 770                 [UNIT_WANTS] = UNIT_WANTED_BY,
 771                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
 772                 [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY,
 773                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 774                 [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 775                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
 776                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
 777                 [UNIT_BEFORE] = UNIT_AFTER,
 778                 [UNIT_AFTER] = UNIT_BEFORE
 779         };
 780         int r;
 781
 782         assert(u);
 783         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
 784         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
 785         assert(other);
 786
 787         /* We won't allow dependencies on ourselves. We will not
 788          * consider them an error however. */
 789         if (u == other)
 790                 return 0;
 791
 792         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
 793                 return r;
 794
 795         if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
 796                 return r;
 797
 798         if ((r = set_put(u->meta.dependencies[d], other)) < 0)
 799                 return r;
 800
 801         if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
 802                 set_remove(u->meta.dependencies[d], other);
 803                 return r;
 804         }
 805
 806         return 0;
 807 }