manager.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 <signal.h>
   8 #include <sys/signalfd.h>
   9 #include <sys/wait.h>
  10 #include <unistd.h>
  11 #include <sys/poll.h>
  12
  13 #include "manager.h"
  14 #include "hashmap.h"
  15 #include "macro.h"
  16 #include "strv.h"
  17 #include "log.h"
  18
  19 Manager* manager_new(void) {
  20         Manager *m;
  21         sigset_t mask;
  22         struct epoll_event ev;
  23
  24         if (!(m = new0(Manager, 1)))
  25                 return NULL;
  26
  27         m->signal_fd = m->epoll_fd = -1;
  28
  29         if (!(m->names = hashmap_new(string_hash_func, string_compare_func)))
  30                 goto fail;
  31
  32         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
  33                 goto fail;
  34
  35         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
  36                 goto fail;
  37
  38         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
  39                 goto fail;
  40
  41         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
  42                 goto fail;
  43
  44         assert_se(sigemptyset(&mask) == 0);
  45         assert_se(sigaddset(&mask, SIGCHLD) == 0);
  46         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
  47
  48         if ((m->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
  49                 goto fail;
  50
  51         zero(ev);
  52         ev.events = EPOLLIN;
  53         ev.data.fd = m->signal_fd;
  54
  55         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_fd, &ev) < 0)
  56                 goto fail;
  57
  58         return m;
  59
  60 fail:
  61         manager_free(m);
  62         return NULL;
  63 }
  64
  65 void manager_free(Manager *m) {
  66         Name *n;
  67         Job *j;
  68
  69         assert(m);
  70
  71         while ((n = hashmap_first(m->names)))
  72                 name_free(n);
  73
  74         while ((j = hashmap_steal_first(m->transaction_jobs)))
  75                 job_free(j);
  76
  77         hashmap_free(m->names);
  78         hashmap_free(m->jobs);
  79         hashmap_free(m->transaction_jobs);
  80         hashmap_free(m->watch_pids);
  81
  82         if (m->epoll_fd >= 0)
  83                 close_nointr(m->epoll_fd);
  84         if (m->signal_fd >= 0)
  85                 close_nointr(m->signal_fd);
  86
  87         free(m);
  88 }
  89
  90 static void transaction_delete_job(Manager *m, Job *j) {
  91         assert(m);
  92         assert(j);
  93
  94         /* Deletes one job from the transaction */
  95
  96         manager_transaction_unlink_job(m, j);
  97
  98         if (!j->linked)
  99                 job_free(j);
 100 }
 101
 102 static void transaction_delete_name(Manager *m, Name *n) {
 103         Job *j;
 104
 105         /* Deletes all jobs associated with a certain name from the
 106          * transaction */
 107
 108         while ((j = hashmap_get(m->transaction_jobs, n)))
 109                 transaction_delete_job(m, j);
 110 }
 111
 112 static void transaction_abort(Manager *m) {
 113         Job *j;
 114
 115         assert(m);
 116
 117         while ((j = hashmap_first(m->transaction_jobs)))
 118                 if (j->linked)
 119                         transaction_delete_job(m, j);
 120                 else
 121                         job_free(j);
 122
 123         assert(hashmap_isempty(m->transaction_jobs));
 124         assert(!m->transaction_anchor);
 125 }
 126
 127 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 128         JobDependency *l;
 129
 130         assert(m);
 131
 132         /* A recursive sweep through the graph that marks all names
 133          * that matter to the anchor job, i.e. are directly or
 134          * indirectly a dependency of the anchor job via paths that
 135          * are fully marked as mattering. */
 136
 137         for (l = j ? j->subject_list : m->transaction_anchor; l; l = l->subject_next) {
 138
 139                 /* This link does not matter */
 140                 if (!l->matters)
 141                         continue;
 142
 143                 /* This name has already been marked */
 144                 if (l->object->generation == generation)
 145                         continue;
 146
 147                 l->object->matters_to_anchor = true;
 148                 l->object->generation = generation;
 149
 150                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 151         }
 152 }
 153
 154 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 155         JobDependency *l, *last;
 156
 157         assert(j);
 158         assert(other);
 159         assert(j->name == other->name);
 160         assert(!j->linked);
 161
 162         /* Merges 'other' into 'j' and then deletes j. */
 163
 164         j->type = t;
 165         j->state = JOB_WAITING;
 166         j->forced = j->forced || other->forced;
 167
 168         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 169
 170         /* Patch us in as new owner of the JobDependency objects */
 171         last = NULL;
 172         for (l = other->subject_list; l; l = l->subject_next) {
 173                 assert(l->subject == other);
 174                 l->subject = j;
 175                 last = l;
 176         }
 177
 178         /* Merge both lists */
 179         if (last) {
 180                 last->subject_next = j->subject_list;
 181                 if (j->subject_list)
 182                         j->subject_list->subject_prev = last;
 183                 j->subject_list = other->subject_list;
 184         }
 185
 186         /* Patch us in as new owner of the JobDependency objects */
 187         last = NULL;
 188         for (l = other->object_list; l; l = l->object_next) {
 189                 assert(l->object == other);
 190                 l->object = j;
 191                 last = l;
 192         }
 193
 194         /* Merge both lists */
 195         if (last) {
 196                 last->object_next = j->object_list;
 197                 if (j->object_list)
 198                         j->object_list->object_prev = last;
 199                 j->object_list = other->object_list;
 200         }
 201
 202         /* Kill the other job */
 203         other->subject_list = NULL;
 204         other->object_list = NULL;
 205         transaction_delete_job(m, other);
 206 }
 207
 208 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 209         Job *k;
 210
 211         assert(j);
 212
 213         /* Tries to delete one item in the linked list
 214          * j->transaction_next->transaction_next->... that conflicts
 215          * whith another one, in an attempt to make an inconsistent
 216          * transaction work. */
 217
 218         /* We rely here on the fact that if a merged with b does not
 219          * merge with c, either a or b merge with c neither */
 220         LIST_FOREACH(transaction, j, j)
 221                 LIST_FOREACH(transaction, k, j->transaction_next) {
 222                         Job *d;
 223
 224                         /* Is this one mergeable? Then skip it */
 225                         if (job_type_is_mergeable(j->type, k->type))
 226                                 continue;
 227
 228                         /* Ok, we found two that conflict, let's see if we can
 229                          * drop one of them */
 230                         if (!j->matters_to_anchor)
 231                                 d = j;
 232                         else if (!k->matters_to_anchor)
 233                                 d = k;
 234                         else
 235                                 return -ENOEXEC;
 236
 237                         /* Ok, we can drop one, so let's do so. */
 238                         log_debug("Try to fix job merging by deleting job %s/%s", name_id(d->name), job_type_to_string(d->type));
 239                         transaction_delete_job(m, d);
 240                         return 0;
 241                 }
 242
 243         return -EINVAL;
 244 }
 245
 246 static int transaction_merge_jobs(Manager *m) {
 247         Job *j;
 248         Iterator i;
 249         int r;
 250
 251         assert(m);
 252
 253         /* First step, check whether any of the jobs for one specific
 254          * task conflict. If so, try to drop one of them. */
 255         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 256                 JobType t;
 257                 Job *k;
 258
 259                 t = j->type;
 260                 LIST_FOREACH(transaction, k, j->transaction_next) {
 261                         if ((r = job_type_merge(&t, k->type)) >= 0)
 262                                 continue;
 263
 264                         /* OK, we could not merge all jobs for this
 265                          * action. Let's see if we can get rid of one
 266                          * of them */
 267
 268                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 269                                 /* Ok, we managed to drop one, now
 270                                  * let's ask our callers to call us
 271                                  * again after garbage collecting */
 272                                 return -EAGAIN;
 273
 274                         /* We couldn't merge anything. Failure */
 275                         return r;
 276                 }
 277         }
 278
 279         /* Second step, merge the jobs. */
 280         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 281                 JobType t = j->type;
 282                 Job *k;
 283
 284                 /* Merge all transactions */
 285                 LIST_FOREACH(transaction, k, j->transaction_next)
 286                         assert_se(job_type_merge(&t, k->type) == 0);
 287
 288                 /* If an active job is mergeable, merge it too */
 289                 if (j->name->meta.job)
 290                         job_type_merge(&t, j->name->meta.job->type); /* Might fail. Which is OK */
 291
 292                 while ((k = j->transaction_next)) {
 293                         if (j->linked) {
 294                                 transaction_merge_and_delete_job(m, k, j, t);
 295                                 j = k;
 296                         } else
 297                                 transaction_merge_and_delete_job(m, j, k, t);
 298                 }
 299
 300                 assert(!j->transaction_next);
 301                 assert(!j->transaction_prev);
 302         }
 303
 304         return 0;
 305 }
 306
 307 static bool name_matters_to_anchor(Name *n, Job *j) {
 308         assert(n);
 309         assert(!j->transaction_prev);
 310
 311         /* Checks whether at least one of the jobs for this name
 312          * matters to the anchor. */
 313
 314         LIST_FOREACH(transaction, j, j)
 315                 if (j->matters_to_anchor)
 316                         return true;
 317
 318         return false;
 319 }
 320
 321 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
 322         Iterator i;
 323         Name *n;
 324         int r;
 325
 326         assert(m);
 327         assert(j);
 328         assert(!j->transaction_prev);
 329
 330         /* Does a recursive sweep through the ordering graph, looking
 331          * for a cycle. If we find cycle we try to break it. */
 332
 333         /* Did we find a cycle? */
 334         if (j->marker && j->generation == generation) {
 335                 Job *k;
 336
 337                 /* So, we already have been here. We have a
 338                  * cycle. Let's try to break it. We go backwards in
 339                  * our path and try to find a suitable job to
 340                  * remove. We use the marker to find our way back,
 341                  * since smart how we are we stored our way back in
 342                  * there. */
 343
 344                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
 345
 346                         if (!k->linked &&
 347                             !name_matters_to_anchor(k->name, k)) {
 348                                 /* Ok, we can drop this one, so let's
 349                                  * do so. */
 350                                 log_debug("Breaking order cycle by deleting job %s/%s", name_id(k->name), job_type_to_string(k->type));
 351                                 transaction_delete_name(m, k->name);
 352                                 return -EAGAIN;
 353                         }
 354
 355                         /* Check if this in fact was the beginning of
 356                          * the cycle */
 357                         if (k == j)
 358                                 break;
 359                 }
 360
 361                 return -ENOEXEC;
 362         }
 363
 364         /* Make the marker point to where we come from, so that we can
 365          * find our way backwards if we want to break a cycle */
 366         j->marker = from;
 367         j->generation = generation;
 368
 369         /* We assume that the the dependencies are bidirectional, and
 370          * hence can ignore NAME_AFTER */
 371         SET_FOREACH(n, j->name->meta.dependencies[NAME_BEFORE], i) {
 372                 Job *o;
 373
 374                 /* Is there a job for this name? */
 375                 if (!(o = hashmap_get(m->transaction_jobs, n)))
 376
 377                         /* Ok, there is no job for this in the
 378                          * transaction, but maybe there is already one
 379                          * running? */
 380                         if (!(o = n->meta.job))
 381                                 continue;
 382
 383                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
 384                         return r;
 385         }
 386
 387         return 0;
 388 }
 389
 390 static int transaction_verify_order(Manager *m, unsigned *generation) {
 391         Job *j;
 392         int r;
 393         Iterator i;
 394
 395         assert(m);
 396         assert(generation);
 397
 398         /* Check if the ordering graph is cyclic. If it is, try to fix
 399          * that up by dropping one of the jobs. */
 400
 401         HASHMAP_FOREACH(j, m->transaction_jobs, i)
 402                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
 403                         return r;
 404
 405         return 0;
 406 }
 407
 408 static void transaction_collect_garbage(Manager *m) {
 409         bool again;
 410
 411         assert(m);
 412
 413         /* Drop jobs that are not required by any other job */
 414
 415         do {
 416                 Iterator i;
 417                 Job *j;
 418
 419                 again = false;
 420
 421                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 422                         if (j->object_list)
 423                                 continue;
 424
 425                         log_debug("Garbage collecting job %s/%s", name_id(j->name), job_type_to_string(j->type));
 426                         transaction_delete_job(m, j);
 427                         again = true;
 428                         break;
 429                 }
 430
 431         } while (again);
 432 }
 433
 434 static int transaction_is_destructive(Manager *m, JobMode mode) {
 435         Iterator i;
 436         Job *j;
 437
 438         assert(m);
 439
 440         /* Checks whether applying this transaction means that
 441          * existing jobs would be replaced */
 442
 443         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 444
 445                 /* Assume merged */
 446                 assert(!j->transaction_prev);
 447                 assert(!j->transaction_next);
 448
 449                 if (j->name->meta.job &&
 450                     j->name->meta.job != j &&
 451                     !job_type_is_superset(j->type, j->name->meta.job->type))
 452                         return -EEXIST;
 453         }
 454
 455         return 0;
 456 }
 457
 458 static void transaction_minimize_impact(Manager *m) {
 459         bool again;
 460         assert(m);
 461
 462         /* Drops all unnecessary jobs that reverse already active jobs
 463          * or that stop a running service. */
 464
 465         do {
 466                 Job *j;
 467                 Iterator i;
 468
 469                 again = false;
 470
 471                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 472                         LIST_FOREACH(transaction, j, j) {
 473
 474                                 /* If it matters, we shouldn't drop it */
 475                                 if (j->matters_to_anchor)
 476                                         continue;
 477
 478                                 /* Would this stop a running service?
 479                                  * Would this change an existing job?
 480                                  * If so, let's drop this entry */
 481                                 if ((j->type != JOB_STOP || NAME_IS_INACTIVE_OR_DEACTIVATING(name_active_state(j->name))) &&
 482                                     (!j->name->meta.job  || job_type_is_conflicting(j->type, j->name->meta.job->state)))
 483                                         continue;
 484
 485                                 /* Ok, let's get rid of this */
 486                                 log_debug("Deleting %s/%s to minimize impact", name_id(j->name), job_type_to_string(j->type));
 487                                 transaction_delete_job(m, j);
 488                                 again = true;
 489                                 break;
 490                         }
 491
 492                         if (again)
 493                                 break;
 494                 }
 495
 496         } while (again);
 497 }
 498
 499 static int transaction_apply(Manager *m, JobMode mode) {
 500         Iterator i;
 501         Job *j;
 502         int r;
 503
 504         /* Moves the transaction jobs to the set of active jobs */
 505
 506         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 507                 /* Assume merged */
 508                 assert(!j->transaction_prev);
 509                 assert(!j->transaction_next);
 510
 511                 if (j->linked)
 512                         continue;
 513
 514                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
 515                         goto rollback;
 516         }
 517
 518         while ((j = hashmap_steal_first(m->transaction_jobs))) {
 519                 if (j->linked)
 520                         continue;
 521
 522                 if (j->name->meta.job)
 523                         job_free(j->name->meta.job);
 524
 525                 j->name->meta.job = j;
 526                 j->linked = true;
 527
 528                 /* We're fully installed. Now let's free data we don't
 529                  * need anymore. */
 530
 531                 assert(!j->transaction_next);
 532                 assert(!j->transaction_prev);
 533
 534                 while (j->subject_list)
 535                         job_dependency_free(j->subject_list);
 536                 while (j->object_list)
 537                         job_dependency_free(j->object_list);
 538         }
 539
 540         m->transaction_anchor = NULL;
 541
 542         return 0;
 543
 544 rollback:
 545
 546         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 547                 if (j->linked)
 548                         continue;
 549
 550                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
 551         }
 552
 553         return r;
 554 }
 555
 556 static int transaction_activate(Manager *m, JobMode mode) {
 557         int r;
 558         unsigned generation = 1;
 559
 560         assert(m);
 561
 562         /* This applies the changes recorded in transaction_jobs to
 563          * the actual list of jobs, if possible. */
 564
 565         /* First step: figure out which jobs matter */
 566         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
 567
 568         /* Second step: Try not to stop any running services if
 569          * we don't have to. Don't try to reverse running
 570          * jobs if we don't have to. */
 571         transaction_minimize_impact(m);
 572
 573         for (;;) {
 574                 /* Third step: Let's remove unneeded jobs that might
 575                  * be lurking. */
 576                 transaction_collect_garbage(m);
 577
 578                 /* Fourth step: verify order makes sense and correct
 579                  * cycles if necessary and possible */
 580                 if ((r = transaction_verify_order(m, &generation)) >= 0)
 581                         break;
 582
 583                 if (r != -EAGAIN)
 584                         goto rollback;
 585
 586                 /* Let's see if the resulting transaction ordering
 587                  * graph is still cyclic... */
 588         }
 589
 590         for (;;) {
 591                 /* Fifth step: let's drop unmergeable entries if
 592                  * necessary and possible, merge entries we can
 593                  * merge */
 594                 if ((r = transaction_merge_jobs(m)) >= 0)
 595                         break;
 596
 597                 if (r != -EAGAIN)
 598                         goto rollback;
 599
 600                 /* Sixth step: an entry got dropped, let's garbage
 601                  * collect its dependencies. */
 602                 transaction_collect_garbage(m);
 603
 604                 /* Let's see if the resulting transaction still has
 605                  * unmergeable entries ... */
 606         }
 607
 608         /* Seventh step: check whether we can actually apply this */
 609         if (mode == JOB_FAIL)
 610                 if ((r = transaction_is_destructive(m, mode)) < 0)
 611                         goto rollback;
 612
 613         /* Eights step: apply changes */
 614         if ((r = transaction_apply(m, mode)) < 0)
 615                 goto rollback;
 616
 617         assert(hashmap_isempty(m->transaction_jobs));
 618         assert(!m->transaction_anchor);
 619
 620         return 0;
 621
 622 rollback:
 623         transaction_abort(m);
 624         return r;
 625 }
 626
 627 static Job* transaction_add_one_job(Manager *m, JobType type, Name *name, bool force, bool *is_new) {
 628         Job *j, *f;
 629         int r;
 630
 631         assert(m);
 632         assert(name);
 633
 634         /* Looks for an axisting prospective job and returns that. If
 635          * it doesn't exist it is created and added to the prospective
 636          * jobs list. */
 637
 638         f = hashmap_get(m->transaction_jobs, name);
 639
 640         LIST_FOREACH(transaction, j, f) {
 641                 assert(j->name == name);
 642
 643                 if (j->type == type) {
 644                         if (is_new)
 645                                 *is_new = false;
 646                         return j;
 647                 }
 648         }
 649
 650         if (name->meta.job && name->meta.job->type == type)
 651                 j = name->meta.job;
 652         else if (!(j = job_new(m, type, name)))
 653                 return NULL;
 654
 655         j->generation = 0;
 656         j->marker = NULL;
 657         j->matters_to_anchor = false;
 658         j->forced = force;
 659
 660         LIST_PREPEND(Job, transaction, f, j);
 661
 662         if ((r = hashmap_replace(m->transaction_jobs, name, f)) < 0) {
 663                 job_free(j);
 664                 return NULL;
 665         }
 666
 667         if (is_new)
 668                 *is_new = true;
 669
 670         return j;
 671 }
 672
 673 void manager_transaction_unlink_job(Manager *m, Job *j) {
 674         assert(m);
 675         assert(j);
 676
 677         if (j->transaction_prev)
 678                 j->transaction_prev->transaction_next = j->transaction_next;
 679         else if (j->transaction_next)
 680                 hashmap_replace(m->transaction_jobs, j->name, j->transaction_next);
 681         else
 682                 hashmap_remove_value(m->transaction_jobs, j->name, j);
 683
 684         if (j->transaction_next)
 685                 j->transaction_next->transaction_prev = j->transaction_prev;
 686
 687         j->transaction_prev = j->transaction_next = NULL;
 688
 689         while (j->subject_list)
 690                 job_dependency_free(j->subject_list);
 691
 692         while (j->object_list) {
 693                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
 694
 695                 job_dependency_free(j->object_list);
 696
 697                 if (other) {
 698                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
 699                                   name_id(other->name), job_type_to_string(other->type),
 700                                   name_id(j->name), job_type_to_string(j->type));
 701                         transaction_delete_job(m, other);
 702                 }
 703         }
 704 }
 705
 706 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Name *name, Job *by, bool matters, bool force, Job **_ret) {
 707         Job *ret;
 708         Iterator i;
 709         Name *dep;
 710         int r;
 711         bool is_new;
 712
 713         assert(m);
 714         assert(type < _JOB_TYPE_MAX);
 715         assert(name);
 716
 717         if (name->meta.load_state != NAME_LOADED)
 718                 return -EINVAL;
 719
 720         if (!name_job_is_applicable(name, type))
 721                 return -EBADR;
 722
 723         /* First add the job. */
 724         if (!(ret = transaction_add_one_job(m, type, name, force, &is_new)))
 725                 return -ENOMEM;
 726
 727         /* Then, add a link to the job. */
 728         if (!job_dependency_new(by, ret, matters))
 729                 return -ENOMEM;
 730
 731         if (is_new) {
 732                 /* Finally, recursively add in all dependencies. */
 733                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
 734                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRES], i)
 735                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
 736                                         goto fail;
 737                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUIRES], i)
 738                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
 739                                         goto fail;
 740                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_WANTS], i)
 741                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
 742                                         goto fail;
 743                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUISITE], i)
 744                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
 745                                         goto fail;
 746                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUISITE], i)
 747                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
 748                                         goto fail;
 749                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_CONFLICTS], i)
 750                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
 751                                         goto fail;
 752
 753                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
 754
 755                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRED_BY], i)
 756                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
 757                                         goto fail;
 758                 }
 759
 760                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
 761         }
 762
 763         return 0;
 764
 765 fail:
 766         return r;
 767 }
 768
 769 int manager_add_job(Manager *m, JobType type, Name *name, JobMode mode, bool force, Job **_ret) {
 770         int r;
 771         Job *ret;
 772
 773         assert(m);
 774         assert(type < _JOB_TYPE_MAX);
 775         assert(name);
 776         assert(mode < _JOB_MODE_MAX);
 777
 778         if ((r = transaction_add_job_and_dependencies(m, type, name, NULL, true, force, &ret))) {
 779                 transaction_abort(m);
 780                 return r;
 781         }
 782
 783         if ((r = transaction_activate(m, mode)) < 0)
 784                 return r;
 785
 786         if (_ret)
 787                 *_ret = ret;
 788
 789         return 0;
 790 }
 791
 792 Job *manager_get_job(Manager *m, uint32_t id) {
 793         assert(m);
 794
 795         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
 796 }
 797
 798 Name *manager_get_name(Manager *m, const char *name) {
 799         assert(m);
 800         assert(name);
 801
 802         return hashmap_get(m->names, name);
 803 }
 804
 805 static void dispatch_load_queue(Manager *m) {
 806         Meta *meta;
 807
 808         assert(m);
 809
 810         /* Make sure we are not run recursively */
 811         if (m->dispatching_load_queue)
 812                 return;
 813
 814         m->dispatching_load_queue = true;
 815
 816         /* Dispatches the load queue. Takes a name from the queue and
 817          * tries to load its data until the queue is empty */
 818
 819         while ((meta = m->load_queue)) {
 820                 assert(meta->linked);
 821                 assert(meta->in_load_queue);
 822
 823                 name_load(NAME(meta));
 824         }
 825
 826         m->dispatching_load_queue = false;
 827 }
 828
 829 int manager_load_name(Manager *m, const char *name, Name **_ret) {
 830         Name *ret;
 831         int r;
 832
 833         assert(m);
 834         assert(name);
 835         assert(_ret);
 836
 837         /* This will load the service information files, but not actually
 838          * start any services or anything */
 839
 840         if ((ret = manager_get_name(m, name))) {
 841                 *_ret = ret;
 842                 return 0;
 843         }
 844
 845         if (!(ret = name_new(m)))
 846                 return -ENOMEM;
 847
 848         if ((r = name_add_name(ret, name)) < 0) {
 849                 name_free(ret);
 850                 return r;
 851         }
 852
 853         if ((r = name_link(ret)) < 0) {
 854                 name_free(ret);
 855                 return r;
 856         }
 857
 858         /* At this point the new entry is created and linked. However
 859          * not loaded. Now load this entry and all its dependencies
 860          * recursively */
 861
 862         dispatch_load_queue(m);
 863
 864         *_ret = ret;
 865         return 0;
 866 }
 867
 868 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
 869         Iterator i;
 870         Job *j;
 871
 872         assert(s);
 873         assert(f);
 874
 875         HASHMAP_FOREACH(j, s->jobs, i)
 876                 job_dump(j, f, prefix);
 877 }
 878
 879 void manager_dump_names(Manager *s, FILE *f, const char *prefix) {
 880         Iterator i;
 881         Name *n;
 882         const char *t;
 883
 884         assert(s);
 885         assert(f);
 886
 887         HASHMAP_FOREACH_KEY(n, t, s->names, i)
 888                 if (name_id(n) == t)
 889                         name_dump(n, f, prefix);
 890 }
 891
 892 void manager_clear_jobs(Manager *m) {
 893         Job *j;
 894
 895         assert(m);
 896
 897         transaction_abort(m);
 898
 899         while ((j = hashmap_first(m->jobs)))
 900                 job_free(j);
 901 }
 902
 903 void manager_dispatch_run_queue(Manager *m) {
 904         Job *j;
 905
 906         if (m->dispatching_run_queue)
 907                 return;
 908
 909         m->dispatching_run_queue = true;
 910
 911         while ((j = m->run_queue)) {
 912                 assert(j->linked);
 913                 assert(j->in_run_queue);
 914
 915                 job_run_and_invalidate(j);
 916         }
 917
 918         m->dispatching_run_queue = false;
 919 }
 920
 921 static int manager_dispatch_sigchld(Manager *m) {
 922         assert(m);
 923
 924         for (;;) {
 925                 siginfo_t si;
 926                 Name *n;
 927
 928                 zero(si);
 929                 if (waitid(P_ALL, 0, &si, WNOHANG) < 0)
 930                         return -errno;
 931
 932                 if (si.si_pid == 0)
 933                         break;
 934
 935                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
 936                         continue;
 937
 938                 if (!(n = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
 939                         continue;
 940
 941                 NAME_VTABLE(n)->sigchld_event(n, si.si_pid, si.si_code, si.si_status);
 942         }
 943
 944         return 0;
 945 }
 946
 947 static int manager_process_signal_fd(Manager *m) {
 948         ssize_t n;
 949         struct signalfd_siginfo sfsi;
 950         bool sigchld = false;
 951
 952         assert(m);
 953
 954         for (;;) {
 955                 if ((n = read(m->signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
 956
 957                         if (n >= 0)
 958                                 return -EIO;
 959
 960                         if (errno == EAGAIN)
 961                                 return 0;
 962
 963                         return -errno;
 964                 }
 965
 966                 if (sfsi.ssi_signo == SIGCHLD)
 967                         sigchld = true;
 968         }
 969
 970         if (sigchld)
 971                 return manager_dispatch_sigchld(m);
 972
 973         return 0;
 974 }
 975
 976 static int process_event(Manager *m, struct epoll_event *ev) {
 977         int r;
 978
 979         assert(m);
 980         assert(ev);
 981
 982         switch (ev->data.u32) {
 983
 984                 case MANAGER_SIGNAL:
 985                         assert(ev->data.fd == m->signal_fd);
 986
 987                         /* An incoming signal? */
 988                         if (ev->events != POLLIN)
 989                                 return -EINVAL;
 990
 991                         if ((r = manager_process_signal_fd(m)) < 0)
 992                                 return -r;
 993
 994                         break;
 995
 996                 case MANAGER_FD: {
 997                         Name *n;
 998
 999                         /* Some fd event, to be dispatched to the names */
1000                         assert_se(n = ev->data.ptr);
1001                         NAME_VTABLE(n)->fd_event(n, ev->data.fd, ev->events);
1002                         break;
1003                 }
1004
1005                 case MANAGER_TIMER: {
1006                         Name *n;
1007                         uint64_t u;
1008                         ssize_t k;
1009
1010                         /* Some timer event, to be dispatched to the names */
1011                         if ((k = read(ev->data.fd, &u, sizeof(u))) != sizeof(u)) {
1012
1013                                 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1014                                         break;
1015
1016                                 return k < 0 ? -errno : -EIO;
1017                         }
1018
1019                         assert_se(n = ev->data.ptr);
1020                         NAME_VTABLE(n)->timer_event(n, ev->data.fd, u);
1021                         break;
1022                 }
1023
1024                 default:
1025                         assert_not_reached("Unknown epoll event type.");
1026         }
1027
1028         return 0;
1029 }
1030
1031 int manager_loop(Manager *m) {
1032         int r;
1033
1034         assert(m);
1035
1036         for (;;) {
1037                 struct epoll_event events[32];
1038                 int n, i;
1039
1040                 manager_dispatch_run_queue(m);
1041
1042                 if ((n = epoll_wait(m->epoll_fd, events, ELEMENTSOF(events), -1)) < 0) {
1043
1044                         if (errno == -EINTR)
1045                                 continue;
1046
1047                         return -errno;
1048                 }
1049
1050                 for (i = 0; i < n; i++)
1051                         if ((r = process_event(m, events + i)) < 0)
1052                                 return r;
1053         }
1054 }