manager.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #include <assert.h>
   4 #include <errno.h>
   5 #include <string.h>
   6
   7 #include "manager.h"
   8 #include "hashmap.h"
   9 #include "macro.h"
  10 #include "strv.h"
  11 #include "log.h"
  12
  13 Manager* manager_new(void) {
  14         Manager *m;
  15
  16         if (!(m = new0(Manager, 1)))
  17                 return NULL;
  18
  19         if (!(m->names = hashmap_new(string_hash_func, string_compare_func)))
  20                 goto fail;
  21
  22         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
  23                 goto fail;
  24
  25         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
  26                 goto fail;
  27
  28         return m;
  29
  30 fail:
  31         manager_free(m);
  32         return NULL;
  33 }
  34
  35 void manager_free(Manager *m) {
  36         Name *n;
  37         Job *j;
  38
  39         assert(m);
  40
  41         while ((n = hashmap_first(m->names)))
  42                 name_free(n);
  43
  44         while ((j = hashmap_steal_first(m->transaction_jobs)))
  45                 job_free(j);
  46
  47         hashmap_free(m->names);
  48         hashmap_free(m->jobs);
  49         hashmap_free(m->transaction_jobs);
  50
  51         free(m);
  52 }
  53
  54 static void transaction_delete_job(Manager *m, Job *j) {
  55         assert(m);
  56         assert(j);
  57
  58         /* Deletes one job from the transaction */
  59
  60         manager_transaction_unlink_job(m, j);
  61
  62         if (!j->linked)
  63                 job_free(j);
  64 }
  65
  66 static void transaction_delete_name(Manager *m, Name *n) {
  67         Job *j;
  68
  69         /* Deletes all jobs associated with a certain name from the
  70          * transaction */
  71
  72         while ((j = hashmap_get(m->transaction_jobs, n)))
  73                 transaction_delete_job(m, j);
  74 }
  75
  76 static void transaction_abort(Manager *m) {
  77         Job *j;
  78
  79         assert(m);
  80
  81         while ((j = hashmap_first(m->transaction_jobs)))
  82                 if (j->linked)
  83                         transaction_delete_job(m, j);
  84                 else
  85                         job_free(j);
  86
  87         assert(hashmap_isempty(m->transaction_jobs));
  88         assert(!m->transaction_anchor);
  89 }
  90
  91 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
  92         JobDependency *l;
  93
  94         assert(m);
  95
  96         /* A recursive sweep through the graph that marks all names
  97          * that matter to the anchor job, i.e. are directly or
  98          * indirectly a dependency of the anchor job via paths that
  99          * are fully marked as mattering. */
 100
 101         for (l = j ? j->subject_list : m->transaction_anchor; l; l = l->subject_next) {
 102
 103                 /* This link does not matter */
 104                 if (!l->matters)
 105                         continue;
 106
 107                 /* This name has already been marked */
 108                 if (l->object->generation == generation)
 109                         continue;
 110
 111                 l->object->matters_to_anchor = true;
 112                 l->object->generation = generation;
 113
 114                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 115         }
 116 }
 117
 118 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 119         JobDependency *l, *last;
 120
 121         assert(j);
 122         assert(other);
 123         assert(j->name == other->name);
 124         assert(!j->linked);
 125
 126         /* Merges 'other' into 'j' and then deletes j. */
 127
 128         j->type = t;
 129         j->state = JOB_WAITING;
 130         j->forced = j->forced || other->forced;
 131
 132         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 133
 134         /* Patch us in as new owner of the JobDependency objects */
 135         last = NULL;
 136         for (l = other->subject_list; l; l = l->subject_next) {
 137                 assert(l->subject == other);
 138                 l->subject = j;
 139                 last = l;
 140         }
 141
 142         /* Merge both lists */
 143         if (last) {
 144                 last->subject_next = j->subject_list;
 145                 if (j->subject_list)
 146                         j->subject_list->subject_prev = last;
 147                 j->subject_list = other->subject_list;
 148         }
 149
 150         /* Patch us in as new owner of the JobDependency objects */
 151         last = NULL;
 152         for (l = other->object_list; l; l = l->object_next) {
 153                 assert(l->object == other);
 154                 l->object = j;
 155                 last = l;
 156         }
 157
 158         /* Merge both lists */
 159         if (last) {
 160                 last->object_next = j->object_list;
 161                 if (j->object_list)
 162                         j->object_list->object_prev = last;
 163                 j->object_list = other->object_list;
 164         }
 165
 166         /* Kill the other job */
 167         other->subject_list = NULL;
 168         other->object_list = NULL;
 169         transaction_delete_job(m, other);
 170 }
 171
 172 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 173         Job *k;
 174
 175         assert(j);
 176
 177         /* Tries to delete one item in the linked list
 178          * j->transaction_next->transaction_next->... that conflicts
 179          * whith another one, in an attempt to make an inconsistent
 180          * transaction work. */
 181
 182         /* We rely here on the fact that if a merged with b does not
 183          * merge with c, either a or b merge with c neither */
 184         for (; j; j = j->transaction_next)
 185                 for (k = j->transaction_next; k; k = k->transaction_next) {
 186                         Job *d;
 187
 188                         /* Is this one mergeable? Then skip it */
 189                         if (job_type_is_mergeable(j->type, k->type))
 190                                 continue;
 191
 192                         /* Ok, we found two that conflict, let's see if we can
 193                          * drop one of them */
 194                         if (!j->matters_to_anchor)
 195                                 d = j;
 196                         else if (!k->matters_to_anchor)
 197                                 d = k;
 198                         else
 199                                 return -ENOEXEC;
 200
 201                         /* Ok, we can drop one, so let's do so. */
 202                         log_debug("Try to fix job merging by deleting job %s/%s", name_id(d->name), job_type_to_string(d->type));
 203                         transaction_delete_job(m, d);
 204                         return 0;
 205                 }
 206
 207         return -EINVAL;
 208 }
 209
 210 static int transaction_merge_jobs(Manager *m) {
 211         Job *j;
 212         void *state;
 213         int r;
 214
 215         assert(m);
 216
 217         /* First step, check whether any of the jobs for one specific
 218          * task conflict. If so, try to drop one of them. */
 219         HASHMAP_FOREACH(j, m->transaction_jobs, state) {
 220                 JobType t;
 221                 Job *k;
 222
 223                 t = j->type;
 224                 for (k = j->transaction_next; k; k = k->transaction_next) {
 225                         if ((r = job_type_merge(&t, k->type)) >= 0)
 226                                 continue;
 227
 228                         /* OK, we could not merge all jobs for this
 229                          * action. Let's see if we can get rid of one
 230                          * of them */
 231
 232                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 233                                 /* Ok, we managed to drop one, now
 234                                  * let's ask our callers to call us
 235                                  * again after garbage collecting */
 236                                 return -EAGAIN;
 237
 238                         /* We couldn't merge anything. Failure */
 239                         return r;
 240                 }
 241         }
 242
 243         /* Second step, merge the jobs. */
 244         HASHMAP_FOREACH(j, m->transaction_jobs, state) {
 245                 JobType t = j->type;
 246                 Job *k;
 247
 248                 /* Merge all transactions */
 249                 for (k = j->transaction_next; k; k = k->transaction_next)
 250                         assert_se(job_type_merge(&t, k->type) == 0);
 251
 252                 /* If an active job is mergeable, merge it too */
 253                 if (j->name->meta.job)
 254                         job_type_merge(&t, j->name->meta.job->type); /* Might fail. Which is OK */
 255
 256                 while ((k = j->transaction_next)) {
 257                         if (j->linked) {
 258                                 transaction_merge_and_delete_job(m, k, j, t);
 259                                 j = k;
 260                         } else
 261                                 transaction_merge_and_delete_job(m, j, k, t);
 262                 }
 263
 264                 assert(!j->transaction_next);
 265                 assert(!j->transaction_prev);
 266         }
 267
 268         return 0;
 269 }
 270
 271 static bool name_matters_to_anchor(Name *n, Job *j) {
 272         assert(n);
 273         assert(!j->transaction_prev);
 274
 275         /* Checks whether at least one of the jobs for this name
 276          * matters to the anchor. */
 277
 278         for (; j; j = j->transaction_next)
 279                 if (j->matters_to_anchor)
 280                         return true;
 281
 282         return false;
 283 }
 284
 285 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
 286         void *state;
 287         Name *n;
 288         int r;
 289
 290         assert(m);
 291         assert(j);
 292         assert(!j->transaction_prev);
 293
 294         /* Does a recursive sweep through the ordering graph, looking
 295          * for a cycle. If we find cycle we try to break it. */
 296
 297         /* Did we find a cycle? */
 298         if (j->marker && j->generation == generation) {
 299                 Job *k;
 300
 301                 /* So, we already have been here. We have a
 302                  * cycle. Let's try to break it. We go backwards in
 303                  * our path and try to find a suitable job to
 304                  * remove. We use the marker to find our way back,
 305                  * since smart how we are we stored our way back in
 306                  * there. */
 307
 308                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
 309
 310                         if (!k->linked &&
 311                             !name_matters_to_anchor(k->name, k)) {
 312                                 /* Ok, we can drop this one, so let's
 313                                  * do so. */
 314                                 log_debug("Breaking order cycle by deleting job %s/%s", name_id(k->name), job_type_to_string(k->type));
 315                                 transaction_delete_name(m, k->name);
 316                                 return -EAGAIN;
 317                         }
 318
 319                         /* Check if this in fact was the beginning of
 320                          * the cycle */
 321                         if (k == j)
 322                                 break;
 323                 }
 324
 325                 return -ENOEXEC;
 326         }
 327
 328         /* Make the marker point to where we come from, so that we can
 329          * find our way backwards if we want to break a cycle */
 330         j->marker = from;
 331         j->generation = generation;
 332
 333         /* We assume that the the dependencies are bidirectional, and
 334          * hence can ignore NAME_AFTER */
 335         SET_FOREACH(n, j->name->meta.dependencies[NAME_BEFORE], state) {
 336                 Job *o;
 337
 338                 /* Is there a job for this name? */
 339                 if (!(o = hashmap_get(m->transaction_jobs, n)))
 340
 341                         /* Ok, there is no job for this in the
 342                          * transaction, but maybe there is already one
 343                          * running? */
 344                         if (!(o = n->meta.job))
 345                                 continue;
 346
 347                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
 348                         return r;
 349         }
 350
 351         return 0;
 352 }
 353
 354 static int transaction_verify_order(Manager *m, unsigned *generation) {
 355         Job *j;
 356         int r;
 357         void *state;
 358
 359         assert(m);
 360         assert(generation);
 361
 362         /* Check if the ordering graph is cyclic. If it is, try to fix
 363          * that up by dropping one of the jobs. */
 364
 365         HASHMAP_FOREACH(j, m->transaction_jobs, state)
 366                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
 367                         return r;
 368
 369         return 0;
 370 }
 371
 372 static void transaction_collect_garbage(Manager *m) {
 373         bool again;
 374
 375         assert(m);
 376
 377         /* Drop jobs that are not required by any other job */
 378
 379         do {
 380                 void *state;
 381                 Job *j;
 382
 383                 again = false;
 384
 385                 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
 386                         if (j->object_list)
 387                                 continue;
 388
 389                         log_debug("Garbage collecting job %s/%s", name_id(j->name), job_type_to_string(j->type));
 390                         transaction_delete_job(m, j);
 391                         again = true;
 392                         break;
 393                 }
 394
 395         } while (again);
 396 }
 397
 398 static int transaction_is_destructive(Manager *m, JobMode mode) {
 399         void *state;
 400         Job *j;
 401
 402         assert(m);
 403
 404         /* Checks whether applying this transaction means that
 405          * existing jobs would be replaced */
 406
 407         HASHMAP_FOREACH(j, m->transaction_jobs, state) {
 408
 409                 /* Assume merged */
 410                 assert(!j->transaction_prev);
 411                 assert(!j->transaction_next);
 412
 413                 if (j->name->meta.job &&
 414                     j->name->meta.job != j &&
 415                     !job_type_is_superset(j->type, j->name->meta.job->type))
 416                         return -EEXIST;
 417         }
 418
 419         return 0;
 420 }
 421
 422 static void transaction_minimize_impact(Manager *m) {
 423         bool again;
 424         assert(m);
 425
 426         /* Drops all unnecessary jobs that reverse already active jobs
 427          * or that stop a running service. */
 428
 429         do {
 430                 Job *j;
 431                 void *state;
 432
 433                 again = false;
 434
 435                 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
 436                         for (; j; j = j->transaction_next) {
 437
 438                                 /* If it matters, we shouldn't drop it */
 439                                 if (j->matters_to_anchor)
 440                                         continue;
 441
 442                                 /* Would this stop a running service?
 443                                  * Would this change an existing job?
 444                                  * If so, let's drop this entry */
 445                                 if ((j->type != JOB_STOP || NAME_IS_INACTIVE_OR_DEACTIVATING(name_active_state(j->name))) &&
 446                                     (!j->name->meta.job  || job_type_is_conflicting(j->type, j->name->meta.job->state)))
 447                                         continue;
 448
 449                                 /* Ok, let's get rid of this */
 450                                 log_debug("Deleting %s/%s to minimize impact", name_id(j->name), job_type_to_string(j->type));
 451                                 transaction_delete_job(m, j);
 452                                 again = true;
 453                                 break;
 454                         }
 455
 456                         if (again)
 457                                 break;
 458                 }
 459
 460         } while (again);
 461 }
 462
 463 static int transaction_apply(Manager *m, JobMode mode) {
 464         void *state;
 465         Job *j;
 466         int r;
 467
 468         /* Moves the transaction jobs to the set of active jobs */
 469
 470         HASHMAP_FOREACH(j, m->transaction_jobs, state) {
 471                 /* Assume merged */
 472                 assert(!j->transaction_prev);
 473                 assert(!j->transaction_next);
 474
 475                 if (j->linked)
 476                         continue;
 477
 478                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
 479                         goto rollback;
 480         }
 481
 482         while ((j = hashmap_steal_first(m->transaction_jobs))) {
 483                 if (j->linked)
 484                         continue;
 485
 486                 if (j->name->meta.job)
 487                         job_free(j->name->meta.job);
 488
 489                 j->name->meta.job = j;
 490                 j->linked = true;
 491
 492                 /* We're fully installed. Now let's free data we don't
 493                  * need anymore. */
 494
 495                 assert(!j->transaction_next);
 496                 assert(!j->transaction_prev);
 497
 498                 while (j->subject_list)
 499                         job_dependency_free(j->subject_list);
 500                 while (j->object_list)
 501                         job_dependency_free(j->object_list);
 502         }
 503
 504         m->transaction_anchor = NULL;
 505
 506         return 0;
 507
 508 rollback:
 509
 510         HASHMAP_FOREACH(j, m->transaction_jobs, state) {
 511                 if (j->linked)
 512                         continue;
 513
 514                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
 515         }
 516
 517         return r;
 518 }
 519
 520 static int transaction_activate(Manager *m, JobMode mode) {
 521         int r;
 522         unsigned generation = 1;
 523
 524         assert(m);
 525
 526         /* This applies the changes recorded in transaction_jobs to
 527          * the actual list of jobs, if possible. */
 528
 529         /* First step: figure out which jobs matter */
 530         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
 531
 532         /* Second step: Try not to stop any running services if
 533          * we don't have to. Don't try to reverse running
 534          * jobs if we don't have to. */
 535         transaction_minimize_impact(m);
 536
 537         for (;;) {
 538                 /* Third step: Let's remove unneeded jobs that might
 539                  * be lurking. */
 540                 transaction_collect_garbage(m);
 541
 542                 /* Fourth step: verify order makes sense and correct
 543                  * cycles if necessary and possible */
 544                 if ((r = transaction_verify_order(m, &generation)) >= 0)
 545                         break;
 546
 547                 if (r != -EAGAIN)
 548                         goto rollback;
 549
 550                 /* Let's see if the resulting transaction ordering
 551                  * graph is still cyclic... */
 552         }
 553
 554         for (;;) {
 555                 /* Fifth step: let's drop unmergeable entries if
 556                  * necessary and possible, merge entries we can
 557                  * merge */
 558                 if ((r = transaction_merge_jobs(m)) >= 0)
 559                         break;
 560
 561                 if (r != -EAGAIN)
 562                         goto rollback;
 563
 564                 /* Sixth step: an entry got dropped, let's garbage
 565                  * collect its dependencies. */
 566                 transaction_collect_garbage(m);
 567
 568                 /* Let's see if the resulting transaction still has
 569                  * unmergeable entries ... */
 570         }
 571
 572         /* Seventh step: check whether we can actually apply this */
 573         if (mode == JOB_FAIL)
 574                 if ((r = transaction_is_destructive(m, mode)) < 0)
 575                         goto rollback;
 576
 577         /* Eights step: apply changes */
 578         if ((r = transaction_apply(m, mode)) < 0)
 579                 goto rollback;
 580
 581         assert(hashmap_isempty(m->transaction_jobs));
 582         assert(!m->transaction_anchor);
 583
 584         return 0;
 585
 586 rollback:
 587         transaction_abort(m);
 588         return r;
 589 }
 590
 591 static Job* transaction_add_one_job(Manager *m, JobType type, Name *name, bool force, bool *is_new) {
 592         Job *j, *f;
 593         int r;
 594
 595         assert(m);
 596         assert(name);
 597
 598         /* Looks for an axisting prospective job and returns that. If
 599          * it doesn't exist it is created and added to the prospective
 600          * jobs list. */
 601
 602         f = hashmap_get(m->transaction_jobs, name);
 603
 604         for (j = f; j; j = j->transaction_next) {
 605                 assert(j->name == name);
 606
 607                 if (j->type == type) {
 608                         if (is_new)
 609                                 *is_new = false;
 610                         return j;
 611                 }
 612         }
 613
 614         if (name->meta.job && name->meta.job->type == type)
 615                 j = name->meta.job;
 616         else if (!(j = job_new(m, type, name)))
 617                 return NULL;
 618
 619         if ((r = hashmap_replace(m->transaction_jobs, name, j)) < 0) {
 620                 job_free(j);
 621                 return NULL;
 622         }
 623
 624         j->transaction_next = f;
 625
 626         if (f)
 627                 f->transaction_prev = j;
 628
 629         j->generation = 0;
 630         j->marker = NULL;
 631         j->matters_to_anchor = false;
 632         j->forced = force;
 633
 634         if (is_new)
 635                 *is_new = true;
 636
 637         return j;
 638 }
 639
 640 void manager_transaction_unlink_job(Manager *m, Job *j) {
 641         assert(m);
 642         assert(j);
 643
 644         if (j->transaction_prev)
 645                 j->transaction_prev->transaction_next = j->transaction_next;
 646         else if (j->transaction_next)
 647                 hashmap_replace(m->transaction_jobs, j->name, j->transaction_next);
 648         else
 649                 hashmap_remove_value(m->transaction_jobs, j->name, j);
 650
 651         if (j->transaction_next)
 652                 j->transaction_next->transaction_prev = j->transaction_prev;
 653
 654         j->transaction_prev = j->transaction_next = NULL;
 655
 656         while (j->subject_list)
 657                 job_dependency_free(j->subject_list);
 658
 659         while (j->object_list) {
 660                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
 661
 662                 job_dependency_free(j->object_list);
 663
 664                 if (other) {
 665                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
 666                                   name_id(other->name), job_type_to_string(other->type),
 667                                   name_id(j->name), job_type_to_string(j->type));
 668                         transaction_delete_job(m, other);
 669                 }
 670         }
 671 }
 672
 673 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Name *name, Job *by, bool matters, bool force, Job **_ret) {
 674         Job *ret;
 675         void *state;
 676         Name *dep;
 677         int r;
 678         bool is_new;
 679
 680         assert(m);
 681         assert(type < _JOB_TYPE_MAX);
 682         assert(name);
 683
 684         if (name->meta.load_state != NAME_LOADED)
 685                 return -EINVAL;
 686
 687         if (!job_type_is_applicable(type, name->meta.type))
 688                 return -EBADR;
 689
 690         /* First add the job. */
 691         if (!(ret = transaction_add_one_job(m, type, name, force, &is_new)))
 692                 return -ENOMEM;
 693
 694         /* Then, add a link to the job. */
 695         if (!job_dependency_new(by, ret, matters))
 696                 return -ENOMEM;
 697
 698         if (is_new) {
 699                 /* Finally, recursively add in all dependencies. */
 700                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
 701                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRES], state)
 702                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL))  != -EBADR)
 703                                         goto fail;
 704                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUIRES], state)
 705                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) != -EBADR)
 706                                         goto fail;
 707                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_WANTS], state)
 708                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) != -EBADR)
 709                                         goto fail;
 710                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUISITE], state)
 711                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) != -EBADR)
 712                                         goto fail;
 713                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUISITE], state)
 714                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) != -EBADR)
 715                                         goto fail;
 716                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_CONFLICTS], state)
 717                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) != -EBADR)
 718                                         goto fail;
 719
 720                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
 721
 722                         SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRED_BY], state)
 723                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL))  != -EBADR)
 724                                         goto fail;
 725                 }
 726
 727                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
 728         }
 729
 730         return 0;
 731
 732 fail:
 733         return r;
 734 }
 735
 736 int manager_add_job(Manager *m, JobType type, Name *name, JobMode mode, bool force, Job **_ret) {
 737         int r;
 738         Job *ret;
 739
 740         assert(m);
 741         assert(type < _JOB_TYPE_MAX);
 742         assert(name);
 743         assert(mode < _JOB_MODE_MAX);
 744
 745         if ((r = transaction_add_job_and_dependencies(m, type, name, NULL, true, force, &ret))) {
 746                 transaction_abort(m);
 747                 return r;
 748         }
 749
 750         if ((r = transaction_activate(m, mode)) < 0)
 751                 return r;
 752
 753         if (_ret)
 754                 *_ret = ret;
 755
 756         return 0;
 757 }
 758
 759 Job *manager_get_job(Manager *m, uint32_t id) {
 760         assert(m);
 761
 762         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
 763 }
 764
 765 Name *manager_get_name(Manager *m, const char *name) {
 766         assert(m);
 767         assert(name);
 768
 769         return hashmap_get(m->names, name);
 770 }
 771
 772 static int dispatch_load_queue(Manager *m) {
 773         Meta *meta;
 774
 775         assert(m);
 776
 777         /* Make sure we are not run recursively */
 778         if (m->dispatching_load_queue)
 779                 return 0;
 780
 781         m->dispatching_load_queue = true;
 782
 783         /* Dispatches the load queue. Takes a name from the queue and
 784          * tries to load its data until the queue is empty */
 785
 786         while ((meta = m->load_queue)) {
 787                 name_load(NAME(meta));
 788                 LIST_REMOVE(Meta, m->load_queue, meta);
 789         }
 790
 791         m->dispatching_load_queue = false;
 792
 793         return 0;
 794 }
 795
 796 int manager_load_name(Manager *m, const char *name, Name **_ret) {
 797         Name *ret;
 798         NameType t;
 799         int r;
 800         char *n;
 801
 802         assert(m);
 803         assert(name);
 804         assert(_ret);
 805
 806         if (!name_is_valid(name))
 807                 return -EINVAL;
 808
 809         /* This will load the service information files, but not actually
 810          * start any services or anything */
 811
 812         if ((ret = manager_get_name(m, name)))
 813                 goto finish;
 814
 815         if ((t = name_type_from_string(name)) == _NAME_TYPE_INVALID)
 816                 return -EINVAL;
 817
 818         if (!(ret = name_new(m)))
 819                 return -ENOMEM;
 820
 821         ret->meta.type = t;
 822
 823         if (!(n = strdup(name))) {
 824                 name_free(ret);
 825                 return -ENOMEM;
 826         }
 827
 828         if ((r = set_put(ret->meta.names, n)) < 0) {
 829                 name_free(ret);
 830                 free(n);
 831                 return r;
 832         }
 833
 834         if ((r = name_link(ret)) < 0) {
 835                 name_free(ret);
 836                 return r;
 837         }
 838
 839         /* At this point the new entry is created and linked. However,
 840          * not loaded. Now load this entry and all its dependencies
 841          * recursively */
 842
 843         dispatch_load_queue(m);
 844
 845 finish:
 846
 847         *_ret = ret;
 848         return 0;
 849 }
 850
 851 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
 852         void *state;
 853         Job *j;
 854
 855         assert(s);
 856         assert(f);
 857
 858         HASHMAP_FOREACH(j, s->jobs, state)
 859                 job_dump(j, f, prefix);
 860 }
 861
 862 void manager_dump_names(Manager *s, FILE *f, const char *prefix) {
 863         void *state;
 864         Name *n;
 865         const char *t;
 866
 867         assert(s);
 868         assert(f);
 869
 870         HASHMAP_FOREACH_KEY(n, t, s->names, state)
 871                 if (name_id(n) == t)
 872                         name_dump(n, f, prefix);
 873 }
 874
 875 void manager_clear_jobs(Manager *m) {
 876         Job *j;
 877
 878         assert(m);
 879
 880         transaction_abort(m);
 881
 882         while ((j = hashmap_first(m->jobs)))
 883                 job_free(j);
 884 }