src/core/job.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #pragma once
   4
   5 /***
   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 ***/
  23
  24 #include <stdbool.h>
  25
  26 #include "sd-event.h"
  27
  28 #include "list.h"
  29 #include "unit-name.h"
  30
  31 typedef struct Job Job;
  32 typedef struct JobDependency JobDependency;
  33 typedef enum JobType JobType;
  34 typedef enum JobState JobState;
  35 typedef enum JobMode JobMode;
  36 typedef enum JobResult JobResult;
  37
  38 /* Be careful when changing the job types! Adjust job_merging_table[] accordingly! */
  39 enum JobType {
  40         JOB_START,                  /* if a unit does not support being started, we'll just wait until it becomes active */
  41         JOB_VERIFY_ACTIVE,
  42
  43         JOB_STOP,
  44
  45         JOB_RELOAD,                 /* if running, reload */
  46
  47         /* Note that restarts are first treated like JOB_STOP, but
  48          * then instead of finishing are patched to become
  49          * JOB_START. */
  50         JOB_RESTART,                /* If running, stop. Then start unconditionally. */
  51
  52         _JOB_TYPE_MAX_MERGING,
  53
  54         /* JOB_NOP can enter into a transaction, but as it won't pull in
  55          * any dependencies and it uses the special 'nop_job' slot in Unit,
  56          * it won't have to merge with anything (except possibly into another
  57          * JOB_NOP, previously installed). JOB_NOP is special-cased in
  58          * job_type_is_*() functions so that the transaction can be
  59          * activated. */
  60         JOB_NOP = _JOB_TYPE_MAX_MERGING, /* do nothing */
  61
  62         _JOB_TYPE_MAX_IN_TRANSACTION,
  63
  64         /* JOB_TRY_RESTART can never appear in a transaction, because
  65          * it always collapses into JOB_RESTART or JOB_NOP before entering.
  66          * Thus we never need to merge it with anything. */
  67         JOB_TRY_RESTART = _JOB_TYPE_MAX_IN_TRANSACTION, /* if running, stop and then start */
  68
  69         /* JOB_RELOAD_OR_START won't enter into a transaction and cannot result
  70          * from transaction merging (there's no way for JOB_RELOAD and
  71          * JOB_START to meet in one transaction). It can result from a merge
  72          * during job installation, but then it will immediately collapse into
  73          * one of the two simpler types. */
  74         JOB_RELOAD_OR_START,        /* if running, reload, otherwise start */
  75
  76         _JOB_TYPE_MAX,
  77         _JOB_TYPE_INVALID = -1
  78 };
  79
  80 enum JobState {
  81         JOB_WAITING,
  82         JOB_RUNNING,
  83         _JOB_STATE_MAX,
  84         _JOB_STATE_INVALID = -1
  85 };
  86
  87 enum JobMode {
  88         JOB_FAIL,                /* Fail if a conflicting job is already queued */
  89         JOB_REPLACE,             /* Replace an existing conflicting job */
  90         JOB_REPLACE_IRREVERSIBLY,/* Like JOB_REPLACE + produce irreversible jobs */
  91         JOB_ISOLATE,             /* Start a unit, and stop all others */
  92         JOB_FLUSH,               /* Flush out all other queued jobs when queing this one */
  93         JOB_IGNORE_DEPENDENCIES, /* Ignore both requirement and ordering dependencies */
  94         JOB_IGNORE_REQUIREMENTS, /* Ignore requirement dependencies */
  95         _JOB_MODE_MAX,
  96         _JOB_MODE_INVALID = -1
  97 };
  98
  99 enum JobResult {
 100         JOB_DONE,                /* Job completed successfully */
 101         JOB_CANCELED,            /* Job canceled by a conflicting job installation or by explicit cancel request */
 102         JOB_TIMEOUT,             /* Job timeout elapsed */
 103         JOB_FAILED,              /* Job failed */
 104         JOB_DEPENDENCY,          /* A required dependency job did not result in JOB_DONE */
 105         JOB_SKIPPED,             /* Negative result of JOB_VERIFY_ACTIVE */
 106         JOB_INVALID,             /* JOB_RELOAD of inactive unit */
 107         JOB_ASSERT,              /* Couldn't start a unit, because an assert didn't hold */
 108         JOB_UNSUPPORTED,         /* Couldn't start a unit, because the unit type is not supported on the system */
 109         _JOB_RESULT_MAX,
 110         _JOB_RESULT_INVALID = -1
 111 };
 112
 113 #include "unit.h"
 114
 115 struct JobDependency {
 116         /* Encodes that the 'subject' job needs the 'object' job in
 117          * some way. This structure is used only while building a transaction. */
 118         Job *subject;
 119         Job *object;
 120
 121         LIST_FIELDS(JobDependency, subject);
 122         LIST_FIELDS(JobDependency, object);
 123
 124         bool matters;
 125         bool conflicts;
 126 };
 127
 128 struct Job {
 129         Manager *manager;
 130         Unit *unit;
 131
 132         LIST_FIELDS(Job, transaction);
 133         LIST_FIELDS(Job, run_queue);
 134         LIST_FIELDS(Job, dbus_queue);
 135
 136         LIST_HEAD(JobDependency, subject_list);
 137         LIST_HEAD(JobDependency, object_list);
 138
 139         /* Used for graph algs as a "I have been here" marker */
 140         Job* marker;
 141         unsigned generation;
 142
 143         uint32_t id;
 144
 145         JobType type;
 146         JobState state;
 147
 148         sd_event_source *timer_event_source;
 149         usec_t begin_usec;
 150
 151         /*
 152          * This tracks where to send signals, and also which clients
 153          * are allowed to call DBus methods on the job (other than
 154          * root).
 155          *
 156          * There can be more than one client, because of job merging.
 157          */
 158         sd_bus_track *clients;
 159         char **deserialized_clients;
 160
 161         JobResult result;
 162
 163         bool installed:1;
 164         bool in_run_queue:1;
 165         bool matters_to_anchor:1;
 166         bool in_dbus_queue:1;
 167         bool sent_dbus_new_signal:1;
 168         bool ignore_order:1;
 169         bool irreversible:1;
 170 };
 171
 172 Job* job_new(Unit *unit, JobType type);
 173 Job* job_new_raw(Unit *unit);
 174 void job_free(Job *job);
 175 Job* job_install(Job *j);
 176 int job_install_deserialized(Job *j);
 177 void job_uninstall(Job *j);
 178 void job_dump(Job *j, FILE*f, const char *prefix);
 179 int job_serialize(Job *j, FILE *f, FDSet *fds);
 180 int job_deserialize(Job *j, FILE *f, FDSet *fds);
 181 int job_coldplug(Job *j);
 182
 183 JobDependency* job_dependency_new(Job *subject, Job *object, bool matters, bool conflicts);
 184 void job_dependency_free(JobDependency *l);
 185
 186 int job_merge(Job *j, Job *other);
 187
 188 JobType job_type_lookup_merge(JobType a, JobType b) _pure_;
 189
 190 _pure_ static inline bool job_type_is_mergeable(JobType a, JobType b) {
 191         return job_type_lookup_merge(a, b) >= 0;
 192 }
 193
 194 _pure_ static inline bool job_type_is_conflicting(JobType a, JobType b) {
 195         return a != JOB_NOP && b != JOB_NOP && !job_type_is_mergeable(a, b);
 196 }
 197
 198 _pure_ static inline bool job_type_is_superset(JobType a, JobType b) {
 199         /* Checks whether operation a is a "superset" of b in its actions */
 200         if (b == JOB_NOP)
 201                 return true;
 202         if (a == JOB_NOP)
 203                 return false;
 204         return a == job_type_lookup_merge(a, b);
 205 }
 206
 207 bool job_type_is_redundant(JobType a, UnitActiveState b) _pure_;
 208
 209 /* Collapses a state-dependent job type into a simpler type by observing
 210  * the state of the unit which it is going to be applied to. */
 211 JobType job_type_collapse(JobType t, Unit *u);
 212
 213 int job_type_merge_and_collapse(JobType *a, JobType b, Unit *u);
 214
 215 void job_add_to_run_queue(Job *j);
 216 void job_add_to_dbus_queue(Job *j);
 217
 218 int job_start_timer(Job *j);
 219
 220 int job_run_and_invalidate(Job *j);
 221 int job_finish_and_invalidate(Job *j, JobResult result, bool recursive);
 222
 223 char *job_dbus_path(Job *j);
 224
 225 void job_shutdown_magic(Job *j);
 226
 227 const char* job_type_to_string(JobType t) _const_;
 228 JobType job_type_from_string(const char *s) _pure_;
 229
 230 const char* job_state_to_string(JobState t) _const_;
 231 JobState job_state_from_string(const char *s) _pure_;
 232
 233 const char* job_mode_to_string(JobMode t) _const_;
 234 JobMode job_mode_from_string(const char *s) _pure_;
 235
 236 const char* job_result_to_string(JobResult t) _const_;
 237 JobResult job_result_from_string(const char *s) _pure_;
 238
 239 int job_get_timeout(Job *j, uint64_t *timeout) _pure_;