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 #include <inttypes.h>
  26 #include <errno.h>
  27
  28 typedef struct Job Job;
  29 typedef struct JobDependency JobDependency;
  30 typedef enum JobType JobType;
  31 typedef enum JobState JobState;
  32 typedef enum JobMode JobMode;
  33 typedef enum JobResult JobResult;
  34
  35 /* Be careful when changing the job types! Adjust job_merging_table[] accordingly! */
  36 enum JobType {
  37         JOB_START,                  /* if a unit does not support being started, we'll just wait until it becomes active */
  38         JOB_VERIFY_ACTIVE,
  39
  40         JOB_STOP,
  41
  42         JOB_RELOAD,                 /* if running, reload */
  43
  44         /* Note that restarts are first treated like JOB_STOP, but
  45          * then instead of finishing are patched to become
  46          * JOB_START. */
  47         JOB_RESTART,                /* If running, stop. Then start unconditionally. */
  48
  49         _JOB_TYPE_MAX_MERGING,
  50
  51         /* JOB_NOP can enter into a transaction, but as it won't pull in
  52          * any dependencies, it won't have to merge with anything.
  53          * job_install() avoids the problem of merging JOB_NOP too (it's
  54          * special-cased, only merges with other JOB_NOPs). */
  55         JOB_NOP = _JOB_TYPE_MAX_MERGING, /* do nothing */
  56
  57         _JOB_TYPE_MAX_IN_TRANSACTION,
  58
  59         /* JOB_TRY_RESTART can never appear in a transaction, because
  60          * it always collapses into JOB_RESTART or JOB_NOP before entering.
  61          * Thus we never need to merge it with anything. */
  62         JOB_TRY_RESTART = _JOB_TYPE_MAX_IN_TRANSACTION, /* if running, stop and then start */
  63
  64         /* JOB_RELOAD_OR_START won't enter into a transaction and cannot result
  65          * from transaction merging (there's no way for JOB_RELOAD and
  66          * JOB_START to meet in one transaction). It can result from a merge
  67          * during job installation, but then it will immediately collapse into
  68          * one of the two simpler types. */
  69         JOB_RELOAD_OR_START,        /* if running, reload, otherwise start */
  70
  71         _JOB_TYPE_MAX,
  72         _JOB_TYPE_INVALID = -1
  73 };
  74
  75 enum JobState {
  76         JOB_WAITING,
  77         JOB_RUNNING,
  78         _JOB_STATE_MAX,
  79         _JOB_STATE_INVALID = -1
  80 };
  81
  82 enum JobMode {
  83         JOB_FAIL,                /* Fail if a conflicting job is already queued */
  84         JOB_REPLACE,             /* Replace an existing conflicting job */
  85         JOB_REPLACE_IRREVERSIBLY,/* Like JOB_REPLACE + produce irreversible jobs */
  86         JOB_ISOLATE,             /* Start a unit, and stop all others */
  87         JOB_FLUSH,               /* Flush out all other queued jobs when queing this one */
  88         JOB_IGNORE_DEPENDENCIES, /* Ignore both requirement and ordering dependencies */
  89         JOB_IGNORE_REQUIREMENTS, /* Ignore requirement dependencies */
  90         _JOB_MODE_MAX,
  91         _JOB_MODE_INVALID = -1
  92 };
  93
  94 enum JobResult {
  95         JOB_DONE,                /* Job completed successfully */
  96         JOB_CANCELED,            /* Job canceled by a conflicting job installation or by explicit cancel request */
  97         JOB_TIMEOUT,             /* JobTimeout elapsed */
  98         JOB_FAILED,              /* Job failed */
  99         JOB_DEPENDENCY,          /* A required dependency job did not result in JOB_DONE */
 100         JOB_SKIPPED,             /* Negative result of JOB_VERIFY_ACTIVE */
 101         JOB_INVALID,             /* JOB_RELOAD of inactive unit */
 102         _JOB_RESULT_MAX,
 103         _JOB_RESULT_INVALID = -1
 104 };
 105
 106 #include "sd-event.h"
 107 #include "manager.h"
 108 #include "unit.h"
 109 #include "hashmap.h"
 110 #include "list.h"
 111
 112 struct JobDependency {
 113         /* Encodes that the 'subject' job needs the 'object' job in
 114          * some way. This structure is used only while building a transaction. */
 115         Job *subject;
 116         Job *object;
 117
 118         LIST_FIELDS(JobDependency, subject);
 119         LIST_FIELDS(JobDependency, object);
 120
 121         bool matters;
 122         bool conflicts;
 123 };
 124
 125 struct Job {
 126         Manager *manager;
 127         Unit *unit;
 128
 129         LIST_FIELDS(Job, transaction);
 130         LIST_FIELDS(Job, run_queue);
 131         LIST_FIELDS(Job, dbus_queue);
 132
 133         LIST_HEAD(JobDependency, subject_list);
 134         LIST_HEAD(JobDependency, object_list);
 135
 136         /* Used for graph algs as a "I have been here" marker */
 137         Job* marker;
 138         unsigned generation;
 139
 140         uint32_t id;
 141
 142         JobType type;
 143         JobState state;
 144
 145         sd_event_source *timer_event_source;
 146         usec_t begin_usec;
 147
 148         /* There can be more than one client, because of job merging. */
 149         sd_bus_track *subscribed;
 150         char **deserialized_subscribed;
 151
 152         JobResult result;
 153
 154         bool installed:1;
 155         bool in_run_queue:1;
 156         bool matters_to_anchor:1;
 157         bool override:1;
 158         bool in_dbus_queue:1;
 159         bool sent_dbus_new_signal:1;
 160         bool ignore_order:1;
 161         bool irreversible:1;
 162 };
 163
 164 Job* job_new(Unit *unit, JobType type);
 165 Job* job_new_raw(Unit *unit);
 166 void job_free(Job *job);
 167 Job* job_install(Job *j);
 168 int job_install_deserialized(Job *j);
 169 void job_uninstall(Job *j);
 170 void job_dump(Job *j, FILE*f, const char *prefix);
 171 int job_serialize(Job *j, FILE *f, FDSet *fds);
 172 int job_deserialize(Job *j, FILE *f, FDSet *fds);
 173 int job_coldplug(Job *j);
 174
 175 JobDependency* job_dependency_new(Job *subject, Job *object, bool matters, bool conflicts);
 176 void job_dependency_free(JobDependency *l);
 177
 178 int job_merge(Job *j, Job *other);
 179
 180 JobType job_type_lookup_merge(JobType a, JobType b) _pure_;
 181
 182 _pure_ static inline bool job_type_is_mergeable(JobType a, JobType b) {
 183         return job_type_lookup_merge(a, b) >= 0;
 184 }
 185
 186 _pure_ static inline bool job_type_is_conflicting(JobType a, JobType b) {
 187         return !job_type_is_mergeable(a, b);
 188 }
 189
 190 _pure_ static inline bool job_type_is_superset(JobType a, JobType b) {
 191         /* Checks whether operation a is a "superset" of b in its actions */
 192         return a == job_type_lookup_merge(a, b);
 193 }
 194
 195 bool job_type_is_redundant(JobType a, UnitActiveState b) _pure_;
 196
 197 /* Collapses a state-dependent job type into a simpler type by observing
 198  * the state of the unit which it is going to be applied to. */
 199 void job_type_collapse(JobType *t, Unit *u);
 200
 201 int job_type_merge_and_collapse(JobType *a, JobType b, Unit *u);
 202
 203 void job_add_to_run_queue(Job *j);
 204 void job_add_to_dbus_queue(Job *j);
 205
 206 int job_start_timer(Job *j);
 207
 208 int job_run_and_invalidate(Job *j);
 209 int job_finish_and_invalidate(Job *j, JobResult result, bool recursive);
 210
 211 char *job_dbus_path(Job *j);
 212
 213 void job_shutdown_magic(Job *j);
 214
 215 const char* job_type_to_string(JobType t) _const_;
 216 JobType job_type_from_string(const char *s) _pure_;
 217
 218 const char* job_state_to_string(JobState t) _const_;
 219 JobState job_state_from_string(const char *s) _pure_;
 220
 221 const char* job_mode_to_string(JobMode t) _const_;
 222 JobMode job_mode_from_string(const char *s) _pure_;
 223
 224 const char* job_result_to_string(JobResult t) _const_;
 225 JobResult job_result_from_string(const char *s) _pure_;
 226
 227 int job_get_timeout(Job *j, uint64_t *timeout) _pure_;