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 and it uses the special 'nop_job' slot in Unit,
  53          * it won't have to merge with anything (except possibly into another
  54          * JOB_NOP, previously installed). JOB_NOP is special-cased in
  55          * job_type_is_*() functions so that the transaction can be
  56          * activated. */
  57         JOB_NOP = _JOB_TYPE_MAX_MERGING, /* do nothing */
  58
  59         _JOB_TYPE_MAX_IN_TRANSACTION,
  60
  61         /* JOB_TRY_RESTART can never appear in a transaction, because
  62          * it always collapses into JOB_RESTART or JOB_NOP before entering.
  63          * Thus we never need to merge it with anything. */
  64         JOB_TRY_RESTART = _JOB_TYPE_MAX_IN_TRANSACTION, /* if running, stop and then start */
  65
  66         /* JOB_RELOAD_OR_START won't enter into a transaction and cannot result
  67          * from transaction merging (there's no way for JOB_RELOAD and
  68          * JOB_START to meet in one transaction). It can result from a merge
  69          * during job installation, but then it will immediately collapse into
  70          * one of the two simpler types. */
  71         JOB_RELOAD_OR_START,        /* if running, reload, otherwise start */
  72
  73         _JOB_TYPE_MAX,
  74         _JOB_TYPE_INVALID = -1
  75 };
  76
  77 enum JobState {
  78         JOB_WAITING,
  79         JOB_RUNNING,
  80         _JOB_STATE_MAX,
  81         _JOB_STATE_INVALID = -1
  82 };
  83
  84 enum JobMode {
  85         JOB_FAIL,                /* Fail if a conflicting job is already queued */
  86         JOB_REPLACE,             /* Replace an existing conflicting job */
  87         JOB_REPLACE_IRREVERSIBLY,/* Like JOB_REPLACE + produce irreversible jobs */
  88         JOB_ISOLATE,             /* Start a unit, and stop all others */
  89         JOB_FLUSH,               /* Flush out all other queued jobs when queing this one */
  90         JOB_IGNORE_DEPENDENCIES, /* Ignore both requirement and ordering dependencies */
  91         JOB_IGNORE_REQUIREMENTS, /* Ignore requirement dependencies */
  92         _JOB_MODE_MAX,
  93         _JOB_MODE_INVALID = -1
  94 };
  95
  96 enum JobResult {
  97         JOB_DONE,                /* Job completed successfully */
  98         JOB_CANCELED,            /* Job canceled by a conflicting job installation or by explicit cancel request */
  99         JOB_TIMEOUT,             /* Job timeout elapsed */
 100         JOB_FAILED,              /* Job failed */
 101         JOB_DEPENDENCY,          /* A required dependency job did not result in JOB_DONE */
 102         JOB_SKIPPED,             /* Negative result of JOB_VERIFY_ACTIVE */
 103         JOB_INVALID,             /* JOB_RELOAD of inactive unit */
 104         JOB_ASSERT,              /* Couldn't start a unit, because an assert didn't hold */
 105         JOB_UNSUPPORTED,         /* Couldn't start a unit, because the unit type is not supported on the system */
 106         _JOB_RESULT_MAX,
 107         _JOB_RESULT_INVALID = -1
 108 };
 109
 110 #include "sd-event.h"
 111 #include "manager.h"
 112 #include "unit.h"
 113 #include "hashmap.h"
 114 #include "list.h"
 115
 116 struct JobDependency {
 117         /* Encodes that the 'subject' job needs the 'object' job in
 118          * some way. This structure is used only while building a transaction. */
 119         Job *subject;
 120         Job *object;
 121
 122         LIST_FIELDS(JobDependency, subject);
 123         LIST_FIELDS(JobDependency, object);
 124
 125         bool matters;
 126         bool conflicts;
 127 };
 128
 129 struct Job {
 130         Manager *manager;
 131         Unit *unit;
 132
 133         LIST_FIELDS(Job, transaction);
 134         LIST_FIELDS(Job, run_queue);
 135         LIST_FIELDS(Job, dbus_queue);
 136
 137         LIST_HEAD(JobDependency, subject_list);
 138         LIST_HEAD(JobDependency, object_list);
 139
 140         /* Used for graph algs as a "I have been here" marker */
 141         Job* marker;
 142         unsigned generation;
 143
 144         uint32_t id;
 145
 146         JobType type;
 147         JobState state;
 148
 149         sd_event_source *timer_event_source;
 150         usec_t begin_usec;
 151
 152         /*
 153          * This tracks where to send signals, and also which clients
 154          * are allowed to call DBus methods on the job (other than
 155          * root).
 156          *
 157          * There can be more than one client, because of job merging.
 158          */
 159         sd_bus_track *clients;
 160         char **deserialized_clients;
 161
 162         JobResult result;
 163
 164         bool installed:1;
 165         bool in_run_queue:1;
 166         bool matters_to_anchor:1;
 167         bool override:1;
 168         bool in_dbus_queue:1;
 169         bool sent_dbus_new_signal:1;
 170         bool ignore_order:1;
 171         bool irreversible:1;
 172 };
 173
 174 Job* job_new(Unit *unit, JobType type);
 175 Job* job_new_raw(Unit *unit);
 176 void job_free(Job *job);
 177 Job* job_install(Job *j);
 178 int job_install_deserialized(Job *j);
 179 void job_uninstall(Job *j);
 180 void job_dump(Job *j, FILE*f, const char *prefix);
 181 int job_serialize(Job *j, FILE *f, FDSet *fds);
 182 int job_deserialize(Job *j, FILE *f, FDSet *fds);
 183 int job_coldplug(Job *j);
 184
 185 JobDependency* job_dependency_new(Job *subject, Job *object, bool matters, bool conflicts);
 186 void job_dependency_free(JobDependency *l);
 187
 188 int job_merge(Job *j, Job *other);
 189
 190 JobType job_type_lookup_merge(JobType a, JobType b) _pure_;
 191
 192 _pure_ static inline bool job_type_is_mergeable(JobType a, JobType b) {
 193         return job_type_lookup_merge(a, b) >= 0;
 194 }
 195
 196 _pure_ static inline bool job_type_is_conflicting(JobType a, JobType b) {
 197         return a != JOB_NOP && b != JOB_NOP && !job_type_is_mergeable(a, b);
 198 }
 199
 200 _pure_ static inline bool job_type_is_superset(JobType a, JobType b) {
 201         /* Checks whether operation a is a "superset" of b in its actions */
 202         if (b == JOB_NOP)
 203                 return true;
 204         if (a == JOB_NOP)
 205                 return false;
 206         return a == job_type_lookup_merge(a, b);
 207 }
 208
 209 bool job_type_is_redundant(JobType a, UnitActiveState b) _pure_;
 210
 211 /* Collapses a state-dependent job type into a simpler type by observing
 212  * the state of the unit which it is going to be applied to. */
 213 void job_type_collapse(JobType *t, Unit *u);
 214
 215 int job_type_merge_and_collapse(JobType *a, JobType b, Unit *u);
 216
 217 void job_add_to_run_queue(Job *j);
 218 void job_add_to_dbus_queue(Job *j);
 219
 220 int job_start_timer(Job *j);
 221
 222 int job_run_and_invalidate(Job *j);
 223 int job_finish_and_invalidate(Job *j, JobResult result, bool recursive);
 224
 225 char *job_dbus_path(Job *j);
 226
 227 void job_shutdown_magic(Job *j);
 228
 229 const char* job_type_to_string(JobType t) _const_;
 230 JobType job_type_from_string(const char *s) _pure_;
 231
 232 const char* job_state_to_string(JobState t) _const_;
 233 JobState job_state_from_string(const char *s) _pure_;
 234
 235 const char* job_mode_to_string(JobMode t) _const_;
 236 JobMode job_mode_from_string(const char *s) _pure_;
 237
 238 const char* job_result_to_string(JobResult t) _const_;
 239 JobResult job_result_from_string(const char *s) _pure_;
 240
 241 int job_get_timeout(Job *j, uint64_t *timeout) _pure_;