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Diffstat (limited to 'src/core/job.h')
| -rw-r--r-- | src/core/job.h | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/src/core/job.h b/src/core/job.h new file mode 100644 index 0000000..1b9bcdd --- /dev/null +++ b/src/core/job.h @@ -0,0 +1,239 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +#pragma once + +#include <stdbool.h> + +#include "sd-event.h" + +#include "list.h" +#include "unit-name.h" + +typedef struct Job Job; +typedef struct JobDependency JobDependency; +typedef enum JobType JobType; +typedef enum JobState JobState; +typedef enum JobMode JobMode; +typedef enum JobResult JobResult; + +/* Be careful when changing the job types! Adjust job_merging_table[] accordingly! */ +enum JobType { + JOB_START, /* if a unit does not support being started, we'll just wait until it becomes active */ + JOB_VERIFY_ACTIVE, + + JOB_STOP, + + JOB_RELOAD, /* if running, reload */ + + /* Note that restarts are first treated like JOB_STOP, but + * then instead of finishing are patched to become + * JOB_START. */ + JOB_RESTART, /* If running, stop. Then start unconditionally. */ + + _JOB_TYPE_MAX_MERGING, + + /* JOB_NOP can enter into a transaction, but as it won't pull in + * any dependencies and it uses the special 'nop_job' slot in Unit, + * it won't have to merge with anything (except possibly into another + * JOB_NOP, previously installed). JOB_NOP is special-cased in + * job_type_is_*() functions so that the transaction can be + * activated. */ + JOB_NOP = _JOB_TYPE_MAX_MERGING, /* do nothing */ + + _JOB_TYPE_MAX_IN_TRANSACTION, + + /* JOB_TRY_RESTART can never appear in a transaction, because + * it always collapses into JOB_RESTART or JOB_NOP before entering. + * Thus we never need to merge it with anything. */ + JOB_TRY_RESTART = _JOB_TYPE_MAX_IN_TRANSACTION, /* if running, stop and then start */ + + /* Similar to JOB_TRY_RESTART but collapses to JOB_RELOAD or JOB_NOP */ + JOB_TRY_RELOAD, + + /* JOB_RELOAD_OR_START won't enter into a transaction and cannot result + * from transaction merging (there's no way for JOB_RELOAD and + * JOB_START to meet in one transaction). It can result from a merge + * during job installation, but then it will immediately collapse into + * one of the two simpler types. */ + JOB_RELOAD_OR_START, /* if running, reload, otherwise start */ + + _JOB_TYPE_MAX, + _JOB_TYPE_INVALID = -1 +}; + +enum JobState { + JOB_WAITING, + JOB_RUNNING, + _JOB_STATE_MAX, + _JOB_STATE_INVALID = -1 +}; + +enum JobMode { + JOB_FAIL, /* Fail if a conflicting job is already queued */ + JOB_REPLACE, /* Replace an existing conflicting job */ + JOB_REPLACE_IRREVERSIBLY,/* Like JOB_REPLACE + produce irreversible jobs */ + JOB_ISOLATE, /* Start a unit, and stop all others */ + JOB_FLUSH, /* Flush out all other queued jobs when queing this one */ + JOB_IGNORE_DEPENDENCIES, /* Ignore both requirement and ordering dependencies */ + JOB_IGNORE_REQUIREMENTS, /* Ignore requirement dependencies */ + _JOB_MODE_MAX, + _JOB_MODE_INVALID = -1 +}; + +enum JobResult { + JOB_DONE, /* Job completed successfully (or skipped due to a failed ConditionXYZ=) */ + JOB_CANCELED, /* Job canceled by a conflicting job installation or by explicit cancel request */ + JOB_TIMEOUT, /* Job timeout elapsed */ + JOB_FAILED, /* Job failed */ + JOB_DEPENDENCY, /* A required dependency job did not result in JOB_DONE */ + JOB_SKIPPED, /* Negative result of JOB_VERIFY_ACTIVE */ + JOB_INVALID, /* JOB_RELOAD of inactive unit */ + JOB_ASSERT, /* Couldn't start a unit, because an assert didn't hold */ + JOB_UNSUPPORTED, /* Couldn't start a unit, because the unit type is not supported on the system */ + JOB_COLLECTED, /* Job was garbage collected, since nothing needed it anymore */ + JOB_ONCE, /* Unit was started before, and hence can't be started again */ + _JOB_RESULT_MAX, + _JOB_RESULT_INVALID = -1 +}; + +#include "unit.h" + +struct JobDependency { + /* Encodes that the 'subject' job needs the 'object' job in + * some way. This structure is used only while building a transaction. */ + Job *subject; + Job *object; + + LIST_FIELDS(JobDependency, subject); + LIST_FIELDS(JobDependency, object); + + bool matters:1; + bool conflicts:1; +}; + +struct Job { + Manager *manager; + Unit *unit; + + LIST_FIELDS(Job, transaction); + LIST_FIELDS(Job, run_queue); + LIST_FIELDS(Job, dbus_queue); + LIST_FIELDS(Job, gc_queue); + + LIST_HEAD(JobDependency, subject_list); + LIST_HEAD(JobDependency, object_list); + + /* Used for graph algs as a "I have been here" marker */ + Job* marker; + unsigned generation; + + uint32_t id; + + JobType type; + JobState state; + + sd_event_source *timer_event_source; + usec_t begin_usec; + usec_t begin_running_usec; + + /* + * This tracks where to send signals, and also which clients + * are allowed to call DBus methods on the job (other than + * root). + * + * There can be more than one client, because of job merging. + */ + sd_bus_track *bus_track; + char **deserialized_clients; + + JobResult result; + + bool installed:1; + bool in_run_queue:1; + bool matters_to_anchor:1; + bool in_dbus_queue:1; + bool sent_dbus_new_signal:1; + bool ignore_order:1; + bool irreversible:1; + bool in_gc_queue:1; + bool ref_by_private_bus:1; +}; + +Job* job_new(Unit *unit, JobType type); +Job* job_new_raw(Unit *unit); +void job_unlink(Job *job); +Job* job_free(Job *job); +Job* job_install(Job *j); +int job_install_deserialized(Job *j); +void job_uninstall(Job *j); +void job_dump(Job *j, FILE *f, const char *prefix); +int job_serialize(Job *j, FILE *f); +int job_deserialize(Job *j, FILE *f); +int job_coldplug(Job *j); + +JobDependency* job_dependency_new(Job *subject, Job *object, bool matters, bool conflicts); +void job_dependency_free(JobDependency *l); + +int job_merge(Job *j, Job *other); + +JobType job_type_lookup_merge(JobType a, JobType b) _pure_; + +_pure_ static inline bool job_type_is_mergeable(JobType a, JobType b) { + return job_type_lookup_merge(a, b) >= 0; +} + +_pure_ static inline bool job_type_is_conflicting(JobType a, JobType b) { + return a != JOB_NOP && b != JOB_NOP && !job_type_is_mergeable(a, b); +} + +_pure_ static inline bool job_type_is_superset(JobType a, JobType b) { + /* Checks whether operation a is a "superset" of b in its actions */ + if (b == JOB_NOP) + return true; + if (a == JOB_NOP) + return false; + return a == job_type_lookup_merge(a, b); +} + +bool job_type_is_redundant(JobType a, UnitActiveState b) _pure_; + +/* Collapses a state-dependent job type into a simpler type by observing + * the state of the unit which it is going to be applied to. */ +JobType job_type_collapse(JobType t, Unit *u); + +int job_type_merge_and_collapse(JobType *a, JobType b, Unit *u); + +void job_add_to_run_queue(Job *j); +void job_add_to_dbus_queue(Job *j); + +int job_start_timer(Job *j, bool job_running); + +int job_run_and_invalidate(Job *j); +int job_finish_and_invalidate(Job *j, JobResult result, bool recursive, bool already); + +char *job_dbus_path(Job *j); + +void job_shutdown_magic(Job *j); + +int job_get_timeout(Job *j, usec_t *timeout) _pure_; + +bool job_may_gc(Job *j); +void job_add_to_gc_queue(Job *j); + +int job_get_before(Job *j, Job*** ret); +int job_get_after(Job *j, Job*** ret); + +DEFINE_TRIVIAL_CLEANUP_FUNC(Job*, job_free); + +const char* job_type_to_string(JobType t) _const_; +JobType job_type_from_string(const char *s) _pure_; + +const char* job_state_to_string(JobState t) _const_; +JobState job_state_from_string(const char *s) _pure_; + +const char* job_mode_to_string(JobMode t) _const_; +JobMode job_mode_from_string(const char *s) _pure_; + +const char* job_result_to_string(JobResult t) _const_; +JobResult job_result_from_string(const char *s) _pure_; + +const char* job_type_to_access_method(JobType t); |