include/qemu/job.h

   1 /*
   2  * Declarations for background jobs
   3  *
   4  * Copyright (c) 2011 IBM Corp.
   5  * Copyright (c) 2012, 2018 Red Hat, Inc.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #ifndef JOB_H
  27 #define JOB_H
  28
  29 #include "qapi/qapi-types-block-core.h"
  30 #include "qemu/queue.h"
  31
  32 typedef struct JobDriver JobDriver;
  33
  34 /**
  35  * Long-running operation.
  36  */
  37 typedef struct Job {
  38     /** The ID of the job. May be NULL for internal jobs. */
  39     char *id;
  40
  41     /** The type of this job. */
  42     const JobDriver *driver;
  43
  44     /** Current state; See @JobStatus for details. */
  45     JobStatus status;
  46
  47     /** Element of the list of jobs */
  48     QLIST_ENTRY(Job) job_list;
  49 } Job;
  50
  51 /**
  52  * Callbacks and other information about a Job driver.
  53  */
  54 struct JobDriver {
  55     /** Derived Job struct size */
  56     size_t instance_size;
  57
  58     /** Enum describing the operation */
  59     JobType job_type;
  60 };
  61
  62
  63 /**
  64  * Create a new long-running job and return it.
  65  *
  66  * @job_id: The id of the newly-created job, or %NULL for internal jobs
  67  * @driver: The class object for the newly-created job.
  68  * @errp: Error object.
  69  */
  70 void *job_create(const char *job_id, const JobDriver *driver, Error **errp);
  71
  72 /** Frees the @job object. */
  73 void job_delete(Job *job);
  74
  75 /** Returns the JobType of a given Job. */
  76 JobType job_type(const Job *job);
  77
  78 /** Returns the enum string for the JobType of a given Job. */
  79 const char *job_type_str(const Job *job);
  80
  81 /**
  82  * Get the next element from the list of block jobs after @job, or the
  83  * first one if @job is %NULL.
  84  *
  85  * Returns the requested job, or %NULL if there are no more jobs left.
  86  */
  87 Job *job_next(Job *job);
  88
  89 /**
  90  * Get the job identified by @id (which must not be %NULL).
  91  *
  92  * Returns the requested job, or %NULL if it doesn't exist.
  93  */
  94 Job *job_get(const char *id);
  95
  96 /**
  97  * Check whether the verb @verb can be applied to @job in its current state.
  98  * Returns 0 if the verb can be applied; otherwise errp is set and -EPERM
  99  * returned.
 100  */
 101 int job_apply_verb(Job *job, JobVerb verb, Error **errp);
 102
 103 /* TODO To be removed from the public interface */
 104 void job_state_transition(Job *job, JobStatus s1);
 105
 106 #endif