programs/charon/charon/queues/job_queue.h

   1 /**
   2  * @file job_queue.h
   3  *
   4  * @brief Interface of job_queue_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 #ifndef JOB_QUEUE_H_
  24 #define JOB_QUEUE_H_
  25
  26 #include <types.h>
  27 #include <queues/jobs/job.h>
  28
  29 typedef struct job_queue_t job_queue_t;
  30
  31 /**
  32  * @brief The job queue stores jobs, which will be processed by the thread_pool_t.
  33  *
  34  * Jobs are added from various sources, from the threads and
  35  * from the event_queue_t.
  36  * Although the job-queue is based on a linked_list_t
  37  * all access functions are thread-save implemented.
  38  *
  39  * @b Constructors:
  40  * - job_queue_create()
  41  *
  42  * @ingroup queues
  43  */
  44 struct job_queue_t {
  45
  46         /**
  47          * @brief Returns number of jobs in queue.
  48          *
  49          * @param job_queue_t   calling object
  50          * @returns                     number of items in queue
  51          */
  52         int (*get_count) (job_queue_t *job_queue);
  53
  54         /**
  55          * @brief Get the next job from the queue.
  56          *
  57          * If the queue is empty, this function blocks until a job can be returned.
  58          * After using, the returned job has to get destroyed by the caller.
  59          *
  60          * @param job_queue_t   calling object
  61          * @param[out] job              pointer to a job pointer where to job is returned to
  62          * @return                              next job
  63          */
  64         job_t *(*get) (job_queue_t *job_queue);
  65
  66         /**
  67          * @brief Adds a job to the queue.
  68          *
  69          * This function is non blocking and adds a job_t to the list.
  70          * The specific job object has to get destroyed by the thread which
  71          * removes the job.
  72          *
  73          * @param job_queue_t   calling object
  74          * @param job                   job to add to the queue (job is not copied)
  75          */
  76         void (*add) (job_queue_t *job_queue, job_t *job);
  77
  78         /**
  79          * @brief Destroys a job_queue object.
  80          *
  81          * @warning The caller of this function has to make sure
  82          * that no thread is going to add or get a job from the job_queue
  83          * after calling this function.
  84          *
  85          * @param job_queue_t   calling object
  86          */
  87         void (*destroy) (job_queue_t *job_queue);
  88 };
  89
  90 /**
  91  * @brief Creates an empty job_queue.
  92  *
  93  * @return job_queue_t object
  94  *
  95  * @ingroup queues
  96  */
  97 job_queue_t *job_queue_create();
  98
  99 #endif /*JOB_QUEUE_H_*/