src/charon/queues/event_queue.h

   1 /**
   2  * @file event_queue.h
   3  *
   4  * @brief Interface of job_queue_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005-2006 Martin Willi
  10  * Copyright (C) 2005 Jan Hutter
  11  * Hochschule fuer Technik Rapperswil
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License as published by the
  15  * Free Software Foundation; either version 2 of the License, or (at your
  16  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  17  *
  18  * This program is distributed in the hope that it will be useful, but
  19  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  20  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  21  * for more details.
  22  */
  23
  24 #ifndef EVENT_QUEUE_H_
  25 #define EVENT_QUEUE_H_
  26
  27 typedef struct event_queue_t event_queue_t;
  28
  29 #include <sys/time.h>
  30
  31 #include <library.h>
  32 #include <queues/jobs/job.h>
  33
  34 /**
  35  * @brief Event-Queue used to store timed events.
  36  *
  37  * Added events are sorted. The get method blocks until
  38  * the time is elapsed to process the next event. The get
  39  * method is called from the scheduler_t thread, which
  40  * will add the jobs to to job_queue_t for further processing.
  41  *
  42  * Although the event-queue is based on a linked_list_t
  43  * all access functions are thread-save implemented.
  44  *
  45  * @b Constructors:
  46  * - event_queue_create()
  47  *
  48  * @ingroup queues
  49  */
  50 struct event_queue_t {
  51
  52         /**
  53          * @brief Returns number of events in queue.
  54          *
  55          * @param event_queue   calling object
  56          * @return                              number of events in queue
  57          */
  58         int (*get_count) (event_queue_t *event_queue);
  59
  60         /**
  61          * @brief Get the next job from the event-queue.
  62          *
  63          * If no event is pending, this function blocks until a job can be returned.
  64          *
  65          * @param event_queue   calling object
  66          * @param[out] job              pointer to a job pointer where to job is returned to
  67          * @return                              next job
  68          */
  69         job_t *(*get) (event_queue_t *event_queue);
  70
  71         /**
  72          * @brief Adds a event to the queue, using a relative time.
  73          *
  74          * This function is non blocking and adds a job_t at a specific time to the list.
  75          * The specific job object has to get destroyed by the thread which
  76          * removes the job.
  77          *
  78          * @param event_queue   calling object
  79          * @param[in] job               job to add to the queue (job is not copied)
  80          * @param[in] time              relative time, when the event has to get fired
  81          */
  82         void (*add_relative) (event_queue_t *event_queue, job_t *job, u_int32_t ms);
  83
  84         /**
  85          * @brief Adds a event to the queue, using an absolute time.
  86          *
  87          * This function is non blocking and adds a job_t at a specific time to the list.
  88          * The specific job object has to get destroyed by the thread which
  89          * removes the job.
  90          *
  91          * @param event_queue   calling object
  92          * @param[in] job               job to add to the queue (job is not copied)
  93          * @param[in] time              absolute time, when the event has to get fired
  94          */
  95         void (*add_absolute) (event_queue_t *event_queue, job_t *job, timeval_t time);
  96
  97         /**
  98          * @brief Destroys a event_queue object.
  99          *
 100          * @warning The caller of this function has to make sure
 101          * that no thread is going to add or get an event from the event_queue
 102          * after calling this function.
 103          *
 104          * @param event_queue   calling object
 105          */
 106         void (*destroy) (event_queue_t *event_queue);
 107 };
 108
 109 /**
 110  * @brief Creates an empty event_queue.
 111  *
 112  * @returns event_queue_t object
 113  *
 114  * @ingroup queues
 115  */
 116 event_queue_t *event_queue_create(void);
 117
 118 #endif /*EVENT_QUEUE_H_*/