Source/charon/queues/event_queue.h

   1 /**
   2  * @file event_queue.h
   3  *
   4  * @brief Event-Queue based on class linked_list_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 EVENT_QUEUE_H_
  24 #define EVENT_QUEUE_H_
  25
  26 #include <sys/time.h>
  27
  28 #include <types.h>
  29 #include <queues/jobs/job.h>
  30
  31 /**
  32  * @brief Event-Queue used to store timed events.
  33  *
  34  * Although the event-queue is based on a linked_list_t
  35  * all access functions are thread-save implemented.
  36  */
  37 typedef struct event_queue_s event_queue_t;
  38
  39 struct event_queue_s {
  40
  41         /**
  42          * @brief Returns number of events in queue.
  43          *
  44          * @param event_queue   calling object
  45          * @return                              number of events in queue
  46          */
  47         int (*get_count) (event_queue_t *event_queue);
  48
  49         /**
  50          * @brief Get the next job from the event-queue.
  51          *
  52          * If no event is pending, this function blocks until a job can be returned.
  53          *
  54          * @param event_queue   calling object
  55          * @param[out] job              pointer to a job pointer where to job is returned to
  56          * @return                              - SUCCESS if succeeded
  57          *                                              - FAILED otherwisesa
  58          */
  59         status_t (*get) (event_queue_t *event_queue, job_t **job);
  60
  61         /**
  62          * @brief Adds a event to the queue, using a relative time.
  63          *
  64          * This function is non blocking and adds a job_t at a specific time to the list.
  65          * The specific job object has to get destroyed by the thread which
  66          * removes the job.
  67          *
  68          * @param event_queue   calling object
  69          * @param[in] job               job to add to the queue (job is not copied)
  70          * @param[in] time              relative time, when the event has to get fired
  71          * @returns
  72          *                                              - SUCCESS if succeeded
  73          *                                              - FAILED otherwise
  74          */
  75         status_t (*add_relative) (event_queue_t *event_queue, job_t *job, u_int32_t ms);
  76
  77         /**
  78          * @brief Adds a event to the queue, using an absolute time.
  79          *
  80          * This function is non blocking and adds a job_t at a specific time to the list.
  81          * The specific job object has to get destroyed by the thread which
  82          * removes the job.
  83          *
  84          * @param event_queue   calling object
  85          * @param[in]                   job job to add to the queue (job is not copied)
  86          * @param[in]                   absolute time time, when the event has to get fired
  87          * @returns
  88          *                                              - SUCCESS if succeeded
  89          *                                              - FAILED otherwise
  90          */
  91         status_t (*add_absolute) (event_queue_t *event_queue, job_t *job, timeval_t time);
  92
  93         /**
  94          * @brief Destroys a event_queue object.
  95          *
  96          * @warning The caller of this function has to make sure
  97          * that no thread is going to add or get an event from the event_queue
  98          * after calling this function.
  99          *
 100          * @param event_queue   calling object
 101          * @returns                             always SUCCESS
 102          */
 103         status_t (*destroy) (event_queue_t *event_queue);
 104 };
 105
 106 /**
 107  * @brief Creates an empty event_queue
 108  *
 109  * @returns
 110  *                      - Empty event_queue_t object
 111  *                      - NULL if memory allocation failed
 112  */
 113 event_queue_t *event_queue_create();
 114 #endif /*EVENT_QUEUE_H_*/