programs/charon/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 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 typedef struct event_queue_t event_queue_t;
  32
  33 /**
  34  * @brief Event-Queue used to store timed events.
  35  *
  36  * Added events are sorted. The get method blocks until
  37  * the time is elapsed to process the next event. The get
  38  * method is called from the scheduler_t thread, which
  39  * will add the jobs to to job_queue_t for further processing.
  40  *
  41  * Although the event-queue is based on a linked_list_t
  42  * all access functions are thread-save implemented.
  43  *
  44  * @b Constructors:
  45  * - event_queue_create()
  46  *
  47  * @ingroup queues
  48  */
  49 struct event_queue_t {
  50
  51         /**
  52          * @brief Returns number of events in queue.
  53          *
  54          * @param event_queue   calling object
  55          * @return                              number of events in queue
  56          */
  57         int (*get_count) (event_queue_t *event_queue);
  58
  59         /**
  60          * @brief Get the next job from the event-queue.
  61          *
  62          * If no event is pending, this function blocks until a job can be returned.
  63          *
  64          * @param event_queue   calling object
  65          * @param[out] job              pointer to a job pointer where to job is returned to
  66          * @return                              next job
  67          */
  68         job_t *(*get) (event_queue_t *event_queue);
  69
  70         /**
  71          * @brief Adds a event to the queue, using a relative time.
  72          *
  73          * This function is non blocking and adds a job_t at a specific time to the list.
  74          * The specific job object has to get destroyed by the thread which
  75          * removes the job.
  76          *
  77          * @param event_queue   calling object
  78          * @param[in] job               job to add to the queue (job is not copied)
  79          * @param[in] time              relative time, when the event has to get fired
  80          */
  81         void (*add_relative) (event_queue_t *event_queue, job_t *job, u_int32_t ms);
  82
  83         /**
  84          * @brief Adds a event to the queue, using an absolute time.
  85          *
  86          * This function is non blocking and adds a job_t at a specific time to the list.
  87          * The specific job object has to get destroyed by the thread which
  88          * removes the job.
  89          *
  90          * @param event_queue   calling object
  91          * @param[in]                   job job to add to the queue (job is not copied)
  92          * @param[in]                   absolute time time, when the event has to get fired
  93          */
  94         void (*add_absolute) (event_queue_t *event_queue, job_t *job, timeval_t time);
  95
  96         /**
  97          * @brief Destroys a event_queue object.
  98          *
  99          * @warning The caller of this function has to make sure
 100          * that no thread is going to add or get an event from the event_queue
 101          * after calling this function.
 102          *
 103          * @param event_queue   calling object
 104          */
 105         void (*destroy) (event_queue_t *event_queue);
 106 };
 107
 108 /**
 109  * @brief Creates an empty event_queue.
 110  *
 111  * @returns event_queue_t object
 112  *
 113  * @ingroup queues
 114  */
 115 event_queue_t *event_queue_create();
 116
 117 #endif /*EVENT_QUEUE_H_*/