Source/charon/queues/send_queue.c

   1 /**
   2  * @file send_queue.c
   3  *
   4  * @brief Send-Queue based on 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  #include <pthread.h>
  24
  25 #include "send_queue.h"
  26
  27 #include <utils/allocator.h>
  28 #include <utils/linked_list.h>
  29
  30  /**
  31  * @brief Private Variables and Functions of send_queue class
  32  *
  33  */
  34 typedef struct private_send_queue_s private_send_queue_t;
  35
  36
  37 struct private_send_queue_s {
  38         /**
  39          * Public part of the send_queue_t object
  40          */
  41         send_queue_t public;
  42
  43         /**
  44          * The packets are stored in a linked list
  45          */
  46         linked_list_t *list;
  47
  48         /**
  49          * access to linked_list is locked through this mutex
  50          */
  51         pthread_mutex_t mutex;
  52
  53         /**
  54          * If the queue is empty a thread has to wait
  55          * This condvar is used to wake up such a thread
  56          */
  57         pthread_cond_t condvar;
  58 };
  59
  60
  61 /**
  62  * @brief implements function get_count of send_queue_t
  63  */
  64 static int get_count(private_send_queue_t *this)
  65 {
  66         int count;
  67         pthread_mutex_lock(&(this->mutex));
  68         count = this->list->get_count(this->list);
  69         pthread_mutex_unlock(&(this->mutex));
  70         return count;
  71 }
  72
  73  /**
  74  * @brief implements function get of send_queue_t
  75  */
  76 static status_t get(private_send_queue_t *this, packet_t **packet)
  77 {
  78         int oldstate;
  79         pthread_mutex_lock(&(this->mutex));
  80         /* go to wait while no packets available */
  81
  82         while(this->list->get_count(this->list) == 0)
  83         {
  84                 /* add mutex unlock handler for cancellation, enable cancellation */
  85                 pthread_cleanup_push((void(*)(void*))pthread_mutex_unlock, (void*)&(this->mutex));
  86                 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate);
  87                 pthread_cond_wait( &(this->condvar), &(this->mutex));
  88
  89                 /* reset cancellation, remove mutex-unlock handler (without executing) */
  90                 pthread_setcancelstate(oldstate, NULL);
  91                 pthread_cleanup_pop(0);
  92         }
  93         this->list->remove_first(this->list,(void **) packet);
  94         pthread_mutex_unlock(&(this->mutex));
  95         return SUCCESS;
  96 }
  97
  98  /**
  99  * @brief implements function add of send_queue_t
 100  */
 101 static status_t add(private_send_queue_t *this, packet_t *packet)
 102 {
 103         pthread_mutex_lock(&(this->mutex));
 104         this->list->insert_last(this->list,packet);
 105         pthread_cond_signal( &(this->condvar));
 106         pthread_mutex_unlock(&(this->mutex));
 107         return SUCCESS;
 108 }
 109
 110  /**
 111  * @brief implements function destroy of send_queue_t
 112  *
 113  */
 114 static status_t destroy (private_send_queue_t *this)
 115 {
 116
 117         /* destroy all packets in list before destroying list */
 118         while (this->list->get_count(this->list) > 0)
 119         {
 120                 packet_t *packet;
 121                 if (this->list->remove_first(this->list,(void *) &packet) != SUCCESS)
 122                 {
 123                         this->list->destroy(this->list);
 124                         break;
 125                 }
 126                 packet->destroy(packet);
 127         }
 128         this->list->destroy(this->list);
 129
 130         pthread_mutex_destroy(&(this->mutex));
 131
 132         pthread_cond_destroy(&(this->condvar));
 133
 134         allocator_free(this);
 135         return SUCCESS;
 136 }
 137
 138  /*
 139  *
 140  * Documented in header
 141  */
 142 send_queue_t *send_queue_create()
 143 {
 144         linked_list_t *linked_list = linked_list_create();
 145         if (linked_list == NULL)
 146         {
 147                 return NULL;
 148         }
 149
 150         private_send_queue_t *this = allocator_alloc_thing(private_send_queue_t);
 151         if (this == NULL)
 152         {
 153                 linked_list->destroy(linked_list);
 154                 return NULL;
 155         }
 156
 157         this->public.get_count = (int(*)(send_queue_t*)) get_count;
 158         this->public.get = (status_t(*)(send_queue_t*, packet_t**)) get;
 159         this->public.add = (status_t(*)(send_queue_t*, packet_t*)) add;
 160         this->public.destroy = (status_t(*)(send_queue_t*)) destroy;
 161
 162         this->list = linked_list;
 163         pthread_mutex_init(&(this->mutex), NULL);
 164         pthread_cond_init(&(this->condvar), NULL);
 165
 166         return (&this->public);
 167 }