Source/charon/queues/send_queue.c

   1 /**
   2  * @file send_queue.c
   3  *
   4  * @brief Implementation of send_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 #include <pthread.h>
  24
  25 #include "send_queue.h"
  26
  27 #include <utils/allocator.h>
  28 #include <utils/linked_list.h>
  29
  30
  31 typedef struct private_send_queue_t private_send_queue_t;
  32
  33  /**
  34  * @brief Private Variables and Functions of send_queue class
  35  *
  36  */
  37 struct private_send_queue_t {
  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  * implements send_queue_t.get_count
  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  * implements send_queue_t.get
  75  */
  76 static packet_t *get(private_send_queue_t *this)
  77 {
  78         int oldstate;
  79         packet_t *packet;
  80         pthread_mutex_lock(&(this->mutex));
  81         /* go to wait while no packets available */
  82
  83         while(this->list->get_count(this->list) == 0)
  84         {
  85                 /* add mutex unlock handler for cancellation, enable cancellation */
  86                 pthread_cleanup_push((void(*)(void*))pthread_mutex_unlock, (void*)&(this->mutex));
  87                 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate);
  88                 pthread_cond_wait( &(this->condvar), &(this->mutex));
  89
  90                 /* reset cancellation, remove mutex-unlock handler (without executing) */
  91                 pthread_setcancelstate(oldstate, NULL);
  92                 pthread_cleanup_pop(0);
  93         }
  94         this->list->remove_first(this->list,(void **)&packet);
  95         pthread_mutex_unlock(&(this->mutex));
  96         return packet;
  97 }
  98
  99  /**
 100  * implements send_queue_t.add
 101  */
 102 static void add(private_send_queue_t *this, packet_t *packet)
 103 {
 104         pthread_mutex_lock(&(this->mutex));
 105         this->list->insert_last(this->list,packet);
 106         pthread_cond_signal( &(this->condvar));
 107         pthread_mutex_unlock(&(this->mutex));
 108 }
 109
 110  /**
 111  * implements send_queue_t.destroy
 112  */
 113 static void destroy (private_send_queue_t *this)
 114 {
 115
 116         /* destroy all packets in list before destroying list */
 117         while (this->list->get_count(this->list) > 0)
 118         {
 119                 packet_t *packet;
 120                 if (this->list->remove_first(this->list,(void *) &packet) != SUCCESS)
 121                 {
 122                         this->list->destroy(this->list);
 123                         break;
 124                 }
 125                 packet->destroy(packet);
 126         }
 127         this->list->destroy(this->list);
 128
 129         pthread_mutex_destroy(&(this->mutex));
 130
 131         pthread_cond_destroy(&(this->condvar));
 132
 133         allocator_free(this);
 134 }
 135
 136  /*
 137  *
 138  * Documented in header
 139  */
 140 send_queue_t *send_queue_create()
 141 {
 142         private_send_queue_t *this = allocator_alloc_thing(private_send_queue_t);
 143
 144         this->public.get_count = (int(*)(send_queue_t*)) get_count;
 145         this->public.get = (packet_t*(*)(send_queue_t*)) get;
 146         this->public.add = (void(*)(send_queue_t*, packet_t*)) add;
 147         this->public.destroy = (void(*)(send_queue_t*)) destroy;
 148
 149         this->list = linked_list_create();
 150         pthread_mutex_init(&(this->mutex), NULL);
 151         pthread_cond_init(&(this->condvar), NULL);
 152
 153         return (&this->public);
 154 }