Source/charon/job_queue.c

   1 /**
   2  * @file job_queue.c
   3  *
   4  * @brief Job-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 <stdlib.h>
  24 #include <pthread.h>
  25 #include <freeswan.h>
  26 #include <pluto/constants.h>
  27 #include <pluto/defs.h>
  28
  29 #include "job_queue.h"
  30
  31 /**
  32  * @brief implements function destroy of job_t
  33  */
  34 static status_t job_destroy(job_t *job)
  35 {
  36         pfree(job);
  37         return SUCCESS;
  38 }
  39
  40 /*
  41  * Creates a job (documented in header-file)
  42  */
  43 job_t *job_create(job_type_t type, void *assigned_data)
  44 {
  45         job_t *this = alloc_thing(job_t, "job_t");
  46
  47         this->destroy = job_destroy;
  48
  49         this->type = type;
  50         this->assigned_data = assigned_data;
  51
  52         return this;
  53 }
  54
  55 /**
  56  * @brief Private Variables and Functions of job_queue class
  57  *
  58  */
  59 typedef struct private_job_queue_s private_job_queue_t;
  60
  61
  62 struct private_job_queue_s {
  63         job_queue_t public;
  64
  65         /**
  66          * The jobs are stored in a linked list
  67          */
  68         linked_list_t *list;
  69         /**
  70          * access to linked_list is locked through this mutex
  71          */
  72         pthread_mutex_t mutex;
  73
  74         /**
  75          * If the queue is empty a thread has to wait
  76          * This condvar is used to wake up such a thread
  77          */
  78         pthread_cond_t condvar;
  79 };
  80
  81
  82 /**
  83  * @brief implements function get_count of job_queue_t
  84  */
  85 status_t get_count(private_job_queue_t *this, int *count)
  86 {
  87         pthread_mutex_lock(&(this->mutex));
  88         *count = this->list->count;
  89         pthread_mutex_unlock(&(this->mutex));
  90         return SUCCESS;
  91 }
  92
  93 /**
  94  * @brief implements function get of job_queue_t
  95  */
  96 status_t get(private_job_queue_t *this, job_t **job)
  97 {
  98         pthread_mutex_lock(&(this->mutex));
  99         // add mutex unlock handler for cancellation
 100         pthread_cleanup_push((void(*)(void*))pthread_mutex_unlock, (void*)&(this->mutex));
 101         // go to wait while no jobs available
 102         while(this->list->count == 0)
 103         {
 104                 pthread_cond_wait( &(this->condvar), &(this->mutex));
 105         }
 106         // remove mutex-unlock handler
 107         pthread_cleanup_pop(1);
 108
 109         this->list->remove_first(this->list,(void **) job);
 110         pthread_mutex_unlock(&(this->mutex));
 111         return SUCCESS;
 112 }
 113
 114 /**
 115  * @brief implements function add of job_queue_t
 116  */
 117 status_t add(private_job_queue_t *this, job_t *job)
 118 {
 119         pthread_mutex_lock(&(this->mutex));
 120         this->list->insert_last(this->list,job);
 121         pthread_cond_signal( &(this->condvar));
 122         pthread_mutex_unlock(&(this->mutex));
 123         return SUCCESS;
 124 }
 125
 126 /**
 127  * @brief implements function destroy of job_queue_t
 128  *
 129  */
 130 status_t job_queue_destroy (private_job_queue_t *this)
 131 {
 132         while (this->list->count > 0)
 133         {
 134                 job_t *job;
 135                 if (this->list->remove_first(this->list,(void *) &job) != SUCCESS)
 136                 {
 137                         this->list->destroy(this->list);
 138                         break;
 139                 }
 140                 job->destroy(job);
 141         }
 142         this->list->destroy(this->list);
 143
 144         pthread_mutex_destroy(&(this->mutex));
 145
 146         pthread_cond_destroy(&(this->condvar));
 147
 148         pfree(this);
 149         return SUCCESS;
 150 }
 151
 152 /*
 153  *
 154  * Documented in header
 155  */
 156 job_queue_t *job_queue_create()
 157 {
 158         linked_list_t *linked_list = linked_list_create();
 159         if (linked_list == NULL)
 160         {
 161                 return NULL;
 162         }
 163
 164         private_job_queue_t *this = alloc_thing(private_job_queue_t, "private_job_queue_t");
 165         if (this == NULL)
 166         {
 167                 linked_list->destroy(linked_list);
 168                 return NULL;
 169         }
 170
 171         this->public.get_count = (status_t(*)(job_queue_t*, int*))get_count;
 172         this->public.get = (status_t(*)(job_queue_t*, job_t**))get;
 173         this->public.add = (status_t(*)(job_queue_t*, job_t*))add;
 174         this->public.destroy = (status_t(*)(job_queue_t*))job_queue_destroy;
 175
 176         this->list = linked_list;
 177         pthread_mutex_init(&(this->mutex), NULL);
 178         pthread_cond_init(&(this->condvar), NULL);
 179
 180         return (&this->public);
 181 }