155 lines
3.7 KiB
C
155 lines
3.7 KiB
C
/**
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* @file send_queue.c
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*
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* @brief Implementation of send_queue_t.
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*
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*/
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/*
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* Copyright (C) 2005 Jan Hutter, Martin Willi
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* Hochschule fuer Technik Rapperswil
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*/
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#include <pthread.h>
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#include "send_queue.h"
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#include <utils/allocator.h>
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#include <utils/linked_list.h>
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typedef struct private_send_queue_t private_send_queue_t;
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/**
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* @brief Private Variables and Functions of send_queue class
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*
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*/
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struct private_send_queue_t {
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/**
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* Public part of the send_queue_t object
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*/
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send_queue_t public;
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/**
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* The packets are stored in a linked list
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*/
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linked_list_t *list;
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/**
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* access to linked_list is locked through this mutex
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*/
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pthread_mutex_t mutex;
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/**
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* If the queue is empty a thread has to wait
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* This condvar is used to wake up such a thread
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*/
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pthread_cond_t condvar;
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};
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/**
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* implements send_queue_t.get_count
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*/
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static int get_count(private_send_queue_t *this)
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{
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int count;
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pthread_mutex_lock(&(this->mutex));
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count = this->list->get_count(this->list);
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pthread_mutex_unlock(&(this->mutex));
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return count;
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}
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/**
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* implements send_queue_t.get
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*/
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static packet_t *get(private_send_queue_t *this)
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{
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int oldstate;
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packet_t *packet;
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pthread_mutex_lock(&(this->mutex));
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/* go to wait while no packets available */
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while(this->list->get_count(this->list) == 0)
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{
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/* add mutex unlock handler for cancellation, enable cancellation */
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pthread_cleanup_push((void(*)(void*))pthread_mutex_unlock, (void*)&(this->mutex));
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pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate);
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pthread_cond_wait( &(this->condvar), &(this->mutex));
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/* reset cancellation, remove mutex-unlock handler (without executing) */
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pthread_setcancelstate(oldstate, NULL);
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pthread_cleanup_pop(0);
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}
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this->list->remove_first(this->list,(void **)&packet);
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pthread_mutex_unlock(&(this->mutex));
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return packet;
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}
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/**
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* implements send_queue_t.add
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*/
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static void add(private_send_queue_t *this, packet_t *packet)
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{
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pthread_mutex_lock(&(this->mutex));
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this->list->insert_last(this->list,packet);
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pthread_cond_signal( &(this->condvar));
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pthread_mutex_unlock(&(this->mutex));
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}
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/**
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* implements send_queue_t.destroy
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*/
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static void destroy (private_send_queue_t *this)
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{
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/* destroy all packets in list before destroying list */
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while (this->list->get_count(this->list) > 0)
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{
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packet_t *packet;
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if (this->list->remove_first(this->list,(void *) &packet) != SUCCESS)
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{
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this->list->destroy(this->list);
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break;
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}
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packet->destroy(packet);
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}
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this->list->destroy(this->list);
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pthread_mutex_destroy(&(this->mutex));
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pthread_cond_destroy(&(this->condvar));
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allocator_free(this);
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}
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/*
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*
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* Documented in header
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*/
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send_queue_t *send_queue_create()
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{
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private_send_queue_t *this = allocator_alloc_thing(private_send_queue_t);
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this->public.get_count = (int(*)(send_queue_t*)) get_count;
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this->public.get = (packet_t*(*)(send_queue_t*)) get;
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this->public.add = (void(*)(send_queue_t*, packet_t*)) add;
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this->public.destroy = (void(*)(send_queue_t*)) destroy;
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this->list = linked_list_create();
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pthread_mutex_init(&(this->mutex), NULL);
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pthread_cond_init(&(this->condvar), NULL);
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return (&this->public);
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}
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