LookingGlass/client/src/ll.c
2019-03-28 11:02:36 +11:00

160 lines
2.9 KiB
C

/*
KVMGFX Client - A KVM Client for VGA Passthrough
Copyright (C) 2017-2019 Geoffrey McRae <geoff@hostfission.com>
https://looking-glass.hostfission.com
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "ll.h"
#include "utils.h"
#include <stdlib.h>
#include <assert.h>
struct ll_item
{
void * data;
struct ll_item * next;
};
struct ll
{
struct ll_item * head;
struct ll_item * tail;
struct ll_item * pos;
unsigned int count;
LG_Lock lock;
};
struct ll * ll_new()
{
struct ll * list = malloc(sizeof(struct ll));
list->head = NULL;
list->tail = NULL;
list->pos = NULL;
LG_LOCK_INIT(list->lock);
return list;
}
void ll_free(struct ll * list)
{
// never free a list with items in it!
assert(!list->head);
LG_LOCK_FREE(list->lock);
free(list);
}
void ll_push(struct ll * list, void * data)
{
struct ll_item * item = malloc(sizeof(struct ll_item));
item->data = data;
item->next = NULL;
LG_LOCK(list->lock);
if (!list->head)
{
list->head = item;
list->tail = item;
LG_UNLOCK(list->lock);
return;
}
++list->count;
list->tail->next = item;
list->tail = item;
LG_UNLOCK(list->lock);
}
bool ll_shift(struct ll * list, void ** data)
{
LG_LOCK(list->lock);
if (!list->head)
{
LG_UNLOCK(list->lock);
return false;
}
--list->count;
struct ll_item * item = list->head;
list->head = item->next;
list->pos = NULL;
LG_UNLOCK(list->lock);
if (data)
*data = item->data;
free(item);
return true;
}
bool ll_peek_head(struct ll * list, void ** data)
{
LG_LOCK(list->lock);
if (!list->head)
{
LG_UNLOCK(list->lock);
return false;
}
*data = list->head->data;
LG_UNLOCK(list->lock);
return true;
}
unsigned int ll_count(struct ll * list)
{
return list->count;
}
void ll_reset (struct ll * list)
{
LG_LOCK(list->lock);
list->pos = NULL;
LG_UNLOCK(list->lock);
}
bool ll_walk(struct ll * list, void ** data)
{
LG_LOCK(list->lock);
if (!list->pos)
{
if (!list->head)
{
LG_UNLOCK(list->lock);
return false;
}
list->pos = list->head;
}
else
{
if (!list->pos->next)
{
LG_UNLOCK(list->lock);
return false;
}
list->pos = list->pos->next;
}
*data = list->pos->data;
LG_UNLOCK(list->lock);
return true;
}