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/*-
* Copyright (c) 2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/queue.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <pjdlog.h>
#include "rangelock.h"
#ifndef PJDLOG_ASSERT
#include <assert.h>
#define PJDLOG_ASSERT(...) assert(__VA_ARGS__)
#endif
#define RANGELOCKS_MAGIC 0x94310c
struct rangelocks {
int rls_magic; /* Magic value. */
TAILQ_HEAD(, rlock) rls_locks; /* List of locked ranges. */
};
struct rlock {
off_t rl_start;
off_t rl_end;
TAILQ_ENTRY(rlock) rl_next;
};
int
rangelock_init(struct rangelocks **rlsp)
{
struct rangelocks *rls;
PJDLOG_ASSERT(rlsp != NULL);
rls = malloc(sizeof(*rls));
if (rls == NULL)
return (-1);
TAILQ_INIT(&rls->rls_locks);
rls->rls_magic = RANGELOCKS_MAGIC;
*rlsp = rls;
return (0);
}
void
rangelock_free(struct rangelocks *rls)
{
struct rlock *rl;
PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
rls->rls_magic = 0;
while ((rl = TAILQ_FIRST(&rls->rls_locks)) != NULL) {
TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
free(rl);
}
free(rls);
}
int
rangelock_add(struct rangelocks *rls, off_t offset, off_t length)
{
struct rlock *rl;
PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
rl = malloc(sizeof(*rl));
if (rl == NULL)
return (-1);
rl->rl_start = offset;
rl->rl_end = offset + length;
TAILQ_INSERT_TAIL(&rls->rls_locks, rl, rl_next);
return (0);
}
void
rangelock_del(struct rangelocks *rls, off_t offset, off_t length)
{
struct rlock *rl;
PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
if (rl->rl_start == offset && rl->rl_end == offset + length)
break;
}
PJDLOG_ASSERT(rl != NULL);
TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
free(rl);
}
bool
rangelock_islocked(struct rangelocks *rls, off_t offset, off_t length)
{
struct rlock *rl;
off_t end;
PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
end = offset + length;
TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
if (rl->rl_start < end && rl->rl_end > offset)
break;
}
return (rl != NULL);
}
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