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/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr_arch_file_io.h"
#if APR_HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
APR_DECLARE(apr_status_t) apr_file_lock(apr_file_t *thefile, int type)
{
int rc;
#if defined(HAVE_FCNTL_H)
{
struct flock l = { 0 };
int fc;
l.l_whence = SEEK_SET; /* lock from current point */
l.l_start = 0; /* begin lock at this offset */
l.l_len = 0; /* lock to end of file */
if ((type & APR_FLOCK_TYPEMASK) == APR_FLOCK_SHARED)
l.l_type = F_RDLCK;
else
l.l_type = F_WRLCK;
fc = (type & APR_FLOCK_NONBLOCK) ? F_SETLK : F_SETLKW;
/* keep trying if fcntl() gets interrupted (by a signal) */
while ((rc = fcntl(thefile->filedes, fc, &l)) < 0 && errno == EINTR)
continue;
if (rc == -1) {
/* on some Unix boxes (e.g., Tru64), we get EACCES instead
* of EAGAIN; we don't want APR_STATUS_IS_EAGAIN() matching EACCES
* since that breaks other things, so fix up the retcode here
*/
if (errno == EACCES) {
return EAGAIN;
}
return errno;
}
}
#elif defined(HAVE_SYS_FILE_H)
{
int ltype;
if ((type & APR_FLOCK_TYPEMASK) == APR_FLOCK_SHARED)
ltype = LOCK_SH;
else
ltype = LOCK_EX;
if ((type & APR_FLOCK_NONBLOCK) != 0)
ltype |= LOCK_NB;
/* keep trying if flock() gets interrupted (by a signal) */
while ((rc = flock(thefile->filedes, ltype)) < 0 && errno == EINTR)
continue;
if (rc == -1)
return errno;
}
#else
#error No file locking mechanism is available.
#endif
return APR_SUCCESS;
}
APR_DECLARE(apr_status_t) apr_file_unlock(apr_file_t *thefile)
{
int rc;
#if defined(HAVE_FCNTL_H)
{
struct flock l = { 0 };
l.l_whence = SEEK_SET; /* lock from current point */
l.l_start = 0; /* begin lock at this offset */
l.l_len = 0; /* lock to end of file */
l.l_type = F_UNLCK;
/* keep trying if fcntl() gets interrupted (by a signal) */
while ((rc = fcntl(thefile->filedes, F_SETLKW, &l)) < 0
&& errno == EINTR)
continue;
if (rc == -1)
return errno;
}
#elif defined(HAVE_SYS_FILE_H)
{
/* keep trying if flock() gets interrupted (by a signal) */
while ((rc = flock(thefile->filedes, LOCK_UN)) < 0 && errno == EINTR)
continue;
if (rc == -1)
return errno;
}
#else
#error No file locking mechanism is available.
#endif
return APR_SUCCESS;
}
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