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/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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.
*/
/* implement flockfile(), ftrylockfile() and funlockfile()
*
* we can't use the OpenBSD implementation which uses kernel-specific
* APIs not available on Linux.
*
* Instead, we use a pthread_mutex_t within the FILE* internal state.
* See fileext.h for details.
*
* the behaviour, if fclose() is called while the corresponding
* file is locked is totally undefined.
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "fileext.h"
void
flockfile(FILE * fp)
{
if (fp != NULL) {
_FLOCK_LOCK(fp);
}
}
int
ftrylockfile(FILE *fp)
{
/* The specification for ftrylockfile() says it returns 0 on success,
* or non-zero on error. So return an errno code directly on error.
*/
int ret = EINVAL;
if (fp != NULL) {
ret = _FLOCK_TRYLOCK(fp);
}
return ret;
}
void
funlockfile(FILE * fp)
{
if (fp != NULL) {
_FLOCK_UNLOCK(fp);
}
}
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