| /* |
| * 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); |
| } |
| } |