9831ad3ce6
For Honeycomb, we added proper file thread-safety for all FILE* operations. However, we did implement that by using an out-of-band hash table to map FILE* pointers to phtread_mutex_t mutexes, because we couldn't change the size of 'struct _sFILE' without breaking the ABI. It turns out that our BSD-derived code already has some support code to extend FILE* objects, so use it instead. See libc/stdio/fileext.h This patch gets rid of the hash table, and put the mutex directly into the sFILE extension. Change-Id: If1c3fe0a0a89da49c568e9a7560b7827737ff4d0
75 lines
2.3 KiB
C
75 lines
2.3 KiB
C
/*
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* Copyright (C) 2008 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/* implement flockfile(), ftrylockfile() and funlockfile()
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*
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* we can't use the OpenBSD implementation which uses kernel-specific
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* APIs not available on Linux.
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*
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* Instead, we use a pthread_mutex_t within the FILE* internal state.
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* See fileext.h for details.
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*
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* the behaviour, if fclose() is called while the corresponding
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* file is locked is totally undefined.
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*/
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include "fileext.h"
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void
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flockfile(FILE * fp)
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{
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if (fp != NULL) {
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_FLOCK_LOCK(fp);
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}
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}
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int
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ftrylockfile(FILE *fp)
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{
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/* The specification for ftrylockfile() says it returns 0 on success,
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* or non-zero on error. So return an errno code directly on error.
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*/
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int ret = EINVAL;
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if (fp != NULL) {
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ret = _FLOCK_TRYLOCK(fp);
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}
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return ret;
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}
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void
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funlockfile(FILE * fp)
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{
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if (fp != NULL) {
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_FLOCK_UNLOCK(fp);
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}
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}
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