f582340a6a
Fix the handle locking in stdio to use flockfile/funlockfile internally when and where required. Macros in <stdio.h> are updated to automatically call the underlying functions when the process is threaded to obtain the necessary locking. A private mutex is added to protect __sglue, the internal list of FILE handles, and another to protect the one-time initialization. Some routines in libc that use getc() change to use getc_unlocked() as they're either protected by their own lock or aren't thread-safe routines anyway. Based on OpenBSD change by guenther@openbsd.org http://www.mail-archive.com/source-changes@cvs.openbsd.org/msg01015.html Bug: 3446659 Change-Id: Ie82116e358c541718d6709ec45ca6796be5a007b
98 lines
2.7 KiB
C
98 lines
2.7 KiB
C
/* $OpenBSD: fflush.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
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/*-
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Chris Torek.
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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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* 1. 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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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT 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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#include <errno.h>
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#include <stdio.h>
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#include "local.h"
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/* Flush a single file, or (if fp is NULL) all files. */
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int
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fflush(FILE *fp)
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{
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int r;
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if (fp == NULL)
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return (_fwalk(__sflush_locked));
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FLOCKFILE(fp);
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if ((fp->_flags & (__SWR | __SRW)) == 0) {
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errno = EBADF;
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r = EOF;
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} else
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r = __sflush(fp);
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FUNLOCKFILE(fp);
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return (r);
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}
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int
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__sflush(FILE *fp)
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{
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unsigned char *p;
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int n, t;
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t = fp->_flags;
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if ((t & __SWR) == 0)
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return (0);
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if ((p = fp->_bf._base) == NULL)
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return (0);
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n = fp->_p - p; /* write this much */
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/*
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* Set these immediately to avoid problems with longjmp and to allow
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* exchange buffering (via setvbuf) in user write function.
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*/
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fp->_p = p;
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fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
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for (; n > 0; n -= t, p += t) {
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t = (*fp->_write)(fp->_cookie, (char *)p, n);
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if (t <= 0) {
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fp->_flags |= __SERR;
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return (EOF);
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}
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}
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return (0);
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}
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int
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__sflush_locked(FILE *fp)
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{
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int r;
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FLOCKFILE(fp);
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r = __sflush(fp);
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FUNLOCKFILE(fp);
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return (r);
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}
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