platform_bionic/libc/stdio/stdio.c
Elliott Hughes 8885dcc779 Add TEMP_FAILURE_RETRY to stdio's low-level read/write functions.
This is correctness rather than performance, but found while investigating
performance.

Bug: 18593728
Change-Id: Idbdfed89d1931fcfae65db29d662108d4bbd9b65
2015-01-20 16:18:32 -08:00

90 lines
2.8 KiB
C

/* $OpenBSD: stdio.c,v 1.9 2005/08/08 08:05:36 espie Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include "local.h"
/*
* Small standard I/O/seek/close functions.
* These maintain the `known seek offset' for seek optimisation.
*/
int
__sread(void *cookie, char *buf, int n)
{
FILE *fp = cookie;
int ret;
ret = TEMP_FAILURE_RETRY(read(fp->_file, buf, n));
/* if the read succeeded, update the current offset */
if (ret >= 0)
fp->_offset += ret;
else
fp->_flags &= ~__SOFF; /* paranoia */
return (ret);
}
int
__swrite(void *cookie, const char *buf, int n)
{
FILE *fp = cookie;
if (fp->_flags & __SAPP)
(void) TEMP_FAILURE_RETRY(lseek(fp->_file, (off_t)0, SEEK_END));
fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */
return TEMP_FAILURE_RETRY(write(fp->_file, buf, n));
}
fpos_t
__sseek(void *cookie, fpos_t offset, int whence)
{
FILE *fp = cookie;
off_t ret;
ret = TEMP_FAILURE_RETRY(lseek(fp->_file, (off_t)offset, whence));
if (ret == (off_t)-1)
fp->_flags &= ~__SOFF;
else {
fp->_flags |= __SOFF;
fp->_offset = ret;
}
return (ret);
}
int
__sclose(void *cookie)
{
return TEMP_FAILURE_RETRY(close(((FILE *)cookie)->_file));
}