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/*-
* Copyright (c) 1990 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)refill.c 5.3 (Berkeley) 2/24/91";*/
static char *rcsid = "$Id: refill.c,v 1.1 1995/10/18 08:43:08 deraadt Exp $";
#endif /* LIBC_SCCS and not lint */
#include <pthread.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include "local.h"
#include "glue.h"
extern pthread_mutex_t __sfp_mutex;
extern pthread_cond_t __sfp_cond;
extern struct glue __sglue;
extern int __sfp_state;
/* This function is very similar to __swalk_sflush */
static void __swalk_lflush()
{
register FILE *fp, *savefp;
register int n, saven;
register struct glue *g, *saveg;
/* Only allow other threads to read __sglue */
pthread_mutex_lock(&__sfp_mutex);
__sfp_state++;
pthread_mutex_unlock(&__sfp_mutex);
saven = 0;
saveg = NULL;
savefp = NULL;
for (g = &__sglue; g != NULL; g = g->next) {
for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) {
if ((fp->_flags & (__SLBF|__SWR)) == __SLBF|__SWR) {
/* Is there anything to flush? */
if (fp->_bf._base && (fp->_bf._base - fp->_p)) {
if (ftrylockfile(fp)) { /* Can we flush it */
if (!saven) { /* No, save first fp we can't flush */
saven;
saveg = g;
savefp = fp;
continue;
}
(void) __sflush(fp);
}
}
}
}
}
if (savefp) {
for (g = saveg; g != NULL; g = g->next) {
for (fp = savefp, n = saven + 1; --n >= 0; fp++) {
if ((fp->_flags & (__SLBF|__SWR)) == __SLBF|__SWR) {
/* Anything to flush */
while (fp->_bf._base && (fp->_bf._base - fp->_p)) {
if (ftrylockfile(fp)) { /* Can we flush it */
pthread_yield();
continue;
}
(void) __sflush(fp);
}
}
}
}
}
/* If no other readers wakeup a thread waiting to do __sfp */
pthread_mutex_lock(&__sfp_mutex);
if (! (--__sfp_state)) {
pthread_cond_signal(&__sfp_cond);
}
pthread_mutex_unlock(&__sfp_mutex);
}
/*
* Refill a stdio buffer.
* Return EOF on eof or error, 0 otherwise.
*/
__srefill(fp)
register FILE *fp;
{
/* make sure stdio is set up */
pthread_once(&__sdidinit, __sinit);
fp->_r = 0; /* largely a convenience for callers */
/* SysV does not make this test; take it out for compatibility */
if (fp->_flags & __SEOF)
return (EOF);
/* if not already reading, have to be reading and writing */
if ((fp->_flags & __SRD) == 0) {
if ((fp->_flags & __SRW) == 0) {
errno = EBADF;
return (EOF);
}
/* switch to reading */
if (fp->_flags & __SWR) {
if (__sflush(fp))
return (EOF);
fp->_flags &= ~__SWR;
fp->_w = 0;
fp->_lbfsize = 0;
}
fp->_flags |= __SRD;
} else {
/*
* We were reading. If there is an ungetc buffer,
* we must have been reading from that. Drop it,
* restoring the previous buffer (if any). If there
* is anything in that buffer, return.
*/
if (HASUB(fp)) {
FREEUB(fp);
if ((fp->_r = fp->_ur) != 0) {
fp->_p = fp->_up;
return (0);
}
}
}
if (fp->_bf._base == NULL)
__smakebuf(fp);
/*
* Before reading from a line buffered or unbuffered file,
* flush all line buffered output files, per the ANSI C
* standard.
*/
if (fp->_flags & (__SLBF|__SNBF))
__swalk_lflush();
fp->_p = fp->_bf._base;
fp->_r = __sread(fp, (char *)fp->_p, fp->_bf._size);
fp->_flags &= ~__SMOD; /* buffer contents are again pristine */
if (fp->_r <= 0) {
if (fp->_r == 0)
fp->_flags |= __SEOF;
else {
fp->_r = 0;
fp->_flags |= __SERR;
}
return (EOF);
}
return (0);
}
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