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freebsd-dev/lib/libc/stdio/fread.c

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BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
/*-
* 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.
* 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[] = "@(#)fread.c 8.2 (Berkeley) 12/11/93";
#endif /* LIBC_SCCS and not lint */
Fix the style of the SCM ID's. I believe have made all of libc .c's as consistent as possible.
2002-03-22 21:53:29 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
Remove _THREAD_SAFE and make libc thread-safe by default by adding (weak definitions to) stubs for some of the pthread functions. If the threads library is linked in, the real pthread functions will pulled in. Use the following convention for system calls wrapped by the threads library: __sys_foo - actual system call _foo - weak definition to __sys_foo foo - weak definition to __sys_foo Change all libc uses of system calls wrapped by the threads library from foo to _foo. In order to define the prototypes for _foo(), we introduce namespace.h and un-namespace.h (suggested by bde). All files that need to reference these system calls, should include namespace.h before any standard includes, then include un-namespace.h after the standard includes and before any local includes. <db.h> is an exception and shouldn't be included in between namespace.h and un-namespace.h namespace.h will define foo to _foo, and un-namespace.h will undefine foo. Try to eliminate some of the recursive calls to MT-safe functions in libc/stdio in preparation for adding a mutex to FILE. We have recursive mutexes, but would like to avoid using them if possible. Remove uneeded includes of <errno.h> from a few files. Add $FreeBSD$ to a few files in order to pass commitprep. Approved by: -arch
2001-01-24 13:01:12 +00:00
#include "namespace.h"
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
#include <stdio.h>
#include <string.h>
Remove _THREAD_SAFE and make libc thread-safe by default by adding (weak definitions to) stubs for some of the pthread functions. If the threads library is linked in, the real pthread functions will pulled in. Use the following convention for system calls wrapped by the threads library: __sys_foo - actual system call _foo - weak definition to __sys_foo foo - weak definition to __sys_foo Change all libc uses of system calls wrapped by the threads library from foo to _foo. In order to define the prototypes for _foo(), we introduce namespace.h and un-namespace.h (suggested by bde). All files that need to reference these system calls, should include namespace.h before any standard includes, then include un-namespace.h after the standard includes and before any local includes. <db.h> is an exception and shouldn't be included in between namespace.h and un-namespace.h namespace.h will define foo to _foo, and un-namespace.h will undefine foo. Try to eliminate some of the recursive calls to MT-safe functions in libc/stdio in preparation for adding a mutex to FILE. We have recursive mutexes, but would like to avoid using them if possible. Remove uneeded includes of <errno.h> from a few files. Add $FreeBSD$ to a few files in order to pass commitprep. Approved by: -arch
2001-01-24 13:01:12 +00:00
#include "un-namespace.h"
Reviewed by: julian and (hsu?) Submitted by: John Birrel(L?) changes for threadsafe operations
1996-01-22 00:02:33 +00:00
#include "local.h"
Add FILE locking stubs for libc. Change the FILE locking to support kernel threads when linked with libpthread (which you haven't see yet). This requires that libc become thread-safe and thread-aware, testing __isthreaded before attempting to do lock/unlock calls. The impact on non-threaded programs is minor. This change works with libc_r, so it's the best compromise.
1998-04-11 07:40:47 +00:00
#include "libc_private.h"
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
With current pthread implementations, a mutex initialization will allocate a memory block. sscanf calls __svfscanf which in turn calls fread, fread triggers mutex initialization but the mutex is not destroyed in sscanf, this leads to memory leak. To avoid the memory leak and performance issue, we create a none MT-safe version of fread: __fread, and instead let __svfscanf call __fread. PR: threads/90392 Patch submitted by: dhartmei MFC after: 7 days
2005-12-16 02:50:53 +00:00
/*
* MT-safe version
*/
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
size_t
With current pthread implementations, a mutex initialization will allocate a memory block. sscanf calls __svfscanf which in turn calls fread, fread triggers mutex initialization but the mutex is not destroyed in sscanf, this leads to memory leak. To avoid the memory leak and performance issue, we create a none MT-safe version of fread: __fread, and instead let __svfscanf call __fread. PR: threads/90392 Patch submitted by: dhartmei MFC after: 7 days
2005-12-16 02:50:53 +00:00
fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
{
Fix fread() to return a correct value on platforms where sizeof(int) != sizeof(size_t), i.e. on all 64-bit platforms. Reported by: Andrey V. Elsukov MFC after: 3 days
2008-12-01 14:33:34 +00:00
size_t ret;
With current pthread implementations, a mutex initialization will allocate a memory block. sscanf calls __svfscanf which in turn calls fread, fread triggers mutex initialization but the mutex is not destroyed in sscanf, this leads to memory leak. To avoid the memory leak and performance issue, we create a none MT-safe version of fread: __fread, and instead let __svfscanf call __fread. PR: threads/90392 Patch submitted by: dhartmei MFC after: 7 days
2005-12-16 02:50:53 +00:00
FLOCKFILE(fp);
ret = __fread(buf, size, count, fp);
FUNLOCKFILE(fp);
return (ret);
}
size_t
__fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
{
Remove 'register' keyword.
2002-03-21 18:49:23 +00:00
size_t resid;
char *p;
int r;
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
size_t total;
/*
* The ANSI standard requires a return value of 0 for a count
* or a size of 0. Peculiarily, it imposes no such requirements
* on fwrite; it only requires fread to be broken.
*/
if ((resid = count * size) == 0)
return (0);
Basic support for wide character I/O: getwc(), fgetwc(), getwchar(), putwc(), fputwc(), putwchar(), ungetwc(), fwide().
2002-08-13 09:30:41 +00:00
ORIENT(fp, -1);
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
if (fp->_r < 0)
fp->_r = 0;
total = resid;
p = buf;
while (resid > (r = fp->_r)) {
(void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
fp->_p += r;
/* fp->_r = 0 ... done in __srefill */
p += r;
resid -= r;
if (__srefill(fp)) {
/* no more input: return partial result */
return ((total - resid) / size);
}
}
(void)memcpy((void *)p, (void *)fp->_p, resid);
fp->_r -= resid;
fp->_p += resid;
return (count);
}
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