mirror of https://github.com/tongzx/nt5src
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
401 lines
12 KiB
401 lines
12 KiB
/***
|
|
*fflush.c - flush a stream buffer
|
|
*
|
|
* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
|
|
*
|
|
*Purpose:
|
|
* defines fflush() - flush the buffer on a stream
|
|
* _flushall() - flush all stream buffers
|
|
*
|
|
*Revision History:
|
|
* 09-01-83 RN initial version
|
|
* 11-02-87 JCR Multi-thread support
|
|
* 12-11-87 JCR Added "_LOAD_DS" to declaration
|
|
* 01-13-88 JCR Removed unnecessary calls to mthread fileno/feof/ferror
|
|
* 05-27-88 PHG Merge DLL and normal versions
|
|
* 06-14-88 JCR Use near pointer to reference _iob[] entries
|
|
* 08-24-88 GJF Don't use FP_OFF() macro for the 386
|
|
* 08-17-89 GJF Clean up, now specific to OS/2 2.0 (i.e., 386 flat
|
|
* model). Also fixed copyright and indents.
|
|
* 11-29-89 GJF Added support for fflush(NULL) (per ANSI). Merged in
|
|
* flushall().
|
|
* 01-24-90 GJF Fixed fflush(NULL) functionality to comply with ANSI
|
|
* (must only call fflush() for output streams)
|
|
* 03-16-90 GJF Made calling type _CALLTYPE1, added #include
|
|
* <cruntime.h> and removed #include <register.h>.
|
|
* 03-26-90 GJF Made flsall() _CALLTYPE4.
|
|
* 05-09-90 SBM _fflush_lk became _flush, added new [_]fflush[_lk]
|
|
* 07-11-90 SBM Commit mode on a per stream basis
|
|
* 10-02-90 GJF New-style function declarators.
|
|
* 12-12-90 GJF Fixed mis-placed paran in ternary expr commiting the
|
|
* buffers.
|
|
* 01-16-91 SRW Reversed test of _commit return value
|
|
* 01-21-91 GJF ANSI naming.
|
|
* 06-05-91 GJF On a successful _flush of a read/write stream in write
|
|
* mode, clear _IOWRT so that the next operation can be a
|
|
* read. ANSI requirement (C700 bug #2531).
|
|
* 07-30-91 GJF Added support for termination scheme used on
|
|
* non-Cruiser targets [_WIN32_].
|
|
* 08-19-91 JCR Added _exitflag, _endstdio
|
|
* 03-16-92 SKS Moved _cflush to the initializer module (in assembler)
|
|
* 03-27-92 DJM POSIX support.
|
|
* 08-26-92 GJF Include unistd.h for POSIX build.
|
|
* 03-18-93 CFW fflush_lk returns 0 before exit.
|
|
* 03-19-93 GJF Revised flsall() so that, in multi-thread models,
|
|
* unused streams are not locked unnecessarily.
|
|
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
|
|
* 05-10-93 GJF Purged ftell call accidently checked in 3/10/93.
|
|
* 10-29-93 GJF Define entry for termination section (used to be in
|
|
* in i386\cinitstd.asm). Also, replaced MTHREAD with
|
|
* _MT.
|
|
* 04-05-94 GJF #ifdef-ed out _cflush definition for msvcrt*.dll, it
|
|
* is unnecessary.
|
|
* 08-18-94 GJF Moved terminator stuff (including _cflush def) to
|
|
* _file.c
|
|
* 02-17-95 GJF Appended Mac version of source file (somewhat cleaned
|
|
* up), with appropriate #ifdef-s.
|
|
* 03-07-95 GJF Changed flsall() to iterate over the __piob[] table.
|
|
* Also, changed to locks based on __piob.
|
|
* 12-28-95 GJF Repaced reference to _NSTREAM_ with _nstream (users
|
|
* may change the max. number of supported streams).
|
|
* 08-01-96 RDK Change termination pointer data type to static.
|
|
* 02-13-98 GJF Changes for Win64: added int cast to pointer diff.
|
|
* 02-27-98 GJF Exception-safe locking.
|
|
* 04-28-99 PML Wrap __declspec(allocate()) in _CRTALLOC macro.
|
|
* 05-17-99 PML Remove all Macintosh support.
|
|
*
|
|
*******************************************************************************/
|
|
|
|
#include <sect_attribs.h>
|
|
#include <cruntime.h>
|
|
#ifdef _POSIX_
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
#endif
|
|
#include <stdio.h>
|
|
#include <file2.h>
|
|
#include <io.h>
|
|
#include <mtdll.h>
|
|
#include <internal.h>
|
|
|
|
|
|
/* Values passed to flsall() to distinguish between _flushall() and
|
|
* fflush(NULL) behavior
|
|
*/
|
|
#define FLUSHALL 1
|
|
#define FFLUSHNULL 0
|
|
|
|
/* Core routine for fflush(NULL) and flushall()
|
|
*/
|
|
static int __cdecl flsall(int);
|
|
|
|
|
|
/***
|
|
*int fflush(stream) - flush the buffer on a stream
|
|
*
|
|
*Purpose:
|
|
* if file open for writing and buffered, flush the buffer. if problems
|
|
* flushing the buffer, set the stream flag to error
|
|
* Always flushes the stdio stream and forces a commit to disk if file
|
|
* was opened in commit mode.
|
|
*
|
|
*Entry:
|
|
* FILE *stream - stream to flush
|
|
*
|
|
*Exit:
|
|
* returns 0 if flushed successfully, or no buffer to flush
|
|
* returns EOF and sets file error flag if fails.
|
|
* FILE struct entries affected: _ptr, _cnt, _flag.
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
#ifdef _MT
|
|
|
|
int __cdecl fflush (
|
|
REG1 FILE *stream
|
|
)
|
|
{
|
|
int rc;
|
|
|
|
/* if stream is NULL, flush all streams
|
|
*/
|
|
if ( stream == NULL )
|
|
return(flsall(FFLUSHNULL));
|
|
|
|
_lock_str(stream);
|
|
|
|
__try {
|
|
rc = _fflush_lk(stream);
|
|
}
|
|
__finally {
|
|
_unlock_str(stream);
|
|
}
|
|
|
|
return(rc);
|
|
}
|
|
|
|
|
|
/***
|
|
*_fflush_lk() - Flush the buffer on a stream (stream is already locked)
|
|
*
|
|
*Purpose:
|
|
* Core flush routine; assumes stream lock is held by caller.
|
|
*
|
|
* [See fflush() above for more information.]
|
|
*
|
|
*Entry:
|
|
* [See fflush()]
|
|
*Exit:
|
|
* [See fflush()]
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
int __cdecl _fflush_lk (
|
|
REG1 FILE *str
|
|
)
|
|
{
|
|
|
|
#else /* non multi-thread */
|
|
|
|
int __cdecl fflush (
|
|
REG1 FILE *str
|
|
)
|
|
{
|
|
|
|
/* if stream is NULL, flush all streams */
|
|
if ( str == NULL ) {
|
|
return(flsall(FFLUSHNULL));
|
|
}
|
|
|
|
#endif /* rejoin common code */
|
|
|
|
if (_flush(str) != 0) {
|
|
/* _flush failed, don't attempt to commit */
|
|
return(EOF);
|
|
}
|
|
|
|
/* lowio commit to ensure data is written to disk */
|
|
#ifndef _POSIX_
|
|
if (str->_flag & _IOCOMMIT) {
|
|
return (_commit(_fileno(str)) ? EOF : 0);
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
|
|
/***
|
|
*int _flush(stream) - flush the buffer on a single stream
|
|
*
|
|
*Purpose:
|
|
* If file open for writing and buffered, flush the buffer. If
|
|
* problems flushing the buffer, set the stream flag to error.
|
|
* Multi-thread version assumes stream lock is held by caller.
|
|
*
|
|
*Entry:
|
|
* FILE* stream - stream to flush
|
|
*
|
|
*Exit:
|
|
* Returns 0 if flushed successfully, or if no buffer to flush.,
|
|
* Returns EOF and sets file error flag if fails.
|
|
* File struct entries affected: _ptr, _cnt, _flag.
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
int __cdecl _flush (
|
|
FILE *str
|
|
)
|
|
{
|
|
REG1 FILE *stream;
|
|
REG2 int rc = 0; /* assume good return */
|
|
REG3 int nchar;
|
|
|
|
/* Init pointer to stream */
|
|
stream = str;
|
|
|
|
#ifdef _POSIX_
|
|
|
|
/*
|
|
* Insure that EBADF is returned whenever the underlying
|
|
* file descriptor is closed.
|
|
*/
|
|
|
|
if (-1 == fcntl(fileno(stream), F_GETFL))
|
|
return(EOF);
|
|
|
|
/*
|
|
* Posix ignores read streams to insure that the result of
|
|
* ftell() is the same before and after fflush(), and to
|
|
* avoid seeking on pipes, ttys, etc.
|
|
*/
|
|
|
|
if ((stream->_flag & (_IOREAD | _IOWRT)) == _IOREAD) {
|
|
return 0;
|
|
}
|
|
|
|
#endif /* _POSIX_ */
|
|
|
|
if ((stream->_flag & (_IOREAD | _IOWRT)) == _IOWRT && bigbuf(stream)
|
|
&& (nchar = (int)(stream->_ptr - stream->_base)) > 0)
|
|
{
|
|
#ifdef _POSIX_
|
|
if ( write(fileno(stream), stream->_base, nchar) == nchar ) {
|
|
#else
|
|
if ( _write(_fileno(stream), stream->_base, nchar) == nchar ) {
|
|
#endif
|
|
/* if this is a read/write file, clear _IOWRT so that
|
|
* next operation can be a read
|
|
*/
|
|
if ( _IORW & stream->_flag )
|
|
stream->_flag &= ~_IOWRT;
|
|
}
|
|
else {
|
|
stream->_flag |= _IOERR;
|
|
rc = EOF;
|
|
}
|
|
}
|
|
|
|
stream->_ptr = stream->_base;
|
|
stream->_cnt = 0;
|
|
|
|
return(rc);
|
|
}
|
|
|
|
|
|
/***
|
|
*int _flushall() - flush all output buffers
|
|
*
|
|
*Purpose:
|
|
* flushes all the output buffers to the file, clears all input buffers.
|
|
*
|
|
*Entry:
|
|
* None.
|
|
*
|
|
*Exit:
|
|
* returns number of open streams
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
int __cdecl _flushall (
|
|
void
|
|
)
|
|
{
|
|
return(flsall(FLUSHALL));
|
|
}
|
|
|
|
|
|
/***
|
|
*static int flsall(flushflag) - flush all output buffers
|
|
*
|
|
*Purpose:
|
|
* Flushes all the output buffers to the file and, if FLUSHALL is passed,
|
|
* clears all input buffers. Core routine for both fflush(NULL) and
|
|
* flushall().
|
|
*
|
|
* MTHREAD Note: All the locking/unlocking required for both fflush(NULL)
|
|
* and flushall() is performed in this routine.
|
|
*
|
|
*Entry:
|
|
* int flushflag - flag indicating the exact semantics, there are two
|
|
* legal values: FLUSHALL and FFLUSHNULL
|
|
*
|
|
*Exit:
|
|
* if flushflag == FFLUSHNULL then flsbuf returns:
|
|
0, if successful
|
|
* EOF, if an error occurs while flushing one of the streams
|
|
*
|
|
* if flushflag == FLUSHALL then flsbuf returns the number of streams
|
|
* successfully flushed
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
static int __cdecl flsall (
|
|
int flushflag
|
|
)
|
|
{
|
|
REG1 int i;
|
|
int count = 0;
|
|
int errcode = 0;
|
|
|
|
#ifdef _MT
|
|
_mlock(_IOB_SCAN_LOCK);
|
|
__try {
|
|
#endif
|
|
|
|
for ( i = 0 ; i < _nstream ; i++ ) {
|
|
|
|
if ( (__piob[i] != NULL) && (inuse((FILE *)__piob[i])) ) {
|
|
|
|
#ifdef _MT
|
|
/*
|
|
* lock the stream. this is not done until testing
|
|
* the stream is in use to avoid unnecessarily creating
|
|
* a lock for every stream. the price is having to
|
|
* retest the stream after the lock has been asserted.
|
|
*/
|
|
_lock_str2(i, __piob[i]);
|
|
|
|
__try {
|
|
/*
|
|
* if the stream is STILL in use (it may have been
|
|
* closed before the lock was asserted), see about
|
|
* flushing it.
|
|
*/
|
|
if ( inuse((FILE *)__piob[i]) ) {
|
|
#endif
|
|
|
|
if ( flushflag == FLUSHALL ) {
|
|
/*
|
|
* FLUSHALL functionality: fflush the read or
|
|
* write stream and, if successful, update the
|
|
* count of flushed streams
|
|
*/
|
|
if ( _fflush_lk(__piob[i]) != EOF )
|
|
/* update count of successfully flushed
|
|
* streams
|
|
*/
|
|
count++;
|
|
}
|
|
else if ( (flushflag == FFLUSHNULL) &&
|
|
(((FILE *)__piob[i])->_flag & _IOWRT) ) {
|
|
/*
|
|
* FFLUSHNULL functionality: fflush the write
|
|
* stream and kept track of the error, if one
|
|
* occurs
|
|
*/
|
|
if ( _fflush_lk(__piob[i]) == EOF )
|
|
errcode = EOF;
|
|
}
|
|
|
|
#ifdef _MT
|
|
}
|
|
}
|
|
__finally {
|
|
_unlock_str2(i, __piob[i]);
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
#ifdef _MT
|
|
}
|
|
__finally {
|
|
_munlock(_IOB_SCAN_LOCK);
|
|
}
|
|
#endif
|
|
|
|
if ( flushflag == FLUSHALL )
|
|
return(count);
|
|
else
|
|
return(errcode);
|
|
}
|