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Diffstat (limited to 'private/crt32/stdio/_sftbuf.c')
| -rw-r--r-- | private/crt32/stdio/_sftbuf.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/private/crt32/stdio/_sftbuf.c b/private/crt32/stdio/_sftbuf.c new file mode 100644 index 000000000..ec81c7657 --- /dev/null +++ b/private/crt32/stdio/_sftbuf.c @@ -0,0 +1,223 @@ +/*** +*_sftbuf.c - temporary buffering initialization and flushing +* +* Copyright (c) 1985-1992, Microsoft Corporation. All rights reserved. +* +*Purpose: +* temporary buffering initialization and flushing. if stdout/err is +* unbuffered, buffer it temporarily so that string is sent to kernel as +* a batch of chars, not char-at-a-time. if appropriate, make buffering +* permanent. +* +* [NOTE 1: These routines assume that the temporary buffering is only +* used for output. In particular, note that _stbuf() sets _IOWRT.] +* +* [NOTE 2: It is valid for this module to assign a value directly to +* _flag instead of simply twiddling bits since we are initializing the +* buffer data base.] +* +*Revision History: +* 09-01-83 RN initial version +* 06-26-85 TC added code to _stbuf to allow variable buffer lengths +* ??-??-?? TC fixed case in _flbuf where flag is off, but a temporary +* buffer still needs to be fflushed. +* 05-27-87 JCR protect mode does not know about stdprn. +* 06-26-87 JCR Conditionalized out code in _ftbuf that caused +* redirected stdout to be flushed on every call. +* 07-01-87 JCR Put in code to support re-entrant calling from +* interrupt level (MSC only). +* 08-06-87 JCR Fixed a _ftbuf() problem pertaining to stderr/stdprn +* when _bufout is being used by stdout. +* 08-07-87 JCR (1) When assigning _bufout to an _iob, we now set the +* _IOWRT flag. This fixes a bug involving freopen() +* issued against one of the std handles. +* (2) Removed some annoying commented out code. +* 08-13-87 JCR _ftbuf() does NOT clear _IOWRT now. Fixes a bug where +* _getstream() would reassign stdout because none of the +* flags were set. +* 09-28-87 JCR Corrected _iob2 indexing (now uses _iob_index() macro). +* 11-05-87 JCR Re-written for multi-thread support and simplicity +* 01-11-88 JCR Merged mthread version into normal version +* 01-13-88 SKS Changed bogus "_fileno_lk" to "fileno" +* 06-06-88 JCR Optimized _iob2 references +* 06-10-88 JCR Use near pointer to reference _iob[] entries +* 06-27-88 JCR Added stdprn temporary buffering support (DOS only), +* and made buffer allocation dynamic; also added _IOFLRTN +* (flush stream on per routine basis). +* 08-25-88 GJF Modified to also work for the 386 (small model only). +* 06-20-89 PHG Changed return value to void +* 08-28-89 JCR Removed _NEAR_ for 386 +* 02-15-90 GJF _iob[], _iob2[] merge. Also, fixed copyright and +* indents. +* 03-16-90 GJF Made calling type _CALLTYPE1, added #include +* <cruntime.h> and removed #include <register.h>. Also, +* removed some leftover 16-bit DOS support. +* 03-27-90 GJF Added #include <io.h>. +* 05-29-90 SBM Use _flush, not [_]fflush[_lk] +* 07-23-90 SBM Replaced <assertm.h> by <assert.h> +* 10-03-90 GJF New-style function declarator. +* 01-22-91 GJF ANSI naming. +* 03-27-92 DJM POSIX support. +* 08-26-92 GJF Include unistd.h for POSIX build. +* +*******************************************************************************/ + +#include <cruntime.h> +#ifdef _POSIX_ +#include <unistd.h> +#endif +#include <stdio.h> +#include <file2.h> +#include <io.h> +#include <assert.h> +#include <internal.h> +#include <malloc.h> +#ifdef MTHREAD +#include <os2dll.h> +#endif + +/* Buffer pointers for stdout and stderr */ +void *_stdbuf[2] = { NULL, NULL}; + +/*** +*int _stbuf(stream) - set temp buffer on stdout, stdprn, stderr +* +*Purpose: +* if stdout/stderr is still unbuffered, buffer it. +* this function works intimately with _ftbuf, and accompanies it in +* bracketing normally unbuffered output. these functions intended for +* library use only. +* +* Multi-thread: It is assumed that the caller has already aquired the +* stream lock. +* +*Entry: +* FILE *stream - stream to temp buffer +* +*Exit: +* returns 1 if buffer initialized, 0 if not +* sets fields in stdout or stderr to indicate buffering +* +*Exceptions: +* +*******************************************************************************/ + +int _CALLTYPE1 _stbuf ( + FILE *str + ) +{ + REG1 FILE *stream; + int index; + + assert(str != NULL); + + /* Init near stream pointer */ + stream = str; + + /* do nothing if not a tty device */ +#ifdef _POSIX_ + if (!isatty(fileno(stream))) +#else + if (!_isatty(_fileno(stream))) +#endif + return(0); + + /* Make sure stream is stdout/stderr and init _stdbuf index */ + if (stream == stdout) + index = 0; + else if (stream == stderr) + index = 1; + else + return(0); + + _cflush++; /* force library pre-termination procedure */ + + /* Make sure the stream is not already buffered. */ + if (anybuf(stream)) + return(0); + + /* Allocate a buffer for this stream if we haven't done so yet. */ + if (_stdbuf[index] == NULL) + if ( (_stdbuf[index]=malloc(BUFSIZ)) == NULL ) + return(0); /* error */ + + /* Set up the buffer */ + stream->_ptr = stream->_base = _stdbuf[index]; + stream->_cnt = stream->_bufsiz = BUFSIZ; + stream->_flag |= (_IOWRT | _IOYOURBUF | _IOFLRTN); + + return(1); +} + + +/*** +*void _ftbuf(flag, stream) - take temp buffering off a stream +* +*Purpose: +* If stdout/stderr is being buffered and it is a device, _flush and +* dismantle the buffer. if it's not a device, leave the buffering on. +* This function works intimately with _stbuf, and accompanies it in +* bracketing normally unbuffered output. these functions intended for +* library use only +* +* Multi-thread: It is assumed that the caller has already aquired the +* stream lock. +* +*Entry: +* int flag - a flag to tell whether to dismantle temp buffering on a +* stream +* FILE *stream - the stream +* +*Exit: +* no return value +* sets fields in stdout/stderr +* +*Exceptions: +* +*******************************************************************************/ + +void _CALLTYPE1 _ftbuf ( + int flag, + FILE *str + ) +{ + REG1 FILE *stream; + + assert(flag == 0 || flag == 1); + + /* Init near stream pointers */ + stream = str; + + if (flag) { + + if (stream->_flag & _IOFLRTN) { + + /* Flush the stream and tear down temp buffering. */ + _flush(stream); + stream->_flag &= ~(_IOYOURBUF | _IOFLRTN); + stream->_bufsiz = 0; + stream->_base = stream->_ptr = NULL; + } + + /* Note: If we expand the functionality of the _IOFLRTN bit to + include other streams, we may want to clear that bit here under + an 'else' clause (i.e., clear bit in the case that we leave the + buffer permanently assigned. Given our current use of the bit, + the extra code is not needed. */ + + } /* end flag = 1 */ + +#ifndef MTHREAD +/* NOTE: Currently, writing to the same string at interrupt level does not + work in multi-thread programs. */ + +/* The following code is needed if an interrupt occurs between calls + to _stbuf/_ftbuf and the interrupt handler also calls _stbuf/_ftbuf. */ + + else + if (stream->_flag & _IOFLRTN) + _flush(stream); + +#endif /* MTHREAD */ + +} |