bionic/libc/include/stdio.h
Kenny Root f582340a6a Fix the handle locking in stdio
Fix the handle locking in stdio to use flockfile/funlockfile
internally when and where required.  Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking.  A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization.  Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.

Based on OpenBSD change by guenther@openbsd.org
http://www.mail-archive.com/source-changes@cvs.openbsd.org/msg01015.html

Bug: 3446659
Change-Id: Ie82116e358c541718d6709ec45ca6796be5a007b
2011-02-14 09:32:56 -08:00

460 lines
14 KiB
C

/* $OpenBSD: stdio.h,v 1.35 2006/01/13 18:10:09 miod Exp $ */
/* $NetBSD: stdio.h,v 1.18 1996/04/25 18:29:21 jtc Exp $ */
/*-
* 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. 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.
*
* @(#)stdio.h 5.17 (Berkeley) 6/3/91
*/
#ifndef _STDIO_H_
#define _STDIO_H_
#include <sys/cdefs.h>
#include <sys/_types.h>
/* va_list and size_t must be defined by stdio.h according to Posix */
#define __need___va_list
#include <stdarg.h>
/* note that this forces stddef.h to *only* define size_t */
#define __need_size_t
#include <stddef.h>
#include <stddef.h>
#if __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE
#include <sys/types.h> /* XXX should be removed */
#endif
#ifndef _SIZE_T_DEFINED_
#define _SIZE_T_DEFINED_
typedef unsigned long size_t;
#endif
#ifndef _OFF_T_DEFINED_
#define _OFF_T_DEFINED_
typedef long off_t;
#endif
#ifndef NULL
#ifdef __GNUG__
#define NULL __null
#else
#define NULL 0L
#endif
#endif
#define _FSTDIO /* Define for new stdio with functions. */
typedef off_t fpos_t; /* stdio file position type */
/*
* NB: to fit things in six character monocase externals, the stdio
* code uses the prefix `__s' for stdio objects, typically followed
* by a three-character attempt at a mnemonic.
*/
/* stdio buffers */
struct __sbuf {
unsigned char *_base;
int _size;
};
/*
* stdio state variables.
*
* The following always hold:
*
* if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
* _lbfsize is -_bf._size, else _lbfsize is 0
* if _flags&__SRD, _w is 0
* if _flags&__SWR, _r is 0
*
* This ensures that the getc and putc macros (or inline functions) never
* try to write or read from a file that is in `read' or `write' mode.
* (Moreover, they can, and do, automatically switch from read mode to
* write mode, and back, on "r+" and "w+" files.)
*
* _lbfsize is used only to make the inline line-buffered output stream
* code as compact as possible.
*
* _ub, _up, and _ur are used when ungetc() pushes back more characters
* than fit in the current _bf, or when ungetc() pushes back a character
* that does not match the previous one in _bf. When this happens,
* _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
* _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
*
* NOTE: if you change this structure, you also need to update the
* std() initializer in findfp.c.
*/
typedef struct __sFILE {
unsigned char *_p; /* current position in (some) buffer */
int _r; /* read space left for getc() */
int _w; /* write space left for putc() */
short _flags; /* flags, below; this FILE is free if 0 */
short _file; /* fileno, if Unix descriptor, else -1 */
struct __sbuf _bf; /* the buffer (at least 1 byte, if !NULL) */
int _lbfsize; /* 0 or -_bf._size, for inline putc */
/* operations */
void *_cookie; /* cookie passed to io functions */
int (*_close)(void *);
int (*_read)(void *, char *, int);
fpos_t (*_seek)(void *, fpos_t, int);
int (*_write)(void *, const char *, int);
/* extension data, to avoid further ABI breakage */
struct __sbuf _ext;
/* data for long sequences of ungetc() */
unsigned char *_up; /* saved _p when _p is doing ungetc data */
int _ur; /* saved _r when _r is counting ungetc data */
/* tricks to meet minimum requirements even when malloc() fails */
unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */
unsigned char _nbuf[1]; /* guarantee a getc() buffer */
/* separate buffer for fgetln() when line crosses buffer boundary */
struct __sbuf _lb; /* buffer for fgetln() */
/* Unix stdio files get aligned to block boundaries on fseek() */
int _blksize; /* stat.st_blksize (may be != _bf._size) */
fpos_t _offset; /* current lseek offset */
} FILE;
__BEGIN_DECLS
extern FILE __sF[];
__END_DECLS
#define __SLBF 0x0001 /* line buffered */
#define __SNBF 0x0002 /* unbuffered */
#define __SRD 0x0004 /* OK to read */
#define __SWR 0x0008 /* OK to write */
/* RD and WR are never simultaneously asserted */
#define __SRW 0x0010 /* open for reading & writing */
#define __SEOF 0x0020 /* found EOF */
#define __SERR 0x0040 /* found error */
#define __SMBF 0x0080 /* _buf is from malloc */
#define __SAPP 0x0100 /* fdopen()ed in append mode */
#define __SSTR 0x0200 /* this is an sprintf/snprintf string */
#define __SOPT 0x0400 /* do fseek() optimisation */
#define __SNPT 0x0800 /* do not do fseek() optimisation */
#define __SOFF 0x1000 /* set iff _offset is in fact correct */
#define __SMOD 0x2000 /* true => fgetln modified _p text */
#define __SALC 0x4000 /* allocate string space dynamically */
#define __SIGN 0x8000 /* ignore this file in _fwalk */
/*
* The following three definitions are for ANSI C, which took them
* from System V, which brilliantly took internal interface macros and
* made them official arguments to setvbuf(), without renaming them.
* Hence, these ugly _IOxxx names are *supposed* to appear in user code.
*
* Although numbered as their counterparts above, the implementation
* does not rely on this.
*/
#define _IOFBF 0 /* setvbuf should set fully buffered */
#define _IOLBF 1 /* setvbuf should set line buffered */
#define _IONBF 2 /* setvbuf should set unbuffered */
#define BUFSIZ 1024 /* size of buffer used by setbuf */
#define EOF (-1)
/*
* FOPEN_MAX is a minimum maximum, and should be the number of descriptors
* that the kernel can provide without allocation of a resource that can
* fail without the process sleeping. Do not use this for anything.
*/
#define FOPEN_MAX 20 /* must be <= OPEN_MAX <sys/syslimits.h> */
#define FILENAME_MAX 1024 /* must be <= PATH_MAX <sys/syslimits.h> */
/* System V/ANSI C; this is the wrong way to do this, do *not* use these. */
#if __BSD_VISIBLE || __XPG_VISIBLE
#define P_tmpdir "/tmp/"
#endif
#define L_tmpnam 1024 /* XXX must be == PATH_MAX */
#define TMP_MAX 308915776
#ifndef SEEK_SET
#define SEEK_SET 0 /* set file offset to offset */
#endif
#ifndef SEEK_CUR
#define SEEK_CUR 1 /* set file offset to current plus offset */
#endif
#ifndef SEEK_END
#define SEEK_END 2 /* set file offset to EOF plus offset */
#endif
#define stdin (&__sF[0])
#define stdout (&__sF[1])
#define stderr (&__sF[2])
/*
* Functions defined in ANSI C standard.
*/
__BEGIN_DECLS
void clearerr(FILE *);
int fclose(FILE *);
int feof(FILE *);
int ferror(FILE *);
int fflush(FILE *);
int fgetc(FILE *);
int fgetpos(FILE *, fpos_t *);
char *fgets(char *, int, FILE *);
FILE *fopen(const char *, const char *);
int fprintf(FILE *, const char *, ...);
int fputc(int, FILE *);
int fputs(const char *, FILE *);
size_t fread(void *, size_t, size_t, FILE *);
FILE *freopen(const char *, const char *, FILE *);
int fscanf(FILE *, const char *, ...);
int fseek(FILE *, long, int);
int fseeko(FILE *, off_t, int);
int fsetpos(FILE *, const fpos_t *);
long ftell(FILE *);
off_t ftello(FILE *);
size_t fwrite(const void *, size_t, size_t, FILE *);
int getc(FILE *);
int getchar(void);
char *gets(char *);
#if __BSD_VISIBLE && !defined(__SYS_ERRLIST)
#define __SYS_ERRLIST
extern int sys_nerr; /* perror(3) external variables */
extern char *sys_errlist[];
#endif
void perror(const char *);
int printf(const char *, ...);
int putc(int, FILE *);
int putchar(int);
int puts(const char *);
int remove(const char *);
int rename(const char *, const char *);
void rewind(FILE *);
int scanf(const char *, ...);
void setbuf(FILE *, char *);
int setvbuf(FILE *, char *, int, size_t);
int sprintf(char *, const char *, ...);
int sscanf(const char *, const char *, ...);
FILE *tmpfile(void);
char *tmpnam(char *);
int ungetc(int, FILE *);
int vfprintf(FILE *, const char *, __va_list);
int vprintf(const char *, __va_list);
int vsprintf(char *, const char *, __va_list);
#if __ISO_C_VISIBLE >= 1999 || __BSD_VISIBLE
int snprintf(char *, size_t, const char *, ...)
__attribute__((__format__ (printf, 3, 4)))
__attribute__((__nonnull__ (3)));
int vfscanf(FILE *, const char *, __va_list)
__attribute__((__format__ (scanf, 2, 0)))
__attribute__((__nonnull__ (2)));
int vscanf(const char *, __va_list)
__attribute__((__format__ (scanf, 1, 0)))
__attribute__((__nonnull__ (1)));
int vsnprintf(char *, size_t, const char *, __va_list)
__attribute__((__format__ (printf, 3, 0)))
__attribute__((__nonnull__ (3)));
int vsscanf(const char *, const char *, __va_list)
__attribute__((__format__ (scanf, 2, 0)))
__attribute__((__nonnull__ (2)));
#endif /* __ISO_C_VISIBLE >= 1999 || __BSD_VISIBLE */
__END_DECLS
/*
* Functions defined in POSIX 1003.1.
*/
#if __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE
#define L_ctermid 1024 /* size for ctermid(); PATH_MAX */
#define L_cuserid 9 /* size for cuserid(); UT_NAMESIZE + 1 */
__BEGIN_DECLS
#if 0 /* MISSING FROM BIONIC */
char *ctermid(char *);
char *cuserid(char *);
#endif /* MISSING */
FILE *fdopen(int, const char *);
int fileno(FILE *);
#if (__POSIX_VISIBLE >= 199209)
int pclose(FILE *);
FILE *popen(const char *, const char *);
#endif
#if __POSIX_VISIBLE >= 199506
void flockfile(FILE *);
int ftrylockfile(FILE *);
void funlockfile(FILE *);
/*
* These are normally used through macros as defined below, but POSIX
* requires functions as well.
*/
int getc_unlocked(FILE *);
int getchar_unlocked(void);
int putc_unlocked(int, FILE *);
int putchar_unlocked(int);
#endif /* __POSIX_VISIBLE >= 199506 */
#if __XPG_VISIBLE
char *tempnam(const char *, const char *);
#endif
__END_DECLS
#endif /* __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE */
/*
* Routines that are purely local.
*/
#if __BSD_VISIBLE
__BEGIN_DECLS
int asprintf(char **, const char *, ...)
__attribute__((__format__ (printf, 2, 3)))
__attribute__((__nonnull__ (2)));
char *fgetln(FILE *, size_t *);
int fpurge(FILE *);
int getw(FILE *);
int putw(int, FILE *);
void setbuffer(FILE *, char *, int);
int setlinebuf(FILE *);
int vasprintf(char **, const char *, __va_list)
__attribute__((__format__ (printf, 2, 0)))
__attribute__((__nonnull__ (2)));
__END_DECLS
/*
* Stdio function-access interface.
*/
__BEGIN_DECLS
FILE *funopen(const void *,
int (*)(void *, char *, int),
int (*)(void *, const char *, int),
fpos_t (*)(void *, fpos_t, int),
int (*)(void *));
__END_DECLS
#define fropen(cookie, fn) funopen(cookie, fn, 0, 0, 0)
#define fwopen(cookie, fn) funopen(cookie, 0, fn, 0, 0)
#endif /* __BSD_VISIBLE */
/*
* Functions internal to the implementation.
*/
__BEGIN_DECLS
int __srget(FILE *);
int __swbuf(int, FILE *);
__END_DECLS
/*
* The __sfoo macros are here so that we can
* define function versions in the C library.
*/
#define __sgetc(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
#if defined(__GNUC__)
static __inline int __sputc(int _c, FILE *_p) {
if (--_p->_w >= 0 || (_p->_w >= _p->_lbfsize && (char)_c != '\n'))
return (*_p->_p++ = _c);
else
return (__swbuf(_c, _p));
}
#else
/*
* This has been tuned to generate reasonable code on the vax using pcc.
*/
#define __sputc(c, p) \
(--(p)->_w < 0 ? \
(p)->_w >= (p)->_lbfsize ? \
(*(p)->_p = (c)), *(p)->_p != '\n' ? \
(int)*(p)->_p++ : \
__swbuf('\n', p) : \
__swbuf((int)(c), p) : \
(*(p)->_p = (c), (int)*(p)->_p++))
#endif
#define __sfeof(p) (((p)->_flags & __SEOF) != 0)
#define __sferror(p) (((p)->_flags & __SERR) != 0)
#define __sclearerr(p) ((void)((p)->_flags &= ~(__SERR|__SEOF)))
#define __sfileno(p) ((p)->_file)
extern int __isthreaded;
#define feof(p) (!__isthreaded ? __sfeof(p) : (feof)(p))
#define ferror(p) (!__isthreaded ? __sferror(p) : (ferror)(p))
#define clearerr(p) (!__isthreaded ? __sclearerr(p) : (clearerr)(p))
#if __POSIX_VISIBLE
#define fileno(p) (!__isthreaded ? __sfileno(p) : (fileno)(p))
#endif
#define getc(fp) (!__isthreaded ? __sgetc(fp) : (getc)(fp))
#if __BSD_VISIBLE
/*
* The macro implementations of putc and putc_unlocked are not
* fully POSIX compliant; they do not set errno on failure
*/
#define putc(x, fp) (!__isthreaded ? __sputc(x, fp) : (putc)(x, fp))
#endif /* __BSD_VISIBLE */
#ifndef lint
#if __POSIX_VISIBLE >= 199506
#define getc_unlocked(fp) __sgetc(fp)
/*
* The macro implementations of putc and putc_unlocked are not
* fully POSIX compliant; they do not set errno on failure
*/
#if __BSD_VISIBLE
#define putc_unlocked(x, fp) __sputc(x, fp)
#endif /* __BSD_VISIBLE */
#endif /* __POSIX_VISIBLE >= 199506 */
#endif /* lint */
#define getchar() getc(stdin)
#define putchar(x) putc(x, stdout)
#define getchar_unlocked() getc_unlocked(stdin)
#define putchar_unlocked(c) putc_unlocked(c, stdout)
#ifdef _GNU_SOURCE
/*
* glibc defines dprintf(int, const char*, ...), which is poorly named
* and likely to conflict with locally defined debugging printfs
* fdprintf is a better name, and some programs that use fdprintf use a
* #define fdprintf dprintf for compatibility
*/
int fdprintf(int, const char*, ...);
int vfdprintf(int, const char*, __va_list);
#endif /* _GNU_SOURCE */
#endif /* _STDIO_H_ */