libs/newlib-cygwin
libs/newlib-cygwin
4
0
Fork 0
mirror of git://sourceware.org/git/newlib-cygwin.git synced 2025-01-22 06:57:36 +08:00
Code Issues Projects Releases Wiki Activity
newlib-cygwin/newlib/libc/stdio/local.h
Sebastian Huber b0cb9f85ca Use global stdio streams for all configurations 
The _REENT_GLOBAL_STDIO_STREAMS was introduced by commit
668a4c8722090fffd10869dbb15b879651c1370d in 2017.  Since then it was enabled by
default for RTEMS.  Recently, the option was enabled for Cygwin which
previously used an alternative implementation to use global stdio streams.

In Newlib, the stdio streams are defined to thread-specific pointers
_reent::_stdin, _reent::_stdout and _reent::_stderr.  If the option is disabled
(the default for most systems), then these pointers are initialized to
thread-specific FILE objects which use file descriptors 0, 1, and 2,
respectively.  There are at least three problems with this:

(1) The thread-specific FILE objects are closed by _reclaim_reent().  This
    leads to problems with language run-time libraries that provide wrappers to
    the C/POSIX stdio streams (for example C++ and Ada), since they use the
    thread-specific FILE objects of the initialization thread.  In case the
    initialization thread is deleted, then they use freed memory.

(2) Since thread-specific FILE objects are used with a common output device via
    file descriptors 0, 1 and 2, the locking at FILE object level cannot ensure
    atomicity of the output, e.g. a call to printf().

(3) There are resource managment issues, see:

    https://sourceware.org/pipermail/newlib/2022/019558.html

    https://bugs.linaro.org/show_bug.cgi?id=5841

This patch enables the _REENT_GLOBAL_STDIO_STREAMS behaviour for all Newlib
configurations and removes the option.  This removes a couple of #ifdef blocks.
2022-06-10 20:13:52 +02:00

321 lines
11 KiB
C
Raw Blame History

/*
* Copyright (c) 1990, 2007 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* and/or other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* %W% (UofMD/Berkeley) %G%
*/
/*
* Information local to this implementation of stdio,
* in particular, macros and private variables.
*/
#include <_ansi.h>
#include <reent.h>
#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#ifdef __SCLE
# include <io.h>
#endif
/* The following define determines if the per-reent stdin, stdout and stderr
streams are closed during _reclaim_reent(). The stdin, stdout and stderr
streams are initialized to use file descriptors 0, 1 and 2 respectively. In
case _STDIO_CLOSE_PER_REENT_STD_STREAMS is defined these file descriptors
will be closed via close() provided the owner of the reent structure
triggerd the on demand reent initilization, see CHECK_INIT(). */
#if !defined(__tirtos__)
#define _STDIO_CLOSE_PER_REENT_STD_STREAMS
#endif
/* The following macros are supposed to replace calls to _flockfile/_funlockfile
and __sfp_lock_acquire/__sfp_lock_release. In case of multi-threaded
environments using pthreads, it's not sufficient to lock the stdio functions
against concurrent threads accessing the same data, the locking must also be
secured against thread cancellation.
The below macros have to be used in pairs. The _newlib_XXX_start macro
starts with a opening curly brace, the _newlib_XXX_end macro ends with a
closing curly brace, so the start macro and the end macro mark the code
start and end of a critical section. In case the code leaves the critical
section before reaching the end of the critical section's code end, use
the appropriate _newlib_XXX_exit macro. */
#if !defined (__SINGLE_THREAD__) && defined (_POSIX_THREADS) \
&& !defined (__rtems__)
#define _STDIO_WITH_THREAD_CANCELLATION_SUPPORT
#endif
#if defined(__SINGLE_THREAD__) || defined(__IMPL_UNLOCKED__)
# define _newlib_flockfile_start(_fp)
# define _newlib_flockfile_exit(_fp)
# define _newlib_flockfile_end(_fp)
# define _newlib_sfp_lock_start()
# define _newlib_sfp_lock_exit()
# define _newlib_sfp_lock_end()
#elif defined(_STDIO_WITH_THREAD_CANCELLATION_SUPPORT)
#include <pthread.h>
/* Start a stream oriented critical section: */
# define _newlib_flockfile_start(_fp) \
{ \
int __oldfpcancel; \
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &__oldfpcancel); \
if (!(_fp->_flags2 & __SNLK)) \
_flockfile (_fp)
/* Exit from a stream oriented critical section prematurely: */
# define _newlib_flockfile_exit(_fp) \
if (!(_fp->_flags2 & __SNLK)) \
_funlockfile (_fp); \
pthread_setcancelstate (__oldfpcancel, &__oldfpcancel);
/* End a stream oriented critical section: */
# define _newlib_flockfile_end(_fp) \
if (!(_fp->_flags2 & __SNLK)) \
_funlockfile (_fp); \
pthread_setcancelstate (__oldfpcancel, &__oldfpcancel); \
}
/* Start a stream list oriented critical section: */
# define _newlib_sfp_lock_start() \
{ \
int __oldsfpcancel; \
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &__oldsfpcancel); \
__sfp_lock_acquire ()
/* Exit from a stream list oriented critical section prematurely: */
# define _newlib_sfp_lock_exit() \
__sfp_lock_release (); \
pthread_setcancelstate (__oldsfpcancel, &__oldsfpcancel);
/* End a stream list oriented critical section: */
# define _newlib_sfp_lock_end() \
__sfp_lock_release (); \
pthread_setcancelstate (__oldsfpcancel, &__oldsfpcancel); \
}
#else /* !__SINGLE_THREAD__ && !__IMPL_UNLOCKED__ && !_STDIO_WITH_THREAD_CANCELLATION_SUPPORT */
# define _newlib_flockfile_start(_fp) \
{ \
if (!(_fp->_flags2 & __SNLK)) \
_flockfile (_fp)
# define _newlib_flockfile_exit(_fp) \
if (!(_fp->_flags2 & __SNLK)) \
_funlockfile(_fp); \
# define _newlib_flockfile_end(_fp) \
if (!(_fp->_flags2 & __SNLK)) \
_funlockfile(_fp); \
}
# define _newlib_sfp_lock_start() \
{ \
__sfp_lock_acquire ()
# define _newlib_sfp_lock_exit() \
__sfp_lock_release ();
# define _newlib_sfp_lock_end() \
__sfp_lock_release (); \
}
#endif /* __SINGLE_THREAD__ || __IMPL_UNLOCKED__ */
extern wint_t __fgetwc (struct _reent *, FILE *);
extern wint_t __fputwc (struct _reent *, wchar_t, FILE *);
extern u_char *__sccl (char *, u_char *fmt);
extern int __svfscanf_r (struct _reent *,FILE *, const char *,va_list);
extern int __ssvfscanf_r (struct _reent *,FILE *, const char *,va_list);
extern int __svfiscanf_r (struct _reent *,FILE *, const char *,va_list);
extern int __ssvfiscanf_r (struct _reent *,FILE *, const char *,va_list);
extern int __svfwscanf_r (struct _reent *,FILE *, const wchar_t *,va_list);
extern int __ssvfwscanf_r (struct _reent *,FILE *, const wchar_t *,va_list);
extern int __svfiwscanf_r (struct _reent *,FILE *, const wchar_t *,va_list);
extern int __ssvfiwscanf_r (struct _reent *,FILE *, const wchar_t *,va_list);
int _svfprintf_r (struct _reent *, FILE *, const char *,
va_list)
_ATTRIBUTE ((__format__ (__printf__, 3, 0)));
int _svfiprintf_r (struct _reent *, FILE *, const char *,
va_list)
_ATTRIBUTE ((__format__ (__printf__, 3, 0)));
int _svfwprintf_r (struct _reent *, FILE *, const wchar_t *,
va_list);
int _svfiwprintf_r (struct _reent *, FILE *, const wchar_t *,
va_list);
extern FILE *__sfp (struct _reent *);
extern int __sflags (struct _reent *,const char*, int*);
extern int __sflush_r (struct _reent *,FILE *);
#ifdef _STDIO_BSD_SEMANTICS
extern int __sflushw_r (struct _reent *,FILE *);
#endif
extern int __srefill_r (struct _reent *,FILE *);
extern _READ_WRITE_RETURN_TYPE __sread (struct _reent *, void *, char *,
_READ_WRITE_BUFSIZE_TYPE);
extern _READ_WRITE_RETURN_TYPE __seofread (struct _reent *, void *,
char *,
_READ_WRITE_BUFSIZE_TYPE);
extern _READ_WRITE_RETURN_TYPE __swrite (struct _reent *, void *,
const char *,
_READ_WRITE_BUFSIZE_TYPE);
extern _fpos_t __sseek (struct _reent *, void *, _fpos_t, int);
extern int __sclose (struct _reent *, void *);
extern int __stextmode (int);
extern void __sinit (struct _reent *);
extern void __smakebuf_r (struct _reent *, FILE *);
extern int __swhatbuf_r (struct _reent *, FILE *, size_t *, int *);
extern int __submore (struct _reent *, FILE *);
#ifdef __LARGE64_FILES
extern _fpos64_t __sseek64 (struct _reent *, void *, _fpos64_t, int);
extern _READ_WRITE_RETURN_TYPE __swrite64 (struct _reent *, void *,
const char *,
_READ_WRITE_BUFSIZE_TYPE);
#endif
/* Called by the main entry point fns to ensure stdio has been initialized. */
#define CHECK_INIT(ptr, fp) \
do \
{ \
struct _reent *_check_init_ptr = (ptr); \
if ((_check_init_ptr) && !(_check_init_ptr)->__cleanup) \
__sinit (_check_init_ptr); \
} \
while (0)
/* Return true and set errno and stream error flag iff the given FILE
cannot be written now. */
#define cantwrite(ptr, fp) \
((((fp)->_flags & __SWR) == 0 || (fp)->_bf._base == NULL) && \
__swsetup_r(ptr, fp))
/* Test whether the given stdio file has an active ungetc buffer;
release such a buffer, without restoring ordinary unread data. */
#define HASUB(fp) ((fp)->_ub._base != NULL)
#define FREEUB(ptr, fp) { \
if ((fp)->_ub._base != (fp)->_ubuf) \
_free_r(ptr, (char *)(fp)->_ub._base); \
(fp)->_ub._base = NULL; \
}
/* Test for an fgetline() buffer. */
#define HASLB(fp) ((fp)->_lb._base != NULL)
#define FREELB(ptr, fp) { _free_r(ptr,(char *)(fp)->_lb._base); \
(fp)->_lb._base = NULL; }
#ifdef _WIDE_ORIENT
/*
* Set the orientation for a stream. If o > 0, the stream has wide-
* orientation. If o < 0, the stream has byte-orientation.
*/
#define ORIENT(fp,ori) \
do \
{ \
if (!((fp)->_flags & __SORD)) \
{ \
(fp)->_flags |= __SORD; \
if (ori > 0) \
(fp)->_flags2 |= __SWID; \
else \
(fp)->_flags2 &= ~__SWID; \
} \
} \
while (0)
#else
#define ORIENT(fp,ori)
#endif
/* WARNING: _dcvt is defined in the stdlib directory, not here! */
char *_dcvt (struct _reent *, char *, double, int, int, char, int);
char *_sicvt (char *, short, char);
char *_icvt (char *, int, char);
char *_licvt (char *, long, char);
#ifdef __GNUC__
char *_llicvt (char *, long long, char);
#endif
#define CVT_BUF_SIZE 128
#define NDYNAMIC 4 /* add four more whenever necessary */
#ifdef __SINGLE_THREAD__
#define __sfp_lock_acquire()
#define __sfp_lock_release()
#define __sinit_lock_acquire()
#define __sinit_lock_release()
#else
void __sfp_lock_acquire (void);
void __sfp_lock_release (void);
#endif
/* Types used in positional argument support in vfprinf/vfwprintf.
The implementation is char/wchar_t dependent but the class and state
tables are only defined once in vfprintf.c. */
typedef enum __packed {
ZERO, /* '0' */
DIGIT, /* '1-9' */
DOLLAR, /* '$' */
MODFR, /* spec modifier */
SPEC, /* format specifier */
DOT, /* '.' */
STAR, /* '*' */
FLAG, /* format flag */
OTHER, /* all other chars */
MAX_CH_CLASS /* place-holder */
} __CH_CLASS;
typedef enum __packed {
START, /* start */
SFLAG, /* seen a flag */
WDIG, /* seen digits in width area */
WIDTH, /* processed width */
SMOD, /* seen spec modifier */
SDOT, /* seen dot */
VARW, /* have variable width specifier */
VARP, /* have variable precision specifier */
PREC, /* processed precision */
VWDIG, /* have digits in variable width specification */
VPDIG, /* have digits in variable precision specification */
DONE, /* done */
MAX_STATE, /* place-holder */
} __STATE;
typedef enum __packed {
NOOP, /* do nothing */
NUMBER, /* build a number from digits */
SKIPNUM, /* skip over digits */
GETMOD, /* get and process format modifier */
GETARG, /* get and process argument */
GETPW, /* get variable precision or width */
GETPWB, /* get variable precision or width and pushback fmt char */
GETPOS, /* get positional parameter value */
PWPOS, /* get positional parameter value for variable width or precision */
} __ACTION;
extern const __CH_CLASS __chclass[256];
extern const __STATE __state_table[MAX_STATE][MAX_CH_CLASS];
extern const __ACTION __action_table[MAX_STATE][MAX_CH_CLASS];
Reference in New Issue View Git Blame Copy Permalink