include/sys/reent.h

   1 /* This header file provides the reentrancy.  */
   2
   3 /* WARNING: All identifiers here must begin with an underscore.  This file is
   4    included by stdio.h and others and we therefore must only use identifiers
   5    in the namespace allotted to us.  */
   6
   7 #ifndef _SYS_REENT_H_
   8 #ifdef __cplusplus
   9 extern "C" {
  10 #endif
  11 #define _SYS_REENT_H_
  12
  13 #include <_ansi.h>
  14 #include <sys/_types.h>
  15
  16 #ifndef __Long
  17 #if __LONG_MAX__ == 2147483647L
  18 #define __Long long
  19 typedef unsigned __Long __ULong;
  20 #elif __INT_MAX__ == 2147483647
  21 #define __Long int
  22 typedef unsigned __Long __ULong;
  23 #endif
  24 #endif
  25
  26 #ifndef __Long
  27 #define __Long __int32_t
  28 typedef __uint32_t __ULong;
  29 #endif
  30
  31 struct _glue
  32 {
  33   struct _glue *_next;
  34   int _niobs;
  35   struct __sFILE *_iobs;
  36 };
  37
  38 struct _Bigint
  39 {
  40   struct _Bigint *_next;
  41   int _k, _maxwds, _sign, _wds;
  42   __ULong _x[1];
  43 };
  44
  45 /* needed by reentrant structure */
  46 struct __tm
  47 {
  48   int   __tm_sec;
  49   int   __tm_min;
  50   int   __tm_hour;
  51   int   __tm_mday;
  52   int   __tm_mon;
  53   int   __tm_year;
  54   int   __tm_wday;
  55   int   __tm_yday;
  56   int   __tm_isdst;
  57 };
  58
  59 /*
  60  * atexit() support
  61  */
  62
  63 #define _ATEXIT_SIZE 32 /* must be at least 32 to guarantee ANSI conformance */
  64
  65 struct _atexit {
  66         struct  _atexit *_next;                 /* next in list */
  67         int     _ind;                           /* next index in this table */
  68         void    (*_fns[_ATEXIT_SIZE])(void);    /* the table itself */
  69 };
  70
  71 /*
  72  * Stdio buffers.
  73  *
  74  * This and __sFILE are defined here because we need them for struct _reent,
  75  * but we don't want stdio.h included when stdlib.h is.
  76  */
  77
  78 struct __sbuf {
  79         unsigned char *_base;
  80         int     _size;
  81 };
  82
  83 /*
  84  * We need fpos_t for the following, but it doesn't have a leading "_",
  85  * so we use _fpos_t instead.
  86  */
  87
  88 typedef long _fpos_t;           /* XXX must match off_t in <sys/types.h> */
  89                                 /* (and must be `long' for now) */
  90
  91 /*
  92  * Stdio state variables.
  93  *
  94  * The following always hold:
  95  *
  96  *      if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
  97  *              _lbfsize is -_bf._size, else _lbfsize is 0
  98  *      if _flags&__SRD, _w is 0
  99  *      if _flags&__SWR, _r is 0
 100  *
 101  * This ensures that the getc and putc macros (or inline functions) never
 102  * try to write or read from a file that is in `read' or `write' mode.
 103  * (Moreover, they can, and do, automatically switch from read mode to
 104  * write mode, and back, on "r+" and "w+" files.)
 105  *
 106  * _lbfsize is used only to make the inline line-buffered output stream
 107  * code as compact as possible.
 108  *
 109  * _ub, _up, and _ur are used when ungetc() pushes back more characters
 110  * than fit in the current _bf, or when ungetc() pushes back a character
 111  * that does not match the previous one in _bf.  When this happens,
 112  * _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
 113  * _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
 114  */
 115
 116 struct __sFILE {
 117   unsigned char *_p;    /* current position in (some) buffer */
 118   int   _r;             /* read space left for getc() */
 119   int   _w;             /* write space left for putc() */
 120   short _flags;         /* flags, below; this FILE is free if 0 */
 121   short _file;          /* fileno, if Unix descriptor, else -1 */
 122   struct __sbuf _bf;    /* the buffer (at least 1 byte, if !NULL) */
 123   int   _lbfsize;       /* 0 or -_bf._size, for inline putc */
 124
 125   /* operations */
 126   _PTR  _cookie;        /* cookie passed to io functions */
 127
 128   _READ_WRITE_RETURN_TYPE _EXFUN((*_read),(_PTR _cookie, char *_buf, int _n));
 129   _READ_WRITE_RETURN_TYPE _EXFUN((*_write),(_PTR _cookie, const char *_buf,
 130                                             int _n));
 131   _fpos_t _EXFUN((*_seek),(_PTR _cookie, _fpos_t _offset, int _whence));
 132   int   _EXFUN((*_close),(_PTR _cookie));
 133
 134   /* separate buffer for long sequences of ungetc() */
 135   struct __sbuf _ub;    /* ungetc buffer */
 136   unsigned char *_up;   /* saved _p when _p is doing ungetc data */
 137   int   _ur;            /* saved _r when _r is counting ungetc data */
 138
 139   /* tricks to meet minimum requirements even when malloc() fails */
 140   unsigned char _ubuf[3];       /* guarantee an ungetc() buffer */
 141   unsigned char _nbuf[1];       /* guarantee a getc() buffer */
 142
 143   /* separate buffer for fgetline() when line crosses buffer boundary */
 144   struct __sbuf _lb;    /* buffer for fgetline() */
 145
 146   /* Unix stdio files get aligned to block boundaries on fseek() */
 147   int   _blksize;       /* stat.st_blksize (may be != _bf._size) */
 148   int   _offset;        /* current lseek offset */
 149
 150   struct _reent *_data;
 151 };
 152
 153 /*
 154  * rand48 family support
 155  *
 156  * Copyright (c) 1993 Martin Birgmeier
 157  * All rights reserved.
 158  *
 159  * You may redistribute unmodified or modified versions of this source
 160  * code provided that the above copyright notice and this and the
 161  * following conditions are retained.
 162  *
 163  * This software is provided ``as is'', and comes with no warranties
 164  * of any kind. I shall in no event be liable for anything that happens
 165  * to anyone/anything when using this software.
 166  */
 167 #define        _RAND48_SEED_0  (0x330e)
 168 #define        _RAND48_SEED_1  (0xabcd)
 169 #define        _RAND48_SEED_2  (0x1234)
 170 #define        _RAND48_MULT_0  (0xe66d)
 171 #define        _RAND48_MULT_1  (0xdeec)
 172 #define        _RAND48_MULT_2  (0x0005)
 173 #define        _RAND48_ADD     (0x000b)
 174 struct _rand48 {
 175   unsigned short _seed[3];
 176   unsigned short _mult[3];
 177   unsigned short _add;
 178 };
 179
 180 /*
 181  * struct _reent
 182  *
 183  * This structure contains *all* globals needed by the library.
 184  * It's raison d'etre is to facilitate threads by making all library routines
 185  * reentrant.  IE: All state information is contained here.
 186  */
 187
 188 struct _reent
 189 {
 190   /* local copy of errno */
 191   int _errno;
 192
 193   /* FILE is a big struct and may change over time.  To try to achieve binary
 194      compatibility with future versions, put stdin,stdout,stderr here.
 195      These are pointers into member __sf defined below.  */
 196   struct __sFILE *_stdin, *_stdout, *_stderr;
 197
 198   int  _inc;                    /* used by tmpnam */
 199   char _emergency[25];
 200
 201   int _current_category;        /* used by setlocale */
 202   _CONST char *_current_locale;
 203
 204   int __sdidinit;               /* 1 means stdio has been init'd */
 205
 206   void _EXFUN((*__cleanup),(struct _reent *));
 207
 208   /* used by mprec routines */
 209   struct _Bigint *_result;
 210   int _result_k;
 211   struct _Bigint *_p5s;
 212   struct _Bigint **_freelist;
 213
 214   /* used by some fp conversion routines */
 215   int _cvtlen;                  /* should be size_t */
 216   char *_cvtbuf;
 217
 218   union
 219     {
 220       struct
 221         {
 222           unsigned int _unused_rand;
 223           char * _strtok_last;
 224           char _asctime_buf[26];
 225           struct __tm _localtime_buf;
 226           int _gamma_signgam;
 227           __extension__ unsigned long long _rand_next;
 228           struct _rand48 _r48;
 229         } _reent;
 230   /* Two next two fields were once used by malloc.  They are no longer
 231      used. They are used to preserve the space used before so as to
 232      allow addition of new reent fields and keep binary compatibility.   */
 233       struct
 234         {
 235 #define _N_LISTS 30
 236           unsigned char * _nextf[_N_LISTS];
 237           unsigned int _nmalloc[_N_LISTS];
 238         } _unused;
 239     } _new;
 240
 241   /* atexit stuff */
 242   struct _atexit *_atexit;      /* points to head of LIFO stack */
 243   struct _atexit _atexit0;      /* one guaranteed table, required by ANSI */
 244
 245   /* signal info */
 246   void (**(_sig_func))(int);
 247
 248   /* These are here last so that __sFILE can grow without changing the offsets
 249      of the above members (on the off chance that future binary compatibility
 250      would be broken otherwise).  */
 251   struct _glue __sglue;                 /* root of glue chain */
 252   struct __sFILE __sf[3];               /* first three file descriptors */
 253 };
 254
 255 #define _NULL 0
 256
 257 #define _REENT_INIT(var) \
 258   { 0, &var.__sf[0], &var.__sf[1], &var.__sf[2], 0, "", 0, "C", \
 259     0, _NULL, _NULL, 0, _NULL, _NULL, 0, _NULL, { {0, _NULL, "", \
 260     { 0,0,0,0,0,0,0,0}, 0, 1, \
 261     {{_RAND48_SEED_0, _RAND48_SEED_1, _RAND48_SEED_2}, \
 262      {_RAND48_MULT_0, _RAND48_MULT_1, _RAND48_MULT_2}, _RAND48_ADD}} } }
 263
 264 /*
 265  * All references to struct _reent are via this pointer.
 266  * Internally, newlib routines that need to reference it should use _REENT.
 267  */
 268
 269 #ifndef __ATTRIBUTE_IMPURE_PTR__
 270 #define __ATTRIBUTE_IMPURE_PTR__
 271 #endif
 272
 273 extern struct _reent *_impure_ptr __ATTRIBUTE_IMPURE_PTR__;
 274
 275 void _reclaim_reent _PARAMS ((struct _reent *));
 276
 277 /* #define _REENT_ONLY define this to get only reentrant routines */
 278
 279 #ifndef _REENT_ONLY
 280 #define _REENT _impure_ptr
 281 #endif
 282
 283 #ifdef __cplusplus
 284 }
 285 #endif
 286 #endif /* _SYS_REENT_H_ */