1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* 24 * Copyright 2001 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 29 /* All Rights Reserved */ 30 31 #pragma ident "%Z%%M% %I% %E% SMI" 32 /* 33 * UNIX shell 34 */ 35 36 #include "defs.h" 37 38 39 /* 40 * storage allocator 41 * (circular first fit strategy) 42 */ 43 44 #define BUSY 01 45 #define busy(x) (Rcheat((x)->word) & BUSY) 46 47 unsigned brkincr = BRKINCR; 48 struct blk *blokp; /* current search pointer */ 49 struct blk *bloktop; /* top of arena (last blok) */ 50 51 unsigned char *brkbegin; 52 unsigned char *setbrk(); 53 54 void addblok(unsigned int); 55 56 #ifdef __STDC__ 57 void * 58 #else 59 char * 60 #endif 61 alloc(nbytes) 62 size_t nbytes; 63 { 64 unsigned rbytes = round(nbytes+BYTESPERWORD, BYTESPERWORD); 65 66 if (stakbot == 0) { 67 addblok((unsigned)0); 68 } 69 70 for (;;) 71 { 72 int c = 0; 73 struct blk *p = blokp; 74 struct blk *q; 75 76 do 77 { 78 if (!busy(p)) 79 { 80 while (!busy(q = p->word)) 81 p->word = q->word; 82 if ((char *)q - (char *)p >= rbytes) 83 { 84 blokp = (struct blk *) 85 ((char *)p + rbytes); 86 if (q > blokp) 87 blokp->word = p->word; 88 p->word = (struct blk *) 89 (Rcheat(blokp) | BUSY); 90 return ((char *)(p + 1)); 91 } 92 } 93 q = p; 94 p = (struct blk *)(Rcheat(p->word) & ~BUSY); 95 } while (p > q || (c++) == 0); 96 addblok(rbytes); 97 } 98 } 99 100 void 101 addblok(unsigned int reqd) 102 { 103 if (stakbot == 0) { 104 brkbegin = setbrk(3 * BRKINCR); 105 bloktop = (struct blk *)brkbegin; 106 } 107 108 if (stakbas != staktop) { 109 unsigned char *rndstak; 110 struct blk *blokstak; 111 112 if (staktop >= brkend) 113 growstak(staktop); 114 pushstak(0); 115 rndstak = (unsigned char *)round(staktop, BYTESPERWORD); 116 blokstak = (struct blk *)(stakbas) - 1; 117 blokstak->word = stakbsy; 118 stakbsy = blokstak; 119 bloktop->word = (struct blk *)(Rcheat(rndstak) | BUSY); 120 bloktop = (struct blk *)(rndstak); 121 } 122 reqd += brkincr; 123 reqd &= ~(brkincr - 1); 124 blokp = bloktop; 125 /* 126 * brkend points to the first invalid address. 127 * make sure bloktop is valid. 128 */ 129 if ((unsigned char *)&bloktop->word >= brkend) { 130 if (setbrk((unsigned)((unsigned char *) 131 (&bloktop->word) - brkend + sizeof (struct blk))) == 132 (unsigned char *)-1) 133 error(nospace); 134 } 135 bloktop = bloktop->word = (struct blk *)(Rcheat(bloktop) + reqd); 136 if ((unsigned char *)&bloktop->word >= brkend) { 137 if (setbrk((unsigned)((unsigned char *) 138 (&bloktop->word) - brkend + sizeof (struct blk))) == 139 (unsigned char *)-1) 140 error(nospace); 141 } 142 bloktop->word = (struct blk *)(brkbegin + 1); 143 { 144 unsigned char *stakadr = (unsigned char *) 145 (bloktop + 2); 146 unsigned char *sp = stakadr; 147 if (reqd = (staktop-stakbot)) { 148 if (stakadr + reqd >= brkend) 149 growstak(stakadr + reqd); 150 while (reqd-- > 0) 151 *sp++ = *stakbot++; 152 sp--; 153 } 154 staktop = sp; 155 if (staktop >= brkend) 156 growstak(staktop); 157 stakbas = stakbot = stakadr; 158 } 159 } 160 161 void 162 free(ap) 163 void *ap; 164 { 165 struct blk *p; 166 167 if ((p = (struct blk *)ap) && p < bloktop && p > (struct blk *)brkbegin) 168 { 169 #ifdef DEBUG 170 chkbptr(p); 171 #endif 172 --p; 173 p->word = (struct blk *)(Rcheat(p->word) & ~BUSY); 174 } 175 176 177 } 178 179 180 #ifdef DEBUG 181 182 chkbptr(ptr) 183 struct blk *ptr; 184 { 185 int exf = 0; 186 struct blk *p = (struct blk *)brkbegin; 187 struct blk *q; 188 int us = 0, un = 0; 189 190 for (;;) 191 { 192 q = (struct blk *)(Rcheat(p->word) & ~BUSY); 193 194 if (p+1 == ptr) 195 exf++; 196 197 if (q < (struct blk *)brkbegin || q > bloktop) 198 abort(3); 199 200 if (p == bloktop) 201 break; 202 203 if (busy(p)) 204 us += q - p; 205 else 206 un += q - p; 207 208 if (p >= q) 209 abort(4); 210 211 p = q; 212 } 213 if (exf == 0) 214 abort(1); 215 } 216 217 218 chkmem() 219 { 220 struct blk *p = (struct blk *)brkbegin; 221 struct blk *q; 222 int us = 0, un = 0; 223 224 for (;;) { 225 q = (struct blk *)(Rcheat(p->word) & ~BUSY); 226 227 if (q < (struct blk *)brkbegin || q > bloktop) 228 abort(3); 229 230 if (p == bloktop) 231 break; 232 233 if (busy(p)) 234 us += q - p; 235 else 236 un += q - p; 237 238 if (p >= q) 239 abort(4); 240 241 p = q; 242 } 243 244 prs("un/used/avail "); 245 prn(un); 246 blank(); 247 prn(us); 248 blank(); 249 prn((char *)bloktop - brkbegin - (un + us)); 250 newline(); 251 252 } 253 254 #endif 255 256 size_t 257 blklen(q) 258 char *q; 259 { 260 struct blk *pp = (struct blk *)q; 261 struct blk *p; 262 263 --pp; 264 p = (struct blk *)(Rcheat(pp->word) & ~BUSY); 265 266 return ((size_t)((long)p - (long)q)); 267 } 268 269 /* 270 * This is a really hasty hack at putting realloc() in the shell, along 271 * with alloc() and free(). I really hate having to do things like this, 272 * hacking in something before I understand _why_ libcollate does any 273 * memory (re)allocation, let alone feel comfortable with this particular 274 * implementation of realloc, assuming it actually gets used by anything. 275 * 276 * I plan to revist this, for now this is just to get sh to compile so 277 * that xcu4 builds may be done and we get xcu4 on our desktops. 278 * 279 * Eric Brunner, 10/21/94 280 * 281 * Implemented a variation on the suggested fix in Trusted Solaris 2.5, 282 * then forward ported the fix into the mainline shell. 283 * 284 * 3/3/99 285 */ 286 #ifdef __STDC__ 287 void * 288 realloc(pp, nbytes) 289 void *pp; 290 size_t nbytes; 291 #else 292 char * 293 realloc(pp, nbytes) 294 char *pp; 295 size_t nbytes; 296 #endif 297 { 298 char *q; 299 size_t blen; 300 301 if (pp == NULL) 302 return (alloc(nbytes)); 303 if ((nbytes == 0) && (pp != NULL)) 304 free(pp); 305 306 blen = blklen(pp); 307 308 if (blen < nbytes) { /* need to grow */ 309 q = alloc(nbytes); 310 memcpy(q, pp, blen); 311 free(pp); 312 return ((char *)q); 313 } else if (blen == nbytes) { /* do nothing */ 314 return (pp); 315 } else { /* free excess */ 316 q = alloc(nbytes); 317 memcpy(q, pp, nbytes); 318 free(pp); 319 return ((char *)q); 320 } 321 322 #ifdef undef 323 /* 324 * all of what follows is the _idea_ of what is going to be done 325 * getting the size of the block is a problem -- what follows 326 * is _not_ "real", since "sizeof" isn't going to tell me any 327 * thing usefull, probably have to travers the list to the next 328 * blk, then subtract ptr addrs ... and be careful not to leave 329 * holes. 330 */ 331 p = (struct blk *)pp; 332 if (sizeof (p) < nbytes) { /* need to grow */ 333 q = alloc(nbytes); 334 memcpy(q, pp, sizeof (p)); 335 free(pp); 336 return ((char *)q); 337 } else if (sizeof (p) == nbytes) { /* do nothing */ 338 return (pp); 339 } else { /* free excess */ 340 q = alloc(nbytes); 341 memcpy(q, pp, nbytes); 342 free(pp); 343 return ((char *)q); 344 } 345 #endif 346 } 347