1/* $Header: /src/pub/tcsh/tc.alloc.c,v 3.39 2005/01/05 16:06:14 christos Exp $ */
2/*
3 * tc.alloc.c (Caltech) 2/21/82
4 * Chris Kingsley, kingsley@cit-20.
5 *
6 * This is a very fast storage allocator. It allocates blocks of a small
7 * number of different sizes, and keeps free lists of each size. Blocks that
8 * don't exactly fit are passed up to the next larger size. In this
9 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
10 * This is designed for use in a program that uses vast quantities of memory,
11 * but bombs when it runs out.
12 */
13/*-
14 * Copyright (c) 1980, 1991 The Regents of the University of California.
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 * 3. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 */
41#include "sh.h"
42
43RCSID("$Id: tc.alloc.c,v 3.39 2005/01/05 16:06:14 christos Exp $")
44
45static char *memtop = NULL; /* PWP: top of current memory */
46static char *membot = NULL; /* PWP: bottom of allocatable memory */
47
48int dont_free = 0;
49
50#ifdef WINNT_NATIVE
51# define malloc fmalloc
52# define free ffree
53# define calloc fcalloc
54# define realloc frealloc
55#endif /* WINNT_NATIVE */
56
57#ifndef SYSMALLOC
58
59#undef RCHECK
60#undef DEBUG
61
62#ifdef SX
63extern void* sbrk();
64#endif
65/*
66 * Lots of os routines are busted and try to free invalid pointers.
67 * Although our free routine is smart enough and it will pick bad
68 * pointers most of the time, in cases where we know we are going to get
69 * a bad pointer, we'd rather leak.
70 */
71
72#ifndef NULL
73#define NULL 0
74#endif
75
76typedef unsigned char U_char; /* we don't really have signed chars */
77typedef unsigned int U_int;
78typedef unsigned short U_short;
79typedef unsigned long U_long;
80
81
82/*
83 * The overhead on a block is at least 4 bytes. When free, this space
84 * contains a pointer to the next free block, and the bottom two bits must
85 * be zero. When in use, the first byte is set to MAGIC, and the second
86 * byte is the size index. The remaining bytes are for alignment.
87 * If range checking is enabled and the size of the block fits
88 * in two bytes, then the top two bytes hold the size of the requested block
89 * plus the range checking words, and the header word MINUS ONE.
90 */
91
92
93#define MEMALIGN(a) (((a) + ROUNDUP) & ~ROUNDUP)
94
95union overhead {
96 union overhead *ov_next; /* when free */
97 struct {
98 U_char ovu_magic; /* magic number */
99 U_char ovu_index; /* bucket # */
100#ifdef RCHECK
101 U_short ovu_size; /* actual block size */
102 U_int ovu_rmagic; /* range magic number */
103#endif
104 } ovu;
105#define ov_magic ovu.ovu_magic
106#define ov_index ovu.ovu_index
107#define ov_size ovu.ovu_size
108#define ov_rmagic ovu.ovu_rmagic
109};
110
111#define MAGIC 0xfd /* magic # on accounting info */
112#define RMAGIC 0x55555555 /* magic # on range info */
113#ifdef RCHECK
114#define RSLOP sizeof (U_int)
115#else
116#define RSLOP 0
117#endif
118
119
120#define ROUNDUP 7
121
122/*
123 * nextf[i] is the pointer to the next free block of size 2^(i+3). The
124 * smallest allocatable block is 8 bytes. The overhead information
125 * precedes the data area returned to the user.
126 */
127#define NBUCKETS ((sizeof(long) << 3) - 3)
128static union overhead *nextf[NBUCKETS] IZERO_STRUCT;
129
130/*
131 * nmalloc[i] is the difference between the number of mallocs and frees
132 * for a given block size.
133 */
134static U_int nmalloc[NBUCKETS] IZERO_STRUCT;
135
136#ifndef lint
137static int findbucket __P((union overhead *, int));
138static void morecore __P((int));
139#endif
140
141
142#ifdef DEBUG
143# define CHECK(a, str, p) \
144 if (a) { \
145 xprintf(str, p); \
146 xprintf(" (memtop = %lx membot = %lx)\n", memtop, membot); \
147 abort(); \
148 }
149#else
150# define CHECK(a, str, p) \
151 if (a) { \
152 xprintf(str, p); \
153 xprintf(" (memtop = %lx membot = %lx)\n", memtop, membot); \
154 return; \
155 }
156#endif
157
158memalign_t
159malloc(nbytes)
160 size_t nbytes;
161{
162#ifndef lint
163 union overhead *p;
164 int bucket = 0;
165 unsigned shiftr;
166
167 /*
168 * Convert amount of memory requested into closest block size stored in
169 * hash buckets which satisfies request. Account for space used per block
170 * for accounting.
171 */
172#ifdef SUNOS4
173 /*
174 * SunOS localtime() overwrites the 9th byte on an 8 byte malloc()....
175 * so we get one more...
176 * From Michael Schroeder: This is not true. It depends on the
177 * timezone string. In Europe it can overwrite the 13th byte on a
178 * 12 byte malloc.
179 * So we punt and we always allocate an extra byte.
180 */
181 nbytes++;
182#endif
183
184 nbytes = MEMALIGN(MEMALIGN(sizeof(union overhead)) + nbytes + RSLOP);
185 shiftr = (nbytes - 1) >> 2;
186
187 /* apart from this loop, this is O(1) */
188 while ((shiftr >>= 1) != 0)
189 bucket++;
190 /*
191 * If nothing in hash bucket right now, request more memory from the
192 * system.
193 */
194 if (nextf[bucket] == NULL)
195 morecore(bucket);
196 if ((p = (union overhead *) nextf[bucket]) == NULL) {
197 child++;
198#ifndef DEBUG
199 stderror(ERR_NOMEM);
200#else
201 showall(NULL, NULL);
202 xprintf(CGETS(19, 1, "nbytes=%d: Out of memory\n"), nbytes);
203 abort();
204#endif
205 /* fool lint */
206 return ((memalign_t) 0);
207 }
208 /* remove from linked list */
209 nextf[bucket] = nextf[bucket]->ov_next;
210 p->ov_magic = MAGIC;
211 p->ov_index = bucket;
212 nmalloc[bucket]++;
213#ifdef RCHECK
214 /*
215 * Record allocated size of block and bound space with magic numbers.
216 */
217 p->ov_size = (p->ov_index <= 13) ? nbytes - 1 : 0;
218 p->ov_rmagic = RMAGIC;
219 *((U_int *) (((caddr_t) p) + nbytes - RSLOP)) = RMAGIC;
220#endif
221 return ((memalign_t) (((caddr_t) p) + MEMALIGN(sizeof(union overhead))));
222#else
223 if (nbytes)
224 return ((memalign_t) 0);
225 else
226 return ((memalign_t) 0);
227#endif /* !lint */
228}
229
230#ifndef lint
231/*
232 * Allocate more memory to the indicated bucket.
233 */
234static void
235morecore(bucket)
236 int bucket;
237{
238 union overhead *op;
239 int rnu; /* 2^rnu bytes will be requested */
240 int nblks; /* become nblks blocks of the desired size */
241 int siz;
242
243 if (nextf[bucket])
244 return;
245 /*
246 * Insure memory is allocated on a page boundary. Should make getpageize
247 * call?
248 */
249 op = (union overhead *) sbrk(0);
250 memtop = (char *) op;
251 if (membot == NULL)
252 membot = memtop;
253 if ((long) op & 0x3ff) {
254 memtop = (char *) sbrk((int) (1024 - ((long) op & 0x3ff)));
255 memtop += (long) (1024 - ((long) op & 0x3ff));
256 }
257
258 /* take 2k unless the block is bigger than that */
259 rnu = (bucket <= 8) ? 11 : bucket + 3;
260 nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */
261 memtop = (char *) sbrk(1 << rnu); /* PWP */
262 op = (union overhead *) memtop;
263 /* no more room! */
264 if ((long) op == -1)
265 return;
266 memtop += (long) (1 << rnu);
267 /*
268 * Round up to minimum allocation size boundary and deduct from block count
269 * to reflect.
270 */
271 if (((U_long) op) & ROUNDUP) {
272 op = (union overhead *) (((U_long) op + (ROUNDUP + 1)) & ~ROUNDUP);
273 nblks--;
274 }
275 /*
276 * Add new memory allocated to that on free list for this hash bucket.
277 */
278 nextf[bucket] = op;
279 siz = 1 << (bucket + 3);
280 while (--nblks > 0) {
281 op->ov_next = (union overhead *) (((caddr_t) op) + siz);
282 op = (union overhead *) (((caddr_t) op) + siz);
283 }
284 op->ov_next = NULL;
285}
286
287#endif
288
289void
290free(cp)
291 ptr_t cp;
292{
293#ifndef lint
294 int size;
295 union overhead *op;
296
297 /*
298 * the don't free flag is there so that we avoid os bugs in routines
299 * that free invalid pointers!
300 */
301 if (cp == NULL || dont_free)
302 return;
303 CHECK(!memtop || !membot,
304 CGETS(19, 2, "free(%lx) called before any allocations."), cp);
305 CHECK(cp > (ptr_t) memtop,
306 CGETS(19, 3, "free(%lx) above top of memory."), cp);
307 CHECK(cp < (ptr_t) membot,
308 CGETS(19, 4, "free(%lx) below bottom of memory."), cp);
309 op = (union overhead *) (((caddr_t) cp) - MEMALIGN(sizeof(union overhead)));
310 CHECK(op->ov_magic != MAGIC,
311 CGETS(19, 5, "free(%lx) bad block."), cp);
312
313#ifdef RCHECK
314 if (op->ov_index <= 13)
315 CHECK(*(U_int *) ((caddr_t) op + op->ov_size + 1 - RSLOP) != RMAGIC,
316 CGETS(19, 6, "free(%lx) bad range check."), cp);
317#endif
318 CHECK(op->ov_index >= NBUCKETS,
319 CGETS(19, 7, "free(%lx) bad block index."), cp);
320 size = op->ov_index;
321 op->ov_next = nextf[size];
322 nextf[size] = op;
323
324 nmalloc[size]--;
325
326#else
327 if (cp == NULL)
328 return;
329#endif
330}
331
332memalign_t
333calloc(i, j)
334 size_t i, j;
335{
336#ifndef lint
337 char *cp, *scp;
338
339 i *= j;
340 scp = cp = (char *) xmalloc((size_t) i);
341 if (i != 0)
342 do
343 *cp++ = 0;
344 while (--i);
345
346 return ((memalign_t) scp);
347#else
348 if (i && j)
349 return ((memalign_t) 0);
350 else
351 return ((memalign_t) 0);
352#endif
353}
354
355/*
356 * When a program attempts "storage compaction" as mentioned in the
357 * old malloc man page, it realloc's an already freed block. Usually
358 * this is the last block it freed; occasionally it might be farther
359 * back. We have to search all the free lists for the block in order
360 * to determine its bucket: 1st we make one pass thru the lists
361 * checking only the first block in each; if that fails we search
362 * ``realloc_srchlen'' blocks in each list for a match (the variable
363 * is extern so the caller can modify it). If that fails we just copy
364 * however many bytes was given to realloc() and hope it's not huge.
365 */
366#ifndef lint
367/* 4 should be plenty, -1 =>'s whole list */
368static int realloc_srchlen = 4;
369#endif /* lint */
370
371memalign_t
372realloc(cp, nbytes)
373 ptr_t cp;
374 size_t nbytes;
375{
376#ifndef lint
377 U_int onb;
378 union overhead *op;
379 ptr_t res;
380 int i;
381 int was_alloced = 0;
382
383 if (cp == NULL)
384 return (malloc(nbytes));
385 op = (union overhead *) (((caddr_t) cp) - MEMALIGN(sizeof(union overhead)));
386 if (op->ov_magic == MAGIC) {
387 was_alloced++;
388 i = op->ov_index;
389 }
390 else
391 /*
392 * Already free, doing "compaction".
393 *
394 * Search for the old block of memory on the free list. First, check the
395 * most common case (last element free'd), then (this failing) the last
396 * ``realloc_srchlen'' items free'd. If all lookups fail, then assume
397 * the size of the memory block being realloc'd is the smallest
398 * possible.
399 */
400 if ((i = findbucket(op, 1)) < 0 &&
401 (i = findbucket(op, realloc_srchlen)) < 0)
402 i = 0;
403
404 onb = MEMALIGN(nbytes + MEMALIGN(sizeof(union overhead)) + RSLOP);
405
406 /* avoid the copy if same size block */
407 if (was_alloced && (onb <= (U_int) (1 << (i + 3))) &&
408 (onb > (U_int) (1 << (i + 2)))) {
409#ifdef RCHECK
410 /* JMR: formerly this wasn't updated ! */
411 nbytes = MEMALIGN(MEMALIGN(sizeof(union overhead))+nbytes+RSLOP);
412 *((U_int *) (((caddr_t) op) + nbytes - RSLOP)) = RMAGIC;
413 op->ov_rmagic = RMAGIC;
414 op->ov_size = (op->ov_index <= 13) ? nbytes - 1 : 0;
415#endif
416 return ((memalign_t) cp);
417 }
418 if ((res = malloc(nbytes)) == NULL)
419 return ((memalign_t) NULL);
420 if (cp != res) { /* common optimization */
421 /*
422 * christos: this used to copy nbytes! It should copy the
423 * smaller of the old and new size
424 */
425 onb = (1 << (i + 3)) - MEMALIGN(sizeof(union overhead)) - RSLOP;
426 (void) memmove((ptr_t) res, (ptr_t) cp,
427 (size_t) (onb < nbytes ? onb : nbytes));
428 }
429 if (was_alloced)
430 free(cp);
431 return ((memalign_t) res);
432#else
433 if (cp && nbytes)
434 return ((memalign_t) 0);
435 else
436 return ((memalign_t) 0);
437#endif /* !lint */
438}
439
440
441
442#ifndef lint
443/*
444 * Search ``srchlen'' elements of each free list for a block whose
445 * header starts at ``freep''. If srchlen is -1 search the whole list.
446 * Return bucket number, or -1 if not found.
447 */
448static int
449findbucket(freep, srchlen)
450 union overhead *freep;
451 int srchlen;
452{
453 union overhead *p;
454 size_t i;
455 int j;
456
457 for (i = 0; i < NBUCKETS; i++) {
458 j = 0;
459 for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
460 if (p == freep)
461 return (i);
462 j++;
463 }
464 }
465 return (-1);
466}
467
468#endif
469
470
471#else /* SYSMALLOC */
472
473/**
474 ** ``Protected versions'' of malloc, realloc, calloc, and free
475 **
476 ** On many systems:
477 **
478 ** 1. malloc(0) is bad
479 ** 2. free(0) is bad
480 ** 3. realloc(0, n) is bad
481 ** 4. realloc(n, 0) is bad
482 **
483 ** Also we call our error routine if we run out of memory.
484 **/
485memalign_t
486smalloc(n)
487 size_t n;
488{
489 ptr_t ptr;
490
491 n = n ? n : 1;
492
493#ifdef HAVE_SBRK
494 if (membot == NULL)
495 membot = (char*) sbrk(0);
496#endif /* HAVE_SBRK */
497
498 if ((ptr = malloc(n)) == (ptr_t) 0) {
499 child++;
500 stderror(ERR_NOMEM);
501 }
502#ifndef HAVE_SBRK
503 if (memtop < ((char *) ptr) + n)
504 memtop = ((char *) ptr) + n;
505 if (membot == NULL)
506 membot = (char*) ptr;
507#endif /* !HAVE_SBRK */
508 return ((memalign_t) ptr);
509}
510
511memalign_t
512srealloc(p, n)
513 ptr_t p;
514 size_t n;
515{
516 ptr_t ptr;
517
518 n = n ? n : 1;
519
520#ifdef HAVE_SBRK
521 if (membot == NULL)
522 membot = (char*) sbrk(0);
523#endif /* HAVE_SBRK */
524
525 if ((ptr = (p ? realloc(p, n) : malloc(n))) == (ptr_t) 0) {
526 child++;
527 stderror(ERR_NOMEM);
528 }
529#ifndef HAVE_SBRK
530 if (memtop < ((char *) ptr) + n)
531 memtop = ((char *) ptr) + n;
532 if (membot == NULL)
533 membot = (char*) ptr;
534#endif /* !HAVE_SBRK */
535 return ((memalign_t) ptr);
536}
537
538memalign_t
539scalloc(s, n)
540 size_t s, n;
541{
542 char *sptr;
543 ptr_t ptr;
544
545 n *= s;
546 n = n ? n : 1;
547
548#ifdef HAVE_SBRK
549 if (membot == NULL)
550 membot = (char*) sbrk(0);
551#endif /* HAVE_SBRK */
552
553 if ((ptr = malloc(n)) == (ptr_t) 0) {
554 child++;
555 stderror(ERR_NOMEM);
556 }
557
558 sptr = (char *) ptr;
559 if (n != 0)
560 do
561 *sptr++ = 0;
562 while (--n);
563
564#ifndef HAVE_SBRK
565 if (memtop < ((char *) ptr) + n)
566 memtop = ((char *) ptr) + n;
567 if (membot == NULL)
568 membot = (char*) ptr;
569#endif /* !HAVE_SBRK */
570
571 return ((memalign_t) ptr);
572}
573
574void
575sfree(p)
576 ptr_t p;
577{
578 if (p && !dont_free)
579 free(p);
580}
581
582#endif /* SYSMALLOC */
583
584/*
585 * mstats - print out statistics about malloc
586 *
587 * Prints two lines of numbers, one showing the length of the free list
588 * for each size category, the second showing the number of mallocs -
589 * frees for each size category.
590 */
591/*ARGSUSED*/
592void
593showall(v, c)
594 Char **v;
595 struct command *c;
596{
597#ifndef SYSMALLOC
598 size_t i, j;
599 union overhead *p;
600 int totfree = 0, totused = 0;
601
602 xprintf(CGETS(19, 8, "%s current memory allocation:\nfree:\t"), progname);
603 for (i = 0; i < NBUCKETS; i++) {
604 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
605 continue;
606 xprintf(" %4d", j);
607 totfree += j * (1 << (i + 3));
608 }
609 xprintf(CGETS(19, 9, "\nused:\t"));
610 for (i = 0; i < NBUCKETS; i++) {
611 xprintf(" %4u", nmalloc[i]);
612 totused += nmalloc[i] * (1 << (i + 3));
613 }
614 xprintf(CGETS(19, 10, "\n\tTotal in use: %d, total free: %d\n"),
615 totused, totfree);
616 xprintf(CGETS(19, 11,
617 "\tAllocated memory from 0x%lx to 0x%lx. Real top at 0x%lx\n"),
618 (unsigned long) membot, (unsigned long) memtop,
619 (unsigned long) sbrk(0));
620#else
621#ifdef HAVE_SBRK
622 memtop = (char *) sbrk(0);
623#endif /* HAVE_SBRK */
624 xprintf(CGETS(19, 12, "Allocated memory from 0x%lx to 0x%lx (%ld).\n"),
625 (unsigned long) membot, (unsigned long) memtop,
626 (unsigned long) (memtop - membot));
627#endif /* SYSMALLOC */
628 USE(c);
629 USE(v);
630}
2/*
3 * tc.alloc.c (Caltech) 2/21/82
4 * Chris Kingsley, kingsley@cit-20.
5 *
6 * This is a very fast storage allocator. It allocates blocks of a small
7 * number of different sizes, and keeps free lists of each size. Blocks that
8 * don't exactly fit are passed up to the next larger size. In this
9 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
10 * This is designed for use in a program that uses vast quantities of memory,
11 * but bombs when it runs out.
12 */
13/*-
14 * Copyright (c) 1980, 1991 The Regents of the University of California.
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 * 3. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 */
41#include "sh.h"
42
43RCSID("$Id: tc.alloc.c,v 3.39 2005/01/05 16:06:14 christos Exp $")
44
45static char *memtop = NULL; /* PWP: top of current memory */
46static char *membot = NULL; /* PWP: bottom of allocatable memory */
47
48int dont_free = 0;
49
50#ifdef WINNT_NATIVE
51# define malloc fmalloc
52# define free ffree
53# define calloc fcalloc
54# define realloc frealloc
55#endif /* WINNT_NATIVE */
56
57#ifndef SYSMALLOC
58
59#undef RCHECK
60#undef DEBUG
61
62#ifdef SX
63extern void* sbrk();
64#endif
65/*
66 * Lots of os routines are busted and try to free invalid pointers.
67 * Although our free routine is smart enough and it will pick bad
68 * pointers most of the time, in cases where we know we are going to get
69 * a bad pointer, we'd rather leak.
70 */
71
72#ifndef NULL
73#define NULL 0
74#endif
75
76typedef unsigned char U_char; /* we don't really have signed chars */
77typedef unsigned int U_int;
78typedef unsigned short U_short;
79typedef unsigned long U_long;
80
81
82/*
83 * The overhead on a block is at least 4 bytes. When free, this space
84 * contains a pointer to the next free block, and the bottom two bits must
85 * be zero. When in use, the first byte is set to MAGIC, and the second
86 * byte is the size index. The remaining bytes are for alignment.
87 * If range checking is enabled and the size of the block fits
88 * in two bytes, then the top two bytes hold the size of the requested block
89 * plus the range checking words, and the header word MINUS ONE.
90 */
91
92
93#define MEMALIGN(a) (((a) + ROUNDUP) & ~ROUNDUP)
94
95union overhead {
96 union overhead *ov_next; /* when free */
97 struct {
98 U_char ovu_magic; /* magic number */
99 U_char ovu_index; /* bucket # */
100#ifdef RCHECK
101 U_short ovu_size; /* actual block size */
102 U_int ovu_rmagic; /* range magic number */
103#endif
104 } ovu;
105#define ov_magic ovu.ovu_magic
106#define ov_index ovu.ovu_index
107#define ov_size ovu.ovu_size
108#define ov_rmagic ovu.ovu_rmagic
109};
110
111#define MAGIC 0xfd /* magic # on accounting info */
112#define RMAGIC 0x55555555 /* magic # on range info */
113#ifdef RCHECK
114#define RSLOP sizeof (U_int)
115#else
116#define RSLOP 0
117#endif
118
119
120#define ROUNDUP 7
121
122/*
123 * nextf[i] is the pointer to the next free block of size 2^(i+3). The
124 * smallest allocatable block is 8 bytes. The overhead information
125 * precedes the data area returned to the user.
126 */
127#define NBUCKETS ((sizeof(long) << 3) - 3)
128static union overhead *nextf[NBUCKETS] IZERO_STRUCT;
129
130/*
131 * nmalloc[i] is the difference between the number of mallocs and frees
132 * for a given block size.
133 */
134static U_int nmalloc[NBUCKETS] IZERO_STRUCT;
135
136#ifndef lint
137static int findbucket __P((union overhead *, int));
138static void morecore __P((int));
139#endif
140
141
142#ifdef DEBUG
143# define CHECK(a, str, p) \
144 if (a) { \
145 xprintf(str, p); \
146 xprintf(" (memtop = %lx membot = %lx)\n", memtop, membot); \
147 abort(); \
148 }
149#else
150# define CHECK(a, str, p) \
151 if (a) { \
152 xprintf(str, p); \
153 xprintf(" (memtop = %lx membot = %lx)\n", memtop, membot); \
154 return; \
155 }
156#endif
157
158memalign_t
159malloc(nbytes)
160 size_t nbytes;
161{
162#ifndef lint
163 union overhead *p;
164 int bucket = 0;
165 unsigned shiftr;
166
167 /*
168 * Convert amount of memory requested into closest block size stored in
169 * hash buckets which satisfies request. Account for space used per block
170 * for accounting.
171 */
172#ifdef SUNOS4
173 /*
174 * SunOS localtime() overwrites the 9th byte on an 8 byte malloc()....
175 * so we get one more...
176 * From Michael Schroeder: This is not true. It depends on the
177 * timezone string. In Europe it can overwrite the 13th byte on a
178 * 12 byte malloc.
179 * So we punt and we always allocate an extra byte.
180 */
181 nbytes++;
182#endif
183
184 nbytes = MEMALIGN(MEMALIGN(sizeof(union overhead)) + nbytes + RSLOP);
185 shiftr = (nbytes - 1) >> 2;
186
187 /* apart from this loop, this is O(1) */
188 while ((shiftr >>= 1) != 0)
189 bucket++;
190 /*
191 * If nothing in hash bucket right now, request more memory from the
192 * system.
193 */
194 if (nextf[bucket] == NULL)
195 morecore(bucket);
196 if ((p = (union overhead *) nextf[bucket]) == NULL) {
197 child++;
198#ifndef DEBUG
199 stderror(ERR_NOMEM);
200#else
201 showall(NULL, NULL);
202 xprintf(CGETS(19, 1, "nbytes=%d: Out of memory\n"), nbytes);
203 abort();
204#endif
205 /* fool lint */
206 return ((memalign_t) 0);
207 }
208 /* remove from linked list */
209 nextf[bucket] = nextf[bucket]->ov_next;
210 p->ov_magic = MAGIC;
211 p->ov_index = bucket;
212 nmalloc[bucket]++;
213#ifdef RCHECK
214 /*
215 * Record allocated size of block and bound space with magic numbers.
216 */
217 p->ov_size = (p->ov_index <= 13) ? nbytes - 1 : 0;
218 p->ov_rmagic = RMAGIC;
219 *((U_int *) (((caddr_t) p) + nbytes - RSLOP)) = RMAGIC;
220#endif
221 return ((memalign_t) (((caddr_t) p) + MEMALIGN(sizeof(union overhead))));
222#else
223 if (nbytes)
224 return ((memalign_t) 0);
225 else
226 return ((memalign_t) 0);
227#endif /* !lint */
228}
229
230#ifndef lint
231/*
232 * Allocate more memory to the indicated bucket.
233 */
234static void
235morecore(bucket)
236 int bucket;
237{
238 union overhead *op;
239 int rnu; /* 2^rnu bytes will be requested */
240 int nblks; /* become nblks blocks of the desired size */
241 int siz;
242
243 if (nextf[bucket])
244 return;
245 /*
246 * Insure memory is allocated on a page boundary. Should make getpageize
247 * call?
248 */
249 op = (union overhead *) sbrk(0);
250 memtop = (char *) op;
251 if (membot == NULL)
252 membot = memtop;
253 if ((long) op & 0x3ff) {
254 memtop = (char *) sbrk((int) (1024 - ((long) op & 0x3ff)));
255 memtop += (long) (1024 - ((long) op & 0x3ff));
256 }
257
258 /* take 2k unless the block is bigger than that */
259 rnu = (bucket <= 8) ? 11 : bucket + 3;
260 nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */
261 memtop = (char *) sbrk(1 << rnu); /* PWP */
262 op = (union overhead *) memtop;
263 /* no more room! */
264 if ((long) op == -1)
265 return;
266 memtop += (long) (1 << rnu);
267 /*
268 * Round up to minimum allocation size boundary and deduct from block count
269 * to reflect.
270 */
271 if (((U_long) op) & ROUNDUP) {
272 op = (union overhead *) (((U_long) op + (ROUNDUP + 1)) & ~ROUNDUP);
273 nblks--;
274 }
275 /*
276 * Add new memory allocated to that on free list for this hash bucket.
277 */
278 nextf[bucket] = op;
279 siz = 1 << (bucket + 3);
280 while (--nblks > 0) {
281 op->ov_next = (union overhead *) (((caddr_t) op) + siz);
282 op = (union overhead *) (((caddr_t) op) + siz);
283 }
284 op->ov_next = NULL;
285}
286
287#endif
288
289void
290free(cp)
291 ptr_t cp;
292{
293#ifndef lint
294 int size;
295 union overhead *op;
296
297 /*
298 * the don't free flag is there so that we avoid os bugs in routines
299 * that free invalid pointers!
300 */
301 if (cp == NULL || dont_free)
302 return;
303 CHECK(!memtop || !membot,
304 CGETS(19, 2, "free(%lx) called before any allocations."), cp);
305 CHECK(cp > (ptr_t) memtop,
306 CGETS(19, 3, "free(%lx) above top of memory."), cp);
307 CHECK(cp < (ptr_t) membot,
308 CGETS(19, 4, "free(%lx) below bottom of memory."), cp);
309 op = (union overhead *) (((caddr_t) cp) - MEMALIGN(sizeof(union overhead)));
310 CHECK(op->ov_magic != MAGIC,
311 CGETS(19, 5, "free(%lx) bad block."), cp);
312
313#ifdef RCHECK
314 if (op->ov_index <= 13)
315 CHECK(*(U_int *) ((caddr_t) op + op->ov_size + 1 - RSLOP) != RMAGIC,
316 CGETS(19, 6, "free(%lx) bad range check."), cp);
317#endif
318 CHECK(op->ov_index >= NBUCKETS,
319 CGETS(19, 7, "free(%lx) bad block index."), cp);
320 size = op->ov_index;
321 op->ov_next = nextf[size];
322 nextf[size] = op;
323
324 nmalloc[size]--;
325
326#else
327 if (cp == NULL)
328 return;
329#endif
330}
331
332memalign_t
333calloc(i, j)
334 size_t i, j;
335{
336#ifndef lint
337 char *cp, *scp;
338
339 i *= j;
340 scp = cp = (char *) xmalloc((size_t) i);
341 if (i != 0)
342 do
343 *cp++ = 0;
344 while (--i);
345
346 return ((memalign_t) scp);
347#else
348 if (i && j)
349 return ((memalign_t) 0);
350 else
351 return ((memalign_t) 0);
352#endif
353}
354
355/*
356 * When a program attempts "storage compaction" as mentioned in the
357 * old malloc man page, it realloc's an already freed block. Usually
358 * this is the last block it freed; occasionally it might be farther
359 * back. We have to search all the free lists for the block in order
360 * to determine its bucket: 1st we make one pass thru the lists
361 * checking only the first block in each; if that fails we search
362 * ``realloc_srchlen'' blocks in each list for a match (the variable
363 * is extern so the caller can modify it). If that fails we just copy
364 * however many bytes was given to realloc() and hope it's not huge.
365 */
366#ifndef lint
367/* 4 should be plenty, -1 =>'s whole list */
368static int realloc_srchlen = 4;
369#endif /* lint */
370
371memalign_t
372realloc(cp, nbytes)
373 ptr_t cp;
374 size_t nbytes;
375{
376#ifndef lint
377 U_int onb;
378 union overhead *op;
379 ptr_t res;
380 int i;
381 int was_alloced = 0;
382
383 if (cp == NULL)
384 return (malloc(nbytes));
385 op = (union overhead *) (((caddr_t) cp) - MEMALIGN(sizeof(union overhead)));
386 if (op->ov_magic == MAGIC) {
387 was_alloced++;
388 i = op->ov_index;
389 }
390 else
391 /*
392 * Already free, doing "compaction".
393 *
394 * Search for the old block of memory on the free list. First, check the
395 * most common case (last element free'd), then (this failing) the last
396 * ``realloc_srchlen'' items free'd. If all lookups fail, then assume
397 * the size of the memory block being realloc'd is the smallest
398 * possible.
399 */
400 if ((i = findbucket(op, 1)) < 0 &&
401 (i = findbucket(op, realloc_srchlen)) < 0)
402 i = 0;
403
404 onb = MEMALIGN(nbytes + MEMALIGN(sizeof(union overhead)) + RSLOP);
405
406 /* avoid the copy if same size block */
407 if (was_alloced && (onb <= (U_int) (1 << (i + 3))) &&
408 (onb > (U_int) (1 << (i + 2)))) {
409#ifdef RCHECK
410 /* JMR: formerly this wasn't updated ! */
411 nbytes = MEMALIGN(MEMALIGN(sizeof(union overhead))+nbytes+RSLOP);
412 *((U_int *) (((caddr_t) op) + nbytes - RSLOP)) = RMAGIC;
413 op->ov_rmagic = RMAGIC;
414 op->ov_size = (op->ov_index <= 13) ? nbytes - 1 : 0;
415#endif
416 return ((memalign_t) cp);
417 }
418 if ((res = malloc(nbytes)) == NULL)
419 return ((memalign_t) NULL);
420 if (cp != res) { /* common optimization */
421 /*
422 * christos: this used to copy nbytes! It should copy the
423 * smaller of the old and new size
424 */
425 onb = (1 << (i + 3)) - MEMALIGN(sizeof(union overhead)) - RSLOP;
426 (void) memmove((ptr_t) res, (ptr_t) cp,
427 (size_t) (onb < nbytes ? onb : nbytes));
428 }
429 if (was_alloced)
430 free(cp);
431 return ((memalign_t) res);
432#else
433 if (cp && nbytes)
434 return ((memalign_t) 0);
435 else
436 return ((memalign_t) 0);
437#endif /* !lint */
438}
439
440
441
442#ifndef lint
443/*
444 * Search ``srchlen'' elements of each free list for a block whose
445 * header starts at ``freep''. If srchlen is -1 search the whole list.
446 * Return bucket number, or -1 if not found.
447 */
448static int
449findbucket(freep, srchlen)
450 union overhead *freep;
451 int srchlen;
452{
453 union overhead *p;
454 size_t i;
455 int j;
456
457 for (i = 0; i < NBUCKETS; i++) {
458 j = 0;
459 for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
460 if (p == freep)
461 return (i);
462 j++;
463 }
464 }
465 return (-1);
466}
467
468#endif
469
470
471#else /* SYSMALLOC */
472
473/**
474 ** ``Protected versions'' of malloc, realloc, calloc, and free
475 **
476 ** On many systems:
477 **
478 ** 1. malloc(0) is bad
479 ** 2. free(0) is bad
480 ** 3. realloc(0, n) is bad
481 ** 4. realloc(n, 0) is bad
482 **
483 ** Also we call our error routine if we run out of memory.
484 **/
485memalign_t
486smalloc(n)
487 size_t n;
488{
489 ptr_t ptr;
490
491 n = n ? n : 1;
492
493#ifdef HAVE_SBRK
494 if (membot == NULL)
495 membot = (char*) sbrk(0);
496#endif /* HAVE_SBRK */
497
498 if ((ptr = malloc(n)) == (ptr_t) 0) {
499 child++;
500 stderror(ERR_NOMEM);
501 }
502#ifndef HAVE_SBRK
503 if (memtop < ((char *) ptr) + n)
504 memtop = ((char *) ptr) + n;
505 if (membot == NULL)
506 membot = (char*) ptr;
507#endif /* !HAVE_SBRK */
508 return ((memalign_t) ptr);
509}
510
511memalign_t
512srealloc(p, n)
513 ptr_t p;
514 size_t n;
515{
516 ptr_t ptr;
517
518 n = n ? n : 1;
519
520#ifdef HAVE_SBRK
521 if (membot == NULL)
522 membot = (char*) sbrk(0);
523#endif /* HAVE_SBRK */
524
525 if ((ptr = (p ? realloc(p, n) : malloc(n))) == (ptr_t) 0) {
526 child++;
527 stderror(ERR_NOMEM);
528 }
529#ifndef HAVE_SBRK
530 if (memtop < ((char *) ptr) + n)
531 memtop = ((char *) ptr) + n;
532 if (membot == NULL)
533 membot = (char*) ptr;
534#endif /* !HAVE_SBRK */
535 return ((memalign_t) ptr);
536}
537
538memalign_t
539scalloc(s, n)
540 size_t s, n;
541{
542 char *sptr;
543 ptr_t ptr;
544
545 n *= s;
546 n = n ? n : 1;
547
548#ifdef HAVE_SBRK
549 if (membot == NULL)
550 membot = (char*) sbrk(0);
551#endif /* HAVE_SBRK */
552
553 if ((ptr = malloc(n)) == (ptr_t) 0) {
554 child++;
555 stderror(ERR_NOMEM);
556 }
557
558 sptr = (char *) ptr;
559 if (n != 0)
560 do
561 *sptr++ = 0;
562 while (--n);
563
564#ifndef HAVE_SBRK
565 if (memtop < ((char *) ptr) + n)
566 memtop = ((char *) ptr) + n;
567 if (membot == NULL)
568 membot = (char*) ptr;
569#endif /* !HAVE_SBRK */
570
571 return ((memalign_t) ptr);
572}
573
574void
575sfree(p)
576 ptr_t p;
577{
578 if (p && !dont_free)
579 free(p);
580}
581
582#endif /* SYSMALLOC */
583
584/*
585 * mstats - print out statistics about malloc
586 *
587 * Prints two lines of numbers, one showing the length of the free list
588 * for each size category, the second showing the number of mallocs -
589 * frees for each size category.
590 */
591/*ARGSUSED*/
592void
593showall(v, c)
594 Char **v;
595 struct command *c;
596{
597#ifndef SYSMALLOC
598 size_t i, j;
599 union overhead *p;
600 int totfree = 0, totused = 0;
601
602 xprintf(CGETS(19, 8, "%s current memory allocation:\nfree:\t"), progname);
603 for (i = 0; i < NBUCKETS; i++) {
604 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
605 continue;
606 xprintf(" %4d", j);
607 totfree += j * (1 << (i + 3));
608 }
609 xprintf(CGETS(19, 9, "\nused:\t"));
610 for (i = 0; i < NBUCKETS; i++) {
611 xprintf(" %4u", nmalloc[i]);
612 totused += nmalloc[i] * (1 << (i + 3));
613 }
614 xprintf(CGETS(19, 10, "\n\tTotal in use: %d, total free: %d\n"),
615 totused, totfree);
616 xprintf(CGETS(19, 11,
617 "\tAllocated memory from 0x%lx to 0x%lx. Real top at 0x%lx\n"),
618 (unsigned long) membot, (unsigned long) memtop,
619 (unsigned long) sbrk(0));
620#else
621#ifdef HAVE_SBRK
622 memtop = (char *) sbrk(0);
623#endif /* HAVE_SBRK */
624 xprintf(CGETS(19, 12, "Allocated memory from 0x%lx to 0x%lx (%ld).\n"),
625 (unsigned long) membot, (unsigned long) memtop,
626 (unsigned long) (memtop - membot));
627#endif /* SYSMALLOC */
628 USE(c);
629 USE(v);
630}