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Diffstat (limited to 'contrib/tcsh/tc.alloc.c')
| -rw-r--r-- | contrib/tcsh/tc.alloc.c | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/contrib/tcsh/tc.alloc.c b/contrib/tcsh/tc.alloc.c new file mode 100644 index 0000000..b2771db --- /dev/null +++ b/contrib/tcsh/tc.alloc.c @@ -0,0 +1,637 @@ +/* $Header: /src/pub/tcsh/tc.alloc.c,v 3.34 1999/04/20 07:48:49 christos Exp $ */ +/* + * tc.alloc.c (Caltech) 2/21/82 + * Chris Kingsley, kingsley@cit-20. + * + * This is a very fast storage allocator. It allocates blocks of a small + * number of different sizes, and keeps free lists of each size. Blocks that + * don't exactly fit are passed up to the next larger size. In this + * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long. + * This is designed for use in a program that uses vast quantities of memory, + * but bombs when it runs out. + */ +/*- + * Copyright (c) 1980, 1991 The Regents of the University of California. + * All rights reserved. + * + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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. + */ +#include "sh.h" + +RCSID("$Id: tc.alloc.c,v 3.34 1999/04/20 07:48:49 christos Exp $") + +static char *memtop = NULL; /* PWP: top of current memory */ +static char *membot = NULL; /* PWP: bottom of allocatable memory */ + +int dont_free = 0; + +#if defined(_VMS_POSIX) || defined(_AMIGA_MEMORY) +# define NO_SBRK +#endif + +#ifdef WINNT +# define malloc fmalloc +# define free ffree +# define calloc fcalloc +# define realloc frealloc +#endif /* WINNT */ + +#ifndef SYSMALLOC + +#undef RCHECK +#undef DEBUG + +#ifdef SX +extern void* sbrk(); +#endif +/* + * Lots of os routines are busted and try to free invalid pointers. + * Although our free routine is smart enough and it will pick bad + * pointers most of the time, in cases where we know we are going to get + * a bad pointer, we'd rather leak. + */ + +#ifndef NULL +#define NULL 0 +#endif + +typedef unsigned char U_char; /* we don't really have signed chars */ +typedef unsigned int U_int; +typedef unsigned short U_short; +typedef unsigned long U_long; + + +/* + * The overhead on a block is at least 4 bytes. When free, this space + * contains a pointer to the next free block, and the bottom two bits must + * be zero. When in use, the first byte is set to MAGIC, and the second + * byte is the size index. The remaining bytes are for alignment. + * If range checking is enabled and the size of the block fits + * in two bytes, then the top two bytes hold the size of the requested block + * plus the range checking words, and the header word MINUS ONE. + */ + + +#define MEMALIGN(a) (((a) + ROUNDUP) & ~ROUNDUP) + +union overhead { + union overhead *ov_next; /* when free */ + struct { + U_char ovu_magic; /* magic number */ + U_char ovu_index; /* bucket # */ +#ifdef RCHECK + U_short ovu_size; /* actual block size */ + U_int ovu_rmagic; /* range magic number */ +#endif + } ovu; +#define ov_magic ovu.ovu_magic +#define ov_index ovu.ovu_index +#define ov_size ovu.ovu_size +#define ov_rmagic ovu.ovu_rmagic +}; + +#define MAGIC 0xfd /* magic # on accounting info */ +#define RMAGIC 0x55555555 /* magic # on range info */ +#ifdef RCHECK +#define RSLOP sizeof (U_int) +#else +#define RSLOP 0 +#endif + + +#define ROUNDUP 7 + +/* + * nextf[i] is the pointer to the next free block of size 2^(i+3). The + * smallest allocatable block is 8 bytes. The overhead information + * precedes the data area returned to the user. + */ +#define NBUCKETS ((sizeof(long) << 3) - 3) +static union overhead *nextf[NBUCKETS] IZERO_STRUCT; + +/* + * nmalloc[i] is the difference between the number of mallocs and frees + * for a given block size. + */ +static U_int nmalloc[NBUCKETS] IZERO_STRUCT; + +#ifndef lint +static int findbucket __P((union overhead *, int)); +static void morecore __P((int)); +#endif + + +#ifdef DEBUG +# define CHECK(a, str, p) \ + if (a) { \ + xprintf(str, p); \ + xprintf(" (memtop = %lx membot = %lx)\n", memtop, membot); \ + abort(); \ + } +#else +# define CHECK(a, str, p) \ + if (a) { \ + xprintf(str, p); \ + xprintf(" (memtop = %lx membot = %lx)\n", memtop, membot); \ + return; \ + } +#endif + +memalign_t +malloc(nbytes) + register size_t nbytes; +{ +#ifndef lint + register union overhead *p; + register int bucket = 0; + register unsigned shiftr; + + /* + * Convert amount of memory requested into closest block size stored in + * hash buckets which satisfies request. Account for space used per block + * for accounting. + */ +#ifdef SUNOS4 + /* + * SunOS localtime() overwrites the 9th byte on an 8 byte malloc().... + * so we get one more... + * From Michael Schroeder: This is not true. It depends on the + * timezone string. In Europe it can overwrite the 13th byte on a + * 12 byte malloc. + * So we punt and we always allocate an extra byte. + */ + nbytes++; +#endif + + nbytes = MEMALIGN(MEMALIGN(sizeof(union overhead)) + nbytes + RSLOP); + shiftr = (nbytes - 1) >> 2; + + /* apart from this loop, this is O(1) */ + while ((shiftr >>= 1) != 0) + bucket++; + /* + * If nothing in hash bucket right now, request more memory from the + * system. + */ + if (nextf[bucket] == NULL) + morecore(bucket); + if ((p = (union overhead *) nextf[bucket]) == NULL) { + child++; +#ifndef DEBUG + stderror(ERR_NOMEM); +#else + showall(NULL, NULL); + xprintf(CGETS(19, 1, "nbytes=%d: Out of memory\n"), nbytes); + abort(); +#endif + /* fool lint */ + return ((memalign_t) 0); + } + /* remove from linked list */ + nextf[bucket] = nextf[bucket]->ov_next; + p->ov_magic = MAGIC; + p->ov_index = bucket; + nmalloc[bucket]++; +#ifdef RCHECK + /* + * Record allocated size of block and bound space with magic numbers. + */ + p->ov_size = (p->ov_index <= 13) ? nbytes - 1 : 0; + p->ov_rmagic = RMAGIC; + *((U_int *) (((caddr_t) p) + nbytes - RSLOP)) = RMAGIC; +#endif + return ((memalign_t) (((caddr_t) p) + MEMALIGN(sizeof(union overhead)))); +#else + if (nbytes) + return ((memalign_t) 0); + else + return ((memalign_t) 0); +#endif /* !lint */ +} + +#ifndef lint +/* + * Allocate more memory to the indicated bucket. + */ +static void +morecore(bucket) + register int bucket; +{ + register union overhead *op; + register int rnu; /* 2^rnu bytes will be requested */ + register int nblks; /* become nblks blocks of the desired size */ + register int siz; + + if (nextf[bucket]) + return; + /* + * Insure memory is allocated on a page boundary. Should make getpageize + * call? + */ + op = (union overhead *) sbrk(0); + memtop = (char *) op; + if (membot == NULL) + membot = memtop; + if ((long) op & 0x3ff) { + memtop = (char *) sbrk((int) (1024 - ((long) op & 0x3ff))); + memtop += (long) (1024 - ((long) op & 0x3ff)); + } + + /* take 2k unless the block is bigger than that */ + rnu = (bucket <= 8) ? 11 : bucket + 3; + nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */ + memtop = (char *) sbrk(1 << rnu); /* PWP */ + op = (union overhead *) memtop; + /* no more room! */ + if ((long) op == -1) + return; + memtop += (long) (1 << rnu); + /* + * Round up to minimum allocation size boundary and deduct from block count + * to reflect. + */ + if (((U_long) op) & ROUNDUP) { + op = (union overhead *) (((U_long) op + (ROUNDUP + 1)) & ~ROUNDUP); + nblks--; + } + /* + * Add new memory allocated to that on free list for this hash bucket. + */ + nextf[bucket] = op; + siz = 1 << (bucket + 3); + while (--nblks > 0) { + op->ov_next = (union overhead *) (((caddr_t) op) + siz); + op = (union overhead *) (((caddr_t) op) + siz); + } + op->ov_next = NULL; +} + +#endif + +void +free(cp) + ptr_t cp; +{ +#ifndef lint + register int size; + register union overhead *op; + + /* + * the don't free flag is there so that we avoid os bugs in routines + * that free invalid pointers! + */ + if (cp == NULL || dont_free) + return; + CHECK(!memtop || !membot, + CGETS(19, 2, "free(%lx) called before any allocations."), cp); + CHECK(cp > (ptr_t) memtop, + CGETS(19, 3, "free(%lx) above top of memory."), cp); + CHECK(cp < (ptr_t) membot, + CGETS(19, 4, "free(%lx) below bottom of memory."), cp); + op = (union overhead *) (((caddr_t) cp) - MEMALIGN(sizeof(union overhead))); + CHECK(op->ov_magic != MAGIC, + CGETS(19, 5, "free(%lx) bad block."), cp); + +#ifdef RCHECK + if (op->ov_index <= 13) + CHECK(*(U_int *) ((caddr_t) op + op->ov_size + 1 - RSLOP) != RMAGIC, + CGETS(19, 6, "free(%lx) bad range check."), cp); +#endif + CHECK(op->ov_index >= NBUCKETS, + CGETS(19, 7, "free(%lx) bad block index."), cp); + size = op->ov_index; + op->ov_next = nextf[size]; + nextf[size] = op; + + nmalloc[size]--; + +#else + if (cp == NULL) + return; +#endif +} + +memalign_t +calloc(i, j) + size_t i, j; +{ +#ifndef lint + register char *cp, *scp; + + i *= j; + scp = cp = (char *) xmalloc((size_t) i); + if (i != 0) + do + *cp++ = 0; + while (--i); + + return ((memalign_t) scp); +#else + if (i && j) + return ((memalign_t) 0); + else + return ((memalign_t) 0); +#endif +} + +/* + * When a program attempts "storage compaction" as mentioned in the + * old malloc man page, it realloc's an already freed block. Usually + * this is the last block it freed; occasionally it might be farther + * back. We have to search all the free lists for the block in order + * to determine its bucket: 1st we make one pass thru the lists + * checking only the first block in each; if that fails we search + * ``realloc_srchlen'' blocks in each list for a match (the variable + * is extern so the caller can modify it). If that fails we just copy + * however many bytes was given to realloc() and hope it's not huge. + */ +#ifndef lint +/* 4 should be plenty, -1 =>'s whole list */ +static int realloc_srchlen = 4; +#endif /* lint */ + +memalign_t +realloc(cp, nbytes) + ptr_t cp; + size_t nbytes; +{ +#ifndef lint + register U_int onb; + union overhead *op; + ptr_t res; + register int i; + int was_alloced = 0; + + if (cp == NULL) + return (malloc(nbytes)); + op = (union overhead *) (((caddr_t) cp) - MEMALIGN(sizeof(union overhead))); + if (op->ov_magic == MAGIC) { + was_alloced++; + i = op->ov_index; + } + else + /* + * Already free, doing "compaction". + * + * Search for the old block of memory on the free list. First, check the + * most common case (last element free'd), then (this failing) the last + * ``realloc_srchlen'' items free'd. If all lookups fail, then assume + * the size of the memory block being realloc'd is the smallest + * possible. + */ + if ((i = findbucket(op, 1)) < 0 && + (i = findbucket(op, realloc_srchlen)) < 0) + i = 0; + + onb = MEMALIGN(nbytes + MEMALIGN(sizeof(union overhead)) + RSLOP); + + /* avoid the copy if same size block */ + if (was_alloced && (onb <= (U_int) (1 << (i + 3))) && + (onb > (U_int) (1 << (i + 2)))) { +#ifdef RCHECK + /* JMR: formerly this wasn't updated ! */ + nbytes = MEMALIGN(MEMALIGN(sizeof(union overhead))+nbytes+RSLOP); + *((U_int *) (((caddr_t) op) + nbytes - RSLOP)) = RMAGIC; + op->ov_rmagic = RMAGIC; + op->ov_size = (op->ov_index <= 13) ? nbytes - 1 : 0; +#endif + return ((memalign_t) cp); + } + if ((res = malloc(nbytes)) == NULL) + return ((memalign_t) NULL); + if (cp != res) { /* common optimization */ + /* + * christos: this used to copy nbytes! It should copy the + * smaller of the old and new size + */ + onb = (1 << (i + 3)) - MEMALIGN(sizeof(union overhead)) - RSLOP; + (void) memmove((ptr_t) res, (ptr_t) cp, + (size_t) (onb < nbytes ? onb : nbytes)); + } + if (was_alloced) + free(cp); + return ((memalign_t) res); +#else + if (cp && nbytes) + return ((memalign_t) 0); + else + return ((memalign_t) 0); +#endif /* !lint */ +} + + + +#ifndef lint +/* + * Search ``srchlen'' elements of each free list for a block whose + * header starts at ``freep''. If srchlen is -1 search the whole list. + * Return bucket number, or -1 if not found. + */ +static int +findbucket(freep, srchlen) + union overhead *freep; + int srchlen; +{ + register union overhead *p; + register int i, j; + + for (i = 0; i < NBUCKETS; i++) { + j = 0; + for (p = nextf[i]; p && j != srchlen; p = p->ov_next) { + if (p == freep) + return (i); + j++; + } + } + return (-1); +} + +#endif + + +#else /* SYSMALLOC */ + +/** + ** ``Protected versions'' of malloc, realloc, calloc, and free + ** + ** On many systems: + ** + ** 1. malloc(0) is bad + ** 2. free(0) is bad + ** 3. realloc(0, n) is bad + ** 4. realloc(n, 0) is bad + ** + ** Also we call our error routine if we run out of memory. + **/ +memalign_t +smalloc(n) + size_t n; +{ + ptr_t ptr; + + n = n ? n : 1; + +#ifndef NO_SBRK + if (membot == NULL) + membot = (char*) sbrk(0); +#endif /* !NO_SBRK */ + + if ((ptr = malloc(n)) == (ptr_t) 0) { + child++; + stderror(ERR_NOMEM); + } +#ifdef NO_SBRK + if (memtop < ((char *) ptr) + n) + memtop = ((char *) ptr) + n; + if (membot == NULL) + membot = (char*) ptr; +#endif /* NO_SBRK */ + return ((memalign_t) ptr); +} + +memalign_t +srealloc(p, n) + ptr_t p; + size_t n; +{ + ptr_t ptr; + + n = n ? n : 1; + +#ifndef NO_SBRK + if (membot == NULL) + membot = (char*) sbrk(0); +#endif /* NO_SBRK */ + + if ((ptr = (p ? realloc(p, n) : malloc(n))) == (ptr_t) 0) { + child++; + stderror(ERR_NOMEM); + } +#ifdef NO_SBRK + if (memtop < ((char *) ptr) + n) + memtop = ((char *) ptr) + n; + if (membot == NULL) + membot = (char*) ptr; +#endif /* NO_SBRK */ + return ((memalign_t) ptr); +} + +memalign_t +scalloc(s, n) + size_t s, n; +{ + char *sptr; + ptr_t ptr; + + n *= s; + n = n ? n : 1; + +#ifndef NO_SBRK + if (membot == NULL) + membot = (char*) sbrk(0); +#endif /* NO_SBRK */ + + if ((ptr = malloc(n)) == (ptr_t) 0) { + child++; + stderror(ERR_NOMEM); + } + + sptr = (char *) ptr; + if (n != 0) + do + *sptr++ = 0; + while (--n); + +#ifdef NO_SBRK + if (memtop < ((char *) ptr) + n) + memtop = ((char *) ptr) + n; + if (membot == NULL) + membot = (char*) ptr; +#endif /* NO_SBRK */ + + return ((memalign_t) ptr); +} + +void +sfree(p) + ptr_t p; +{ + if (p && !dont_free) + free(p); +} + +#endif /* SYSMALLOC */ + +/* + * mstats - print out statistics about malloc + * + * Prints two lines of numbers, one showing the length of the free list + * for each size category, the second showing the number of mallocs - + * frees for each size category. + */ +/*ARGSUSED*/ +void +showall(v, c) + Char **v; + struct command *c; +{ +#ifndef SYSMALLOC + register int i, j; + register union overhead *p; + int totfree = 0, totused = 0; + + xprintf(CGETS(19, 8, "%s current memory allocation:\nfree:\t"), progname); + for (i = 0; i < NBUCKETS; i++) { + for (j = 0, p = nextf[i]; p; p = p->ov_next, j++) + continue; + xprintf(" %4d", j); + totfree += j * (1 << (i + 3)); + } + xprintf(CGETS(19, 9, "\nused:\t")); + for (i = 0; i < NBUCKETS; i++) { + xprintf(" %4u", nmalloc[i]); + totused += nmalloc[i] * (1 << (i + 3)); + } + xprintf(CGETS(19, 10, "\n\tTotal in use: %d, total free: %d\n"), + totused, totfree); + xprintf(CGETS(19, 11, + "\tAllocated memory from 0x%lx to 0x%lx. Real top at 0x%lx\n"), + (unsigned long) membot, (unsigned long) memtop, + (unsigned long) sbrk(0)); +#else +#ifndef NO_SBRK + memtop = (char *) sbrk(0); +#endif /* !NO_SBRK */ + xprintf(CGETS(19, 12, "Allocated memory from 0x%lx to 0x%lx (%ld).\n"), + (unsigned long) membot, (unsigned long) memtop, + (unsigned long) (memtop - membot)); +#endif /* SYSMALLOC */ + USE(c); + USE(v); +} |
