/* $Header: /p/tcsh/cvsroot/tcsh/tc.alloc.c,v 3.50 2011/12/30 20:55:24 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. 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" #ifdef HAVE_MALLINFO #include #endif RCSID("$tcsh: tc.alloc.c,v 3.50 2011/12/30 20:55:24 christos Exp $") #define RCHECK #define DEBUG static char *memtop = NULL; /* PWP: top of current memory */ static char *membot = NULL; /* PWP: bottom of allocatable memory */ int dont_free = 0; #ifdef WINNT_NATIVE # define malloc fmalloc # define free ffree # define calloc fcalloc # define realloc frealloc #endif /* WINNT_NATIVE */ #if !defined(DEBUG) || defined(SYSMALLOC) static void out_of_memory (void) { static const char msg[] = "Out of memory\n"; write(didfds ? 2 : SHDIAG, msg, strlen(msg)); _exit(1); } #endif #ifndef SYSMALLOC #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 (union overhead *, int); static void morecore (int); #endif #ifdef DEBUG # define CHECK(a, str, p) \ if (a) { \ xprintf(str, p); \ xprintf(" (memtop = %p membot = %p)\n", memtop, membot); \ abort(); \ } #else # define CHECK(a, str, p) \ if (a) { \ xprintf(str, p); \ xprintf(" (memtop = %p membot = %p)\n", memtop, membot); \ return; \ } #endif memalign_t malloc(size_t nbytes) { #ifndef lint union overhead *p; int bucket = 0; 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 = nextf[bucket]) == NULL) { child++; #ifndef DEBUG out_of_memory(); #else showall(NULL, NULL); xprintf(CGETS(19, 1, "nbytes=%zu: 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(int bucket) { union overhead *op; int rnu; /* 2^rnu bytes will be requested */ int nblks; /* become nblks blocks of the desired size */ 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 = 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 = 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(ptr_t cp) { #ifndef lint int size; 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(%p) called before any allocations."), cp); CHECK(cp > (ptr_t) memtop, CGETS(19, 3, "free(%p) above top of memory."), cp); CHECK(cp < (ptr_t) membot, CGETS(19, 4, "free(%p) below bottom of memory."), cp); op = (union overhead *) (((caddr_t) cp) - MEMALIGN(sizeof(union overhead))); CHECK(op->ov_magic != MAGIC, CGETS(19, 5, "free(%p) 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(%p) bad range check."), cp); #endif CHECK(op->ov_index >= NBUCKETS, CGETS(19, 7, "free(%p) 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(size_t i, size_t j) { #ifndef lint char *cp; i *= j; cp = xmalloc(i); memset(cp, 0, i); return ((memalign_t) cp); #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(ptr_t cp, size_t nbytes) { #ifndef lint U_int onb; union overhead *op; ptr_t res; 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(res, cp, 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 */ } /* * On linux, _nss_nis_setnetgrent() calls this function to determine * the usable size of the pointer passed, but this is not a portable * API, so we cannot use our malloc replacement without providing one. * Thanks a lot glibc! */ #ifdef __linux__ #define M_U_S_CONST #else #define M_U_S_CONST #endif size_t malloc_usable_size(M_U_S_CONST void *); size_t malloc_usable_size(M_U_S_CONST void *ptr) { const union overhead *op = (const union overhead *) (((const char *) ptr) - MEMALIGN(sizeof(*op))); if (op->ov_magic == MAGIC) return 1 << (op->ov_index + 2); else return 0; } #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(union overhead *freep, int srchlen) { union overhead *p; size_t i; int 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(size_t n) { ptr_t ptr; n = n ? n : 1; #ifdef HAVE_SBRK if (membot == NULL) membot = sbrk(0); #endif /* HAVE_SBRK */ if ((ptr = malloc(n)) == NULL) out_of_memory(); #ifndef HAVE_SBRK if (memtop < ((char *) ptr) + n) memtop = ((char *) ptr) + n; if (membot == NULL) membot = ptr; #endif /* !HAVE_SBRK */ return ((memalign_t) ptr); } memalign_t srealloc(ptr_t p, size_t n) { ptr_t ptr; n = n ? n : 1; #ifdef HAVE_SBRK if (membot == NULL) membot = sbrk(0); #endif /* HAVE_SBRK */ if ((ptr = (p ? realloc(p, n) : malloc(n))) == NULL) out_of_memory(); #ifndef HAVE_SBRK if (memtop < ((char *) ptr) + n) memtop = ((char *) ptr) + n; if (membot == NULL) membot = ptr; #endif /* !HAVE_SBRK */ return ((memalign_t) ptr); } memalign_t scalloc(size_t s, size_t n) { ptr_t ptr; n *= s; n = n ? n : 1; #ifdef HAVE_SBRK if (membot == NULL) membot = sbrk(0); #endif /* HAVE_SBRK */ if ((ptr = malloc(n)) == NULL) out_of_memory(); memset (ptr, 0, n); #ifndef HAVE_SBRK if (memtop < ((char *) ptr) + n) memtop = ((char *) ptr) + n; if (membot == NULL) membot = ptr; #endif /* !HAVE_SBRK */ return ((memalign_t) ptr); } void sfree(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(Char **v, struct command *c) { #ifndef SYSMALLOC size_t i, j; 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(" %4zd", j); totfree += j * (1 << (i + 3)); } xprintf("\n%s:\t", CGETS(19, 9, "used")); for (i = 0; i < NBUCKETS; i++) { xprintf(" %4d", 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 /* SYSMALLOC */ #ifndef HAVE_MALLINFO #ifdef HAVE_SBRK memtop = sbrk(0); #endif /* HAVE_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)); #else /* HAVE_MALLINFO */ struct mallinfo mi; mi = mallinfo(); xprintf(CGETS(19, 13, "%s current memory allocation:\n"), progname); xprintf(CGETS(19, 14, "Total space allocated from system: %d\n"), mi.arena); xprintf(CGETS(19, 15, "Number of non-inuse chunks: %d\n"), mi.ordblks); xprintf(CGETS(19, 16, "Number of mmapped regions: %d\n"), mi.hblks); xprintf(CGETS(19, 17, "Total space in mmapped regions: %d\n"), mi.hblkhd); xprintf(CGETS(19, 18, "Total allocated space: %d\n"), mi.uordblks); xprintf(CGETS(19, 19, "Total non-inuse space: %d\n"), mi.fordblks); xprintf(CGETS(19, 20, "Top-most, releasable space: %d\n"), mi.keepcost); #endif /* HAVE_MALLINFO */ #endif /* SYSMALLOC */ USE(c); USE(v); }