/* table.h - definitions for tables for keeping track of allocated memory */ /* Copyright (C) 2001-2003 Free Software Foundation, Inc. This file is part of GNU Bash, the Bourne-Again SHell. Bash is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Bash is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Bash. If not, see . */ #ifndef _MTABLE_H #define _MTABLE_H #include "imalloc.h" #ifdef MALLOC_REGISTER /* values for flags byte. */ #define MT_ALLOC 0x01 #define MT_FREE 0x02 /* * Memory table entry. * * MEM is the address of the allocated pointer. * SIZE is the requested allocation size. * FLAGS includes either MT_ALLOC (MEM is allocated) or MT_FREE (MEM is * not allocated). Other flags later. * FUNC is set to the name of the function doing the allocation (from the * `tag' argument to register_alloc(). * FILE and LINE are the filename and line number of the last allocation * and free (depending on STATUS) of MEM. * NALLOC and NFREE are incremented on each allocation that returns MEM or * each free of MEM, respectively (way to keep track of memory reuse * and how well the free lists are working). * */ typedef struct mr_table { PTR_T mem; size_t size; char flags; const char *func; const char *file; int line; int nalloc, nfree; } mr_table_t; #define REG_TABLE_SIZE 8192 extern mr_table_t *mr_table_entry __P((PTR_T)); extern void mregister_alloc __P((const char *, PTR_T, size_t, const char *, int)); extern void mregister_free __P((PTR_T, int, const char *, int)); extern void mregister_describe_mem (); extern void mregister_dump_table __P((void)); extern void mregister_table_init __P((void)); /* NOTE: HASH_MIX taken from dmalloc (http://dmalloc.com) */ /* * void HASH_MIX * * DESCRIPTION: * * Mix 3 32-bit values reversibly. For every delta with one or two * bits set, and the deltas of all three high bits or all three low * bits, whether the original value of a,b,c is almost all zero or is * uniformly distributed. * * If HASH_MIX() is run forward or backward, at least 32 bits in a,b,c * have at least 1/4 probability of changing. If mix() is run * forward, every bit of c will change between 1/3 and 2/3 of the * time. (Well, 22/100 and 78/100 for some 2-bit deltas.) * * HASH_MIX() takes 36 machine instructions, but only 18 cycles on a * superscalar machine (like a Pentium or a Sparc). No faster mixer * seems to work, that's the result of my brute-force search. There * were about 2^68 hashes to choose from. I only tested about a * billion of those. */ #define HASH_MIX(a, b, c) \ do { \ a -= b; a -= c; a ^= (c >> 13); \ b -= c; b -= a; b ^= (a c -= a; c -= b; c ^= (b >> 13); \ a -= b; a -= c; a ^= (c >> 12); \ b -= c; b -= a; b ^= (a c -= a; c -= b; c ^= (b >> 5); \ a -= b; a -= c; a ^= (c >> 3); \ b -= c; b -= a; b ^= (a c -= a; c -= b; c ^= (b >> 15); \ } while(0) #endif /* MALLOC_REGISTER */ #endif /* _MTABLE_H */
