/* * Copyright (c) 1992, 1993, 1996 * Berkeley Software Design, Inc. 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 Berkeley Software * Design, Inc. * * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``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 Berkeley Software Design, Inc. 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. * * BSDI mem.c,v 2.2 1996/04/08 19:32:57 bostic Exp * * $Id: mem.c,v 1.4 1996/09/22 15:42:57 miff Exp $ */ #include <stdio.h> #include "doscmd.h" #define Mark(x) (*(char *) (x)) #define Owner(x) (*(u_short *) ((char *)(x)+1)) #define Size(x) (*(u_short *) ((char *)(x)+3)) #define Next(x) ((char *)(x) + (Size(x)+1)*16) /* exports */ char *dosmem; /* locals */ static int dosmem_size; static char *next_p = (char *)0; static char *end_p = (char *)0xB0000L; static char * core_alloc(int *size) { char *ret; if (*size) { if (*size & 0xfff) { *size = (*size & ~0xfff) + 0x1000; } } else { *size = end_p - next_p; } if (next_p + *size > end_p) { return NULL; } ret = next_p; next_p += *size; return ret; } void mem_free_owner(int owner) { char *mp; debug(D_MEMORY, " : freeow(%04x)\n", owner); for (mp = dosmem; ; mp = Next(mp)) { if (Owner(mp) == owner) Owner(mp) = 0; if (Mark(mp) != 'M') break; } } static void mem_print(void) { char *mp; for (mp = dosmem; ; mp = Next(mp)) { debug(D_ALWAYS, "%05x: mark %c owner %04x size %04x\n", mp, Mark(mp), Owner(mp), Size(mp)); if (Mark(mp) != 'M') break; } } void mem_change_owner(int addr, int owner) { char *mp; debug(D_MEMORY, "%04x: owner (%04x)\n", addr, owner); addr <<= 4; for (mp = dosmem; ; mp = Next(mp)) { if ((int)(mp + 16) == addr) goto found; if (Mark(mp) != 'M') break; } debug(D_ALWAYS, "%05x: illegal block in change owner\n", addr); mem_print(); return; found: Owner(mp) = owner; } void mem_init(void) { int base, avail_memory; base = 0x600; core_alloc(&base); avail_memory = MAX_AVAIL_SEG * 16 - base; dosmem = core_alloc(&avail_memory); if (!dosmem || dosmem != (char *)base) fatal("internal memory error\n"); dosmem_size = avail_memory / 16; debug(D_MEMORY, "dosmem = 0x%x base = 0x%x avail = 0x%x (%dK)\n", dosmem, base, dosmem_size, avail_memory / 1024); Mark(dosmem) = 'Z'; Owner(dosmem) = 0; Size(dosmem) = dosmem_size - 1; } static void mem_unsplit(char *mp, int size) { char *nmp; while (Mark(mp) == 'M' && Size(mp) < size) { nmp = Next(mp); if (Owner(nmp) != 0) break; Size(mp) += Size(nmp) + 1; Mark(mp) = Mark(nmp); } } static void mem_split(char *mp, int size) { char *nmp; int rest; rest = Size(mp) - size; Size(mp) = size; nmp = Next(mp); Mark(nmp) = Mark(mp); Mark(mp) = 'M'; Owner(nmp) = 0; Size(nmp) = rest - 1; } int mem_alloc(int size, int owner, int *biggestp) { char *mp; int biggest; biggest = 0; for (mp = dosmem; ; mp = Next(mp)) { if (Owner(mp) == 0) { if (Size(mp) < size) mem_unsplit(mp, size); if (Size(mp) >= size) goto got; if (Size(mp) > biggest) biggest = Size(mp); } if (Mark(mp) != 'M') break; } debug(D_MEMORY, "%04x: alloc(%04x, owner %04x) failed -> %d\n", 0, size, owner, biggest); if (biggestp) *biggestp = biggest; return 0; got: if (Size(mp) > size) mem_split(mp, size); Owner(mp) = owner; debug(D_MEMORY, "%04x: alloc(%04x, owner %04x)\n", (int)mp/16 + 1, size, owner); if (biggestp) *biggestp = size; return (int)mp/16 + 1; } int mem_adjust(int addr, int size, int *availp) { char *mp; int delta, nxtsiz; debug(D_MEMORY, "%04x: adjust(%05x)\n", addr, size); addr <<= 4; for (mp = dosmem; ; mp = Next(mp)) { if ((int)(mp + 16) == addr) goto found; if (Mark(mp) != 'M') break; } debug(D_ALWAYS, "%05x: illegal block in adjust\n", addr); mem_print(); return -2; found: if (Size(mp) < size) mem_unsplit(mp, size); if (Size(mp) >= size) goto got; debug(D_MEMORY, "%04x: adjust(%04x) failed -> %d\n", (int)mp/16 + 1, size, Size(mp)); if (availp) *availp = Size(mp); return -1; got: if (Size(mp) > size) mem_split(mp, size); debug(D_MEMORY, "%04x: adjust(%04x)\n", (int)mp/16 + 1, size); if (availp) *availp = size; return 0; } #ifdef MEM_TEST mem_check () { struct mem_block *mp; for (mp = mem_blocks.next; mp != &mem_blocks; mp = mp->next) { if (mp->addr + mp->size != mp->next->addr) break; if (mp->inuse && mp->size == 0) return (-1); } if (mp->next != &mem_blocks) return (-1); return (0); } char *blocks[10]; main () { int i; int n; int newsize; mem_init (0, 300); for (i = 0; i < 100000; i++) { n = random () % 10; if (blocks[n]) { newsize = random () % 20; if ((newsize & 1) == 0) newsize = 0; if (0) printf ("adjust %d %x %d\n", n, blocks[n], newsize); mem_adjust (blocks[n], newsize, NULL); if (newsize == 0) blocks[n] = NULL; } else { while ((newsize = random () % 20) == 0) ; if (0) printf ("alloc %d %d\n", n, newsize); blocks[n] = mem_alloc (newsize, NULL); } if (mem_check () < 0) { printf ("==== %d\n", i); mem_print (); } } mem_print (); } #endif /* MEM_TEST */