/*
 * This module derived from code donated to the FreeBSD Project by
 * Matthew Dillon <dillon@backplane.com>
 *
 * Copyright (c) 1998 The FreeBSD Project
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

/*
 * MALLOC.C - malloc equivalent, runs on top of zalloc and uses sbrk
 */

#include "zalloc_defs.h"

static MemPool  MallocPool;

#ifdef DMALLOCDEBUG
static int MallocMax;
static int MallocCount;

void mallocstats(void);
#endif

#ifdef malloc
#undef malloc
#undef free
#endif

static void *Malloc_align(size_t, size_t);

#ifndef MIN
# define MIN(a,b) ((a) <= (b)) ? (a) : (b)
#endif

void *
Malloc(size_t bytes, const char *file __unused, int line __unused)
{
        return (Malloc_align(bytes, 1));
}

void *
Memalign(size_t alignment, size_t bytes, const char *file __unused,
    int line __unused)
{
        if (alignment == 0)
                alignment = 1;

        return (Malloc_align(bytes, alignment));
}

static void *
Malloc_align(size_t bytes, size_t alignment)
{
        Guard *res;

#ifdef USEENDGUARD
        bytes += MALLOCALIGN + 1;
#else
        bytes += MALLOCALIGN;
#endif

        while ((res = znalloc(&MallocPool, bytes, alignment)) == NULL) {
                int incr = (bytes + BLKEXTENDMASK) & ~BLKEXTENDMASK;
                char *base;

                if ((base = sbrk(incr)) == (char *)-1)
                        return (NULL);
                zextendPool(&MallocPool, base, incr);
                zfree(&MallocPool, base, incr);
        }
#ifdef DMALLOCDEBUG
        if (++MallocCount > MallocMax)
                MallocMax = MallocCount;
#endif
#ifdef USEGUARD
        res->ga_Magic = GAMAGIC;
#endif
        res->ga_Bytes = bytes;
#ifdef USEENDGUARD
        *((signed char *)res + bytes - 1) = -2;
#endif

        return ((char *)res + MALLOCALIGN);
}

void
Free(void *ptr, const char *file, int line)
{
        size_t bytes;

        if (ptr != NULL) {
                Guard *res = (void *)((char *)ptr - MALLOCALIGN);

                if (file == NULL)
                        file = "unknown";
#ifdef USEGUARD
                if (res->ga_Magic == GAFREE) {
                        printf("free: duplicate free @ %p from %s:%d\n",
                            ptr, file, line);
                        return;
                }
                if (res->ga_Magic != GAMAGIC) {
                        size_t dump_bytes;

                        dump_bytes = MIN((ptr - MallocPool.mp_Base), 512);
                        hexdump(ptr - dump_bytes, dump_bytes);
                        panic("free: guard1 fail @ %p from %s:%d",
                            ptr, file, line);
                }
                res->ga_Magic = GAFREE;
#endif
#ifdef USEENDGUARD
                if (*((signed char *)res + res->ga_Bytes - 1) == -1) {
                        printf("free: duplicate2 free @ %p from %s:%d\n",
                            ptr, file, line);
                        return;
                }
                if (*((signed char *)res + res->ga_Bytes - 1) != -2)
                        panic("free: guard2 fail @ %p + %zu from %s:%d",
                            ptr, res->ga_Bytes - MALLOCALIGN, file, line);
                *((signed char *)res + res->ga_Bytes - 1) = -1;
#endif

                bytes = res->ga_Bytes;
                zfree(&MallocPool, res, bytes);
#ifdef DMALLOCDEBUG
                --MallocCount;
#endif
        }
}


void *
Calloc(size_t n1, size_t n2, const char *file, int line)
{
        uintptr_t bytes = (uintptr_t)n1 * (uintptr_t)n2;
        void *res;

        if ((res = Malloc(bytes, file, line)) != NULL) {
                bzero(res, bytes);
#ifdef DMALLOCDEBUG
                if (++MallocCount > MallocMax)
                        MallocMax = MallocCount;
#endif
        }
        return (res);
}

/*
 * realloc() - I could be fancier here and free the old buffer before
 *             allocating the new one (saving potential fragmentation
 *             and potential buffer copies).  But I don't bother.
 */

void *
Realloc(void *ptr, size_t size, const char *file, int line)
{
        void *res;
        size_t old;

        if ((res = Malloc(size, file, line)) != NULL) {
                if (ptr != NULL) {
                        Guard *g = (Guard *)((char *)ptr - MALLOCALIGN);

                        old = g->ga_Bytes - MALLOCALIGN;
                        if (old < size)
                                bcopy(ptr, res, old);
                        else
                                bcopy(ptr, res, size);
                        Free(ptr, file, line);
                } else {
#ifdef DMALLOCDEBUG
                        if (++MallocCount > MallocMax)
                                MallocMax = MallocCount;
#ifdef EXITSTATS
                        if (DidAtExit == 0) {
                                DidAtExit = 1;
                                atexit(mallocstats);
                        }
#endif
#endif
                }
        }
        return (res);
}

void *
Reallocf(void *ptr, size_t size, const char *file, int line)
{
        void *res;

        if ((res = Realloc(ptr, size, file, line)) == NULL)
                Free(ptr, file, line);
        return (res);
}

#ifdef DMALLOCDEBUG

void
mallocstats(void)
{
        printf("Active Allocations: %d/%d\n", MallocCount, MallocMax);
#ifdef ZALLOCDEBUG
        zallocstats(&MallocPool);
#endif
}

#endif