mariadb/newbrt/mempool.c

/* -*- mode: C; c-basic-offset: 4 -*- */
#ident "$Id$"
#ident "Copyright (c) 2007, 2008, 2009 Tokutek Inc.  All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."

#include "includes.h"

void toku_mempool_init(struct mempool *mp, void *base, size_t size) {
    // printf("mempool_init %p %p %d\n", mp, base, size);
    assert(base != 0 && size<(1U<<31)); // used to be assert(size >= 0), but changed to size_t so now let's make sure it's not more than 2GB...
    mp->base = base;
    mp->size = size;
    mp->free_offset = 0;
    mp->frag_size = 0;
}

void toku_mempool_fini(struct mempool *mp __attribute__((unused))) {
    // printf("mempool_fini %p %p %d %d\n", mp, mp->base, mp->size, mp->frag_size);
}

void *toku_mempool_get_base(struct mempool *mp) {
    return mp->base;
}

size_t toku_mempool_get_size(struct mempool *mp) {
    return mp->size;
}

size_t toku_mempool_get_frag_size(struct mempool *mp) {
    return mp->frag_size;
}

void *toku_mempool_malloc(struct mempool *mp, size_t size, int alignment) {
    assert(mp->free_offset <= mp->size);
    void *vp;
    size_t offset = (mp->free_offset + (alignment-1)) & ~(alignment-1);
    //printf("mempool_malloc size=%ld base=%p free_offset=%ld mp->size=%ld offset=%ld\n", size, mp->base, mp->free_offset, mp->size, offset);
    if (offset + size > mp->size) {
        vp = 0;
    } else {
        vp = (char *)mp->base + offset;
        mp->free_offset = offset + size;
    }
    assert(mp->free_offset <= mp->size);
    assert(((long)vp & (alignment-1)) == 0);
    assert(vp == 0 || toku_mempool_inrange(mp, vp, size));
    //printf("mempool returning %p\n", vp);
    return vp;
}

// if vp is null then we are freeing something, but not specifying what.  The data won't be freed until compression is done.
void toku_mempool_mfree(struct mempool *mp, void *vp, size_t size) {
    if (vp) assert(toku_mempool_inrange(mp, vp, size));
    mp->frag_size += size;
    assert(mp->frag_size <= mp->size);
}