root/usr/src/lib/libumem/common/vmem_base.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright 2012 Joyent, Inc. All rights reserved.
 */

#include "vmem_base.h"
#include "umem_base.h"

uint_t vmem_backend = 0;
uint_t vmem_allocator = VM_BESTFIT;

vmem_t *
vmem_heap_arena(vmem_alloc_t **allocp, vmem_free_t **freep)
{
        static mutex_t arena_mutex = DEFAULTMUTEX;

        /*
         * Allow the init thread through, block others until the init completes
         */
        if (umem_ready != UMEM_READY && umem_init_thr != thr_self() &&
            umem_init() == 0)
                return (NULL);

        (void) mutex_lock(&arena_mutex);
        if (vmem_heap == NULL)
                vmem_heap_init();
        (void) mutex_unlock(&arena_mutex);

        if (allocp != NULL)
                *allocp = vmem_heap_alloc;
        if (freep != NULL)
                *freep = vmem_heap_free;
        return (vmem_heap);
}