zfs/lib/libumem/vmem_base.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include "vmem_base.h"
  30 #include "umem_base.h"
  31
  32 uint_t vmem_backend = 0;
  33
  34 vmem_t *
  35 vmem_heap_arena(vmem_alloc_t **allocp, vmem_free_t **freep)
  36 {
  37         static mutex_t arena_mutex = DEFAULTMUTEX;
  38
  39         /*
  40          * Allow the init thread through, block others until the init completes
  41          */
  42         if (umem_ready != UMEM_READY && umem_init_thr != thr_self() &&
  43             umem_init() == 0)
  44                 return (NULL);
  45
  46         (void) mutex_lock(&arena_mutex);
  47         if (vmem_heap == NULL)
  48                 vmem_heap_init();
  49         (void) mutex_unlock(&arena_mutex);
  50
  51         if (allocp != NULL)
  52                 *allocp = vmem_heap_alloc;
  53         if (freep != NULL)
  54                 *freep = vmem_heap_free;
  55         return (vmem_heap);
  56 }