bsd/vm/vm_pager.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * Mach Operating System
  32  * Copyright (c) 1987 Carnegie-Mellon University
  33  * All rights reserved.  The CMU software License Agreement specifies
  34  * the terms and conditions for use and redistribution.
  35  */
  36 /*
  37  *      File:   vm_pager.h
  38  *      Author: Avadis Tevanian, Jr., Michael Wayne Young
  39  *
  40  *      Copyright (C) 1986, Avadis Tevanian, Jr., Michael Wayne Young
  41  *      Copyright (C) 1985, Avadis Tevanian, Jr., Michael Wayne Young
  42  *
  43  *      Pager routine interface definition
  44  */
  45
  46 #ifndef _VM_PAGER_
  47 #define _VM_PAGER_
  48
  49 #include <mach/boolean.h>
  50
  51 struct  pager_struct {
  52         boolean_t       is_device;
  53 };
  54 typedef struct pager_struct     *vm_pager_t;
  55 #define vm_pager_null           ((vm_pager_t) 0)
  56
  57 #define PAGER_SUCCESS           0  /* page read or written */
  58 #define PAGER_ABSENT            1  /* pager does not have page */
  59 #define PAGER_ERROR             2  /* pager unable to read or write page */
  60
  61 #ifdef  KERNEL
  62 typedef int             pager_return_t;
  63
  64 extern vm_pager_t               vm_pager_allocate(void);
  65 extern void                             vm_pager_deallocate(void);
  66 extern pager_return_t   vm_pager_get(void);
  67 extern pager_return_t   vm_pager_put(void);
  68 extern boolean_t                vm_pager_has_page(void);
  69 #endif  /* KERNEL */
  70
  71 #endif  /* _VM_PAGER_ */