bsd/vm/vm_pager.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Mach Operating System
  24  * Copyright (c) 1987 Carnegie-Mellon University
  25  * All rights reserved.  The CMU software License Agreement specifies
  26  * the terms and conditions for use and redistribution.
  27  */
  28 /*
  29  *      File:   vm_pager.h
  30  *      Author: Avadis Tevanian, Jr., Michael Wayne Young
  31  *
  32  *      Copyright (C) 1986, Avadis Tevanian, Jr., Michael Wayne Young
  33  *      Copyright (C) 1985, Avadis Tevanian, Jr., Michael Wayne Young
  34  *
  35  *      Pager routine interface definition
  36  */
  37
  38 #ifndef _VM_PAGER_
  39 #define _VM_PAGER_
  40
  41 #include <mach/boolean.h>
  42
  43 struct  pager_struct {
  44         boolean_t       is_device;
  45 };
  46 typedef struct pager_struct     *vm_pager_t;
  47 #define vm_pager_null           ((vm_pager_t) 0)
  48
  49 #define PAGER_SUCCESS           0  /* page read or written */
  50 #define PAGER_ABSENT            1  /* pager does not have page */
  51 #define PAGER_ERROR             2  /* pager unable to read or write page */
  52
  53 #ifdef  KERNEL
  54 typedef int             pager_return_t;
  55
  56 extern vm_pager_t               vm_pager_allocate(void);
  57 extern void                             vm_pager_deallocate(void);
  58 extern pager_return_t   vm_pager_get(void);
  59 extern pager_return_t   vm_pager_put(void);
  60 extern boolean_t                vm_pager_has_page(void);
  61 #endif  /* KERNEL */
  62
  63 #endif  /* _VM_PAGER_ */