text: /* vm.h: VIRTUAL MEMORY INTERFACE
   *
   * $Id$
   * Copyright (c) 2014 Ravenbrook Limited.  See end of file for license.
   */
  
  #ifndef vm_h
  #define vm_h
  
  #include "mpmtypes.h"
  
  
  /* VMStruct -- virtual memory structure
   *
   * Unlike most other datatypes we permit this structure to be moved
   * around in memory, and in particular, allocated temporarily on the
   * stack, to help with bootstrapping. Look for uses of VMCopy.
   */
  
  #define VMSig           ((Sig)0x519B3999) /* SIGnature VM */
  
  typedef struct VMStruct {
    Sig sig;                      /* <design/sig> */
    Size pageSize;                /* operating system page size */
    void *block;                  /* unaligned base of mmap'd memory */
    Addr base, limit;             /* aligned boundaries of reserved space */
    Size reserved;                /* total reserved address space */
    Size mapped;                  /* total mapped memory */
  } VMStruct;
  
  
  #define VMPageSize(vm) RVALUE((vm)->pageSize)
  #define VMBase(vm) RVALUE((vm)->base)
  #define VMLimit(vm) RVALUE((vm)->limit)
  #define VMReserved(vm) RVALUE((vm)->reserved)
  #define VMMapped(vm) RVALUE((vm)->mapped)
  
  extern Size PageSize(void);
  extern Size (VMPageSize)(VM vm);
  extern Bool VMCheck(VM vm);
  extern Res VMParamFromArgs(void *params, size_t paramSize, ArgList args);
  extern Res VMInit(VM vmReturn, Size size, Size grainSize, void *params);
  extern void VMFinish(VM vm);
  extern Addr (VMBase)(VM vm);
  extern Addr (VMLimit)(VM vm);
  extern Res VMMap(VM vm, Addr base, Addr limit);
  extern void VMUnmap(VM vm, Addr base, Addr limit);
  extern Size (VMReserved)(VM vm);
  extern Size (VMMapped)(VM vm);
  extern void VMCopy(VM dest, VM src);
  
  
  #endif /* vm_h */
  
  
  /* C. COPYRIGHT AND LICENSE
   *
   * Copyright (C) 2014 Ravenbrook Limited <http://www.ravenbrook.com/>.
   * All rights reserved.  This is an open source license.  Contact
   * Ravenbrook for commercial licensing options.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   * 
   * 1. Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   * 
   * 2. Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   * 
   * 3. Redistributions in any form must be accompanied by information on how
   * to obtain complete source code for this software and any accompanying
   * software that uses this software.  The source code must either be
   * included in the distribution or be available for no more than the cost
   * of distribution plus a nominal fee, and must be freely redistributable
   * under reasonable conditions.  For an executable file, complete source
   * code means the source code for all modules it contains. It does not
   * include source code for modules or files that typically accompany the
   * major components of the operating system on which the executable file
   * runs.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
   * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
   * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  