reactos/subsys/win32k/eng/mem.c

   1 /*
   2  *  ReactOS W32 Subsystem
   3  *  Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 ReactOS Team
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /* $Id$
  20  *
  21  * COPYRIGHT:         See COPYING in the top level directory
  22  * PROJECT:           ReactOS kernel
  23  * PURPOSE:           GDI Driver Memory Management Functions
  24  * FILE:              subsys/win32k/eng/mem.c
  25  * PROGRAMER:         Jason Filby
  26  * REVISION HISTORY:
  27  *                 3/7/1999: Created
  28  */
  29
  30 #include <w32k.h>
  31
  32 #define NDEBUG
  33 #include <debug.h>
  34
  35 typedef struct _USERMEMHEADER
  36   {
  37   ULONG Tag;
  38   ULONG MemSize;
  39   }
  40 USERMEMHEADER, *PUSERMEMHEADER;
  41
  42 /*
  43  * @implemented
  44  */
  45 PVOID STDCALL
  46 EngAllocMem(ULONG Flags,
  47             ULONG MemSize,
  48             ULONG Tag)
  49 {
  50   PVOID newMem;
  51
  52   newMem = ExAllocatePoolWithTag(PagedPool, MemSize, Tag);
  53
  54   if (Flags == FL_ZERO_MEMORY && NULL != newMem)
  55   {
  56     RtlZeroMemory(newMem, MemSize);
  57   }
  58
  59   return newMem;
  60 }
  61
  62 /*
  63  * @implemented
  64  */
  65 VOID STDCALL
  66 EngFreeMem(PVOID Mem)
  67 {
  68   ExFreePool(Mem);
  69 }
  70
  71 /*
  72  * @implemented
  73  */
  74 PVOID STDCALL
  75 EngAllocUserMem(ULONG cj, ULONG Tag)
  76 {
  77   PVOID NewMem = NULL;
  78   NTSTATUS Status;
  79   ULONG MemSize = sizeof(USERMEMHEADER) + cj;
  80   PUSERMEMHEADER Header;
  81
  82   Status = ZwAllocateVirtualMemory(NtCurrentProcess(), &NewMem, 0, &MemSize, MEM_COMMIT, PAGE_READWRITE);
  83
  84   if (! NT_SUCCESS(Status))
  85     {
  86       return NULL;
  87     }
  88
  89   Header = (PUSERMEMHEADER) NewMem;
  90   Header->Tag = Tag;
  91   Header->MemSize = cj;
  92
  93   return (PVOID)(Header + 1);
  94 }
  95
  96 /*
  97  * @implemented
  98  */
  99 VOID STDCALL
 100 EngFreeUserMem(PVOID pv)
 101 {
 102   PUSERMEMHEADER Header = ((PUSERMEMHEADER) pv) - 1;
 103   ULONG MemSize = sizeof(USERMEMHEADER) + Header->MemSize;
 104
 105   ZwFreeVirtualMemory(NtCurrentProcess(), (PVOID *) &Header, &MemSize, MEM_DECOMMIT);
 106 }
 107
 108 /*
 109  * @implemented
 110  */
 111 HANDLE STDCALL
 112 EngSecureMem(PVOID Address, ULONG Length)
 113 {
 114   return MmSecureVirtualMemory(Address, Length, PAGE_READWRITE);
 115 }
 116
 117 /*
 118  * @implemented
 119  */
 120 VOID STDCALL
 121 EngUnsecureMem(HANDLE Mem)
 122 {
 123   return MmUnsecureVirtualMemory((PVOID) Mem);
 124 }
 125
 126 /* EOF */