ntoskrnl/mm/mpw.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 1998, 1999, 2000, 2001 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  * PROJECT:      ReactOS kernel
  22  * FILE:         ntoskrnl/mm/mpw.c
  23  * PURPOSE:      Writes data that has been modified in memory but not on
  24  *               the disk
  25  * PROGRAMMER:   David Welch (welch@cwcom.net)
  26  * UPDATE HISTORY:
  27  *               27/05/98: Created
  28  */
  29
  30 /* INCLUDES ****************************************************************/
  31
  32 #include <ddk/ntddk.h>
  33 #include <internal/ps.h>
  34 #include <internal/mm.h>
  35 #include <internal/cc.h>
  36
  37 #define NDEBUG
  38 #include <internal/debug.h>
  39
  40 /* GLOBALS *******************************************************************/
  41
  42 static HANDLE MpwThreadHandle;
  43 static CLIENT_ID MpwThreadId;
  44 static KEVENT MpwThreadEvent;
  45 static volatile BOOLEAN MpwThreadShouldTerminate;
  46
  47 /* FUNCTIONS *****************************************************************/
  48
  49 NTSTATUS STDCALL
  50 MmWriteDirtyPages(ULONG Target, PULONG Actual)
  51 {
  52   PHYSICAL_ADDRESS Page;
  53   PHYSICAL_ADDRESS NextPage;
  54   NTSTATUS Status;
  55
  56   Page = MmGetLRUFirstUserPage();
  57   while (Page.QuadPart != 0LL && Target > 0)
  58     {
  59       NextPage = MmGetLRUNextUserPage(Page);
  60       if (MmIsDirtyPageRmap(Page))
  61         {
  62           Status = MmWritePagePhysicalAddress(Page);
  63           if (NT_SUCCESS(Status))
  64             {
  65               Target--;
  66             }
  67         }
  68       Page = NextPage;
  69     }
  70   *Actual = Target;
  71   return(STATUS_SUCCESS);
  72 }
  73
  74 NTSTATUS STDCALL
  75 MmMpwThreadMain(PVOID Ignored)
  76 {
  77   NTSTATUS Status;
  78   ULONG PagesWritten;
  79   LARGE_INTEGER Timeout;
  80
  81   Timeout.QuadPart = -50000000;
  82
  83   for(;;)
  84     {
  85       Status = KeWaitForSingleObject(&MpwThreadEvent,
  86                                      0,
  87                                      KernelMode,
  88                                      FALSE,
  89                                      &Timeout);
  90       if (!NT_SUCCESS(Status))
  91         {
  92           DbgPrint("MpwThread: Wait failed\n");
  93           KeBugCheck(0);
  94           return(STATUS_UNSUCCESSFUL);
  95         }
  96       if (MpwThreadShouldTerminate)
  97         {
  98           DbgPrint("MpwThread: Terminating\n");
  99           return(STATUS_SUCCESS);
 100         }
 101
 102       PagesWritten = 0;
 103       MmWriteDirtyPages(128, &PagesWritten);
 104       CcRosFlushDirtyPages(128, &PagesWritten);
 105     }
 106 }
 107
 108 NTSTATUS MmInitMpwThread(VOID)
 109 {
 110   KPRIORITY Priority;
 111   NTSTATUS Status;
 112
 113   MpwThreadShouldTerminate = FALSE;
 114   KeInitializeEvent(&MpwThreadEvent, SynchronizationEvent, FALSE);
 115
 116   Status = PsCreateSystemThread(&MpwThreadHandle,
 117                                 THREAD_ALL_ACCESS,
 118                                 NULL,
 119                                 NULL,
 120                                 &MpwThreadId,
 121                                 MmMpwThreadMain,
 122                                 NULL);
 123   if (!NT_SUCCESS(Status))
 124     {
 125       return(Status);
 126      }
 127
 128   Priority = 1;
 129   NtSetInformationThread(MpwThreadHandle,
 130                          ThreadPriority,
 131                          &Priority,
 132                          sizeof(Priority));
 133
 134   return(STATUS_SUCCESS);
 135 }