reactos/ntoskrnl/mm/pager.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/mm/pager.c
   6  * PURPOSE:         Moves infrequently used data out of memory
   7  *
   8  * PROGRAMMERS:     David Welch (welch@cwcom.net)
   9  */
  10
  11 /* INCLUDES ****************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 /* GLOBALS *******************************************************************/
  18
  19 #if 0
  20 static HANDLE PagerThreadHandle;
  21 static CLIENT_ID PagerThreadId;
  22 static KEVENT PagerThreadEvent;
  23 static BOOLEAN PagerThreadShouldTerminate;
  24 static ULONG PagerThreadWorkCount;
  25 #endif
  26
  27 /* FUNCTIONS *****************************************************************/
  28
  29 #if 0
  30 BOOLEAN
  31 MiIsPagerThread(VOID)
  32 {
  33    return(PsGetCurrentThreadId() == PagerThreadId.UniqueThread);
  34 }
  35
  36 VOID
  37 MiStartPagerThread(VOID)
  38 {
  39    ULONG WasWorking;
  40
  41    WasWorking = InterlockedIncrement(&PagerThreadWorkCount);
  42    if (WasWorking == 1)
  43    {
  44       KeSetEvent(&PagerThreadEvent, IO_NO_INCREMENT, FALSE);
  45    }
  46 }
  47
  48 VOID
  49 MiStopPagerThread(VOID)
  50 {
  51    (VOID)InterlockedDecrement(&PagerThreadWorkCount);
  52 }
  53
  54 static NTSTATUS STDCALL
  55 MmPagerThreadMain(PVOID Ignored)
  56 {
  57    NTSTATUS Status;
  58
  59    for(;;)
  60    {
  61       /* Wake for a low memory situation or a terminate request. */
  62       Status = KeWaitForSingleObject(&PagerThreadEvent,
  63                                      0,
  64                                      KernelMode,
  65                                      FALSE,
  66                                      NULL);
  67       if (!NT_SUCCESS(Status))
  68       {
  69          DbgPrint("PagerThread: Wait failed\n");
  70          KEBUGCHECK(0);
  71       }
  72       if (PagerThreadShouldTerminate)
  73       {
  74          DbgPrint("PagerThread: Terminating\n");
  75          return(STATUS_SUCCESS);
  76       }
  77       do
  78       {
  79          /* Try and make some memory available to the system. */
  80          MmRebalanceMemoryConsumers();
  81       }
  82       while(PagerThreadWorkCount > 0);
  83    }
  84 }
  85
  86 NTSTATUS MmInitPagerThread(VOID)
  87 {
  88    NTSTATUS Status;
  89
  90    PagerThreadShouldTerminate = FALSE;
  91    PagerThreadWorkCount = 0;
  92    KeInitializeEvent(&PagerThreadEvent,
  93                      SynchronizationEvent,
  94                      FALSE);
  95
  96    Status = PsCreateSystemThread(&PagerThreadHandle,
  97                                  THREAD_ALL_ACCESS,
  98                                  NULL,
  99                                  NULL,
 100                                  &PagerThreadId,
 101                                  (PKSTART_ROUTINE) MmPagerThreadMain,
 102                                  NULL);
 103    if (!NT_SUCCESS(Status))
 104    {
 105       return(Status);
 106    }
 107
 108    return(STATUS_SUCCESS);
 109 }
 110 #endif