reactos/ntoskrnl/ps/idle.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/ps/idle.c
   6  * PURPOSE:         Using idle time
   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 /* FUNCTIONS *****************************************************************/
  20
  21 /** System idle thread procedure
  22  *
  23  */
  24 VOID STDCALL
  25 PsIdleThreadMain(PVOID Context)
  26 {
  27    KIRQL oldlvl;
  28
  29    PKPCR Pcr = KeGetCurrentKPCR();
  30
  31    for(;;)
  32      {
  33        if (Pcr->PrcbData.DpcData[0].DpcQueueDepth > 0)
  34          {
  35            KeRaiseIrql(DISPATCH_LEVEL,&oldlvl);
  36            KiDispatchInterrupt();
  37            KeLowerIrql(oldlvl);
  38          }
  39
  40        NtYieldExecution();
  41
  42        Ke386HaltProcessor();
  43      }
  44 }
  45
  46
  47 /** Initialization of system idle thread
  48  *
  49  */
  50 VOID INIT_FUNCTION
  51 PsInitIdleThread(VOID)
  52 {
  53    NTSTATUS Status;
  54    PETHREAD IdleThread;
  55    HANDLE IdleThreadHandle;
  56
  57    Status = PsCreateSystemThread(&IdleThreadHandle,
  58                         THREAD_ALL_ACCESS,
  59                         NULL,
  60                         NULL,
  61                         NULL,
  62                         PsIdleThreadMain,
  63                         NULL);
  64    if(!NT_SUCCESS(Status))
  65    {
  66         DPRINT("Couldn't create Idle System Thread!");
  67         KEBUGCHECK(0);
  68         return;
  69    }
  70    Status = ObReferenceObjectByHandle(IdleThreadHandle,
  71                                       THREAD_ALL_ACCESS,
  72                                       PsThreadType,
  73                                       KernelMode,
  74                                       (PVOID*)&IdleThread,
  75                                       NULL);
  76    if(!NT_SUCCESS(Status))
  77    {
  78         DPRINT("Couldn't get pointer to Idle System Thread!");
  79         KEBUGCHECK(0);
  80         return;
  81    }
  82    NtClose(IdleThreadHandle);
  83    KeGetCurrentKPCR()->PrcbData.IdleThread = &IdleThread->Tcb;
  84    KeSetPriorityThread(&IdleThread->Tcb, LOW_PRIORITY);
  85    KeSetAffinityThread(&IdleThread->Tcb, 1 << 0);
  86
  87 }