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 extern PEPROCESS PsIdleProcess;
  20
  21 /* FUNCTIONS *****************************************************************/
  22
  23 /** System idle thread procedure
  24  *
  25  */
  26 VOID STDCALL
  27 PsIdleThreadMain(PVOID Context)
  28 {
  29    KIRQL oldlvl;
  30
  31    PKPRCB Prcb = KeGetCurrentPrcb();
  32
  33    for(;;)
  34      {
  35        if (Prcb->DpcData[0].DpcQueueDepth > 0)
  36          {
  37            KeRaiseIrql(DISPATCH_LEVEL,&oldlvl);
  38            KiDispatchInterrupt();
  39            KeLowerIrql(oldlvl);
  40          }
  41
  42        NtYieldExecution();
  43
  44        Ke386HaltProcessor();
  45      }
  46 }
  47
  48
  49 /** Initialization of system idle thread
  50  *
  51  */
  52 VOID INIT_FUNCTION
  53 PsInitIdleThread(VOID)
  54 {
  55    NTSTATUS Status;
  56    PETHREAD IdleThread;
  57    KIRQL oldIrql;
  58
  59    Status = PsInitializeThread(PsIdleProcess,
  60                                &IdleThread,
  61                                NULL,
  62                                KernelMode,
  63                                FALSE);
  64    if (!NT_SUCCESS(Status))
  65      {
  66         DPRINT1("Couldn't create idle system thread! Status: 0x%x\n", Status);
  67         KEBUGCHECK(0);
  68         return;
  69      }
  70
  71    IdleThread->StartAddress = PsIdleThreadMain;
  72    Status = KiArchInitThread(&IdleThread->Tcb, PsIdleThreadMain, NULL);
  73    if (!NT_SUCCESS(Status))
  74      {
  75         DPRINT1("Couldn't initialize system idle thread! Status: 0x%x\n", Status);
  76         ObDereferenceObject(IdleThread);
  77         KEBUGCHECK(0);
  78         return;
  79      }
  80
  81    oldIrql = KeAcquireDispatcherDatabaseLock ();
  82    PsUnblockThread(IdleThread, NULL, 0);
  83    KeReleaseDispatcherDatabaseLock(oldIrql);
  84
  85    KeGetCurrentPrcb()->IdleThread = &IdleThread->Tcb;
  86    KeSetPriorityThread(&IdleThread->Tcb, LOW_PRIORITY);
  87    KeSetAffinityThread(&IdleThread->Tcb, 1 << 0);
  88
  89 }