reactos/ntoskrnl/ke/dpc.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnl/ke/dpc.c
   5  * PURPOSE:         Handle DPCs (Delayed Procedure Calls)
   6  * PROGRAMMER:      David Welch (welch@mcmail.com)
   7  * UPDATE HISTORY:
   8  *                28/05/98: Created
   9  */
  10
  11 /*
  12  * NOTE: See also the higher level support routines in ntoskrnl/io/dpc.c
  13  */
  14
  15 /* INCLUDES ***************************************************************/
  16
  17 #include <ddk/ntddk.h>
  18
  19 #define NDEBUG
  20 #include <internal/debug.h>
  21
  22 /* TYPES *******************************************************************/
  23
  24 /* GLOBALS ******************************************************************/
  25
  26 static LIST_ENTRY DpcQueueHead={NULL,NULL};
  27 static KSPIN_LOCK DpcQueueLock={0,};
  28
  29 /* FUNCTIONS ****************************************************************/
  30
  31 VOID KeInitializeDpc(PKDPC Dpc, PKDEFERRED_ROUTINE DeferredRoutine,
  32                      PVOID DeferredContext)
  33 /*
  34  * FUNCTION: Initalizes a DPC
  35  * ARGUMENTS:
  36  *          Dpc = Caller supplied DPC to be initialized
  37  *          DeferredRoutine = Associated DPC callback
  38  *          DeferredContext = Parameter to be passed to the callback
  39  * NOTE: Callers must be running at IRQL PASSIVE_LEVEL
  40  */
  41 {
  42    Dpc->Type=0;
  43    Dpc->DeferredRoutine=DeferredRoutine;
  44    Dpc->DeferredContext=DeferredContext;
  45    Dpc->Lock=0;
  46 }
  47
  48 void KeDrainDpcQueue(void)
  49 /*
  50  * FUNCTION: Called to execute queued dpcs
  51  */
  52 {
  53    PLIST_ENTRY current_entry;
  54    PKDPC current;
  55
  56
  57    KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
  58    current_entry = RemoveHeadList(&DpcQueueHead);
  59    current = CONTAINING_RECORD(current_entry,KDPC,DpcListEntry);
  60    while (current_entry!=(&DpcQueueHead))
  61      {
  62         CHECKPOINT;
  63         current->DeferredRoutine(current,current->DeferredContext,
  64                                  current->SystemArgument1,
  65                                  current->SystemArgument2);
  66         current->Lock=FALSE;
  67         current_entry = RemoveHeadList(&DpcQueueHead);
  68         current = CONTAINING_RECORD(&current_entry,KDPC,DpcListEntry);
  69      }
  70    KeReleaseSpinLockFromDpcLevel(&DpcQueueLock);
  71 //   DPRINT("Finished KeDrainDpcQueue()\n",0);
  72 }
  73
  74 BOOLEAN KeRemoveQueueDpc(PKDPC Dpc)
  75 /*
  76  * FUNCTION: Removes DPC object from the system dpc queue
  77  * ARGUMENTS:
  78  *          Dpc = DPC to remove
  79  * RETURNS: TRUE if the DPC was in the queue
  80  *          FALSE otherwise
  81  */
  82 {
  83    if (!Dpc->Lock)
  84      {
  85         return(FALSE);
  86      }
  87    RemoveEntryList(&Dpc->DpcListEntry);
  88    Dpc->Lock=0;
  89    return(TRUE);
  90 }
  91
  92 BOOLEAN KeInsertQueueDpc(PKDPC dpc, PVOID SystemArgument1,
  93                          PVOID SystemArgument2)
  94 /*
  95  * FUNCTION: Queues a DPC for execution when the IRQL of a processor
  96  * drops below DISPATCH_LEVEL
  97  * ARGUMENTS:
  98  *          Dpc = Initalizes DPC
  99  *          SystemArguments[1-2] = Undocumented
 100  * RETURNS: TRUE if the DPC object wasn't already in the queue
 101  *          FALSE otherwise
 102  */
 103 {
 104    DPRINT("KeInsertQueueDpc()\n",0);
 105    assert(KeGetCurrentIrql()>=DISPATCH_LEVEL);
 106
 107    dpc->Number=0;
 108    dpc->Importance=Medium;
 109    dpc->SystemArgument1=SystemArgument1;
 110    dpc->SystemArgument2=SystemArgument2;
 111    if (dpc->Lock)
 112      {
 113         return(FALSE);
 114      }
 115    KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
 116    InsertHeadList(&DpcQueueHead,&dpc->DpcListEntry);
 117    KeReleaseSpinLockFromDpcLevel(&DpcQueueLock);
 118    dpc->Lock=(PULONG)1;
 119    DPRINT("DpcQueueHead.Flink %x\n",DpcQueueHead.Flink);
 120    DPRINT("Leaving KeInsertQueueDpc()\n",0);
 121    return(TRUE);
 122 }
 123
 124 void KeInitDpc(void)
 125 /*
 126  * FUNCTION: Initialize DPC handling
 127  */
 128 {
 129    InitializeListHead(&DpcQueueHead);
 130 }
 131
 132