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  *                12/3/99:  Phillip Susi: Fixed IRQL problem
  10  */
  11
  12 /*
  13  * NOTE: See also the higher level support routines in ntoskrnl/io/dpc.c
  14  */
  15
  16 /* INCLUDES ***************************************************************/
  17
  18 #include <ddk/ntddk.h>
  19
  20 #define NDEBUG
  21 #include <internal/debug.h>
  22
  23 /* TYPES *******************************************************************/
  24
  25 /* GLOBALS ******************************************************************/
  26
  27 static LIST_ENTRY DpcQueueHead;
  28 static KSPIN_LOCK DpcQueueLock;
  29 ULONG DpcQueueSize = 0;
  30
  31 /* FUNCTIONS ****************************************************************/
  32
  33 VOID STDCALL KeInitializeDpc (PKDPC                     Dpc,
  34                               PKDEFERRED_ROUTINE        DeferredRoutine,
  35                               PVOID                     DeferredContext)
  36 /*
  37  * FUNCTION: Initalizes a DPC
  38  * ARGUMENTS:
  39  *          Dpc = Caller supplied DPC to be initialized
  40  *          DeferredRoutine = Associated DPC callback
  41  *          DeferredContext = Parameter to be passed to the callback
  42  * NOTE: Callers must be running at IRQL PASSIVE_LEVEL
  43  */
  44 {
  45    Dpc->Type=0;
  46    Dpc->DeferredRoutine=DeferredRoutine;
  47    Dpc->DeferredContext=DeferredContext;
  48    Dpc->Lock=0;
  49 }
  50
  51 VOID KeDrainDpcQueue(VOID)
  52 /*
  53  * FUNCTION: Called to execute queued dpcs
  54  */
  55 {
  56    PLIST_ENTRY current_entry;
  57    PKDPC current;
  58    KIRQL oldlvl;
  59
  60    assert_irql(DISPATCH_LEVEL);
  61
  62    if (DpcQueueSize == 0)
  63      {
  64         return;
  65      }
  66    DPRINT("KeDrainDpcQueue()\n");
  67
  68    KeRaiseIrql(HIGH_LEVEL, &oldlvl);
  69    KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
  70    current_entry = RemoveHeadList(&DpcQueueHead);
  71    KeReleaseSpinLockFromDpcLevel(&DpcQueueLock);
  72    KeLowerIrql(oldlvl);
  73    current = CONTAINING_RECORD(current_entry,KDPC,DpcListEntry);
  74    while (current_entry!=(&DpcQueueHead))
  75      {
  76         CHECKPOINT;
  77         DPRINT("DpcQueueSize %d current %x current->DeferredContext %x\n",
  78                DpcQueueSize, current, current->DeferredContext);
  79         DPRINT("current->Flink %x\n", current->DpcListEntry.Flink);
  80         current->DeferredRoutine(current,current->DeferredContext,
  81                                  current->SystemArgument1,
  82                                  current->SystemArgument2);
  83         CHECKPOINT;
  84         current->Lock=FALSE;
  85         KeRaiseIrql(HIGH_LEVEL, &oldlvl);
  86         KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
  87         current_entry = RemoveHeadList(&DpcQueueHead);
  88         DPRINT("current_entry %x\n", current_entry);
  89         DpcQueueSize--;
  90         KeReleaseSpinLockFromDpcLevel(&DpcQueueLock);
  91         KeLowerIrql(oldlvl);
  92         current = CONTAINING_RECORD(current_entry,KDPC,DpcListEntry);
  93         DPRINT("current %x\n", current);
  94      }
  95 }
  96
  97 BOOLEAN STDCALL KeRemoveQueueDpc (PKDPC Dpc)
  98 /*
  99  * FUNCTION: Removes DPC object from the system dpc queue
 100  * ARGUMENTS:
 101  *          Dpc = DPC to remove
 102  * RETURNS: TRUE if the DPC was in the queue
 103  *          FALSE otherwise
 104  */
 105 {
 106    KIRQL oldIrql;
 107
 108    KeAcquireSpinLockAtDpcLevel( &DpcQueueLock );
 109    KeRaiseIrql( HIGH_LEVEL, &oldIrql );
 110    if (!Dpc->Lock)
 111      {
 112         KeReleaseSpinLock(&DpcQueueLock, oldIrql);
 113         return(FALSE);
 114      }
 115    RemoveEntryList(&Dpc->DpcListEntry);
 116    DpcQueueSize--;
 117    Dpc->Lock=0;
 118    KeReleaseSpinLock(&DpcQueueLock, oldIrql);
 119    return(TRUE);
 120 }
 121
 122 BOOLEAN STDCALL KeInsertQueueDpc (PKDPC Dpc,
 123                                   PVOID SystemArgument1,
 124                                   PVOID SystemArgument2)
 125 /*
 126  * FUNCTION: Queues a DPC for execution when the IRQL of a processor
 127  * drops below DISPATCH_LEVEL
 128  * ARGUMENTS:
 129  *          Dpc = Initalizes DPC
 130  *          SystemArguments[1-2] = Undocumented
 131  * RETURNS: TRUE if the DPC object wasn't already in the queue
 132  *          FALSE otherwise
 133  */
 134 {
 135    KIRQL oldlvl;
 136    DPRINT("KeInsertQueueDpc(dpc %x, SystemArgument1 %x, SystemArgument2 %x)\n",
 137           Dpc, SystemArgument1, SystemArgument2);
 138
 139    assert(KeGetCurrentIrql()>=DISPATCH_LEVEL);
 140
 141    Dpc->Number=0;
 142    Dpc->Importance=Medium;
 143    Dpc->SystemArgument1=SystemArgument1;
 144    Dpc->SystemArgument2=SystemArgument2;
 145    if (Dpc->Lock)
 146      {
 147         return(FALSE);
 148      }
 149    KeRaiseIrql( HIGH_LEVEL, &oldlvl );
 150    KeAcquireSpinLockAtDpcLevel(&DpcQueueLock);
 151    InsertHeadList(&DpcQueueHead,&Dpc->DpcListEntry);
 152    DPRINT("Dpc->DpcListEntry.Flink %x\n", Dpc->DpcListEntry.Flink);
 153    DpcQueueSize++;
 154    Dpc->Lock=(PULONG)1;
 155    KeReleaseSpinLock( &DpcQueueLock, oldlvl );
 156    DPRINT("DpcQueueHead.Flink %x\n",DpcQueueHead.Flink);
 157    DPRINT("Leaving KeInsertQueueDpc()\n",0);
 158    return(TRUE);
 159 }
 160
 161 VOID KeInitDpc(VOID)
 162 /*
 163  * FUNCTION: Initialize DPC handling
 164  */
 165 {
 166    InitializeListHead(&DpcQueueHead);
 167    KeInitializeSpinLock(&DpcQueueLock);
 168 }
 169