reactos/drivers/storage/classpnp/clntirp.c

   1 /*++
   2
   3 Copyright (C) Microsoft Corporation, 1991 - 1999
   4
   5 Module Name:
   6
   7     clntirp.c
   8
   9 Abstract:
  10
  11     Client IRP queuing routines for CLASSPNP
  12
  13 Environment:
  14
  15     kernel mode only
  16
  17 Notes:
  18
  19
  20 Revision History:
  21
  22 --*/
  23
  24 #include "classp.h"
  25 #include "debug.h"
  26
  27
  28 /*
  29  *  EnqueueDeferredClientIrp
  30  *
  31  *      Note: we currently do not support Cancel for storage irps.
  32  */
  33 VOID EnqueueDeferredClientIrp(PCLASS_PRIVATE_FDO_DATA FdoData, PIRP Irp)
  34 {
  35     KIRQL oldIrql;
  36
  37     KeAcquireSpinLock(&FdoData->SpinLock, &oldIrql);
  38     InsertTailList(&FdoData->DeferredClientIrpList, &Irp->Tail.Overlay.ListEntry);
  39     KeReleaseSpinLock(&FdoData->SpinLock, oldIrql);
  40 }
  41
  42
  43 /*
  44  *  DequeueDeferredClientIrp
  45  *
  46  */
  47 PIRP DequeueDeferredClientIrp(PCLASS_PRIVATE_FDO_DATA FdoData)
  48 {
  49     KIRQL oldIrql;
  50     PLIST_ENTRY listEntry;
  51     PIRP irp;
  52
  53     KeAcquireSpinLock(&FdoData->SpinLock, &oldIrql);
  54     if (IsListEmpty(&FdoData->DeferredClientIrpList)){
  55         listEntry = NULL;
  56     }
  57     else {
  58         listEntry = RemoveHeadList(&FdoData->DeferredClientIrpList);
  59     }
  60     KeReleaseSpinLock(&FdoData->SpinLock, oldIrql);
  61
  62     if (listEntry == NULL) {
  63         irp = NULL;
  64     } else {
  65         irp = CONTAINING_RECORD(listEntry, IRP, Tail.Overlay.ListEntry);
  66         ASSERT(irp->Type == IO_TYPE_IRP);
  67         InitializeListHead(&irp->Tail.Overlay.ListEntry);
  68     }
  69
  70     return irp;
  71 }
  72
  73
  74