irp cancelation boiler plate, for irp queues you manage yourself
Added: trunk/reactos/doc/irp cancel boilerplate.c
_____
Added: trunk/reactos/doc/irp cancel boilerplate.c
--- trunk/reactos/doc/irp cancel boilerplate.c 2005-03-06 12:37:31 UTC
(rev 13851)
+++ trunk/reactos/doc/irp cancel boilerplate.c 2005-03-06 13:41:18 UTC
(rev 13852)
@@ -0,0 +1,102 @@
+
+
+/*
+Boiler plate for irp cancelation, for irp queues you manage yourself
+-Gunnar
+*/
+
+
+
+CancelRoutine(
+ DEV_OBJ Dev,
+ Irp
+ )
+{
+ //don't need this since we have our own sync. protecting irp
cancellation
+ IoReleaseCancelSpinLock(Irp->CancelIrql);
+
+ theLock = Irp->Tail.Overlay.DriverContext[3];
+
+ Lock(theLock);
+ RemoveEntryList(&Irp->Tail.Overlay.ListEntry);
+ Unlock(theLock);
+
+ Irp->IoStatus.Status = STATUS_CANCELLED;
+ Irp->IoStatus.Information = 0;
+
+ IoCompleteRequest(Irp, IO_NO_INCREMENT);
+
+}
+
+
+QUEUE_BOLIERPLATE
+{
+ Lock(theLock);
+
+ Irp->Tail.Overlay.DriverContext[3] = &theLock;
+
+ IoSetCancelRoutine(Irp, CancelRoutine);
+ if (Irp->Cancel && IoSetCancelRoutine(Irp, NULL))
+ {
+ // IRP has already been cancelled (before we got to queue it),
+ // but we got to remove the cancel routine before the canceler
could,
+ // so complete irp ourself
+
+ Unlock(theLock);
+
+ Irp->IoStatus.Status = STATUS_CANCELLED;
+ Irp->IoStatus.Information = 0;
+ IoCompleteRequest(Irp, IO_NO_INCREMENT);
+
+ return FALSE;
+ }
+
+ //else were ok
+
+
+ Irp->IoStatus.Status = STATUS_PENDING;
+ IoMarkIrpPending(Irp);
+
+ InsertTailList(Queue);
+
+ Unlock(theLock);
+
+}
+
+
+DEQUEUE_BOILERPLATE
+{
+ Lock(theLock);
+
+ Irp = RemoveHeadList(Queue);
+
+ if (!IoSetCancelRoutine(Irp, NULL))
+ {
+ /*
+ Cancel routine WILL be called after we release the spinlock. It
will try to remove
+ the irp from the list and cancel/complete this irp. Since we
allready removed it,
+ make its ListEntry point to itself.
+ */
+
+ InitializeListHead(&Irp->Tail.Overlay.ListEntry);
+ }
+
+
+ /*
+ Cancel routine will NOT be called, canceled or not.
+ The Irp might have been canceled (Irp->Cancel flag set) but we don't
care,
+ since we are to complete this Irp now anyways.
+ */
+
+ Unlock(theLock);
+
+ Irp->IoStatus.Status = STATUS_SUCCESS;
+ Irp->IoStatus.Information = 0;
+ IoCompleteRequest(Irp, IO_NO_INCREMENT);
+
+}
+
+
+
+
+
\ No newline at end of file