IoStartNextPacket

The IoStartNextPacket routine dequeues the next IRP, if any, from the given device object’s associated device queue and calls the driver’s StartIo routine.

VOID 
  IoStartNextPacket(
    IN PDEVICE_OBJECT  DeviceObject,
    IN BOOLEAN  Cancelable
    );

Parameters

DeviceObject

Pointer to the device object for which the IRP is to be dequeued.

Cancelable

Specifies whether IRPs in the device queue can be canceled.

Return Value

None

Headers

Declared in wdm.h and ntddk.h. Include wdm.h or ntddk.h.

Comments

If there are no IRPs currently in the device queue for the target DeviceObject, this routine simply returns control to the caller.

If the driver passed a pointer to a cancel routine when it called IoStartPacket, it should pass TRUE in the Cancelable parameter. If Cancelable is TRUE, the I/O Manager will use the cancel spin lock to protect the device queue and the current IRP.

Drivers that do not have a StartIo routine cannot call IoStartNextPacket.

Callers of IoStartNextPacket must be running at IRQL = DISPATCH_LEVEL. Usually, this routine is called from a device driver’s DpcForIsr or CustomDpc routine, both of which are run at IRQL =DISPATCH_LEVEL.

See Also

DEVICE_OBJECT, IoStartNextPacketByKey, IoStartPacket