IoAllocateController function (ntddk.h)
The IoAllocateController routine sets up the call to a driver-supplied ControllerControl routine as soon as the device controller, represented by the given controller object, is available to carry out an I/O operation for the target device, represented by the given device object.
Syntax
void IoAllocateController(
[in] PCONTROLLER_OBJECT ControllerObject,
[in] PDEVICE_OBJECT DeviceObject,
[in] PDRIVER_CONTROL ExecutionRoutine,
[in, optional] PVOID Context
);
Parameters
[in] ControllerObject
Pointer to a driver-created controller object, usually representing a physical controller to be allocated for an I/O operation on an attached device.
[in] DeviceObject
Pointer to the device object, representing the target device of the current IRP.
[in] ExecutionRoutine
Pointer to the driver-supplied ControllerControl routine.
[in, optional] Context
Pointer to a driver-determined context, passed to the driver's ControllerControl routine when it is called.
Return value
None
Remarks
This routine reserves exclusive access to the hardware controller for the specified device.
The ControllerControl routine returns a value indicating whether the controller remains allocated to the device, either DeallocateObject or KeepObject. If it returns KeepObject, the driver must subsequently call IoFreeController to release the controller object.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available starting with Windows 2000. |
| Target Platform | Universal |
| Header | ntddk.h (include Ntddk.h) |
| Library | NtosKrnl.lib |
| DLL | NtosKrnl.exe |
| IRQL | DISPATCH_LEVEL |
| DDI compliance rules | HwStorPortProhibitedDDIs(storport), IrqlDispatch(storport), IrqlDispatch(storport), IrqlDispatch(wdm), SpNoWait(storport), StorPortStartIo(storport) |