| title | IClientVirtualDevice::GetCommand |
|---|---|
| titlesuffix | SQL Server VDI reference |
| description | This article provides reference for the IClientVirtualDevice::GetCommand command. |
| ms.date | 08/30/2019 |
| ms.prod | sql |
| ms.prod_service | backup-restore |
| ms.technology | backup-restore |
| ms.topic | reference |
| author | mashamsft |
| ms.author | mathoma |
[!INCLUDEappliesto-ss-xxxx-xxxx-xxx-md]
The GetCommand function is used to obtain the next command queued to a device. When requested, this function waits for the next command.
HRESULT IClientVirtualDevice::GetCommand (
DWORD dwTimeOut,
VDC_Command** const ppCmd
);ppCmd When a command is successfully returned, the parameter returns the address of a command to execute. The memory returned is read-only. When the command is completed, this pointer is passed to the CompleteCommand routine. For more information about each command, see Commands.
dwTimeOut This is the time to wait, in milliseconds. Use INFINTE to wait indefinitely. Use 0 to poll for a command. VD_E_TIMEOUT is returned if no command is currently available. If the time-out occurs, the client decides the next action.
| Return Value | Explanation |
|---|---|
| NOERROR | A command was fetched. |
| VD_E_CLOSE | The device has been closed by the server. |
| VD_E_TIMEOUT | No command was available and the time-out expired. |
| VD_E_ABORT | Either the client or the server has used the SignalAbort to force a shutdown. |
When VD_E_CLOSE is returned, SQL Server has closed the device. This is part of the normal shutdown. After all devices have been closed, the client invokes IClientVirtualDeviceSet2::Close to close the virtual device set.
When this routine must block to wait for a command, the thread is left in an Alertable condition.
For more information, see the SQL Server virtual device interface reference overview.