IFSMgr_Block( unsigned long key )
This service has been provided for FSDs to block a thread, for instance when asynchronous requests are being processed. An FSD can call this service with the key to block waiting for an event to complete. This service does not return until the corresponding wake call has been issued on the blocked key via the IFSMgr_Wakeup service. Event processing is enabled while this block is in progress.
key
Suppplies unique identification for the caller of the service. Usually, the address of the appropriate structure itself is passed in as the key so that a wakeup request can be matched with the block request.