> Because the NT OS/2 I/O system is asynchronous by nature, the ability to make a
request and then have it completed at a later time makes it natural for implementing
oplocks. Further, because synchronization is required by the file system to determine
when the caller has completed its oplock update transfers, the file system can use this
feature to block open requests to a file by queueing the I/O Request Packet (IRP) to its
internal file control structure until the oplock owner lets it know that it is finished.