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Updating IoStatusBlock.Status in ZwReadFile/ZwWriteFile

OSR_Community_UserOSR_Community_User Member Posts: 110,217

In my driver, I'm making a call to ZwReadFile() to read certain amount
of bytes from some offset. Error handling is done in this way

NtStatus = ZwReadFile( . . . );
if(NT_STATUS(NtStatus) && (IoStatusBlock.Status == STATSUS_SUCCESS))
return error;

ZwReadFile() is returning a status of STATUS_PENDING (0x00000103) and if

I check the IoStatusBlock.Status will be some junk such as 0xfffffe80
so it will always go to error path. Where as, if I give a little delay
before checking the StatusIoBlock.Status (before the if condition) then
it will be updated with STATUS_SUCCESS and the Information will have the

number bytes read. So as the DDK says I thought of giving the 'Event'
parameter in ZwReadFile() and check it out as my driver is not an
intermediate driver. Apparently this ended with getting Ntstatus code as

0xc0000024 . But there is now sample code or document which explains me
how to use 'Event' parameter . Can anybody explain me what is happening
and what others are doing for such a problem.

Thanx in advance
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