Re: Win32 rename()/unlink() questions

I wrote:
> Stephan Szabo wrote:
>>
>> The question is, what happens if two people have the file open
>> and one goes and tries to delete it? Can the other still read
>> from it?
>
> Yes. I just tested it and it worked. I'll test Bruce's scenario as well:
>
> foo contains: "FOO"
> bar contains: "BAR"
>
> 1. Process 1 opens "foo"
> 2. Process 2 opens "foo"
> 3. Process 1 calls MoveFile("foo", "foo2");
> 4. Process 3 opens "foo" <- Successful?
> 5. Process 1 calls MoveFile("bar", "foo");
> 6. Process 4 opens "foo" <- Successful?
> 7. Process 1 calls DeleteFile("foo2");
> 8. Process 1, 2, 3, 4 all read from their respective handles.

Process 1: "FOO"
Process 2: "FOO"
Process 3: Error - File does not exist
Process 4: "BAR"

Its interesting in that it allows for Unix-style rename() and
unlink() behavior, but with a race condition. Without Stephan's
two MoveFile() trick and the FILE_SHARE_DELETE flag, however,
the result would be Access Denied. Are the places in the backend
that use rename() and unlink() renaming and unlinking files that
are only opened for a brief moment by other backends?

Mike Mascari
mascarm(at)mascari(dot)com