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FltSendMessage - ClientPort use
Dejan_Maksimovic
Member - All Emails Posts: 544
in NTFSD
Hi,
Does anyone know why ClientPort parameter is a pointer to a pointer and not directly a single pointer?
If the variable (let's call it g_ClientPort) is not modified inside FlrSendMessage why does it need a pointer to it? It's defined as _in, and I don't see in the disassembly that it is modified directly, but maybe a subcall does it.
Strangely, I never saw code that copied the variable and passed a pointer to different variables yet :)
OT: what was the email to use to post without going to the forum?
Dejan.
Does anyone know why ClientPort parameter is a pointer to a pointer and not directly a single pointer?
If the variable (let's call it g_ClientPort) is not modified inside FlrSendMessage why does it need a pointer to it? It's defined as _in, and I don't see in the disassembly that it is modified directly, but maybe a subcall does it.
Strangely, I never saw code that copied the variable and passed a pointer to different variables yet :)
OT: what was the email to use to post without going to the forum?
Dejan.
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Comments
It's a cute way to clean up the race between FltSendMessage and FltCloseClientPort without external synchronization:
We'd really prefer everyone just use the forum at this point...We did a bunch of work to "grandfather in" email access to some people when we moved the site 5+ years ago but it's mostly just a pain (and I'm still not over having to give up NNTP access 😂).
-scott
OSR
> and not directly a single pointer?
> >
> > If the variable (let's call it g_ClientPort) is not modified inside
> FlrSendMessage why does it need a pointer to it? It's defined as _in, and I
> don't see in the disassembly that it is modified directly, but maybe a
> subcall does it.
>
> It's a cute way to clean up the race between FltSendMessage and
> FltCloseClientPort without external synchronization:
>
So, it does need for the same variable's address to be passed, and not the
value to be copied around? Thanks!
>
> *
> We'd really prefer everyone just use the forum at this point...We did a
> bunch of work to "grandfather in" email access to some people when we moved
> the site 5+ years ago but it's mostly just a pain (and I'm still not over
> having to give up NNTP access 😂).
>
I don-t think you know how much easier e-mail is
Regards, Dejan.
Correct.
For you maybe but not for the forum or its indentured servants 😁 (I, for one, definitely don't miss seeing broken threads everywhere starting with "RE: re: Re: AW: aw: RE: SV: RE: [NTFSD]")
-scott
OSR