Re: to Find whether the application is alive or dead

From:

"Ben Voigt [C++ MVP]" <rbv@nospam.nospam>

Newsgroups:

microsoft.public.vc.language

Date:

Mon, 27 Apr 2009 12:35:32 -0500

Message-ID:

<76AC136F-DC6F-4C85-B0AE-E4B2E52AE398@microsoft.com>

"Alex Blekhman" <tkfx.REMOVE@yahoo.com> wrote in message
news:#HubD1WxJHA.1712@TK2MSFTNGP03.phx.gbl...

"Ben Voigt [C++ MVP]" wrote:

You can pass A's process ID as a command line parameter to B.exe. Inside
A process call GetProcessId() function to get A's process ID.

Inside B process call OpenProcess() function in order to obtain a handle
to process A. Then you can use this handle with WaitForSingleObject.

DO NOT do this! There's a race condition, process A could exit before
process B calls OpenProcess. Testing for failure of OpenProcess is not
enough because OpenProcess could return a different process than process
A when this happens.

thanks for pointing this out. Yes, I thought it should be quite self
evident that process A must stay alive with that arrangement.

Probably more convenient solution will be to duplicate its own handle
within process A (with DuplicateHandle) in order to make it inheritable.
Then just pass handle value to process B via command line.

That's definitely the easiest, but I don't much like creating processes with
inheritance enabled. Who knows what other handles in the process might have
been created inheritable? It's that horrid "action at a distance" behavior
at work.

Alex