Topic: Windows CreateSemaphore inCGI

[DocDJ]

I am trying to use the Windows CreateSemaphore in a C++ CGI function to provide protection against multi-write-access to a file (within the webserver address space) by multiple instances of my CGI program. I guess I have 3 questions:
1. Will APACHE prevent the multi-access for me?
2. Can I get Apache to prevent multiple instances of the CGI from running at the same time (they are VERY short (millisec long) programs
3. If the answers to the above 2 are "no", can I get help on using CreateSemaphore, because mine always return NULL? (I've tried simple examples with no DACL, unnamed semaphore, etc.)

[James Blond]

1.) No
2.) No

3.) MSDN might your friend

http://msdn.microsoft.com/en-us/library/windows/desktop/ms686946%28v=vs.85%29.aspx

[DocDJ]

I've added the CreateSemaphore and tried it with the default parameters (NULL, 0, 1, NULL) before trying the more complex parameters with a DACL, etc. but it returns an error. So I suspect there is some difference in using CreateSemaphore ina CGI program than when using it in a standalone application.

If anyone has already done this, I would appreciate some hints.