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Shared Memory and inheritance

Posted on 1998-03-27
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Last Modified: 2013-12-03
I am currently using CreateFileMapping() and MapViewOfFile() to create a block of shared memory using 0xFFFFFFFF as the first parameter of the CreatFileMapping() call so its not associated with a file but uses the system paging file.



However, by giving it a name "MY_SHARED_MEM", so both processes will attach to the same area, this leaves me with a problem.



At some point in time, these applications may run on an NT server and so there may be multiple processes running. I only want the main process and the child process *of that main process* to access the shared memory. As it is, I 'think' that if another uses starts a 2nd main process and launches the child, they will attach to the original area, becuase of the name correct?



How can I avoid this, and yet still use the system paging file? . use the CreateProcess to launch the child with handle inheritance set to TRUE if thats necessary to do this. I've read about DuplicateHandle() but not sure how to set it up..can't quite get a grasp on it.



Any help would be appreciated
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Question by:gunn
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Tommy Hui earned 110 total points
ID: 1412338
This is not that unusual. One idea is to not hardcode a specific name, but to use one based off of the processId of the parent. For example, instead of using MY_SHARED_MEM as the name of the filemap, use MY_SHARED_MEM_%PROCESSID%. Then when the parent process launches the child, pass the child the name as an argument.

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