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implement shared memory

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# 1  
Old 02-28-2006
Lightbulb implement shared memory
hi all
I have been asked to implement shared memory in user mode?But Smilie im not understanding how to do this.And what does it mean in user mode?Is it that we need to simulate what kernal does...like attaching ,detaching memory..etc...?
And would also like to know why shared memory is called fastest IPC ?
# 2  
Old 02-28-2006
Sounds like they've asked you to program something you don't have a clue about.

Here's a very good explanation with examples:

http://www.advancedlinuxprogramming....p-ch05-ipc.pdf
# 3  
Old 03-01-2006
shared memory again
Hi all,
Thank you for ur reply.
The link was good.But i am not understanding,somewhere it is mentioned that theres no kernal entry and system calls.But i see there are system calls for shared memory.....i.e.,shmget,shmat,shmctl.Are they not system calls?Dont they have any kernal entry?
# 4  
Old 03-01-2006
Do you want shared memory without any system calls? Cannot be done.

You can use pipes, names pipes, or files to do that. But opening a file requires kernel access as well. So does printing to the screen. So what you're asking doesn't make any sense to me at the moment. Basically, you can think of any compiled C program as an interface to system and kernel calls.

??
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