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in reply to Re: Mmap question
in thread Mmap question

Well I guess thats true, but isnt that more a case of sharing the file, rather than the memory ?

I believe the OP wanted to share the memory allocated my mmap (sharing the address returned by mmap, which isnt possible across unrelated processes).

Maybe that just being pedantic - changes made to the mmap'ed region by one process are almost immediately visible by the other - if thats the level of control required, cool. shmXXX allows for finer grained control, by using data structures in memory - possible in a file but not without some serious work serialising to and from the file representation.

...it is better to be approximately right than precisely wrong. - Warren Buffet

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Re^3: Mmap question
by sgifford (Prior) on Jan 31, 2005 at 17:06 UTC
    I don't understand this:
    shmXXX allows for finer grained control, by using data structures in memory - possible in a file but not without some serious work serialising to and from the file representation.
    How does a SysV shared memory segment support data structures differently than mmap? I've always used them pretty much interchangeably...