Re: [HACKERS] Memory mapping (Was: Safe/Fast I/O ...)

On Wed, 15 Apr 1998, Michal Mosiewicz wrote:
> isolated from files it's possible to close some descriptors without
> throwing buffers. However it seems (tried it) that memory mapping works
> even after a file descriptor is closed. So, is this possible to cross
> the limit of open files by using memory mapping? Or maybe the descriptor
> remains open until munmap call? Or maybe it's just a Linux feature?

Nope, thats how it works.

A good friend of mine used this in some modifications to INN (probably in
INN -current right now).

Sending an article involved opening the file, mmapping it, closing the fd,
writing the mapped area and munmap-ing.

Its pretty slick.

Be careful of the file changing under you.

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