[Python-Dev] const data (was: Unicode patches checked in) (original) (raw)

Vladimir Marangozov Vladimir.Marangozov@inrialpes.fr
Thu, 16 Mar 2000 13:39:42 +0100 (CET)

Greg Stein wrote:

[me] > The static data is shared if the module is a shared object (.so). > If unicodedata is not a .so, then you'll have a seperate copy of the > database in each process. Nope. A shared module means that multiple executables can share the code. Whether the const data resides in an executable or a .so, the OS will map it into readonly memory and share it across all procsses.

I must have been drunk yesterday. You're right.

I don't believe this is Linux specific. This kind of stuff has been done for a long time on the platforms, too.

Yes.

Side note: the most effective way of exposing this const data up to Python (without shoving it onto the heap) is through buffers created via: PyBufferFromMemory(ptr, size) This allows the data to reside in const, shared memory while it is also exposed up to Python.

And to avoid the size increase of the Python library, perhaps unicodedata needs to be uncommented by default in Setup.in (for the release, not now). As M-A pointed out, the module isn't isn't necessary for the normal operation of the interpreter.

-- Vladimir MARANGOZOV | Vladimir.Marangozov@inrialpes.fr http://sirac.inrialpes.fr/~marangoz | tel:(+33-4)76615277 fax:76615252