Set x to to None and del x doesn't release memory in python 2.7.1 (HPUX 11.23, ia64)

[Grant Edwards]

On 2013-03-09, Roy Smith <roy at panix.com> wrote:
> In article <khg6f3$cfr$1 at reader2.panix.com>,
>  Grant Edwards <invalid at invalid.invalid> wrote:
>
>> What I should have said was that there's no way to return to the OS
>> memory obtained via calls to malloc() et al.
>
> That's true (for certain values of "et al").
>
>> and those are the calls that "good" C programmers (like the
>> maintainers of CPython) use.
>
> Well, there is mmap, which is exposed via the Python mmap module.  
> Python doesn't have anything like C++'s "placement new", so there's
> no way to use that memory to hold generic Python objects, but you can
> certainly use mmap to allocate a large chunk of memory, use it, and
> then give it back to the OS.

[example]

I was surprised to find that the object returned by mmap.mmap()
supported file semantics (seek, tell, read, etc.) in addition to byte
buffer semantics.  Usually, the reason one maps a file is that one
doesn't want to use file semantics (which are already supported by the
file object) but wants instead to use buffer semantics.

Using memmap to obtain a "returnable" chunk of memory seems a bit
obtuse, since it requires creating an underlying file of appropriate
size that ends up being superfluous.

-- 
Grant Edwards               grant.b.edwards        Yow! I wonder if I ought
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