From:	Hans-Bernhard Broeker <broeker AT physik DOT rwth-aachen DOT de>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: free() DOESN'T return memory to system
Date:	19 Sep 2000 14:28:34 GMT
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Damian Yerrick <Bullcr_pd_yerrick AT hotmail DOT comremovebullcr_p> wrote:
> On 18 Sep 2000 13:24:30 GMT, Hans-Bernhard Broeker
> <broeker AT physik DOT rwth-aachen DOT de> wrote:

[... regarding free() ... ]
>> It *does* make the memory available for use by later malloc() calls
>>in the same program.

> So what call makes memory available for programs that you spawn()?

None does. DPMI might very well even forbid doing it (haven't really
looked it up).

A spawn()ed program has no particular relationship to its parent,
except that they're running on the same machine, under the same OS.
Actually freeing all freeable heap was a necessity back in the days of
DOS, where the spawn()ed process would need to use the same 640 KB the
parent lived in. Even then, this usually was not done by
compactification of the heap or some such measure, but rather by
swapping out the parent to EMS or harddisk, while the spawn() ran. But
with virtual memory and all that, such trickery should essentially no
longer be needed.
-- 
Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
Even if all the snow were burnt, ashes would remain.

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