[MPlayer-dev-eng] [RFC] libnut demuxer API

[Oded Shimon]

On Thu, Sep 08, 2005 at 03:27:14PM +0300, Ivan Kalvachev wrote:
> 2005/9/8, Reimar D?ffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de>:
> > Hi,
> > On Wed, Sep 07, 2005 at 11:44:39PM +0200, Aurelien Jacobs wrote:
> > > On Wed, 7 Sep 2005 08:45:59 +0300
> > > Oded Shimon <ods15 at ods15.dyndns.org> wrote:
> > > > ahem, yes, malloc :)
> > > > even if you run out of ram, in linux, malloc STILL doesn't fail :P
> > >
> > > That's plain wrong !!
> > [...]
> > > aurel at homer:~/x$ gcc -Wall -o x x.c
> > > aurel at homer:~/x$ ./x 100000000
> > > 0x2aaaaae02010
> > > aurel at homer:~/x$ ./x 1000000000
> > > (nil)
> > 
> > You have been testing whether an application can malloc any amout of
> > RAM, which of course is not the case. Oded was talking about whether
> > malloc can/will fail when you have no more free RAM, which is a
> > different thing!
> 
> Anyway, not using malloc is radiculous. 
> 
> Linux uses an optimistic allocation, that is actually allocate-on use.
> The side effect is that if program allocate more than possible amount
> and they claim it, there won't be enough memory. When such situation
> occurs an memory must be freed, usually by killing an process
> (OOM_Kill). It could be the biggest&new, or the process that tries to
> use the memory.
> 
> The whole point is that it doesn't matter if libnut or the program
> allocates memory. They will behave the same way.
> So use malloc, check for null pointer, and be happy.

Umm, I've forgoten what was the point?

I said that 'nut_demuxer_init' can never fail. Rich pointed out that it 
does a malloc, and can possibly fail, all I was saying, malloc will most 
likely not fail. :) There aren't ANY checks anywhere in libnut for malloc 
returning NULL pointer, because it's pointless. Data is immedeately written 
after the malloc, and program will crash for trying to write to NULL. A 
crash is just about as good as a silly error message "out of memory", as 
that never happens anyway (if it does, you got bigger problems to worry 
about :).

- ods15