Re: [Qemu-devel] [RFC] introduce a dynamic library to expose qemu block API

["Daniel P. Berrange" <berrange@redhat.com>]

On Thu, Jul 19, 2012 at 01:37:11PM +0200, Paolo Bonzini wrote:
> Il 18/07/2012 17:35, Daniel P. Berrange ha scritto:
> > Oh, and will this library depend on glib
> 
> Yes, in all likelihood.
> 
> , and will it have the
> > abort-on-oom behaviour QEMU has ? From a libvirt POV, we won't
> > use any library that aborts-on-oom.
> 
> Out of curiosity, how do you test OOM?

There's two aspects to it. First we forbid use of malloc/free/realloc
in favour of an alternative set of APIs designed such that we can get
compile time errors when people don't check the result for NULL.

  http://berrange.com/posts/2008/05/23/better-living-through-api-design-low-level-memory-allocation/

This has been very successful in ensuring code checks for OOM correctly.
Second there is a mode in our test suites where you can run under
simulated OOM - it runs once to count the total set of mallocs in the
test, and then re-run it 'n' times failing each malloc in turn and
verifying that we correctly report the OOM error condition.

Daniel
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