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From Jeff Trawick <>
Subject Re: rational behind not checking the return value of apr_palloc and apr_pcalloc
Date Wed, 01 Sep 2010 10:35:48 GMT
On Wed, Sep 1, 2010 at 6:15 AM, Graham Leggett <> wrote:

> On 01 Sep 2010, at 6:07 AM, dave b wrote:
>  What is the rational behind not checking the return value of
>> apr_palloc and apr_pcalloc?
> The rationale is to not be forced to check for and handle hundreds of
> potential failure cases when you're probably doomed anyway.

probably more than hundreds ;)

If there's a real world scenario where allocation failures can occur and
must be dealt with more gracefully than segfaulting, I suspect that you can
find a pragmatic way to deal with it much more reliably than relying on each
individual memory allocation to be checked (that will never be implemented
perfectly, and those paths will almost never be exercised anyway).  For
example, a plug-in module might be able to confirm (or fail gracefully) in
an early request hook that enough memory is available to handle the expected
types of requests.

Another way to look at it: If somebody had the time to add all those
checks/error paths, their time would be better spent looking for situations
where httpd would use a lot more memory than normal because of the way
external input was received.

If there's not a repeatable real world scenario to address -- IOW you think
they should be checked "just because" -- there probably won't be any
sympathy here.  With a particular scenario in hand there may be ideas
forthcoming to deal with the situation, whether internal to the web server
or external.


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