On 26/01/2022 08:20, Chris Angelico wrote:
On Wed, 26 Jan 2022 at 19:04, Tony Flury via Python-list
<python-list@python.org> wrote:
So according to that I should increment twice if and only if the calling
code is using the result - which you can't tell in the C code - which is
very odd behaviour.
No, the return value from your C function will *always* have a
reference taken. Whether the return value is "used" or just dropped,
there's always going to be one ref used by the returning itself.
The standard way to return a value is always to incref it, then return
the pointer. That is exactly equivalent to Python saying "return
<thing>".
Incrementing twice is ONLY because you want to leak a reference.
ChrisA
Chris,
You keep saying I am leaking a reference - my original code (not the POC
in the email) wasn't intending to leak a reference, it was incrementing
the reference count in order to accurately count references, from other
objects and i needed to double increment there so that the reference
count remained correct outside of the C code.
I did try to be clear - my intention was never to leak a reference (I
have been writing s/w long enough to know leaks are bad) - my POC code
in the original message was the only code which deliberately leaked a
reference in order to simply illustrate the problem.
I do appreciate the help you have tried to give - so thank you.
--
Anthony Flury
email : anthony.fl...@btinternet.com
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