On Mon, 22 Nov 2004, Arjan van de Ven wrote:
>
>>> this locking construct is rahter awkward; is it possible to refactor the
>>> code such that you can down and up in the same function ?
>>
>> Yes, at the cost of some minor code duplication or the introduction of
>> another variable. Is that preferable? Is holding the lock across function
>> calls a Bad Idea?
>
> holding lock across function calls isn't, unlocking in another function
> than you take the lock is.
> For one it makes auditing the code a lot harder.
>
Also, code like:
down(&mylock);
do_something();
if(fail) {
up(&mylock);
return retval;
}
.. is prone to errors where a lock never gets released on some
corner cases. It's often better to "goto" a common exit point where
the lock is released.
Cheers,
Dick Johnson
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