lkml.org 
[lkml]   [2004]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: adm1026 driver port for kernel 2.6.10-rc2 [RE-REVISED DRIVER]
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
Penguin : Linux version 2.6.9 on an i686 machine (5537.79 BogoMips).
Notice : All mail here is now cached for review by John Ashcroft.
98.36% of all statistics are fiction.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:08    [W:0.053 / U:1.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site