Subj : Re: RCU+SMR
To   : comp.programming.threads
From : Joe Seigh
Date : Mon Jul 11 2005 06:28 pm

David Hopwood wrote:
> Joe Seigh wrote:
> 
>> David Hopwood wrote:
>>
>>> Randy Howard wrote:
>>>
>>>> True.  I've yet to hear of any commercial or popular OSS application 
>>>> bragging about the massive performance benefits achieved through the 
>>>> use of lock-free techniques.
>>>
>>>
>>> I very much doubt that there is enough benefit from using lock-free
>>> techniques in *applications* to justify the complexity cost, and the
>>> effort required to learn how to use them correctly. They belong in
>>> operating systems and language implementations, where these costs are
>>> amortized over many apps.
>>>
>> Depends on the api and usage patterns that you create for the lock-free
>> stuff.
> 
> 
> I don't think it does, really. Note that I was talking about using 
> lock-free
> techniques directly in applications; not using "infrastructure" libraries
> that happen to be implemented using lock-free stuff, but that do not expose
> it to their clients. My argument is that lock-free primitives are 
> inherently
> too complex and error-prone to be exposed directly for general-purpose
> application programming, no matter how well-designed the API.

My experience is that people who believe their low level api are too complex
for normal programmers to use and and only allow useage through a high level
api, generally suck at designing api's.  If the low level api was available,
at least someone else who isn't so bad at api design could try to design a
better one.  And they certainly couldn't design a new or different api if the
low level api wasn't available.  If the only api available is a lock-free
linked list and someone wants to design a lock-free tree, they won't be able
to do one.

Java is a good example here.  There are a lot of classes that are final and
not extendable simply because the class author doesn't trust users to extend
their class even though that is the whole *point* of OOP.  There are design
patterns whose main purpose in being seems to be to get around such restrictions
which is certainly an irony.


-- 
Joe Seigh

When you get lemons, you make lemonade.
When you get hardware, you make software.

.