Subj : Re: recursive mutexes
To   : comp.programming.threads
From : Uenal Mutlu
Date : Thu May 19 2005 12:11 am

"Markus Elfring" wrote
> > Lock-free shared access is IMO an illusion, usabe for some very small
> > and limited cases only, but not for 99.9% of practical requirements.
>
> How "limited" is the application of lock-free algorithms for fundamental data structures
> like trees, linked lists or queues?

Sounds interessting, but I would be convinced only after testing
their performance. And here I doubt it can be faster, because
I myself had experimented with such structures too and had read papers
on this, but unfortunately the performance was very poor due to the
additional code checks one has to make. It sums up and degrades
the performance.

> > And IMO they are also slower than a method which uses locking, even
> > if this might sound counter-intuitive.
>
> Would you like to show benchmarks for such differences in execution speed?
> (Other papers contain statistics that show the opposite runtime behaviour.)

This assumption is by the fact that you need to put more code to check.
That is: more code must be executed;  even just two or three if statements
can mean too much compared to a classical mutex method using atomic counter.

.