Re: [boost] wait-free fast-pathed, bounded-time, 100% starvation-free rw-mutex...

Subject: Re: [boost] wait-free fast-pathed, bounded-time, 100% starvation-free rw-mutex...
From: Chris M. Thomasson (cristom_at_[hidden])
Date: 2009-09-04 00:06:12

"Chris M. Thomasson" <cristom_at_[hidden]> wrote in message 
news:h7ep7q$a5r$1_at_ger.gmane.org...
> "Chris M. Thomasson" <cristom_at_[hidden]> wrote in message 
> news:h7168i$vq4$1_at_ger.gmane.org...
>> "Anthony Williams" <anthony.ajw_at_[hidden]> wrote in message 
>> news:87fxbh1ccf.fsf_at_dell.justsoftwaresolutions.co.uk...
> [...]
>>> For integration with boost, it would be good if the write-lock member
>>> functions could be called "lock()" and "unlock()", whilst the read-lock
>>> member functions are called "lock_shared()" and "unlock_shared()". This
>>> would allow the existing RAII classes to be used with this new rwmutex
>>> type.
>>
>> Okay. I will add the try lock functions and change the function names, 
>> and re-name the class to `fair_rwmutex' to attempt to get across that 
>> it's `SCHED_OTHER'.
>
> Here is some preliminary code which adds some try lock functions, changes 
> the name to `fair_mutex' and renames the `wrlock()/wrunlock()' procedures 
> to `lock()/unlock()':
>
>
> http://pastebin.com/f502d0943
>
>
> I still need to test drive the try lock functions in Relacy to see if I 
> missed anything. As for the `SCHED_OTHER' issue, well, I am not sure how 
> to get around that without sacrificing the 100% starvation free and 
> bounded-time guarantees. Humm...

I forgot to destroy a resource in the failure case of the constructor. Here 
is code without the leak:

http://pastebin.com/f527722e0

Here is the difference between leaky code and corrected code above:

http://pastebin.com/pastebin.php?diff=f527722e0