Re: [boost] A fast-pathed rw-mutex algorithm for Boost...

From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2006-10-26 13:12:33

> Here is my implementation of Terekhov's *fair* read/write algorithm,  
> with upgradable thrown in.  This algorithm is just as you say:  The  
> OS alone decides who gets to run next.
> 
> http://home.twcny.rr.com/hinnant/cpp_extensions/upgrade_mutex.html
> 
> If you don't like the "upgradable" part, it strips out cleanly from  
> the code.  Just delete everything that refers to "upgradable" and  
> you've got a read/write mutex using Terekhov's algorithm (and rename  
> the mutex).

Just two comments for boosters:

-> The Boost.Interprocess upgradable_mutex is this same as Howard's 
algorithm, because I wrote it based on Howard's thorough explanations. 
So if you want to use this algorithm, use Howard's code, since it's 
surely more tested than my implementation. I plan to use Howard's 
algorithm in my next version.

-> Now that there is interest in implementing these mutex types, and the 
committee is considering adding synchronization primitives to the 
standard or TR2, I think we should implement synchronization algorithms 
in Boost.Thread that can be reused by other libraries, like 
Boost.Interprocess. I think that Howard's algorithm can be templatized 
so that everyone can plug its mutexes/condition variables there, and 
they don't have to reinvent the wheel. Even if we add atomic operations 
to that algorithm it will be still valid for shared memory 
synchronization primitives.

My 2 cents,

Ion