[boost] Re: lightweight mutex for MacOS

From: Martin Taylor (martin.taylor_at_[hidden])
Date: 2004-01-29 10:32:48

On 29 Jan 2004, at 14:28, Alexander Terekhov wrote:

>
> Howard Hinnant wrote:
> [...]
>> Alexander, I have no doubt that you will see problems with this
>> implementation, and I appreciate your comments.
>
> Get rid of yield. With yield you basically have a spinlock, not a
> general purpose mutex. Think of a uniprocessor [under priority
> scheduling rules] with some higher priority thread contending for
> a lock currently owned by some lower priority thread.

I thought that the lightweight_mutex didn't have to be a general 
purpose mutex - in fact it explictily says just that in the comments of 
lightweight_mutex.hpp:

//  boost::detail::lightweight_mutex meets a subset of the Mutex concept
//  requirements: 
http://www.boost.org/libs/thread/doc/mutex_concept.html#Mutex
...
//  * Not a general purpose mutex, use boost::mutex, CRITICAL_SECTION or
//    pthread_mutex instead.
...
//  The current implementation can use a pthread_mutex, a 
CRITICAL_SECTION,
//  or a platform-specific spinlock.

Regards,
Martin