Re: [boost] [thread] RFC standard proposed mutex, read-write mutex, condition

From: Peter Dimov (pdimov_at_[hidden])
Date: 2007-08-22 17:09:18

Austin Bingham wrote:

> On 2007-08-22, Howard Hinnant <howard.hinnant_at_[hidden]> wrote:
>> I have two answers:
>>
>> 1.  This is somewhat of a shocking answer, so please read through the
>> second answer before passing judgement:  The proposal purposefully
>> does not mention shared vs exclusive priority.  And I would prefer not
>> to.
>>
>> 2.  The implementation uses an algorithm which I attribute to
>> Alexander Terekhov.
>
> At the risk of defiling a perfectly good metaphor, I think that if
> Alexander's algorithm is the car, then other policies are more like
> light trucks, pontoon boats, and tricycles. That is, the algorithm
> you describe almost certainly works as suggested, but I may really
> want something completely different.

No, you don't. The other policies are broken cars, not other vehicles.

That said, a POSIX rwlock does grant you the ability to shoot yourself in 
the foot by using thread priorities. Readers will not be blocked waiting for 
a pending writer of a lower priority.