synchronized (this[.classinfo]) in druntime and phobos

[Alex Rønne Petersen]

On 29-05-2012 23:31, Andrei Alexandrescu wrote:
> On 5/29/12 1:32 AM, deadalnix wrote:
>> I already did some comment about this.
>>
>> Making any object synchronization is a very bad design decision. It is
>> deadlock prone, it is liquid lock prone, it cause an overhead on any
>> object, and even worse, it is useless most of the time as D promote
>> thread locality (which is very good).
>
> Actually I think such a characterization is superficial and biased to
> the extent it becomes wrong.

Really ? I think he's spot on.

>
> Locks are deadlock-prone by design, whether used with objects or with
> classic procedural programs. In fact they are better confined to objects
> because the association between the protected data and the
> synchronization object is clear.

There is no doubt that synchronization of any kind is hard and 
error-prone no matter how you do it. But do you really think that the 
situation is made better by allowing locking on *anything*, meaning that 
locks are effectively resources shared publicly?

Besides, what's wrong with core.sync.mutex?

>
>> OOP and concurrency are 2 orthogonal topics, and should be handled as
>> such.
>
> Well there would be active objects that contradict that. But really it
> is very natural to encapsulate together some data along with the mutex
> that must be acquired to manipulate it. There are known issues with
> inheritance, but they are not introduced by the approach, only exposed
> by it.
>
>
> Andrei

-- 
Alex Rønne Petersen
alex at lycus.org
http://lycus.org