Re: [boost] [thread] terminating destructor

Subject: Re: [boost] [thread] terminating destructor
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2012-10-25 13:13:39

Le 25/10/12 10:33, Christof Donat a écrit :
> Hi,
>
>>> The third situation below shows a non blocking ~future. But such 
>>> execution
>>> is *disallowed *by the standard because the completion of launched 
>>> thread
>>> would not synchronize with the last release of the shared state.
>>
>> The big question is: why?
>>
>> Can't the destructor detach from the shared state and let the state be
>> cleaned up by the launched thread?
>
> That is what I thought in the first place as well. Yet, the object to 
> destroy
> will live on the stack of the main thread. 
Why?

> Before the function can return, the
> stack frame has to be released and therefore the objects in it have to be
> destroyed. When the destruction is done by the launched thread, either 
> the main
> thread has to wait and there is nothing you can gain that way, or the 
> stack
> would need to be forkable. That would break almost all C++ ABIs around 
> the
> world, I guess.
>
>
Best,
Vicente