[fpc-devel] ref count types / threadsave question

[Jonas Maebe]

On 04/01/19 00:11, Benito van der Zander wrote:
> Hi Fpc Developers',
> 
>> Nobody is talking about the string content. 
> 
> But when they are stored together, that is the same. You can't get one 
> without the other.

You can, since the data can be stored in a different cache line than the 
refcount. But the principle is indeed the same: the data is not 
guaranteed to be synchronised across cores either.

> Sure one core can read 2 after the other core wrote 1.
> 
> I do not see how a core can read 1 after a 2 was written.

There is no difference between the two cases as long as the second read 
happens without an atomic read-modify-write operation..


Jonas