D has the same memory model as C++

[Paul Backus]

On Wednesday, 11 August 2021 at 19:38:38 UTC, Tejas wrote:
> On Wednesday, 11 August 2021 at 19:27:34 UTC, Ali Çehreli wrote:
>> On 8/11/21 12:19 PM, Tejas wrote:
>>
>>> Atleast leave some pointers on where to start :(
>>
>> I DuckDuckGo'ed it for you. :)
>>
>>   https://en.cppreference.com/w/cpp/language/memory_model
>>
>> Then looked it up at Wikipedia too:
>>
>>   https://en.wikipedia.org/wiki/Memory_model_(programming)
>>
>> Ali
>
> I was hoping on material regarding. c++ vs D memory model, not 
> C++ model alone. That's the problem. For pure C++, there's even 
> the paper by Stroustroup et al. which feels pretty definitive.
>
> That's why I asked here whether anyone could tell me about the 
> subtle differences between C++ and D, with regards to memory 
> model, or any other features that share surface resemblance, 
> but are different underneath.

D's memory model is described on this page of the language spec:

https://dlang.org/spec/intro.html

I'm not super familiar with C++'s memory model, but just from 
eyeballing the cppreference page, it looks like the main 
difference between the C++ and D memory models is how they handle 
access to memory from multiple threads. In particular, D makes a 
distinction between "thread-local memory locations", which may 
only be accessed from one thread, and "shared memory locations", 
which may be accessed from multiple threads. In C++, any memory 
location can be accessed from any thread.

The other big difference is that D's spec does not really define 
its terms. What exactly it means for a thread to "access" a 
memory location, or for concurrent accesses to be "synchronized", 
is never actually explained. For these details, it is *probably* 
safe to fill in the blanks with the equivalent definitions from 
C++.