On Tuesday, 22 May 2018 at 21:45:07 UTC, IntegratedDimensions
wrote:
an idea to lock data by removing the reference:
class A
{
Lockable!Data data;
}
The idea is that when the data is going to be used, the user
locks the data. The trick here is that data is a pointer to the
data and the pointer is set to null when locked so no other
data can use it(they see a null reference). To unlock, the data
is reassigned:
auto d = data.lock(); // A.data is now null deals with sync
issues
//use d
d = data.unlock(d); // restores A.data (A.data = d;) and sets d
to null so any future reference is an error(could produce bugs
but should mostly be access violations)
Anyone else trying to use data will see that it is null while
it is locked.
This basically pushes the standard locking mechanisms in to the
Lockable!data(first come first serve) and code that has not
captured the data see's it simply as null.
Anyone use know if there exists an idiom like this and what it
is called? Maybe some idiomatic code that is efficient?
Ideally I'd want to be able to treat the Lockable!Data as Data.
Right now I have to classes(or pointers to structs) and few
weird hacks. I think what I'll have to end up doing is having a
Locked!Data structure that is returned instead or use an UFCS.
The idea being to attach the lock and unlock methods.
Are you aware of NullableRef?
https://dlang.org/library/std/typecons/nullable_ref.html
Does it fit somehow?
