On Thursday, 16 March 2023 at 20:53:28 UTC, Witold wrote:
It crashes at `new_.value`, as `new_` is `null`
It looks like this:
```d
alias VariableAllocator = ThreadLocal!(FreeList!(Mallocator,
Variable.sizeof, unbounded));
```
should be this instead:
```d
alias VariableAllocator = ThreadLocal!(FreeList!(Mallocator,
Variable.sizeof, Variable.sizeof));
```
or
```d
alias VariableAllocator = ThreadLocal!(FreeList!(Mallocator, 0,
Variable.sizeof));
```
Otherwise if the list is empty (which it is at the start), the
free list will attempt to allocate from `Mallocator.instance`,
but not at requested size but rather at `maxSize` of the free
list allocator (that makes sense), which is `unbound`, which is
`size_t.max`, or about 18446 PiB. `malloc` will return null for
such crazy amount.
Also using `Mallocator` as a parent might not be a good idea.
The reason is that while it will allocate memory, it will not
tell GC to scan that area for pointers to other structs. So if
some objects are allocated using normal GC allocator, and only
reference is from Mallocator/FreeList allocated struct, GC will
think this object is unreachable, and clean it up.
Using `GCAllocator` works. I made this handy alias template:
```d
alias ListAllocator(Type) = ThreadLocal!(FreeList!(GCAllocator,
Type.sizeof, Type.sizeof));
```
Then just in a struct:
```d
struct MyStruct(T) {
alias allocator = ListAllocator!(MyStruct!T); // or
typeof(this)
...
auto m = allocator.instance.make!(MyStruct!T)();
...
allocator.instance.dispose(m);
}
