Is basic_registry<>::view<> thread safe ?

[TothBenoit]

Hello, I'm using EnTT to represent a scene and use it across multiple threads to render the scene on multiple windows.

Each thread creates its views to iterate on.
Sometimes during the first frame, calling view() throws an exception deep down in the callstack.
It looks like multiple threads tried to reallocate the same vector.

I read in the docs that iterating over a set of components is permitted as long as the components are neither assigned nor removed which is my case.

But is the view creation supposed to be threadsafe as well ?

Here what the callstack looks like

[skypjack]

In case of non-const views, they can trigger the creation of the underlying pools if they do not exist yet in the registry.
Pools are stored in a vector, so yeah, if you create non-const views from different threads using i.e. an empty registry, it's a race.
This is somehow mentioned here. The approach is the same of the standard library after all. Thread safety isn't guaranteed for non-const containers, and you're probably operating on a non-const registry here. Therefore, it's up to you to pre-create all required pools or properly guard view creation calls.

[TothBenoit]

I was indeed using non-const registry. Changing it to const fixed the issue, thanks !