HANDLE types should support Sync trait

[lzybkr]

I'm new to Rust, so if my understanding is misguided, do let me know.

I'm trying to use a handle - HMODULE in a static HashMap. This is not allowed because the trait std::marker::Sync is not satisfied on *mut winapi::HINSTANCE__.

I think DECLARE_HANDLE should define a type that supports the Sync trait.
Handles are not pointers even though they're defined that way in winnt.h.

[retep998]

You should be wrapping your handles in a newtype so that you can do stuff like automatically closing the handle when dropped. One of the benefits of such a wrapper is you can assert that it is thread safe like so:

struct Handle(HANDLE);
unsafe impl Sync for Handle {}

Related issue: #360

[lzybkr]

I see.

Does it make sense for winapi to define a wrapper type for at least some handle types? So for example, you could have a Raw type that is the pointer, and the wrapper type?

This would also introduce a level of type safety that isn't present in C/C++ with Windows handles.

[retep998]

winapi is strictly raw bindings. It does not attempt to provide wrappers (aside from the minimal amount for COM interfaces) or make anything safe. Anyone is free to create their own library on top of winapi which provides thread safe wrappers.