D3D9 Device + Window soundness safety overhaul

[MaulingMonkey]

I believe I can make d3d9 hwnd handling 100% sound.

Validate HWND on creation

• GetWindowThreadProcessId can be used to get an HWNDs creating thread and process IDs.
  These can be used to enforce that device creation is only done with an appropriate, valid HWND.
  • GetCurrentProcessId
  • GetCurrentThreadId
  • credit to stack overflow

Validation failures can be coerced to Result s, which should be 100% defined behavior.

Detect Device outliving HWND

Now, to detect when an HWND is yanked out from under a device:

Option 1: Hooks

SetWindowsHookExW(WH_CALLWNDPROCRET, ...)
High overhead - hooks every wndproc, including for window handles we don't really care much about.

Option 2: Patch WNDPROCs

SetWindowLongPtrW(hwnd, GWLP_WNDPROC, ...)
Saner, probably? Note that CallWindowProcW is required to call the original WNDPROC sanely.

Error Handling

• Emergency destruction of the device is likely impossible.
• Canceling the destruction of the HWND might be possible (hide it instead?), but would be a bit sketchy?
• Reparenting the device to a new (hidden) HWND might be possible, but would be a bit sketchy?
• bugsalot::bug!(...) + std::process::abort() ?

[MaulingMonkey]

ae1c72a misc. HWND APIs for future hwnd thread ownership testing
c44f2c8 win32::get_window_thread_id