GCAdapter::UseAdapter() reads s_is_adapter_wanted, which gets
initialized by config_guard.~ConfigChangeCallbackGuard(). So we must
wait until after destroying the config guard to know whether we have any
controllers set to GC Adapter.
I am not confident there are no race conditions between s_write_mutex,
s_controller_write_payload_size, and s_controller_write_payload. But
this code should be safer than before.
s_controller_write_payload_size needs to remain an atomic because Read()
loads and stores without holding a mutex, Output() stores while holding
s_write_mutex, and ResetRumble() stores while holding s_read_mutex! I'm
pretty sure this code is wrong, specifically ResetRumble().
You can safely read or write non-atomic integers on multiple threads,
as long as every thread reading or writing it holds the same mutex
while doing so (here, s_mutex).
Removing the atomic accesses makes the code faster, but the actual
performance difference is probably negligible.
On Linux, if shared zlib is present, zlib.h is always available and -lz
links to zlib, even if you don't run find_package(ZLIB).
For some reason I have zlib installed on Windows (possibly from vcpkg),
so find_package(ZLIB) succeeds and ZLIB_FOUND is true.
When Dolphin uses shared zlib on Windows, the problem is that zlib.h
is not in the default include path, and the CMake target is called
ZLIB::ZLIB and there's neither a target nor a library called z.
However, both find_package(ZLIB) and add_subdirectory(Externals/zlib)
create a target called ZLIB::ZLIB, so I'll switch to that instead.
Hopefully this change doesn't break anyone's build.
On Windows, Qt's default system font (MS Shell Dlg 2) is outdated.
Dolphin previously used over 15 lines of code to compute a font
closer to the proper font, but with an approximately correct font size.
Using the QMenu font directly is both more concise and more elegant
(in my opinion).