Replace C++ implementation of swift_beginAccess and swift_endAccess with (almost) pure Swift implementation. Helpers remain in C++ for TLS, getting return addresses, and raising a fatal error on violations.
This change also moves the exclusivity access set head from the shared SwiftTLSContext structure to a dedicated TLS key. This improves performance, which is important for exclusivity checking. This is particularly the case where we can inline TLS access with a constant key, as on Darwin ARM64.
The code that bridges exclusivity tracking into Concurrency remains in C++. The new Swift implementation exposes a few helpers for it to use as a replacement for directly manipulating the C++ implementation.
rdar://161122309
can be reentrantly executed.
I don't think doing this is *actually a good idea*, but corrupting the
runtime is an even worse idea, and the overhead here is very low.
There's no guarantee that e.g. pthread_key_t is an integral type. It could
be some kind of struct, or some other thing that isn't valid as a template
argument.
rdar://90776105
Moved all the threading code to one place. Added explicit support for
Darwin, Linux, Pthreads, C11 threads and Win32 threads, including new
implementations of Once for Linux, Pthreads, C11 and Win32.
rdar://90776105
There's no guarantee that e.g. pthread_key_t is an integral type. It could
be some kind of struct, or some other thing that isn't valid as a template
argument.
rdar://90776105
Moved all the threading code to one place. Added explicit support for
Darwin, Linux, Pthreads, C11 threads and Win32 threads, including new
implementations of Once for Linux, Pthreads, C11 and Win32.
rdar://90776105
