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
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
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
Mike Ash
Philippe Hausler
Alastair Houghton
Alex Hoppen