[−][src]Crate ulock_sys
Bindings for macOS's not-entirely-public ulock API, which provides futex-like functionality.
In general, caveat emptor. It's recommended that you read both the source and the header. In particular, I've not documented the code very much beyond what's in the headers, aside from supported version indications.
Support
This API is available on darwin 16+ (macOS 10.12+, iOS 10.0+, tvOS 10.0+,
watchOS 3.0+, catalyst 13.0+), although some parts are darwin 19+ (macOS
10.15+, iOS 13.0+, TODO: find out the rest). The parts on darwin 19+ are in
the darwin19 module (it's just some additional constants, so not worth
feature gating).
That is to say, this is pretty well supported, over 95% of users on both macOS and iOS will have it (according to statscounter as of Jan 2021).
That said, they're not public, and who knows the future, maybe Apple will remove them. But probably not — they're also used by libc++, and so if they ever went away, code that statically links libc++ would suddenly break, but... who knows, maybe apple will do it.
"weak" linking, cargo features
As a result of that (and so that you can support older versions), if you
enable the experimental-weak feature, we'll expose a module weak which
emulates weak linking and accesses the function via dlsym.
Note that on aarch64 darwin (e.g. "apple silicon", the ARM64 macbooks and
such) by default we don't dlsym even if the "experimental-weakweak"
feature is on unless "weak-aarch64-macos" is also specified. This is because
all OSes on these machines support the API. This can be overridden by
enabling the weak-aarch64-macos feature.
Note that the API of this crate (except for consts) is behind cfg!(target_vendor = "apple").
Modules
| darwin19 | The portion of the API only is supported on Darwin 19 and up (macOS 10.15+, iOS 13.0+). |
Constants
| ULF_NO_ERRNO | Generic flag usable with [ |
| ULF_WAIT_CANCEL_POINT | Flag only for [ |
| ULF_WAIT_WORKQ_DATA_CONTENTION | Flag for [ |
| ULF_WAKE_ALL | Flag for [ |
| ULF_WAKE_THREAD | Flag for [ |
| UL_COMPARE_AND_WAIT | Operation code (these are in bits 0-8) |
| UL_HANDOFFLOCK | Deprecated Obsolete name for |
| UL_OSSPINLOCK | Deprecated Obsolete name for |
| UL_UNFAIR_LOCK | Operation code (these are in bits 0-8) |
Type Definitions
| ULockWaitFn | Alias for the function pointer of [ |
| ULockWakeFn | Alias for the function pointer of [ |