Make sync::raw::Sem use Unsafe to manage mutability instead of *() #14708
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…uting an unsafe pointer
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Jun 7, 2014
Currently, `Sem`, which is used as a building block for all the blocking primitives, uses a very ugly hack to implement `Share` and be able to mutate the stored `WaitQueue` by hiding it all behind a `transmute`d `*()`. This PR replaces all that ugly machinery with `Unsafe`. Beyond being cleaner and not requiring `transmute`, this removes an allocation in the creation and removes an indirection for access.
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Currently,
Sem, which is used as a building block for all the blocking primitives, uses a very ugly hack to implementShareand be able to mutate the storedWaitQueueby hiding it all behind atransmuted*(). This PR replaces all that ugly machinery withUnsafe. Beyond being cleaner and not requiringtransmute, this removes an allocation in the creation and removes an indirection for access.