1c4a5f8d1e
Split sys_common::Mutex in StaticMutex and MovableMutex. The (unsafe) `Mutex` from `sys_common` had a rather complicated interface. You were supposed to call `init()` manually, unless you could guarantee it was neither moved nor used reentrantly. Calling `destroy()` was also optional, although it was unclear if 1) resources might be leaked or not, and 2) if `destroy()` should only be called when `init()` was called. This allowed for a number of interesting (confusing?) different ways to use this `Mutex`, all captured in a single type. In practice, this type was only ever used in two ways: 1. As a static variable. In this case, neither `init()` nor `destroy()` are called. The variable is never moved, and it is never used reentrantly. It is only ever locked using the `LockGuard`, never with `raw_lock`. 2. As a `Box`ed variable. In this case, both `init()` and `destroy()` are called, it will be moved and possibly used reentrantly. No other combinations are used anywhere in `std`. This change simplifies things by splitting this `Mutex` type into two types matching the two use cases: `StaticMutex` and `MovableMutex`. The interface of both new types is now both safer and simpler. The first one does not call nor expose `init`/`destroy`, and the second one calls those automatically in its `new()` and `Drop` functions. Also, the locking functions of `MovableMutex` are no longer unsafe. --- This will also make it easier to conditionally box mutexes later, by moving that decision into sys/sys_common. Some of the mutex implementations (at least those of Wasm and 'sys/unsupported') are safe to move, so wouldn't need a box. ~~(But that's blocked on #76932 for now.)~~ (See #77380.) |
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.. | ||
alloc | ||
backtrace@4083a90168 | ||
core | ||
panic_abort | ||
panic_unwind | ||
proc_macro | ||
profiler_builtins | ||
rtstartup | ||
rustc-std-workspace-alloc | ||
rustc-std-workspace-core | ||
rustc-std-workspace-std | ||
std | ||
stdarch@b422b0180f | ||
term | ||
test | ||
unwind |