LocalIo is unsafe and should not be. #11053
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A-runtime
Area: std's runtime and "pre-main" init for handling backtraces, unwinds, stack overflows
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ghost
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All of this is irrelevant with libgreen gone. |
flip1995
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Jul 14, 2023
Use `cargo build --tests` in CI I noticed that we run a `cargo build` but end up downloading/building a bunch of deps after that for tests in CI https://github.com/rust-lang/rust-clippy/actions/runs/5426673277/jobs/9869019973#step:6:12 https://github.com/rust-lang/rust-clippy/actions/runs/5426673277/jobs/9869019973#step:7:11 This builds the tests in the build step too, it may speed up runs by downloading/building more in parallel changelog: none
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The current implementation of
LocalIoinvolves unsafe borrowing which doesn't transfer ownership of theIoFactory. This unsafe code allows for mutably aliasing theIoFactorymultiple times on the stack (leading to memory unsafety).Fixing this would involve dancing around transferring ownership of the
IoFactorybetween the calls that it makes. My initial idea was forLocalIoto take ownership and give out&mutloans to it, but this is insufficient because when a green task context switches the scheduler must again have ownership of theIoFactory.My best idea for doing this right now is to change all methods on
IoFactoryto take~selfand then right before the M:N methods block they would transfer ownership back to the scheduler. All the 1:1 methods would basically immediately return ownership of the factory back to the localTask.The text was updated successfully, but these errors were encountered: