Fix potential UB in ByteString.hashCode #208
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I thought it shouldn't, but:
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fzhinkin
reviewed
Aug 10, 2023
bytestring/common/src/ByteString.kt
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| @@ -69,6 +70,7 @@ public class ByteString private constructor( | |||
| public constructor(data: ByteArray, startIndex: Int = 0, endIndex: Int = data.size) : | |||
| this(data.copyOfRange(startIndex, endIndex), null) | |||
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| @Volatile | |||
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Does it make sense to add an expect annotation like VolatileInNative and actualize it with Volatile only in native?
Like in this patch
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The nicest alternative would be to somehow perform load/store w/ relaxed memory ordering, though:
https://godbolt.org/z/rEdcobsW3
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Pushed a slightly different version, please check it out.
The nicest alternative would be
Yep. I agree we ruled it out as "no use cases" during the initial design 😅
fzhinkin
approved these changes
Aug 10, 2023
Co-authored-by: Filipp Zhinkin <[email protected]>
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It has a benign JVM data-race on the hashCode field, but on K/N LLVM has no guarantees it will read default or written value (e.g. OoTA is one of the possibilities). The recommendation from K/N folks is to use @volatile here
Fixes #190