Drop redundant fixed pins from UnsafeMemory.WriteRaw - #2257

Open

unsafePtr wants to merge 1 commit into

MessagePack-CSharp:masterfrom

unsafePtr:drop-redundant-fixed-unsafememory

unsafePtr commented May 4, 2026

Contributor

No point to emit fixed here in this case. ref is providing same guarantees. I am going to check other places with fixed as well

https://sharplab.io/#v2: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


          perf: drop redundant fixed pins from UnsafeMemory.WriteRawN

49d6947

unsafePtr commented Jul 8, 2026

Contributor Author

Checked #2170, but it's still better to use the version which I am providing

https://sharplab.io/#v2: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=

EgorBo commented Aug 14, 2026

Note: our personal experience that fixed is much more safer than pinning-free ref arithmetic. The latter is more error prone to GC holes (we had a real example in dotnet/runtime), see https://learn.microsoft.com/en-us/dotnet/standard/unsafe-code/best-practices#4-invalid-managed-pointers-even-if-they-are-never-dereferenced

Chances to spot such bugs are extremely low.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet