Who contributed to .NET on August 16, 2026?

5 developers shipped this update, including Shane Neuville, Joel Christner, StephenMolloy, Sergio0694, and davidwrighton.

What were the notable .NET updates?

Buffer consecutive text nodes when loading XContainer to avoid O(n^2), Partition the ComWrappers RCW cache into per-processor buckets, and [wasm] Encode struct alignment in thunk signatures.

Aug 16, 2026

$ the-wire · showcase

RUNTIME CUTS XML DESERIALIZATION FROM O(N^2) TO LINEAR; COMWRAPPERS LOCK CONTENTION SOLVED

By RepoJournal · Filed 06:59 UTC on August 16, 2026 · About .NET · Composed from the cited sources · methodology

5 people shipped this

Joel Christner @jchristn 2 cited

Shane Neuville @PureWeen 1 cited

StephenMolloy @StephenMolloy 1 cited

Sergio0694 @Sergio0694 1 cited

davidwrighton @davidwrighton 1 cited

The .NET runtime shipped two critical performance fixes overnight that eliminate pathological slowdowns in XML parsing and COM interop, with changes landing across three desks.

XContainer's IXmlSerializable loader has been buffering consecutive text nodes to avoid catastrophic O(n^2) string concatenation when DataContractSerializer or IXmlSerializable.ReadXml surfaces small consecutive text nodes [1]. Separately, ComWrappers RCW identity cache now partitions into per-processor buckets instead of serializing all native-to-managed transitions behind a single ReaderWriterLockSlim, eliminating a process-wide contention point that fires on essentially every COM call [2]. On the WebAssembly front, struct alignment encoding in thunk signatures now distinguishes 16-byte boundaries from 8-byte boundaries, supporting correctly aligned struct-by-value parameters on Wasm [3]. Over in MAUI, PureWeen repaired skill-evaluation fixture failures exposed by recent changes [4]. WatsonWebserver completed a comprehensive test infrastructure migration to Touchstone, a runner-agnostic descriptor framework that consolidates 18 test suites into a single source of truth consumed identically by CLI, xUnit, and NUnit runners [5], while also refreshing dependencies and cutting releases 7.1.1 and clients 7.0.15 [6].

Action items

→ Update to latest .NET runtime for XML deserialization and COM interop improvements dotnet/runtime [plan]
→ Test MAUI fixture repairs before next mobile release dotnet/maui [plan]
→ Review WatsonWebserver 7.1.1 changelog if you consume the library dotnet/WatsonWebserver [monitor]

References

[1] Buffer consecutive text nodes when loading XContainer to avoid O(n^2) ↗ dotnet/runtime
[2] Partition the ComWrappers RCW cache into per-processor buckets ↗ dotnet/runtime
[3] [wasm] Encode struct alignment in thunk signatures ↗ dotnet/runtime
[4] Fix skill evaluation fixtures and failure reporting ↗ dotnet/maui
[5] Migrate test infrastructure to Touchstone (shared source of truth + CLI/xUnit/NUnit runners) ↗ dotnet/WatsonWebserver
[6] Update dependencies, harden API-route serialization tests, cut 7.1.1 / clients 7.0.15 ↗ dotnet/WatsonWebserver