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Tag: performance

76 posts · Page 2 of 8

2026-09-07 dotnet dotnet-11 csharp

How to find the async void handlers causing ANRs in a .NET MAUI Android app

Play Console tells you your ANR rate is over 0.47% and hands you a native stack full of libcoreclr.so frames. Here is how to get from that useless trace to the exact async void event handler that blocked the main thread, using a Looper printer, a SynchronizationContext wrapper that names the state machine, and dotnet-trace over dsrouter.

2026-09-04 dotnet native-aot jit

What is the W^X flag in .NET and does Native AOT need it?

W^X (write xor execute) is the rule that no memory page is writable and executable at the same time. In .NET it is the DOTNET_EnableWriteXorExecute knob, on by default since .NET 7, and it exists entirely for the JIT. Native AOT never reads it. Here is how the runtime implements it, what it costs, and when turning it off is a legitimate fix.

2026-09-01 comparison csharp csharp-14

Returning a Task directly vs async/await passthrough in a C# repository method: which should you use?

Eliding async/await in a repository passthrough saves about 6 ns and 72 bytes, and costs you a stack frame, try/catch semantics, and safe disposal. Keep return await unless the method is a pure passthrough on a measured hot path.

2026-08-31 comparison automapper mapperly

AutoMapper vs Mapperly vs hand-written mapping in 2026

Mapperly is the default for new .NET code: it matches hand-written speed, survives Native AOT, and catches unmapped members at build time. AutoMapper still wins on ProjectTo. Benchmarks and license thresholds included.

2026-08-23 csharp linq dotnet

How to tell whether an IEnumerable<T> has already been materialized in C#

There is no HasBeenEnumerated flag on IEnumerable<T>. Here is what TryGetNonEnumeratedCount actually checks, why Enumerable.Range passes an ICollection<T> test, and the guard that avoids a wasted ToList().

2026-08-18 errors dotnet logging

Fix: CA1873 "Evaluation of this argument may be expensive and unnecessary if logging is disabled"

CA1873 fires on the implicit params object[] allocation, so almost every LogDebug call trips it. Fix it with [LoggerMessage] or an IsEnabled guard.

2026-08-15 comparison dotnet dotnet-11

Zstandard vs Brotli vs Gzip response compression in .NET 11

Zstandard is the right default for dynamic API responses in .NET 11, but not at the quality the ASP.NET Core provider ships with. Benchmarks on real JSON payloads showing why quality 1 beats the default quality 3 on both size and CPU, when Brotli still wins, and why Gzip survives only as a fallback.

2026-08-02 csharp dotnet dotnet-11

How to configure Kestrel to serve HTTP/3 in ASP.NET Core 11

A complete guide to enabling HTTP/3 on Kestrel in ASP.NET Core 11: the HttpProtocols.Http1AndHttp2AndHttp3 endpoint config, MsQuic platform requirements on Windows, Linux, and macOS, why the first request is never HTTP/3, how to verify with HttpClient and middleware, QuicTransportOptions tuning, and the firewall and proxy gotchas that make it silently fall back.

2026-08-02 csharp dotnet dotnet-11

How to replace new Regex(...) with the [GeneratedRegex] source generator in .NET 11

A complete guide to converting new Regex(pattern, RegexOptions.Compiled) into [GeneratedRegex] in .NET 11: the mechanical rewrite, partial methods vs partial properties, measured startup and throughput numbers, the SYSLIB1040-1045 diagnostics, and the two patterns where the generator silently falls back to a cached Regex.

2026-08-02 csharp dotnet dotnet-11

How to run CPU-bound work in a Blazor WebAssembly app with Web Workers in .NET 11

A complete guide to offloading CPU-bound work off the Blazor WebAssembly UI thread in .NET 11: why Task.Run does not help, the new blazorwebworker template, the WebWorkerClient API with cancellation and timeouts, the JSExport marshalling limits, and the second-runtime cost you pay per worker.