Tag: performance

Use await Task.Delay for any timed wait in async code, Thread.Sleep only on a dedicated thread you own, and SpinWait only for sub-microsecond waits inside lock-free code. To wait for a condition, use a signal (ManualResetEventSlim, SemaphoreSlim, TaskCompletionSource) instead of any of the three. Measured on .NET 10.0.10.

A compiled model is generated C# that recreates your EF Core model without running OnModelCreating. Measured on EF Core 11 RC1: model load drops from 714 ms to 215 ms at 500 entities, but the MSBuild route (which replaced EFOptimizeContext) is slower, stale models fail silently, and query filters block generation.

A transparent struct is one the ABI treats exactly like its only field. .NET 11 has no such guarantee: a struct wrapping a double is passed in RCX on Windows x64 but in XMM0 on Linux and macOS. Here is the disassembly from the .NET 11 JIT on three ABIs, the P/Invoke bugs it causes, and how to write wrapper types that are safe at every boundary.

AddDbContextPool hands out one scoped DbContext per DI scope, so it cannot run two queries at once. AddDbContextFactory and AddPooledDbContextFactory give you a context per call, which is what parallel queries need. Measured on EF Core 11 RC 1: the pooled factory creates a context in 342 ns and 40 B versus 17 us and 44 KB.

Check IsCompleted first and read the result through GetAwaiter().GetResult(), which costs 0 bytes. Only fall back to blocking when the ValueTask is still pending, and do that with a cached event and UnsafeOnCompleted instead of AsTask(), which allocates 72 to 208 bytes per call. Measured on .NET 10 and .NET 11 RC1.

EF.Constant inlines a captured value as a SQL literal, EF.Parameter turns a literal into a SQL parameter. Keep EF Core's defaults, use EF.Parameter to stop dynamically built expression trees from recompiling on every call, and use EF.Constant only for a value with a handful of distinct values whose data is skewed enough to need its own plan.

Volatile.Read is an acquire load of one location. Volatile.ReadBarrier, new in .NET 10, is a fence that gives every earlier read acquire semantics. Use Volatile.Read for flags and published references, and ReadBarrier when you need a batch of plain or non-atomic reads to complete before the next memory access, as in a seqlock.

A monorepo with dozens of pubspec.yaml files makes the Dart analysis server build one analysis context per package, which is where the memory and the minute-long startup go. Convert to a pub workspace, exclude generated code in analysis_options.yaml, drop legacy analyzer plugins, and use the Insights page to prove it. Measured on Dart 3.12.2: 2.3x less peak memory and half the cold analysis time.

Ship skwasm with flutter build web --wasm when your dependencies compile to Wasm: it downloads less and rendered 36% more frames than CanvasKit on a heavy scene. On Flutter 3.47.x, keep it single-threaded until the multi-threaded text crash fix leaves beta.

Stephen Toub's Performance Improvements in .NET 11 post shows generic virtual method calls dropping from 6.7 ns and 24 bytes to 1.8 ns and zero allocation. Three RyuJIT pull requests unlocked inlining on the dispatch that used to be the most opaque one in .NET.