Writing High Peformance C# 7 Code
- 1. Writing High Performance C# 7 Code Fons Sonnemans @fonssonnemans
- 2. Fons Sonnemans • Software Development Consultant • Programming Languages • Clipper, Smalltalk, Visual Basic, C# • Platforms • Windows Forms, ASP.NET, XAML (Silverlight, WPF, Windows Phone, Windows 10, Blend) • Databases • MS SQL Server, Oracle • Role • Trainer, Coach, Advisor, Architect, Designer, Windows App Developer • www.reflectionit.nl/training • www.reflectionit.nl/apps 2
- 3. Audience • Who is not a Software Developer • Who is not a C# developer • Who is not using C# 7 • Who is not using C# 7.3 • Who is not using .NET Core 2.0 or 2.1 • Who is not creating 64 bits apps • Who is not using ReSharper • Who is not using (or writing) Code Analyzers • Who does not understand the .NET Garbage Collector (GC) • Who is not having Performance Issues • Who is not writing Structs 3
- 4. How to solve Performance Issues • Choose fast algorithms • Choose optimal data structures • Optimize memory usage • Implement caching • Think over architecture • Layers, Tiers, UI, (Web) API, Message Queues, Cloud, Security, Transactions (locking), Threading (async) • Optimize networking (HTTP, SQL) • Work chunky not chatty • Optimize I/O • Where are you writing your Trace information, files, databases, cloud or ETW? • https://www.youtube.com/watch?v=XfkpjlP0Nq4 4
- 5. What’s new in C# 7 • C# 7.0 • Out Variables • Binary literals & Digit separators • Pattern Matching • Local Functions • Tuples • Deconstruction • Discards • More expression bodied members • Throw expressions • Generalized async return types • Ref Returns and Ref Locals • C# 7.1 • Default Expressions • async Main • Infer tuple names • Pattern-matching with Generics • C# 7.2 • Reference semantics with value types • In parameters, ref readonly, readonly struct, ref struct • private protected access modifier • Non-trailing named arguments • Ref & In Extension Methods • Conditional Ref Operator • C# 7.3 • new generic constraints • Attributes on backing fields • Ref local re-assignment • Stackalloc initializers • Expression variables in initializers • Tuple comparison • Improved overload candidates
- 6. Topics • Measuring & Tools • Stopwatch • Diagnostic Tools • Performance Profiler • Benchmark.NET • ILSpy & SharpLab.io • Garbage Collection • Large Object Heap • Collection Capacity • ArrayPool<T> • Writing Structs • C# 7.0: Anonymous Types vs ValueTuples • BigStruct: ByValue & ByRef • StuctLayout • Boxing & Unboxing • CLR Heap Allocation Analyzer • Equals & GetHashCode • Defensive Copy • C# 7.x • In parameters, • Ref (Readonly) Return & Ref (Readonly) Local • Readonly structs • ErrorProne.NET.Structs • Ref structs, Span<T>, Stackalloc 6
- 7. Heap Reference Types + Value Types storedin Fields of Reference Types .NET Memory - Stack & Heap 7 Stack Value Types + Pointers 1MB on 32Bit 4MB on 64Bit Thread 1 CPU Cache L1 -> L2 -> L3 Thread 2 Thread N Large Object Heap Objects larger than 85KB, mostly arrays Gen 2 + Not Compacted ? Small Object Heap Gen 0 Short-lived ~256KB Gen 1 “Buffer” ~2MB Gen 2 Long-lived ~10MB GC GC L2 Code Heap Process Heap
- 8. Value Types vs. Reference Types • Memory Overhead • http://adamsitnik.com/Value-Types-vs-Reference-Types/ • Value Type (PointStruct) • Reference Type (PointClass) 8 X Y X Y Total: 8 Bytes Total: 8 Bytes Total: 16 Bytes Total: 24 Bytes