What’s New in .NET DevelopmentHabib Heydarian (habibh@microsoft.com)Program Manager, .NET2-303: What’s New in .NET Development

.NET (A *Very* Simplified View)

Runtime

Libraries

Languages Tools .NET

First, a look at .NET 4.5

Client & Device

•Async – for UI responsiveness•Windows Store apps -- WinRT•Windows Phone apps•.NET CF 3.9

Web & Cloud

•Async – for server scaling•ASP.NET MVC4•ASP.NET Web API•ASP.NET Web Pages•Entity Framework Code-First•WebSockets•SignalR•Windows Azure Cloud Services 4.5 Support•Windows Azure Web Sites

Fundamentals

•.NET Async (async + await)•Many new async APIs•WinRT interop•Multi-core JIT•MPGO – NGEN hot/cold splitting•Performance improvements•Reboot and reliability improvements to setup•Support Windows RT

GC•Background GC•LOH heap balancing•LOH fragmentation reduction•GC low latency mode•GC awareness of NUMA and >64 processors•>2GB arrays (or objects)

Libraries•Portable libraries update•.NET Core Profile (Windows 8)•Extension methods for WinRT streams and async•NuGet•Immutable collections•Async for .NET 4•HttpClient for Portable

.NET 4.5 is installed on 100+ million machines!

.NET 4.5.1 in A Nutshell

Developer Productivity

Application Performance

Continuous Innovation

Developer Productivity

In 2005, we introduced a *little* feature called Edit & Continue, but there was something missing….

Sorry to keep you waiting for 8 years…

64-bit Edit and Continue is finally here!• Number 9 all time requested feature on UserVoice!• Works exactly the same as for 32-bit applications• Client (WPF, WinForms, etc.), Store and ASP.NET WAP

projects are supported• For WAP projects, need to enable Edit & Continue in

Project Properties

Wait, there is more…

Method Return Value Inspection• Now available for .NET!• Access via Autos window or in the Immediate window

($ReturnValue)• Can expand return value in the debugger

Async Debugging Improvements• Common question: How did I get here?• Supported for Store Apps, Web apps, Desktop apps in

W8.1• Enhancements to the Call Stack and Tasks window

Visual Studio 2012

Windows Store Development Improvements• Convert System.IO.Stream to IRandomAccessStream

• Allows much easier interop with existing .NET code• Better exception support for WinRT APIs

• System.Exception.Message• System.Exception.StackTrace

• WinRT type system enhancements• Nullable value types in WinRT structs

• 64-bit Edit and Continue support• Managed Return Value Inspection support• Async debugging enhancedments

Convert Stream to IRandomAccessStream• From MSDN Forums…

// EXAMPLE: Get image from URL

var client = new HttpClient();

var stream = await client.GetStreamAsync(imgUrl);

var memoryStream = new MemoryStream();

await stream.CopyToAsync(memoryStream);

var bitmap = new BitmapImage();

bitmap.SetSource(memoryStream); <-- error CS1503: Argument 1: cannot convert from 'System.IO.Stream' to 'Windows.Storage.Streams.IRandomAccessStream‘

bitmap.SetSource(memoryStream.AsRandomAccessStream()); <-- .NET 4.5.1

In .NET 4.5.1:System.IO.WindowsRuntimeStreamExtensions.AsRandomAccessStream(Stream stream)

Rich exception interop support for WinRT APIs• In Windows 8, error propagation for WinRT APIs is

through HRESULT• Important Exception information is lost unless a debugger is

attached• In Windows 8.1, additional error information is available

via System.Exception properties:• Message• StackTrace

Additional exception details from a C++ WinRT Component

WinRT Type System Enhancements• Support Nullable value types in WinRT structs

// Define the "titleAuthor" table of the Microsoft "pubs" database.

public struct titleAuthor

{

// Author ID; format ###-##-####

public string au_id;

// Title ID; format AA####

public string title_id;

// Author ORD is nullable.

public short? au_ord;

// Royalty Percent is nullable.

public int? royaltyper;

}<-- error WME1060: 'System.Nullable<System.Int32>' is not a valid Windows Runtime field type.

<-- error WME1060: 'System.Nullable<System.Int16>' is not a valid Windows Runtime field type.

EF/ADO.NET Connection Resiliency• Provide reliable connection to Azure DB• Automatically retry/reconnect broken connection• Provides great experience for connected devices• It Just Works! No code or configuration changes other

than installing .NET 4.5.1

Application Performance

ASP.NET App SuspensionEnables low latency, high density web sites for on-prem/private cloud

Shipping as part of IIS 8.5 in Windows Server 2012 R2 Preview

Provisioned through the Idle Worker Process Page-out capability in IIS

Early Results from our Performance Lab

ASP.NET App SuspensionIn IIS Settings, set Idle Time-out Action to Suspended

On-demand Large Object Heap CompactionLet me start off by saying that the .NET GC is one well-tuned machine!In general, you should never have to use GC.Collect()CAUTION: With great power comes great responsibility!

On-demand Large Object Heap Compaction• Refresher• Large objects (>85000 bytes) treated specially• Very expensive to compact• Collected with Gen 2

• In .NET 4.5.1, you can now compact the Large Object Heap (LOH) to address heap fragmentation• The LOH mode is part of GCSettings:public static class GCSettings {

public static GCLOHCompactionMode LOHCompactionMode { get; set; }

}

On-demand Large Object Heap Compaction• Two ways to use GC LOH API:

1. Compact LOH right away

2. Compact LOH with the next full blocking GC

GCSettings.LOHCompactionMode = GCLOHCompationMode.CompactOnce;

GC.Collect();

// Next full blocking GC happens at some point, it will be a compacting GC that compacts the whole heap including LOH.

GCSettings.LOHCompactionMode = GCLOHCompationMode.CompactOnce;

On-demand Large Object Heap CompactionI’m going to wrap up by saying…

If you really believe you have a GC heap fragmentation issue (a.k.a. Gynormous GC Fragmentos syndrome), please email:• MaoniS@microsoft.com (our resident GC ninja)

Multi-Core JIT Improvements

Performance data from our test labs

• Minimize application startup time on multi-core CPUs

• Now supported for ASP.NET web sites

• Enabled automatically for ASP.NET apps

15% improvement for cold startup

Consistent Performance Before & After Servicing .NET

• Servicing .NET Framework for 1B+ PCs is a very BIG deal!

• Today, servicing the .NET Framework can lead to degradation in app performance directly afterwards

• This is due to core .NET assemblies being JIT-compiled for a period of time after servicing

• In Windows 8.1, app performance remains consistent even after servicing the .NET Framework

• Results in much better user experience and better battery life on tablets

Continuous Innovation

.NET Framework UpdatesOur goal is to keep the existing values of the .NET Framework while allowing for more agility and innovationExisting Values• Great discoverability (all in in place)• Known quality, maturity and compatibility level• A single license and support policy• Centralized patching for security issues*PLUS* New Values• Faster release cadence with a tighter customer feedback loop• Less friction with using features across .NET platforms

NuGet ReleasesDuring .NET 4.5 we released two components via NuGet:• MEF (Microsoft.Composition) for web and Windows Store apps• TPL Dataflow (Microsoft.Tpl.Dataflow)• These (and new packages) are treated as any other .NET 4.5

component, i.e. are fully supported

.NET (“in box”)

SystemCompositio

n

TPL Dataflo

wHttp

Client AsyncImmutabl

e Collection

s

Announcing: .NET Framework NuGet FeedOne-stop shopping for all of your .NET Framework NuGet packages released by Microsoft• In Visual Studio

20[10,12,13]• On the Web

.NET Framework NuGet Feed• Already enabled in VS 2013 Preview

• In VS 20[10,12]:• Tools.Options.Package Manager• Name: .NET Framework Packages• Source: https://nuget.org/api/v2/curated-feeds/dotnetframework

/

Visual Studio 20[10,12]

What’s New in .NET Development

• 64-bit Edit and Continue

• Method Return Value Inspection

• Async Debugging Enhancements

• Windows Store development improvements

• EF/ADO.NET Connection Resiliency

Developer Productivity

Application Performance

Continuous Innovation

.NET 4.5.1 delivers many new innovations while maintaining a high compatibility bar

• ASP.NET application suspension

• Multi-core JIT improvements

• On-demand large-object heap compaction

• Consistent performance before and after servicing the .NET Framework

• .NET Framework updates

• NuGet releases• Curated .NET

Framework NuGet packages

We would love to hear from you!

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2-303: What’s New in .NET Development

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