Categories
.net Android Development Mono For Android VS 2012

Poor man’s performance profiling

If you have been doing development with Xamarin on Android you have probably noticed the total absence of any profiler, there is not even a decent method to get the high resolution time. Sure, there is Environment.TickCount but the resolution is at best in milliseconds. Pretty useless for performance profiling.

Rarely people use performance profilers on the desktop. Mostly because their applications don’t have complicated stuff and the modern CPUs are hiding most of the non performing code. However mobile devices are far more delicate and have less CPU power, less RAM, less resources in general. Thus slow code is much more notable and visible to end users. There is no better way to profile your code with a performance profiler. Just take a look at RedGate’s ANTS Performance profiler. Unfortunately there are no such tools for Xamarin Android platform even though mobile code should be really optimized.

I present  my solution for getting some useable metrics from your code (the code you have sources for). The code I’ve written was used for MvvmCross performance profiling hence it slightly relies on it (logging, IoC) however it can be easily made standalone if necessary.

Getting high resolution time

Java has java.lang.System.nanoTime() method that returns the highest resolution time available on Android. Xamarin doesn’t provide it through .net, you have to write a wrapper by yourself using java reflection.

public static class JavaLangSystem
{
    static IntPtr class_ref;
    static IntPtr id_nanoTime;
    public readonly static long Avg;

    static JavaLangSystem()
    {
        class_ref = JNIEnv.FindClass("java/lang/System");
        id_nanoTime = JNIEnv.GetStaticMethodID(class_ref, "nanoTime", "()J");

        for (int i = 0; i < 10; i++)
        {
            NanoTime();
        }

        long start = NanoTime();
        for (int i = 0; i < 1000; i++)
        {
            NanoTime();
        }
        Avg = (NanoTime() - start) / 1000;
MvxTrace.TaggedTrace("metrics", "Avg NanoTime reflection is {0}", Avg); } [Register("nanoTime", "()J", "")] public static long NanoTime() { return JNIEnv.CallStaticLongMethod(class_ref, id_nanoTime); } }

Note that I do some calibration in static constructor because of reflection the call to nanoTime() itself consumes some time. I store the average call time into a static variable Avg that I’ll later use.

Accessing high resolution timer through IoC

First part is to create an interface

public interface IHighResolution
{
    long Ticks { get; }
    long Avg { get; }
}

then implement it

public class HighResolution: IHighResolution
{

    #region IHighResolution Members

    public long Ticks
    {
        get { return JavaLangSystem.NanoTime(); }
    }

    public long Avg
    {
        get { return JavaLangSystem.Avg; }
    }

    #endregion
}

and finally register it to IoC provider.

protected override IMvxApplication CreateApp()
{
    Mvx.RegisterType<IHighResolution, HighResolution>();
    return new App();
}

I register it in MvxAndroidSetup derived class (MvvmCross initialization) but if you are not using MvvmCross feel free to register it with IoC provider of your choice on some other initialization place.

This separation comes specially handy if you are to measure PCL assemblies where nanoTime() isn’t accessible.

 

Define class that will store a single measurement

[DebuggerDisplay("{Name} in {Ticks}")]
public class PerfMeasurement
{
    public string Name { get; set; }
    public List<PerfMeasurement> Children;
    public long Ticks { get; set; }

    public int AllChildren
    {
        get
        {
            if (Children == null || Children.Count == 0)
                return 0;
            else
            {
                int sum =0;
                foreach (PerfMeasurement m in Children)
                {
                    sum += 1 + m.AllChildren;
                }
                return sum;
            }
        }
    }
}

There are two interesting features here. First is Children field which holds nested measurements. And the other is AllChildren property that recursively counts all children.

The main measurement class

public static class Metrics
{
    private static readonly IHighResolution highresolution;
    private static readonly long twoAvg;
    
    public static List<PerfMeasurement> RootData { get; private set; }
    private static Stack<PerfMeasurement> stack;
    //         private static int counter;
    
    static Metrics()
    {
        RootData = new List<PerfMeasurement>(100000);
        stack = new Stack<PerfMeasurement>();
        highresolution = Mvx.Resolve<IHighResolution>();
        twoAvg = highresolution.Avg * 2;
    }
    
    public static PerfMeasurement Push(string name)
    {
        PerfMeasurement head;
        if (stack.Count == 0)
        {
            head = new PerfMeasurement { Name = name };
            RootData.Add(head);
        }
        else
        {
            PerfMeasurement previous = stack.Peek();
            head = new PerfMeasurement { Name = name };
            if (previous.Children == null)
                previous.Children = new List<PerfMeasurement>();
            previous.Children.Add(head);
        }
        stack.Push(head);
        return head;
    }
    
    public static void Pull()
    {
        stack.Pop();
        if (stack.Count == 0)
        {
            PerfMeasurement m = RootData[RootData.Count - 1];
            OffsetParents(m);
            Print(m);
        }
    }
    
    private static void OffsetParents(PerfMeasurement m)
    {
        m.Ticks -= m.AllChildren * twoAvg;
        if (m.Children != null)
        {
            foreach (PerfMeasurement child in m.Children)
                OffsetParents(child);
        }
    }
    
    public static void Print(PerfMeasurement metric)
    {
        StringBuilder sb = new StringBuilder();
        Print(metric, sb, 0);
        MvxTrace.TaggedTrace("metrics", sb.ToString());
    }
    
    public static void Print(PerfMeasurement metric, StringBuilder sb, int depth)
    {
        string prepend = new string(' ', depth * 4);
        sb.AppendLine(string.Format("{0}{1} took {2:#,##0}", prepend, metric.Name, metric.Ticks));
        if (metric.Children != null && metric.Children.Count > 0)
        {
            foreach (PerfMeasurement child in metric.Children)
            Print(child, sb, depth + 1);
        }
    }
}

This class acts like a Stack for measurement items defined in earlier one. When item at the root level is pulled it outputs the results of the whole hierarchy linked to it into the (MvvmCross) logging mechanism (Print methods). But before doing that it recursively subtracts the nanoTime() invocation of all children (OffsetParents – for each children it assumes nanoTime() took two average invocations – hence the static field twoAvg).

That’s all we need. However there is one step that will make measurement a bit easier and more clean.

 

Making it easier to use Metrics with a helper class

public class MeasurePerf : IDisposable
{
    private static readonly IHighResolution highresolution;

    private long start;
    private PerfMeasurement m;

    static MeasurePerf()
    {
        highresolution = Mvx.Resolve<IHighResolution>();
    }

    public MeasurePerf(string name)
    {
        m = Metrics.Push(name);
        this.start = highresolution.Ticks;
        
    }

    public void Dispose()
    {
        m.Ticks += highresolution.Ticks - start - highresolution.Avg;
        Metrics.Pull();
    }
}

This class is intended as a wrapper around measured code using using keyword. Measurement looks like:

using (new MeasurePerf("Your comment here"))
{
    // your code here
    // nesting measuring is perfectly fine
}

Here is a sample output I’ve been looking at:

profiler_results

I highlighted the root item. All items are showing their total time (children included). Note the negative numbers. That happens because this kind of measurement isn’t accurate at all (remember, I am subtracting twoAvgs). However it gives you at least some insight of what code is slow and which child is guilty.

So, that’s it. Until Xamarin gives us profilers there is no better way AFAIK. Unfortunately. There is one thing you can do, though. You can tell Xamarin that we need profilers. Perhaps through my uservoice suggestion.

Categories
.net Android Development Mono For Android VS 2012

A week of impressions of developing for Android using Xamarin & MvvmCross

Occasionally I watch road bicycling and it happens that I started following Vuelta 2013. Of course I downloaded the official application for Android as well – to keep an eye on standings. The poor quality of the Android application bothered me a bit. Both the lack of data and poor UI. Most notably I really found it hard to see where my favorite bicyclists are standing.

This triggered a well known feeling in me – I have to create my own Android application instead. For quite some time I was eying Android development but so far I didn’t have a proper motivation.Armed with Xamarin and MvvmCross I dived in. I had almost no experience with Android OS development, very little of Xamarin and none of MvvmCross. The goal was to create a MVVM based application that could leverage the common code along different mobile platforms though the current state is Android only application. I could create a version for iOS and Windows Phone 8 as well, I guess, but I don’t have a Mac (required to build for iOS) nor I want to loose a ton of time to enable Windows Phone development environment for a free application (which is a shame because WP8 development doesn’t look bad at all). Perhaps sometime.

The application itself is available for free through Google Play. Go, get it, while it is still actual.

About Xamarin

What they have done is simply amazing. Porting Mono (.net) stack to mobile platforms that is. Including the latest crazy useful async/await.This gives a .net developer an option to provide common code base for Windows RT, desktop Windows, Windows Phone, Android and iOS and to unleash the .net on platforms MS didn’t want you to. The community is there. But it comes with some quirks. Here are some major ones I found while developing with Visual Studio 2012:

  • debugger is often slow. Sometimes it takes quite a lot of tenths of seconds to be able to inspect variables at a breakpoint
  • async/await debugger breakpoints stop at random lines of code and often “Step Over” or “Step Into” means “Continue running”
  • Portable Class Library support is still a problem (most notably, VS Android projects can’t reference PCL assemblies while Xamarin IDE intellisense goes beserk on PCLs)
  • no profilers available (performance, memory) for Android. These are insanely important for mobile devices. Vote here.
  • price for Indie developers (small shops) might be high

I am not exactly sure whether some of these problems might be attributed to VS or Xamarin integration. Anyway, none of these is a showstopper and I am sure they’ll be addressed.

About MvvmCross

This framework is an excellent open source MVVM starting point for cross platform .net mobile development. @slodge. the author, has done and is still doing an insane job. Not just by creating the framework but he is all over the Internet answering questions and writing (well, mostly recording) documentation and samples. That said there are some problems with MvvmCross:

  • huge framework, takes time to grasp
  • I miss better fundamentals description (i.e how DataContext is transferred to children)
  • sometimes slow (i.e. startup time, ListView bindings). NOTE: since there is no performance profiler available I couldn’t exactly determine why it acts slowly sometimes. Could be Xamarin, could be MvvmCross or Android or my code.
  • some error messages could be better (i.e. suggesting you a solution instead of just reporting errors)

But hey, it is open source and I plan to contribute if time permits.

About Android

It is not hard to learn the basics but it has plenty of small issues and traps one has to be aware of. The fragmentation doesn’t help either nor does java stack but overall it isn’t that big of an issue.

Then there are Intel Android x86 images which are used if you want to run the emulator. (Forget about ARM ones due to the slowness). Intel Android x86 v17 image has a quirk that logs messages like nuts making log window pretty much useless. Then there is the v18 image that fixed overlogging issue but introduced a new one. It’d throw “can’t resolve host” when using HttpClient 99% of the time. This issue might be attributed to Xamarin though as its browser doesn’t exhibit same problems.

Google Play store publishing

Straightforward, no issues. Wait, there is a potential problem. If you want to publish an app on Google Play store you have to comply to US laws, most notably they warn you of using encryption. I wonder why (rhetorical).

So, these are my impressions, after a week of development. Note that I mostly listed problems I’ve encountered not described the (bright points of) products in details.

Feel free to feedback me.

Categories
.net Mono For Android

How to compile MvvmCross v3 sources

As you well know, or you might not, MvvmCross is a cross platform MVVM framework supporting many platforms, such as Android and iOS (both through Xamarin), WPF, WinRT, WP7. Feature worth drooling.

Now, AFAIK there are two versions available. v2 (aka vNext) which is supposedly stable and v3 which is work in progress but holds many improvements. Here is how to get v3 sources compiled for Android (I didn’t test others) in case you run into problems like me.

  1. head to Github repository for v3 branch (optionally)
  2. use git clone –b v3 git://github.com/slodge/MvvmCross.git do fetch sources
  3. open MvvmCross_All.sln solution (using Visual Studio 2012) which references all projects for all platforms. If you don’t have Touch support (or others) Visual Studio will let you know. You can safely ignore those warnings.
  4. build solution. If it does consider yourself lucky, otherwise continue reading.
  5. If you get something like

Error 172 Exception while loading assemblies: System.IO.FileNotFoundException: Could not load assembly ‘Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed’. Perhaps it doesn’t exist in the Mono for Android profile?
File name: ‘Newtonsoft.Json.dll’

then there is a problem with build process. My guess is that it happens because portable class libraries, which Newtonsoft.Json.dll is, aren’t officially supported by Xamarin. Yet.

The workaround is to get Newtonsoft.Json sources (use PCL csproj version), include the project into solution and replace the reference in Plugins\Cirrious\Json\Cirrious.MvvmCross.Plugins.Json project with the Newtonsof.Json project itself.

Now you can run samples, at least I did – tested with Samples\Tutorial\Tutorial.UI.Droid.

There is another build error you might encounter (in general for Xamarin.Android). Sometimes the build process yields a ton of senseless errors (can’t find classes, interfaces, etc.) even though the code should compile. Try building again – most of the times it builds without errors the second time.

If you are interested into MvvmCross project make sure you read Stuart’s blog (creator of MvvmCross).

I have to test it a bit now, so more blog posts on the topic might follow.

Have fun with MVVM everywhere.

Categories
.net DevExpress

An exotic DevEx’ ReportDesigner breaking change in 12.2

If you ever customized (excellent) DevExpress ReportDesigner you might have used this line of code to obtain a reference to IDataSourceCollectionProvider within ReportDesigner class which allows to access field list:

IDataSourceCollectionProvider dataSourceCollectionProvider = 
    designerHost.GetDesigner(designerHost.RootComponent) 
    as IDataSourceCollectionProvider;

This code worked well in 12.1 and perhaps in earlier 12.2 versions but it certainly won’t work in 12.2.5. The bad part is that it fails in runtime, while it still compiles perfectly. At least it fails consistently – always. The reason is that access to various services (IDataSourceCollectionProvider is one of them) is now through ReportDesigner.GetService(Type serviceType) method. Replacing the part above with the one below does the trick:

IDataSourceCollectionProvider dataSourceCollectionProvider = 
    (IDataSourceCollectionProvider)designerHost.GetService(
        typeof(IDataSourceCollectionProvider)
    );

The new is more readable and it could be even better if it used generics. I’d certainly consider this declaration instead:

T GetService<T>()
  where T: class
{
   ...
}

which would yield even more readable assignment:

IDataSourceCollectionProvider dataSourceCollectionProvider = 
    designerHost.GetService<IDataSourceCollectionProvider>();

There you have the fix.

Categories
.net Android Development MonoForAndroid

Just developing for Windows 8 Store gives your privacy a funeral

I was poking around with excellent MonoGame framework by creating a simple game, or better, starting to create a simple game. So far I’ve spent a day to build some infrastructure from scratch and I am able to show a main screen with simple menu items. Nothing really ground-breaking.

The aspect I am most interested right now is cross platform development with MonoGame. Hence my simple game is built with cross platform support from beginning. Main development target is Windows 7 x64 because it is the easiest to debug the application on. I’ve ported the game successfully to Android as well by using Mono For Android – tested on both emulator and my Google Nexus phone. Port means just creating a bootstraper (an Android app that launches the game within an activity) and linking the sources to Mono For Android projects (here Project Linker comes to great help, though shame that Microsoft Patterns And Practices team seemingly abandoned it).

 

 

Windows Phone 8 emulator requirements are insane

Next I wanted to port it to Windows Phone 8 since its SDK is fresh from the oven and MonoGame supports it (not sure at what stage the support is). However, Windows Phone 8 SDK emulator requirements are just too much: Visual Studio 2012, Windows 8 Pro, 4GB RAM, and CPU with SLAT support to run the emulator which in turn runs on Hyper-V. I don’t have a Windows Phone 8 device so I wanted to give the emulator a test run. I have Windows 8 Pro on my laptop but, albeit perfectly functional, the CPU doesn’t feature SLAT. SLAT is required by Hyper-V on client versions of Windows 8. The interesting fact is that VMWare Workstation runs perfectly well without or with SLAT. Be also aware that VMWare Workstation and Hyper-V on Windows 8 won’t coexist peacefully – Workstation will work only when Hyper-V feature isn’t present. The bottom line is that the Windows Phone 8 emulator won’t run on my laptop. I could run it on my workstation but I haven’t migrated to Windows 8 at this time.

Windows 8 development license isn’t something for privacy consciousness

Next I wanted to run a Metro aka Windows Store Apps version of my game. Those should run just fine on my laptop. I started by creating a new Windows Store application and Visual Studio 2012 immediately notified me that I need a developer license for Windows 8 which is free. But reading its privacy statement made me wonder.


When you request a developer license, Microsoft collects information about your PC and the apps installed on it. This information includes your PC’s name, manufacturer, and model; your IP address; a unique identifier generated based on your PC’s hardware configuration; and the edition of Windows you’re using.
….
Microsoft may access or disclose information about you, including the content of your communications, in order to: (a) comply with the law or respond to lawful requests or legal process; (b) protect the rights or property of Microsoft or our customers, including the enforcement of our agreements or policies governing your use of the services; or (c) act on a good faith belief that such access or disclosure is necessary to protect the personal safety of Microsoft employees, customers, or the public. We may also disclose personal information as part of a corporate transaction such as a merger or sale of assets.

Remember, I wanted to test my game locally. And for that I’d need to send all sort of data to Microsoft? What the heck? Furthermore those legal obligations are really flexible. Not that I have anything to hide or against Microsoft but still why do I have to disclose installed applications on my computer and such? Note that I wouldn’t send my data to any company just to test an application on the local machine. So, for the time being, I will skip Windows Store App version as well.

Progress so far:

  • Windows Desktop [checked]
  • Android [checked]
  • Windows Phone 8 [unknown]
  • Windows Store App [unknown]
  • Windows Phone 7 [unknown,soon]

There is only one platform left to try – Windows Phone 7 where I don’t foresee any problems, just didn’t have time yet.

Categories
.net Graphics Hardware Windows 8

Getting proper OpenGL driver for older AMD(ex. ATI) graphics cards on Windows 8

I have a not so new laptop that features ATI Radeon HD 3650 Mobility graphics cards. Which is quite fine for the usual tasks. According to AMD website it features OpenGL 3.2 which is, again, good enough. Nothing spectacular but fine.

Lately I’ve upgraded it to a SSD disk and at the same time I did a fresh Windows 8 install (previously it was Windows 7). Everything worked out very well. The laptop is usable again and quite fast now. Yesterday I tried to experiment with MonoGame, an open source implementation of, now legacy, XNA Framework – the framework that was supposed to run everywhere but Microsoft ditched it for some reason. Anyway, I’ve tried to run a sample MonoGame application and immediately faced a problem. First it was throwing an exception that OpenAL.dll is missing. Odd. I’ve found a standalone installation for OpenAL but the I run into another, more descriptive problem, something like: can’t find entry point for ‘glBindFramebuffer’ in OpenGL32.dll. That basically says that I had a pre-OpenGL 2.0 installed (MonoGame uses OpenTK which in turn requires minimum 2.0 version of OpenGL). How is that possible?

From what I understand the situation is that AMD isn’t supporting the Radeon Mobility HD 3xxx with Windows 8 and hence it doesn’t provide OpenGL drivers. So everything falls back to Microsoft provided OpenGL 1.1. That is nicely shown using GPU Caps Viewer application. This is ever more surprising because we had proper OpenGL drivers for it under Windows 7. If it was a desktop machine I’d consider changing the graphics card but that’s just not possible on the laptop. And I wasn’t quite happy to buy a newer laptop just for that, even more so because my laptop is doing just fine.

The solution

The solution is to install the latest drivers for Windows 7 manually. It is actually quick, easy and it works. You’ll find the procedure in Make Your Old Graphics Drivers Work in Windows 8article on Lockergnome. The only differences from article are that just right clicking on INF file doesn’t work nor the INF file is named exactly like the one in the article – it has higher number, probably because it is a newer one. Instead of the right click->install, which didn’t work, I had to go to Computer->right click->Manage->Device Manager->Display adapters->ATI Mobility Radeon HD 3650->right click->Properties->Driver->Update Driver->Browser my computer for driver software->Let me pick from a list of device drivers on my computer->Select proper INF file.

And voila – now I have OpenGL 3.3 support and MonoGame runs like a charm. Happy OpenGLing!

Categories
.net VS 2012

Visual Studio 2012 and .net 4.5 have officially launched

Read more about the launch on Somasegar’s blog and attend the forthcoming SLODUG meeting (held in Ljubljana, Slovenia, Slovene language) dedicated to this launch – new features presented by four Slovene MVPs (including myself).

Categories
.net Visualizer VS 2008 VS 2010 VS 2012

Righthand Dataset Debugger Visualizer updated to 1.0.8 for Visual Studio 2012

Go, grab the Dataset visualizer test version for Visual Studio 2012 from dedicated page and visit forums as well.

Categories
.net Visualizer VS 2008 VS 2010

Righthand Dataset Debugger Visualizer updated to 1.0.8

Here is the list of what’s have been added/changed in 1.0.8.:

  • Fixed Next Change, Next Error
  • Added contextual menu features on row right click: Delete/Remove row, Accept/Reject row changes, Clear row errors
  • Fixed original value showing (it could appear multiple times)
  • Added a bunch of columns in table list (Errors count, Changed rows count, Rows count, Added rows count, Modified rows count, Deleted rows count). Errors and Changed count are background-lit when non zero to emphasize errors and change presence
  • Renamed File/Commit and Exit to Persist and Exit to avoid confusion (this item persists changes back to the data owner – your application being debugged)
  • A message box warning when closing visualizer when changes are present
  • Empty table’s name is gray in table list
  • Added tooltip on column header showing column’s name, caption, datatype, defaultvalue and whether it is nullable
  • Grouping now works on RowState

Go, grab v1.0.8 from dedicated page and visit forums as well.

Categories
.net Tools

Fuslogvw.exe aka Fusion Log Viewer aka Assembly Binding Log Viewer troubleshooting

What do you do when you have problems with assembly binding? Exceptions don’t tell very much (failed to load for some reason is all you get). You call Fuslogvw.exe to the rescue of course.

But what do you do when Fuslogvw.exe doesn’t work? You delete IE’s temporary internet files. Of course.

You might wonder what do IE’s temporary internet files have to do with fuslogvw? Here is straight from the documentation:

The Fuslogvw.exe (Assembly Binding Log Viewer) uses the Internet Explorer (IE) cache to store its binding log.

And here is the kicker

Due to occasional corruption in the IE cache, the Fuslogvw.exe (Assembly Binding Log Viewer)can sometimes stop showing new binding logs in the viewing window. As a result of this corruption, the .NET binding infrastructure (fusion) cannot write to or read from the binding log. (This issue is not encountered if you use a custom log path.) To fix the corruption and allow fusion to show binding logs again, clear the IE cache by deleting temporary internet files from within the IE Internet Options dialog.

I won’t even start how stupid the decision to use anything from IE for such a core functionality is. Besides fuslogvw will silently do nothing in case of temporary internet files corruption – instead of notifying user of a problem. Excellent and very friendly behaviour.

Anyway, clear temporary files and run fuslogvw under Administration privileges and it should work. If it still doesn’t then block a few people on Twitter, check privacy settings on Facebook and uninstall Chrome. It can’t fail!