CloneOfDuty : Big Fat Zero. I knew I'd never... Xna:Tutorials:CLR Profiler - Docs. <- Back to Tutorials Introduction The CLR Profiler (CLR meaning Common Language Runtime) is a program created by Microsoft which gives detailed information about memory allocation and method calls. It is an invaluable tool for identifying areas of code which allocate too much memory. In short, the CLR Profiler is a must to find areas where your game is allocation-heavy. What problems can too much memory allocation cause? The allocation of memory itself isn't necessarily the problem. The .NET framework provides extremely fast memory allocation due to the way it eliminates memory fragmentation. Since suppressing the garbage collector is not an option, the solution is to eliminate or reduce memory allocation.
Installing the CLR Profiler To install the CLR Profiler: Download the CLR Profiler at: If you get a "Waiting for application to start common language runtime" message in Vista, try running the CLR Profiler as an administrator. 5 Tips and Techniques for Avoiding Automatic GC Collections. Automatic memory management isn't new, but it’s a wonderful thing for programmers. We bring you some tips and techniques to .help you understand a bit more about how .NET’s memory management works, can help you to ensure that you write high-performance .NET code. The .NET garbage collector is, in general, a wonderful thing. It has freed countless programmers from the drudgery both of writing allocation and de-allocation code, and also of tracking down heap corruption and memory leaks (due to bad pointers or de-allocation errors). It allows programmers to simply write code and focus on function without normally needing to care about how memory is actually managed.
This tends to make it much easier for junior programmers to write correct (or at least functional) code, thereby reducing training costs and the time necessary to do things like code reviews. Understanding a bit more about how .NET’s memory management works can help you with both paths. 1. So why does this matter? 2. 3. Get if (! The cost of value types in .NET Compact Framework - Scott Holden's Blog. I often get asked about the difference in performance characteristics between value types (C# struct) and reference types (C# class or Object). In the clr, a value type is located on the stack (in a local variable or argument) or within an object. .NET primitive types, such as Int32, Int16, DateTime, double are all value types. Typically, when there is performance issues related to values types it is because of boxing.
Boxing is an implicit conversion of a value type to an object (reference type). Boxing allocates an object from the GC heap and copies the value into it. The cost of boxing is the allocation, the eventual GC of the object and the copy. Unboxing is the reverse operation that copies the value from the boxed value type to a stack variable. Rule of thumb: If an object is typically going to get boxed, it would be better off being an Object in the first place.
The other area of performance concern for value types revolve around copying them. Scott. WP7, XNA, the GC, and You (and Silverlight too!) Some of you may have come across this helpful blog post recently, discussing when the garbage collector (a/k/a the GC) runs on Windows Phone 7 devices. Anyone who has programmed in XNA for the Xbox 360 before knows the GC well. For those of you new to XNA, there are several tricks and tips for slaying the evil GC monster that eats frames. This applies to Silverlight apps too, though since Silverlight does quite a lot for you automatically, there’s only so much control you have. First, you must leave this site. Not permanently, but just temporarily to go read this post by Shawn Hargreaves: One of the first things you must understand is the difference between value types and reference types.
Classes are an entirely different matter. Void CheckForTrue(bool value) string trueText = "The value is true string falseText = "The value is false if (value == true) Console.WriteLine(trueText); else return; Happion Labs GameDevBlog: Stupid C# Tricks: Dealing With Non-Generational Garbage Collection. Mostly for Nathan: Better men than me have already discussed non-generational GC with XNA Xbox, and a few things you can do to deal with it. Trying to build upon their work - your best buddy is going to be the CLRProfiler.
Once you figure out how to use it, it's an awesome tool that tells you what's allocating the most garbage, when and where. Once you've found trouble spots, there's a variety of things you can do. If there are moments in your game where pauses make sense, (when the user hits the pause button, for example - or in a turn-based game, the beginning of every turn, maybe?) Earlier I said we're using fixed pools. One problem with it (and fixed-pools) is suddenly you lose the advantage of a constructor that is guaranteed to set your object to a known initialized state. One might ask: why use C# to make our game if one of the most useful features of C#, the garbage collection, shouldn't be used on the Xbox? XNA Framework Remote Performance Monitor. XNA/C# Articles « gavpugh.com.
This is simply an index to collect together the XNA and C# technical blog articles I have written. Since I blog about other topics too, I thought it’d be a decent idea to keep these specific posts together here. It also serves as an good starting-point for anyone who has never visited my blog before, but is only really interested in my XNA and C# content. Xbox 360 / Compact Framework Specific Thread-local storage on Xbox 360 Details a fast cross-platform method of implementing Thread-local storage. Includes profiling comparisons against Microsoft implementations. [ThreadStatic] attribute is broken on Xbox 360 With the upgrade to XNA 4.0 the [ThreadStatic] attribute was made available to the Xbox 360. StringBuilder and String Garbage StringBuilder changes in XNA 4.0 With the release of XNA 4.0, a technique I described in a previous blog post to get direct access to the String object of a StringBuilder, stopped working.
Miscellaneous An introduction. Managed Code Performance on Xbox 360 for XNA: Part 2 - GC and Tools - .NET Compact Framework Team. ...continuation of Part 1, it can be found here Memory and Garbage Collection One common concern for game developers is the garbage collector. By design, GCs trade off determinism for convenience. Luckily, keeping the GC predictable is fairly straightforward. Two variables to pay attention to are: How long a GC is taking (aka. GC latency)When and how often a GC happens You’ll want to strike a balance between “how long” and “how often” to get smooth game play.
At 60fps each frame takes about 16.67ms (that’s 1000ms/60frames). So how does one control GC latency? The triggers that cause collection are unchanged from v2.0 as well. Games typically have lots of small objects that represent game state. A concise blog posting about value type boxing can be found here: One more caveat on structs that was touched on in the floating point section: avoid passing and returning large value types by value, and instead use “ref” or “out”. Games.DiscoverThat.co.uk. Home XNA Contents Development Blog Like most people developing using XNA for the Xbox 360 eventually I encountered the frustrating situation where every minute or so my game froze for a few moments.
With only the minimal of investigation the term Garbage Collection came to my attention. What is garbage collection? Garbage collection is the process used to remove unassociated items from the memory heap of the computer or console. The garbage collection process on a Windows PC is typically non-intrusive however the one on the Xbox 360 has a noticable impact on performance. Garbage collection on the Xbox 360 happens when the heap has grown by 1M Bytes since the last garbage collection. Memory usage is not a crime! Before we go too far it is worth pointing out that all programmes NEED to use memory and the heap will always grow.
Many people also confuse memory usage with a memory leak. What is garbage then? Garbage is made up of objects on the heap that we no longer need. That's it. Foreach, Garbage, and the CLR Profiler - Cornflower Blue. I've been doing a lot of thinking lately about foreach, and in what situations it may or may not create garbage. There have been some posts on the forums asking about it, and I recently found out that for some types, the enumerator that is created is a value type, not a reference type. So, foreach loops over those types shouldn't make garbage at all. Why does this matter? In an XNA Framework forum thread, Stephen Strychak, an XNA Framework Developer, explains: "...the performance of your game will degrade if you allow garbage to be generated during gameplay. The problem again is not the for or foreach. The problem is that the garbage collector on the Xbox 360 is less efficient than the one on Windows, and doing a collection can take a long time.
So the bottom line is that you should avoid generating garbage, and using for instead of foreach is one way to do that. " Shawn posted this in a follow up, which is an important point: I wanted to do this for a quick sanity check. Generics in the .NET Compact Framework - Welcome to Live Mesh! Parametric polymorphism (aka Generics) is one of the most interesting new features added to .NET CLR and languages in version 2.0 (Whidbey). There are many good articles describing the feature and its’ implementation for the full .NET CLR. For those who interested in the design fundamentals of generics I’d strongly recommend the article by Don Syme and from Microsoft Research, who originally designed and implemented .NET generics. Many people were asking what .NET Compact Framework generics story is. Although generics were not included into our Whidbey Beta 1 release, I’m very excited to confirm that .NET Compact Framework version 2.0 will also include generics support.
Here is a quick introduction into the feature from Seth Demsey. As I was actively involved into generics work for a past year or so, I’d like to share some details about specifics of .NET Compact Framework approach to generics support, underline some limitations and differences from the full .NET CLR approach. Limitations.