1. Performance in .NET:
Best practices
Sorin Oboroceanu, obs@rms.ro
Vlad Balan, bav@rms.ro
RomSoft, www.rms.ro
Iași, 8th of May 2010

2. Agenda
 Why performance matters
 Serialization
 Reading XML
 Garbage Collection
 JITing

3. Why performance matters
 Everyone loves performance
 Performance=money
 Bing - 2 seconds slower – 4.3% drop in revenue
 Google – 400ms slower – 0.6% drop in searches
 Yahoo! – 400ms slower – 5-9% drop in full page traffic
 Mozilla – 2.2 seconds faster – increased download conversion
15.4%
 Site speed is now taken into account in search rankings

4. Why performance matters
 Better apps – Satisfied customers

5. Our Demo APP
 Uses StackOverflow.com’s data
 Groups users by location
 Displays user locations in a chart
 Will work in a client/server architecture
 Has performance issues 

6. Collections
 Groupping data
 List<T>
 LINQ to Objects
 Dictionary<T,V>
DEMO

7. Client-Server communication
 Retrieving all users on the client
 Grouping data
 List<T>
 LINQ to Objects
 Dictionary<T,V>
DEMO

8. Client-Server communication
 Grouping data on the server
 List<T>
 LINQ to Objects
 Dictionary<T,V>
 Retrieving only location-related data on the client
DEMO

9. Reading XML
 DataSet
 XmlReader
 LINQ to XML
 XmlDocument
DEMO

10. Garbage Collection
 Why memory matters
 Garbage Collector
 Object Finalization

11. Why memory matters
 Inefficient use of memory can impact
 Performance
 Stability
 Scalability
 Other Applications
 Hidden problems in code can cause
 Memory Leaks
 Excessive memory usage
 Unnecessary performance overhead

12. .NET Memory Management
 Small Object Heap (SOH) – Objects < 85K
 Large Object Heap (LOH) – Objects => 85K

13. Small Object Heap (SOH)
GC
SmallObject ObjectB = new
ObjectA
SmallObject();
Global
Objects Small Object Heap
Next Object Pointer
ObjectE
Next Object Pointer
Stack
ObjectD
Next Object Pointer Static
Objects
ObjectC
Next Object Pointer
ObjectB ObjectB
Next Object Pointer
ObjectA Root Reference
ObjectA
Next Object Pointer Child Reference

14. GC - Gen 0
2
1
Generations
Small Object Heap
Gen 0 Next Object Pointer
Global ObjectD
Objects
ObjectC
Next Object Pointer
Gen 1
Static
Stack Objects
ObjectB
Gen 2
Root Reference
ObjectA

15. Large Object Heap (LOH)
GC- Gen2
LargeObject ObjectD= new
LargeObject();
Free space table
Global
Objects Large Object Heap From To
5727400
425000 16777216
ObjectD
94208 182272
Stack Free space
ObjectC ObjectC
Free space
ObjectB
ObjectB
ObjectA
ObjectA

16. GC
Finalization
FinObject ObjectE = new FinObject();
Finalization
Queue
Small Object Heap
Gen 0
Global
Objects ObjectE Finalize() ObjectE
fReachable
ObjectD
Queue
Finalizer
Stack ObjectC thread
Gen 1
ObjectB
ObjectB
ObjectA ObjectA

17. Finalization
 public class Test {
~Test()
{
Cleanup ();
}
private void Cleanup()
{
// clean up unmanaged resources
}
}

18. Disposable pattern
 public class Test : IDisposable{
~Test()
{
Cleanup (false);
}
private void Cleanup(bool codeDispose)
{
if (codeDispose)
{
// dispose managed resources
}
// clean up unmanaged resources
}
public void Dispose()
{
Cleanup (true);
GC.SuppressFinalize(this);
}
}

19. DEMO

20. JITing Console
Managed EXE
static void WriteLine();
static void Main(){
Console.WriteLine(“Hello”); JITCompiler
Console.WriteLine(“GoodBye”);
} static void WriteLine(string);
JITCompiler
MSCorEE.dll
(remaining members)
JITCompiler function{ …
1. Look up the called method in the metadata
2. Get the IL for it from metadata
3. Allocate memory
4. Compile the IL into allocated memory
5. Modify the method’s entry in the Type’s
table so it points to allocated memory Native
6. Jump to the native code contained inside CPU
the memory block. instr.
}

21. JITing Console
Managed EXE
static void WriteLine();
static void Main(){
Console.WriteLine(“Hello”); JITCompiler
Console.WriteLine(“GoodBye”);
} static void WriteLine(string);
Native
MSCorEE.dll
(remaining members)
JITCompiler function{ …
1. Lookup the called method in the metadata
2. Get the IL for it from metadata
3. Allocate memory
4. Compile the IL into allocated memory
5. Modify the method’s entry in the Type’s
table so it points to allocated memory Native
6. Jump to the native code contained inside CPU
the memory block.} instr.

22. DEMO

23. Resources
 CLR via C# 3, Jeffrey Richter
 www.red-gate.com
 www.stackoverflow.com

24. Q&A

25. Please fill the evaluation
form
Thank you very much!
Sorin Oboroceanu, obs@rms.ro
Vlad Balan, bav@rms.ro
RomSoft, www.rms.ro
Iași, 8th of May 2010