This Presentation demonstrates the working of garbage collector in c#,CLR and Memory profiler tool to find the memory leaks.

1. Memory Profiler
Ram
Project Engineer

2. Agenda
Why we need to use Memory Profiler
Basic Under Standing Of CLR
What is Garbage Collection
Basic understanding of Memory Profiler
How to fix Memory Leaks

3. Pre .NET Application Execution
VB6
Non.Net Application
VB6 Compiler
Assembly(.DLL or .EXE)
(Native Code or Machine Code)
Operating System

4. .NET Application Execution
.NET Application
C# VB C++ J# Others
Compile Using Respective Language Compiler
Assembly(.dll,.exe) – Intermediate Language
Intermediate Language
JIT Compiler
Native Code
C
L
R
Operating System

5. .NET Application Execution

6. .NET Framework Version CLR Version
• 1.0 • 1.0
• 1.1 1.1
2.0,3.0,3.5 2.0
4,4.5,4.6 4

7. IS .NET Platform Independent ?

8. Major Features of CLR
• Platform Compatibility ??
• Memory Management

9. Memory Management
Stack Heap
Class Person
{
string Name;
int Age;
}

10. Memory Management
Stack Heap
Static void main()
{
Person p;
}

11. Memory Management
Stack Heap
Static void main()
{
Person p;
}
P

12. Memory Management
Stack Heap
Static void main()
{
new person();
}

13. Memory Management
Stack Heap
Static void main()
{
new person();
}
Person
Name: null
Age:0

14. Memory Management
Stack Heap
Static void main()
{
person p;
new person();
}

15. Memory Management
Stack Heap
Static void main()
{
person p;
new person();
}
Person
Name: null
Age:0
P

16. Memory Management
Stack Heap
Static void main()
{
person p= new person();
}

17. Memory Management
Stack Heap
Static void main()
{
person p=new person();
}
Person
Name: null
Age:0
P 0X123456

18. Memory Management
Stack Heap
Class Person
{
string Name;
int Age;
person(string Name, string Age)
{
this.Name=Name; this.Age=Age;
}

19. Memory Management
Stack Heap
Static void main()
{
person p= new person(ramesh,22);
}

20. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
}
Person
Name: Ramesh
Age:22
P 0X123456

21. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
person p1=new person(Ram,22);
}

22. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
person p1=new person(Ram,22);
}
Person
Name: Ramesh
Age:22
P 0X123456
P1 0X123987
Person
Name: Ram
Age:22

23. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
person p=new person(Ram,22);
}

24. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
p=new person(Ram,22);
}
Person
Name: Ramesh
Age:22
P 0X123456

25. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
p=new person(Ram,22);
}
Person
Name: Ramesh
Age:22
P 0X777777
Person
Name: Ram
Age:22

26. Memory Management
Garbage Collector

27. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
p=new person(Ram,22);
}
Person
Name: Ramesh
Age:22
P 0X123456
Person
Name: Ram
Age:22
Garbage Collector Runs

28. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
p=new person(Ram,22);
}
P 0X123456
Person
Name: Ram
Age:22

29. Memory Management
.NET Manages Memory Automatically
• Creates objects onto managed memory Blocks
• Destroys Objects No Longer in Use

30. Memory Management
.NET Manages Memory Automatically
• Creates objects onto managed memory Blocks
• Destroys Objects No Longer in Use
Allocates objects onto one of two heaps
• Small object Heap(SOH)- Objects <85k
• Large object Heap(LOH)- Objects >=85k

31. Memory Management
Stack Heap
Static void main()
{
person p=new person(Ramesh,22);
}
Person
Name: Ramesh
Age:22
P 0X123456

32. Memory Management
Stack SOH(<85k)
Static void main()
{
person p=new person(Ramesh,22);
}
Person
Name: Ramesh
Age:22
P 0X123456
LOH(>85K)

33. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2

34. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2
obj1 obj2

35. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2
obj1 obj2

36. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2
obj1

37. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2
obj1

38. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2
obj1

39. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2
obj1

40. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0
Gen1
Gen2
Gen2
obj1

41. Memory Management
GC Runs When
• Gen 0 Objects Reach ~256k
• Gen 1 Objects Reach ~2Meg
• Gen 2 Objects Reach ~10Meg

42. Memory Management
Stack SOH(<85k) LOH(>85K)
Heap
Gen0(256k)
Gen1(2Mb)
Gen2(10Mb)
Gen2

43. Memory Problems
Excessive RAM Footprint
• App allocates memory too early or too long
using more memory than needed
• Can Affect other Apps on the System
Excessive Temporary Object Allocation
• Garbage Collection Runs More Frequently
• Executing threads freeze during Garbage
Collection
Memory Leak
Overlooked root references keep objects alive

44. Memory Problems

45. Memory Problems

46. Memory Problems

47. RECAP
•Pre .NET Execution of Application
•.NET Execution of Application
•What is CLR.
•Different types of Memory (Stack, Heap)
•Garbage Collection
•Gen 0,Gen 1,Gen 2
•Memory Problems
•What to Look For

48. Memory Profiling and .NET Memory Profiler
• What is Memory Profiling?
• What is .NET memory profiler?
• How to use .NET memory profiler?
• How to find memory leaks?
• Automatic Memory Analysis

49. What is .NET memory profiler?
.NET Memory Profiler is a powerful tool for finding
memory leaks and optimizing the memory usage in
programs written in C#, VB.NET or any other .NET
Language.
This tool will not fix any memory leaks or bad memory
consumption issues, but will analyze the running
application code and provide results that will be helpful for
us to fix memory issues and to code accordingly.

50. How to use .NET memory profiler?
To profile the memory of an application perform the
following steps:
1. Select the Profile Application command from the menu or toolbar.
2. Use the Browse button or the drop-down list to select the
executable file of the application you want to profile.
3. If you want to supply program arguments, enter the command
line in the Command line arguments field.
4. If you want to profile using the default settings, click Start to start
the application.
5. If you want to modify settings, you can use the Next button to
modify some common settings.
6. When you have decided on the settings, click Start to start the
application.

51. How to use .NET memory profiler?
For analysing the real - time data, check real – time data box on right
panel.
Below is the Total instances, Total bytes and Allocations/sec data of
VLEX captured in Real time:

52. How to find memory leaks?(Manual)
To find the memory leak manually, you can perform the
following steps:
1. Start profiling the application
2. Perform the task you suspect are leaking memory (e.g., open a
document, work with it, and then close it).
This will make sure that all static instances are created.
3. Collect a heap snapshot.(For doing so, click on the camera button
on the right panel)
4. Repeat the task performed under step 2.
5. Collect another heap snapshot.
6. Use the Show types drop-down list to select “With New or
Removed Instances” to show types whose set of instances has
changed between the two snapshots.

53. How to find memory leaks?(Manual)
7. To Select the Types page and try to locate a type that has live
instances that should have been collected.
If no memory leak exists, the instances shown in the Types page should
only be short-lived instances that have not been garbage collected yet.
If a memory leak exists, you should be able to find a type with new
instances that should have been garbage collected.

54. How to find memory leaks?(Manual)
8. Double-click on the type that has live instances that should have been
9. In the Instances table, double-click on one of the new instances.
10. In the Root path table you will get information about why the
selected instance was not garbage collected.

55. Automatic Memory Analysis
Whenever a new snapshot comparison has been
performed, e.g., after collecting a snapshot or changing
the selected or comparison snapshot, .NET Memory
Profiler will start analysing the memory data.
As soon as the analysis is finished, any found issues will be
presented in info panels under the Types/Resources page,
the Type details page, and the Instance details page.
An example of summary issues presented in the info panel
under the Types/Resources page can be seen below:

56. Automatic Memory Analysis

57. Automatic Memory Analysis
The issues presented provide warnings, suggestions, and
information about common memory usage problems. The
severity of an issue is
 Serious Warning : A serious warning indicates an issue that could,
with a high probability, cause memory usage problems, such as memory
or resource leaks.
 Warning: A warning indicates an issue that could cause memory
usage problems, such as memory or resource leaks.
 Minor Warning: A minor warning indicates an issue that could cause
bad memory or resource utilization, but it should not cause problems
like memory leaks.
 Indirect Warning: An indirect warning indicates an issue that is
caused by another warning issue. The issue will contain information
about the issue that causes the direct warning.

58. Ram
Thank You