Garbage Collection

Concept of Garbage Collection

When Microsoft planned to go for a new generation platform called .NET with the new generation language called C#, their first intention is to make a language which is developer friendly to learn and use it with having rich set of APIs to support end users as well. So they put a great thought in Garbage Collection and come out with this model of automatic garbage collection in .NET.

They implemented garbage collector as a separate thread. This thread will be running always at the back end. Some of us may think, running a separate thread will make extra overhead. Yes. It is right. That is why the garbage collector thread is given the lowest priority. But when system finds there is no space in the managed heap (managed heap is nothing but a bunch of memory allocated for the program at run time), then garbage collector thread will be given REALTIME priority (REALTIME priority is the highest priority in Windows) and collect all the un wanted objects.


What is Garbage Collection...

The .NET Framework's garbage collector manages the allocation and release of memory for your application. Each time you create a new object, the common language runtime allocates memory for the object from the managed heap. As long as address space is available in the managed heap, the runtime continues to allocate space for new objects. However, memory is not infinite. Eventually the garbage collector must perform a collection in order to free some memory. The garbage collector's optimizing engine determines the best time to perform a collection, based upon the allocations being made. When the garbage collector performs a collection, it checks for objects in the managed heap that are no longer being used by the application and performs the necessary operations to reclaim their memory.

class First
{
~First()
{
System.Diagnostics.Trace.WriteLine("First's destructor is called.");
}
}

class Second : First
{
~Second()
{
System.Diagnostics.Trace.WriteLine("Second's destructor is called.");
}
}

class Third : Second
{
~Third()
{
System.Diagnostics.Trace.WriteLine("Third's destructor is called.");
}
}

class TestDestructors
{
static void Main()
{
Third t = new Third();
}

}
/* Output (to VS Output Window):
Third's destructor is called.
Second's destructor is called.
First's destructor is called.
*/

class mind
{
~mind()
{

}

public static void Main()
{

}

}
//The destructor implicitly calls Finalize on the base class of the object. Therefore, the previous destructor code is implicitly translated to the following code:

Copy
protected override void Finalize()
{
try
{
// Cleanup statements...
}
finally
{
base.Finalize();
}
}