Garbage Collection (GC) in .NET

Introduction

The Garbage Collector (GC) is a core component of the .NET Framework and .NET Core/ .NET. It automatically manages memory by reclaiming memory occupied by objects that are no longer in use. This relieves developers from the burden of manual memory management, reducing the risk of memory leaks and other related issues.

How the GC Works

The GC operates in a cyclical manner, continuously scanning memory to identify objects that are no longer reachable from a root set of objects (e.g., active threads, static variables). These unreachable objects are marked as garbage and eventually reclaimed for reuse.

The GC uses several algorithms to achieve efficiency, including:

• Mark and Sweep: Marks reachable objects and then sweeps through memory to collect unmarked objects.
• Generational Garbage Collection: Divides memory into generations (younger and older) and focuses collection efforts on the younger generations, where most objects die.
• Concurrent Garbage Collection: Allows the GC to run concurrently with application code, reducing the impact on performance.

GC Configuration

You can configure the GC behavior using the .NET runtime configuration settings. Key settings include:

• Ambient Pressure: Controls the level of concurrency used by the GC.
• Large Object Heap (LOH) Size: Adjusts the size of the LOH, used for larger objects.
• GC Count: Specifies how many GC cycles should run per second.

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