Introduction
The .NET runtime's memory management is a complex process, utilizing various techniques to optimize performance and address memory safety.
We'll cover critical concepts, focusing on how the runtime allocates, uses, and eventually releases memory.
Memory Allocation and Management
The runtime dynamically allocates memory for objects and data structures. The `MemoryPool` is the primary mechanism for this.
Different pools exist for different types of objects - LargePool for long-lived objects, SmallPool for short-lived objects, and more.
Runtime uses a garbage collector to reclaim memory occupied by objects that are no longer in use.
The Garbage Collector
The garbage collector is the core of the memory management process. It continuously scans memory, identifying unreachable objects.
When a collection of objects is identified as garbage, the garbage collector automatically reclaims the memory occupied by those objects. It uses a cycle-based algorithm to minimize pauses.
Key Concepts
Reallocation: When a large object needs more memory, the runtime reallocates it to a larger pool. This involves moving data around, which can cause brief pauses.
Thunking: The runtime can effectively "thunk" memory to a new pool before the old pool is fully cleared, providing some responsiveness.
Pooling: Creating reusable objects or data structures improves efficiency, reducing memory overhead.
Data Structures & Memory Layout
The runtime utilizes data structure layout to optimize memory usage. For example, objects are typically stored in a "free list," allowing for efficient access.
Example (simplified) - Illustrative (Conceptual Only - not fully functional)**
Imagine a simple list of integers. The runtime might create separate memory blocks for each integer, minimizing fragmentation.