Essential .NET, Volume 1: The Common Language Runtime

The CLR Loader

The CLR loader is responsible for loading and initializing assemblies, modules, resources, and types. The CLR loader loads and initializes as little as it can get away with. Unlike the Win32 loader, the CLR loader does not resolve and automatically load the subordinate modules (or assemblies). Rather, the subordinate pieces are loaded on demand only if they are actually needed (as with Visual C++ 6.0's delay-load feature). This not only speeds up program initialization time but also reduces the amount of resources consumed by a running program.

In the CLR, loading typically is triggered by the just in time (JIT) compiler based on types. When the JIT compiler tries to convert a method body from CIL to machine code, it needs access ...