Dynamically Linked Libraries (DLL)

  • Static Linking:
    • Libraries are included in the executable at compile time.
    • Results in larger executables.
    • No need for external library files at runtime.
    • Better performance due to no overhead of loading libraries at runtime.
  • Dynamic Linking:
    • Libraries are linked at runtime.
    • Results in smaller executables.
    • Requires external library files to be present at runtime.
    • Can share libraries between multiple programs, saving memory.

Static Linking refers to the process of copying all library modules used in the program into the final executable at compile time. This means that everything the program needs to run is contained within its executable file, making it larger but self-contained. Since all the code the program needs is in one place, it can run without relying on external library files being present on the system at runtime. This can lead to improved performance because there’s no need to load libraries into memory when the program starts. However, it also means that any update to a library requires the entire program to be recompiled and redistributed.

Dynamic Linking, on the other hand, involves linking the libraries to the program at runtime rather than compile time. This means that the final executable is smaller because it doesn’t contain the actual code of the libraries it uses, just references to them. At runtime, the operating system loads the required library files into memory, which can then be shared across multiple programs, reducing overall memory usage. Dynamic linking allows for libraries to be updated without needing to recompile programs that use them, facilitating easier updates and maintenance. However, it introduces a dependency on the presence of these external libraries at runtime, which can lead to “dependency hell” where managing and resolving library dependencies becomes complex. Additionally, there’s a slight performance overhead due to the time needed to locate and load the library modules when the program starts.