Is it wrong to embed some files in a dll?

Question

Performance wise, is it wrong to embed a file in a resource section of a dll?
This might seem silly, but aim trying to embed some info inside the dll which can later be fetched by some methods, in case the whole solution and documentation is lost and we have only the dll.
What are the downside of doing such a thing?
Is it suggested or prohibited ?

Answer 1

Embedded resources are done very efficiently. Under the hood, it uses the demand paged virtual memory capabilities of the operating system. The exact equivalent of a memory-mapped file. In other words, the resource is directly accessible in memory. And you don't pay for the resource until you start using it. The first access to the resource forces it to be read from the file and copied into RAM. And is very cheap to unmap again, the operating system can simply discard the page. There is no way to make it more efficient.

The other side of the medal is that it is permanently mapped into virtual memory. In other words, your process loses the memory space occupied by the resource. You'll run of out of available address space more quickly, an OutOfMemoryException is more likely.

This is not something you normally worry about until you gobble up, say, half a gigabyte in a 32-bit process. And don't fret about at all in a 64-bit process.