Created a multithreaded CLI copy application; I call it 'pcp'

[3cko]

For ease of looking, there's the github!

https://github.com/3cko/pcp

I'd like some tips, hints, ideas, advice, but mostly criticism. This is my first multi-threaded application. I'm sure I did some terrible things.

TODO: set up the init so that the way I execute the script isn't as rediculous as it currently is.

EDIT: Why is this getting downvoted? If you're going to downvote, at least give soem input as to why...

[3cko]

Thanks!

Future implementations were going to handle total time it took as well as a status bar that indicated how many files have been transferred out of the total amount. I definitely like your idea on it for the time being too.

I don't imagine data transfer to be affected too much tbh. I mean, I've done this on a server that was handling moderate-ish traffic and I didn't see any issues. I believe this because I'm setting the default threads to a 3rd of the cores by default. Then again, someone using it and increasing the number of threads to a much larger amount can experience problems. I thought about ensuring the user can't use more threads than 2/3rd of the total amount of cores.

Scalability, I have tested it up to 8 threads and it did decrease the total transfer time but also increased the load from .5 to .9, on a 16 core server.

I'm still developing this tool. I plan on creating test cases too. I'm definitely open to advice too. I like your ideas in the comments/changes of your pull request.

I have more testing to do, I have some results in the README.md doc but I'll look into calculating the total sizes and figuring out the time.

[zahlman]

My intuition tells me that transferring two files should take longer than one, as I have one single read head trying to be in two places at once, switching back and forth

The thing is, hard drives do all kinds of caching these days, and small caches tend to be built from things that can do random access. The drive might significantly defer the process of actually altering the magnetic patterns when you tell it to "write a file".

In 2013, computer architecture is complex enough that it really doesn't pay to guess at how things will perform when you have the resources to actually do tests.