What are the "must reads" online for learning the ins and outs of multithreading?

Question

Over the last couple months I've been working with programs that involve multi-threading aspects to them. Multi-threaded programs a very new to me and while I understand the crude basics, how to go about designing a multi-threaded program is still beyond my skill-set. I would like to know what resources that people have found online that gave you an "Omg! That makes total sense now!" moment for this topic.

This should probably be a community wiki but due to the latest changes to SO, I can't make it one (that I know of at least).

Edit: I'm aiming toward reading that is language-independent if possible. Though I don't want to discurage anything that might be particular of a language if it is informative enough to general multi-threading program design.

Answer 1

Here are some basic starting points:

I don't want to state the obvious, but there's the Wikipedia article: Wikipedia: Multithreading
There's also a relatively old Linux article here: Multithreading and Linux
  and a POSIX threads tutorial: POSIX threads tutorial
For Windows, here's a great MSDN article: What Every Dev Must Know About Multithreaded Apps

If you want to go get some decent cross-platform multithreading books, there are:

• Threads Primer: A Guide to Multithreaded Programming
  
• Modern Multithreading : Implementing, Testing, and Debugging Multithreaded Java and C++/Pthreads/Win32 Programs
  
• Porgramming POSIX Threads

Answer 2

Herb Sutter has a Dr. Dobbs column called Effective Concurrency that's terrific. It's a little C++-centric but the underlying lessons are well explained and are bite-sized so you don't get overwhelmed.

Answer 3

Threading must-reads

• The Threads FAQ, by Bryan O'Sullivan (hacker extraordinaire)
• The Problem with Threads, by Edward A. Lee (on how and why non-deterministic multi-threading is so difficult)

Concurrency must-reads

• The Free Lunch Is Over, by Herb Sutter (on the pragmatic importance of concurrency)
• The C10K problem, by Dan Kegel (if you plan to do any large-scale network programming)

Answer 4

I see you have been active in C/C++ tags here. In that case the Boost.Thread documentation might be interesting. This provides portable implementations of important threading concepts and states clearly how to use them. If I was starting out as a C++ multithreading programmer, I would absolutely not build this stuff myself but use this library. The author of the library (active on Stack Overflow under his real name) has a book coming out soon, which appears to be available online now for a fee.