uthread-A User Space Threading Library Supporting Multi-Core Systems

Lightweight user threads with support for blocking IO and fast context switching (ie. similar to Erlang or Go but using C)
Fast, scalable load balancing across multiple cores
Lock-free data structures
Supports x86 and x86_64. Further architectures can be added easily.
Supports native event backends on Linux and Solaris
Supports libev event backend

Motivation

Why Events Are A Bad Idea (for high-concurrency servers) - Rob von Behren, Jeremy Condit, and Eric Brewer
- Specifically, the following quote summarizes nicely: "...the duality argument of Lauer and Needham ... implies that good implementations of thread systems and event systems will have similar performance."

Type 'make' to build the library and run the unit tests
Link your application to libfiber.so
Be sure to define the architecture when including libfiber's headers. You can specify the following gcc flags:
- For x86 64 bit: -m64 -DARCH_x86_64
- For x86 32 bit: -m32 -march=i686 -DARCH_x86
libfiber.so overrides many system calls so make sure you know what you're doing
The makefile will attempt to detect gcc split stack support (Go uses this). This requires gcc 4.7 or higher. I recommend using this.
- make CC=gcc-4.7