서버 모델 구상중에...

그리고, connection pool 에서는, 다중화에 대한 rouing만 잘 해결하면, 기본적으로 깔끔한 설계입니다.
자칫 다른 녀석이 요청한 것을 결과로 받는 일이 생기면, 곤란하죠.

리눅스에서는 thread가 vfork라는 일종의 fork(process복제)를 이용해서 구현되어 있습니다.
즉 모든 메모리를 공유하는 process가 thread가 되는 것이지요.
그래서 일반적으로 thread preformance가 Solaris나 NT같은 것에 비해서 많이 떨어집니다.

K.1: What is the implementation model for LinuxThreads?
LinuxThreads follows the so-called "one-to-one" model: each thread is actually a separate process in the kernel. The kernel scheduler takes care of scheduling the threads, just like it schedules regular processes. The threads are created with the Linux clone() system call, which is a generalization of fork() allowing the new process to share the memory space, file descriptors, and signal handlers of the parent.

Advantages of the "one-to-one" model include:

* minimal overhead on CPU-intensive multiprocessing (with about one thread per processor);
* minimal overhead on I/O operations;
* a simple and robust implementation (the kernel scheduler does most of the hard work for us).

The main disadvantage is more expensive context switches on mutex and condition operations, which must go through the kernel. This is mitigated by the fact that context switches in the Linux kernel are pretty efficient.