Merge pull request #25 from tc1989tc/master

add recv and send  function to socket layers
Merge pull request #26 from tc1989tc/master

1.添加锁。解决协议栈问题
修正了调度器在处理死亡线程时还是没有减少running count 的问题。
Merge pull request #23 from gridnow/master

修正调度器