通过研究内核的时间管理算法，学习内核源代码；然后应用这些知识并且使用“信号”建立一种用户空间机制来测量一个多线程程序的执行时间。-By studying core time management algorithm, to study the kernel source code　and then the application of such knowledge and the use of　signal　to establish a mechanism to measure the user space of a multi-threaded program execution time.