使用pthread_cancel取消线程:好习惯还是坏习惯

I have a C++ program on Linux (CentOS 5.3) spawning multiple threads which are in an infinite loop to perform a job and sleep for certain minutes. Now I have to cancel the running threads in case a new configuration notification comes in and freshly start new set of threads, for which i have used pthread_cancel. What I observed was, the threads were not getting stopped even after receiving cancel indication,even some sleeping threads were coming up after the sleep was completed.I have a C++ program on Linux (CentOS 5.3) spaw