Hi Guanjun, I compiled and ran your code on my machine. No unknown exception. Here's the output: # g++ test.cpp # ./a.out This is a pthread. This is a pthread. ********************This is the main thread. This is a pthread. ********************This is the main thread. This is a pthread. This is a pthread. This is a pthread. This is a pthread. This is a pthread. SIncerely, --Eljay
