[boost] About weird behavior with boost.asio 1.63 on linux 2.6.15

Dear All: I have been using boost over 10+ years. The asio library work quite well along with document. Today I get a problem: My development environment: gcc 4.7.3 OABI Linux 2.6.15 boost 1.63 The code looks like below: void myTask(const char *text) { sleep(5); /*for(;;) { //sleep(1); }*/ cout<<"text is "<