说明：  一个实现死锁的程序 使用两个线程 两个信号量 来实现 一个低优先级进程先semtake mutex1 .然后另个一高优先级的抢占后cpu后 分别semtake mutex2 和mutex1 然后低优先级又要semtake mutex2
(An implementation program with two threads deadlock two semaphores to implement a low-priority process first semtake mutex1. And then another one a high priority, respectively, after the taking cpu semtake mutex2 and mutex1 and low priority also semtake mutex2)