为体现内核的优先级天花板思想的策略，设计三个处于不同优先级的任务。在每个任务中，首先申请互斥信号量，延迟200TICKS后释放互斥信号量。通过任务的运行流程体会优先级天花板思想。-In order to reflect the priority of the kernel ceiling thinking of strategy, design three tasks at different priorities. In each task, the first of applications