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 for mutex semaphores, delay 200TICKS and released mutex semaphore. Experience of running processes through the task priority ceiling ideas.