进程的一般形式 可能死锁 不会死锁 Process P Process Q Process p Get A Get B Get A Get B Get A release a release A release B Get B release B release release B进程的一般形式 Process P … Get A … Get B … release A … release B Process Q … Get B … Get A … release B … release A Process P … Get A … release A … Get B … release B 可能死锁 不会死锁