设计一个按优先数调度算法实现处理器调度的程序

提示：

(1)假定系统有5个进程，每个进程用一个PCB来代表。PCB的格式为：

进程名、指针、要求运行时间、优先数、状态。

进程名——P1~P5。

指针——按优先数的大小把5个进程连成队列，用指针指出下一个进程PCB的首地址。

要求运行时间——假设进程需要运行的单位时间数。

优先数——赋予进程的优先数，调度时总是选取优先数大的进程先执行。

状态——假设两种状态，就绪，用R表示，和结束，用E表示。初始状态都为就绪状态。

(2) 每次运行之前，为每个进程任意确定它的“优先数”和“要求运行时间”。

(3) 处理器总是选队首进程运行。采用动态改变优先数的办法，进程每运行1次，优先数减1，要求运行时间减1。

(4) 进程运行一次后，若要求运行时间不等于0，则将它加入队列，否则，将状态改为“结束”，退出队列。

(5) 若就绪队列为空，结束，否则，重复(3)。

-Design a number of priority scheduling algorithm processor scheduling program

  Tip :

( 1 ) The system has five processes, each represented by a PCB . PCB format:

Process name , pointer, run-time requirements , priority number , status.

Process name- P1 ~ P5.

Pointer- according to the size of the five priority number into程连成queue pointer pointed to the next process PCB first address .

The time required to run- assuming unit time required to run several processes .

Priority number- the number of priority given to the process , always select a large number of priority scheduling process executed first .

State- assuming two states , Ready, represented by R , and end with E said . The initial state are ready state.

( 2 ) Before each run , for each process arbitrarily determine its " priority number " and " run-time requirements ."

( 3 ) the processor is always selected first team processes running . Change the priority number of dynamic way to run a process every time , prior