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IPC (:maple_leaf:解决方法 (:three:POSIX进程间通信 (:bread:POSIX是标准, :warning:由于推广问题…

- - - - :one:put put_nowait
      - :two:get get_nowait
      - :three:构造函数
        
        :moneybag:参数
        
        :explode:如果不给参数,就是Queue想有多大就有多大; 否则第一个参数就是Queue能容纳的数据数量
      - :four:qsize
      - :five:empty
    - - :fire:堵塞
        
        :moneybag:get和put如果在空或满的时候,都会处于等待状态. xx_nowait()就会抛异常,所以要放在try里面
      - :fire:Queue内容的数据类型随意
  - - - :one:构造函数
        
        q=Manager().Queue()
    - - orris/process/communication_pool.py
  - - - :question:在进程判断队列为空的时候,如果刚好两个进程都运行到这里,并且队列只有一个成员.这个时候两个都通过条件检验.那么使用get的话,结果是不是就有一个进程得留在那里等
- - - - :explode:内核检查硬件平台都拥有什么硬件，为硬件加载驱动，最终加载根文件系统并运行第一个进程.比如机器重启就会导致内核自举
- - - - :one:mutex initialized to the value 1
      - :two:full initialized to 0
      - :three:empty initialized to N
  - - - :one:semaphore mutex( initialized to 1)
        
        :explode:lock the reader_count to avoid wait(writer) and signal(writer) being performed several times
      - :two:semaphore writer( initialized to 1)
        
        :explode:1: ok to write;0: cannot write
      - :three:integer reader_count( initialized to 0)
    - - :one:readers
        
        :bread:procedure
        
        :one:I come, update the reader_count( synchronized), if I am the first reader, then I have the responsibility of telling the writers that the shared data will not be allowed to write.
        
        :two:reading
        
        :three:When a reader leave, he should decrease the reader_count( synchronized). Besides, if he is the last one to leave, it is his responsibility to tell the writers that they can modify the shared data
        
        do { wait(mutex); readcount++; if (readcount == 1) wait(wrt); signal(mutex); // reading wait(mutex); readcount--; if (readcount == 0) signal(wrt); signal(mutex)； } while (TRUE);
      - :two:writers
        
        wait(writer); //... signal(writer);
        
        :explode:check if I can write.