Python的等效Java函数wait(),notify(),synchronized

Question

我必须在Python 2.7中编写一个类,我有一些问题.我最近来自java背景和学习python

如果我必须在java中做,我会写这些

public class CommandSender extends Thread {
    private boolean isTimeOut;
    private boolean running;
    private ArrayList<Command> waitingList;

    public CommandSender() {
        running = false;
        waitingList = new LinkedList<Command>();
        isTimeOut = false;
    }

    public void run() {
        running = true;
        while (running) {
            synchronized (this) {
                 while (waitingList.isEmpty() && running) {
                     try {
                         wait();
                     } catch (InterruptedException ie) {
                         ie.printStackTrace();
                     }
                  }
                  while (!waitingList.isEmpty() && running) {
                      currentCmd = waitingList.remove(0);
                      // doSomething(currentCmd)
                  }
             }
        }
    }

    public synchronized void sendCommand(Command cmd) {
        waitingList.add(cmd);
        notify();
    }

    public synchronized boolean isTimeOut() {
        return isTimeOut;
    }
}

我现在做了什么

class CommandSender(threading.Thread)

     def __init__(self):
         threading.Thread.__init__(self)
         self.waiting_list = []
         self.running = False
         self.is-time_out = False
         self.my_lock = threading.Lock()

     def run(self):
         self.running = True
         with self.my_lock:
             while len(self.waiting_list) == 0 and self.running:
                 # Don't know what I have to do here
             while len(self.waiting_list) != 0 and self.running:
                 # Do my stuff

     def send_command(self, cmd):
         with self.my_lock:
             self.waiting_list.append(cmd)
             # Notify ?

     def is_time_out(self):
         with self.my_lock:
             return self.is_rime_out

我为每个实例使用一个锁,因为只有一个CommandSender实例

那么如何进行等待/通知过程？我的同步块是否很好用？

谢谢 !

Answer 1

首先，您应该意识到Python的全局解释器锁不允许多个线程同时运行Python代码（尽管线程可以运行例如C代码，例如使用本机代码模块，如果它们适当地释放GIL） 。如果您需要使用 Python 代码来使用多核 CPU，请查看该multiprocessing模块。

现在，直接等价的是类threading.Event。创建一个Event对象，然后使用wait和set。