Android的 - 为什么第二个线程暂停第一个执行？ [英] Android - Why second thread halts execution of the first one?

问题描述

我有一个运行在循环中2个线程的应用程序。第1一个是在1秒的时间间隔更新的曲线图，第二个是更新在60秒的时间间隔另一个图表。第二个任务是花费很长的时间，因为它是quering一些服务器在互联网的3倍，可能并不总是可用，即使是它会占用到5-7s执行。

I have an app that runs 2 threads in loops. 1st one is updating a graph in 1s interval and the second one is updating another graph at 60s interval. The second task is taking a long time since it is quering some server in the internet 3 times that might not always be available and even if it is it will take up to 5-7s to execute.

正在发生的事情是，当我启动第二个线程将暂停第一个执行，这是不是我想要的，我想这两个同时运行。在这里，在Youtube的视频中可以看到应用程序运行的结果。 http://youtu.be/l7K5zSWzlxI
thread_updater1s正在运行一个绿色的曲线图，大的读出，并在角落里一个计时器，所以你很清楚地看到这档11秒。

What is happening is when I launch the second thread it will pause execution of the first one and that is not what I want, I wish both run concurrently. Here in the Youtube video you can see the results of the app running. http://youtu.be/l7K5zSWzlxI "thread_updater1s" is running a green graph, large readout, and a timer in the corner so you clearly see it stalls for 11 seconds.

1）首先这是为什么发生？如何解决它？

1)First of all why is that happening? how to fix it?

2）我知道，我可能不会启动线程正确的。我很难理解如何让东西在Java中的间隔循环运行，我的code一图/胎面正常工作。现在，当我在单独的线程2路我不知道为什么他们没有并发执行。

2)I'm aware that I might not launch the threads properly at all. I had hard time understanding how to make something to run in a interval loop in Java and my code worked fine for one graph/tread. Now when I have 2 loops in separate threads I don't know why they are not executing concurrently.

下面是code：

public class LoopExampleActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);
    thread_updater1s.start();
    thread_updater2.start();
}// end of onCreate

final Runnable r1s = new Runnable() {
    public void run() {
        do_1s_updates(); // those are very quick http calls to the local API server 
    }                    // to get data nessessary for some plot.
                        // They have 1s timeout as well but rarely timeout
};

final Runnable r2 = new Runnable() {
    public void run() {
        do_large_updates(); //This makes 7 long call over the Internet to the slow https
                            //server once every 60s. Has 10s timeout and sometimes takes as much as
                            //7s to execute
        }
};

Thread thread_updater1s = new Thread() {
    @Override
    public void run() {
        try {
            while (true) {
                handler.post(r1s);
                sleep(1000);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
};

Thread thread_updater2 = new Thread() {
    @Override
    public void run() {
        try {
            while (true) {
                handler2.post(r2);
                sleep(60000);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
};

}

PS。请宽容和翔实我只code Java的15天至今完全没有之前的遭遇和教训。

PS. please be forgiving and informative I only code Java for 15 days so far with absolutely no prior experince or lesson.

推荐答案

您需要在线程（而不是发布可运行）的HTTP请求。然后，当你有下载的数据，您可以创建与该数据将更新该Runnable由UI线程执行图形和后一个可运行。下面是一个例子：

You need to make the http requests in the threads (not the posted runnables). Then, when you have the data downloaded, you create a runnable with that data that will update the graph and post that runnable to be executed by the UI thread. Here is an example:

public class LoopExampleActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);
    thread_updater1s.start();
    thread_updater2.start();
}// end of onCreate

Thread thread_updater1s = new Thread() {
    @Override
    public void run() {
        try {
            while (true) {
                final Object data = getDataFromServer1();
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        updateGraph1(data);
                    }
                );
                sleep(1000);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
};

Thread thread_updater2 = new Thread() {
    @Override
    public void run() {
        try {
            while (true) {
                final Object data = getDataFromServer2();
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        updateGraph2(data);
                    }
                );
                sleep(60000);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
};

显然，通过重新您的数据下载presents合适的类改变最终目标数据。

Obviously, change that final Object data by the appropriate class that represents your data downloaded.

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