Android线程未在后台运行

Question

My Thread on Android is not running precisely. I'm starting that from a Service, but somewhy it's not running correctly.

Service:

ServiceHelper sh = new ServiceHelper();
new Thread(sh).start();

public class ServiceHelper implements Runnable {
    public void run() {
        while(true) {
            Log.d(LOG_TAG, "run");
            //1.) sometimes it calls this here: SSLSocket.close();
            //2.) also, sometimes it calls a write operation on this SSLSocket.
            //    but since write can block, I've put this write operation inside an AsyncTask: new WriteAsyncTask().execute(somethingToWrite);
            //    This returns immediately.
            Thread.sleep(1000);
        }
    }
}

And this results logcat like this:

01-10 22:39:54.148 I/TEST(10327): run
01-10 22:40:04.150 I/TEST(10327): run

So there are like 10 seconds that misses this thread. Why could this happen? There are other threads of course which do blocking network operations. But why is this particular thread not running?

I also noticed a very strange thing:

public void run() {
    while(true) {
        Log.i(LOG_TAG, "tick1");
        Thread.sleep(1000);
        Log.i(LOG_TAG, "tick2");
    }
}

And somehow I get this in the log:

01-11 22:06:54.649 I/BGService(10078): tick1
01-11 22:07:50.664 I/BGService(10078): tick2

Between tick1 and tick2 there is one and only one operation: Thread.sleep(1000). How can it block for almost a minute? It is in a Thread, which was started from a Service, but what is the main reason for this huge delay?

Answer 1

Make sure sure you run your Runnable like so:

Thread t = new Thread(new ServiceHelper());
t.start();

Only then will it be started with as a thread.

On a side note, what you are doing is running an infinite loop which will take 100% CPU usage. It's possible that Android will kill or heavily throttle your service to allow other services to run properly.

Answer 2

在while循环内部使用类似这样的内容，您将看到结果

Thread.sleep(1000);