挂起所有线程:使用Threads - ms警告ms

Question

我有2 Thread秒做一些网络计算.当我运行我的应用程序并开始我的第二个后,Thread我得到一个:

Suspending all threads took: ms 警告后跟:

Background sticky concurrent mark sweep GC freed 246745(21MB) AllocSpace objects, 169(6MB) LOS objects, 33% free, 31MB/47MB, paused 1.972ms total 127.267ms 警告.

有时候我会得到那两个警告,有时我会收到很多这两个警告,直到我决定终止应用程序运行.在这一点上,它只是运行主要Thread,基本上什么都不做.这是相关代码:

MainActivity.java:

protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Getting html page through a thread
    this.getHtmlPageThread = new GetHtmlPageThread(URL_STRING);
    this.getHtmlPageThread.start();

    // The thread that will search the web for data
    this.getDataFromTheWebThread = new GetDataFromTheWebThread();

    // Search button click listener
    searchButton.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            // Get the searched lyrics
            searchedLyrics = inputEditText.getText().toString();

            informUserAboutConnectionToTheNet();

            // Starting to search the web for data through a thread
            getDataFromTheWebThread.start();

            if (!getDataFromTheWebThread.isAlive())
            {
                printMap(MainActivity.matchResultMap);
            }
        }
    }); // End of search button click listener

    printMap(MainActivity.matchResultMap);

} // End of onCreate() method

protected void onStart()
{
    super.onStart();

    if (!this.isParseSucceeded()) // Connection to net failed
    {
        if (!getHtmlPageThread.isAlive()) // If the thread is not alive, start it.
        {
            getHtmlPageThread.start(); // Try to connect again
            this.informUserAboutConnectionToTheNet();
        }
    }
    if (!this.isParseSucceeded())
    {
        super.onStart(); // Call onStart() method
    }

} // End of onStart() method

GetHtmlPageThread.java:

public class GetHtmlPageThread extends Thread
{
    private String url;

    public GetHtmlPageThread(String url)
    {
        this.url = url;
    }

    @Override
    public void run()
    {
        try
        {
            MainActivity.htmlPage.setHtmlDocument(this.getParsedDocument(this.url));
            if (MainActivity.htmlPage.getHtmlDocument() != null)
            {
                MainActivity.parsedSucceeded = true; // Parsed succeeded
            }
            else
            {
                MainActivity.parsedSucceeded = false; // Parsed failed
            }
            Thread.sleep(100);
        }
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }
    }

    /**
     * Returns the document object of the url parameter.
     * If the connection is failed , return null.
     *
     * @param url Url to parse
     * @return The document of the url.
     *
     */
    public Document getParsedDocument(String url)
    {
        try
        {
            return Jsoup.connect(url).get();
        }
        catch (IOException e) // On error
        {
            e.printStackTrace();
        }

        return null; // Failed to connect to the url
    }

}

GetDataFromTheWeb.java:

public class GetDataFromTheWebThread extends Thread
{
    public static boolean isFinished = false; // False - the thread is still running. True - the thread is dead

    @Override
    public void run()
    {
        GetDataFromTheWebThread.isFinished = false;
        try
        {
            this.getLyricsPlanetDotComResults(MainActivity.searchedLyrics); // Method for internet computations
            Thread.sleep(100);
        }
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }
        GetDataFromTheWebThread.isFinished = true;
    }
    ...
}

基本上,this.getLyricsPlanetDotComResults(MainActivity.searchedLyrics);第二种方法Thread是进行大量的互联网工作和计算.比准确的网络更多的计算.

所以我想我得到了那些警告,因为第二个Thread太"忙"了？或者也许只是我的活动生命周期与onCreate()方法和onStart()方法的实现是错误的？

毋庸置疑,我没有得到我想要的输出,虽然我调试了应用程序并逐步完成了第二次Thread,它完美地运行.所以,它必须与我Activity的实现有关.

Answer 1

第一行基本上是说垃圾收集器(GC)决定它需要暂停所有线程来完成它的一些工作(例如重定位变量),这需要一些时间.通常那里有一个数字.

第二行是收集的结果.它释放了相当多的内存,你现在有1/3的空闲.它要求你的应用程序暂停2毫秒,总共花费127毫秒收集垃圾.

GC本身并不坏.但是,如果你一直这样做,要么就是你需要大量的内存,或者你做的事情效率低下.重字符串解析,特别是像JSoup这样的东西,可以导致很多小对象(主要是字符串)真正需要在像手机这样的小型存储设备上快速清理,所以在这里看到它并不奇怪.

基本上,这只是一个问题,如果你从GC得到性能打嗝或者你在某个时候要去OOM.如果这些都没有发生,我也不会担心这一点.