更改線程優先級沒有影響

我正在嘗試使用android.os.Process.setThreadPriority()更改主線程的優先級。我以前和優先級改變之後的日誌信息，這裏是代碼：更改線程優先級沒有影響

public class TestActivity extends Activity { 
    public final String TAG="TestActivity"; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     int tid=(int)Thread.currentThread().getId(); 
     Log.d(TAG,"priority before change = " + android.os.Process.getThreadPriority(tid)); 
     Log.d(TAG,"priority before change = "+Thread.currentThread().getPriority()); 
     android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_DISPLAY); 
     Log.d(TAG,"priority after change = " + android.os.Process.getThreadPriority(tid)); 
     Log.d(TAG,"priority after change = " + Thread.currentThread().getPriority()); 
    } 
}

而且我得到以下輸出：

priority before change (getThreadPriority) = 0 
priority before change (currentThread().getPriority) = 5 
priority after change (getThreadPriority) = 0 
priority after change (currentThread().getPriority) = 5

這意味着，優先級沒有改變，任何方法我用它來評估它。 android.os.Process.THREAD_PRIORITY_DISPLAY = -4，所以改變我的輸出後應該等於-4，爲什麼它保持不變？爲什麼android.os.Process.setThreadPriority()沒有效果？

P.S.我閱讀有關線程的Google文檔，但我沒有遇到任何解釋android.os.Process.getThreadPriority()和Thread.currentThread().getPriority()之間差異的問題。爲什麼這些方法返回不同的值？

P.P.S. Thread.currentThread().setPriority()工作正常。

來源

2012-01-26 Eugene Chumak

您正在使用錯誤的ThreadID進行檢查。

要得到正確的ID，你必須使用android.os.Process.myTid（）;

固定碼：

package mypackage.test; 
import android.app.Activity; 
import android.os.Bundle; 
import android.util.Log; 

public class TestActivity extends Activity { 
    public final String TAG="TestActivity"; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     int tid=android.os.Process.myTid(); 

     Log.d(TAG,"priority before change = " + android.os.Process.getThreadPriority(tid)); 
     Log.d(TAG,"priority before change = "+Thread.currentThread().getPriority()); 
     android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_DISPLAY); 
     Log.d(TAG,"priority after change = " + android.os.Process.getThreadPriority(tid)); 
     Log.d(TAG,"priority after change = " + Thread.currentThread().getPriority()); 
    } 
}

日誌輸出：

priority before change = 0 
priority before change = 5 
priority after change = -4 
priority after change = 5

爲了進一步參考：

http://developer.android.com/reference/android/os/Process.html#myTid()

來源

2012-02-22 12:07:22 robotniko

更改線程優先級沒有影響

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