更改线程优先级没有影响

我正在尝试使用android.os.Process.setThreadPriority()更改主线程的优先级。我以前和优先级改变之后的日志信息，这里是代码：更改线程优先级没有影响

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()); 
    } 
}

而且我得到以下输出：

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

这意味着，优先级没有改变，任何方法我用它来评估它。 android.os.Process.THREAD_PRIORITY_DISPLAY = -4，所以改变我的输出后应该等于-4，为什么它保持不变？为什么android.os.Process.setThreadPriority()没有效果？

P.S.我阅读有关线程的Google文档，但我没有遇到任何解释android.os.Process.getThreadPriority()和Thread.currentThread().getPriority()之间差异的问题。为什么这些方法返回不同的值？

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

来源

2012-01-26 Eugene Chumak

您正在使用错误的ThreadID进行检查。

要得到正确的ID，你必须使用android.os.Process.myTid（）;

固定码：

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()); 
    } 
}

日志输出：

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

为了进一步参考：

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

来源

2012-02-22 12:07:22 robotniko

更改线程优先级没有影响

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