多項(xiàng)選擇題

public class SyncTest{  
public static void main（String args） {  
 final StringBuffer s1= new StringBuffer（）；  
 final StringBuffer s2= new StringBuffer（）；  
 new Thread （） {  
 public void run（） {  
synchronized（s1） {  
s2.append（“A”）；  
synchronized（s2） {  
 s2.append（“B”）；  
 System.out.print（s1）；  
 System.out.print（s2）； 
 } 
 }  
 }  
 }.start（）；  
new Thread（） {  
public void run（） {  
synchronized（s2） { 
s2.append（“C”）； 
synchronized（s1） {  
s1.append（“D”）； 
System.out.print（s2）； 
System.out.print（s1）；  
}  
}   
}  
}.start（）；  
}  
}  
Which two statements are true？ （）

A. The program prints “ABBCAD”
B. The program prints “CDDACB”
C. The program prints “ADCBADBC”
D. The output is a non-deterministic point because of a possible deadlock condition.
E. The output is dependent on the threading model of the system the program is running on.

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單項(xiàng)選擇題

public class X implements Runnable （  
private int x；  
private int y；  
 public static void main（String args） （  
X that = new X（）；  
（new Thread（that）） . start（ ）； 
 （new Thread（that）） . start（ ）；  
）  
 public synchronized void run（ ） （  
 for （；；） （  
 x++；  
 y++；  
 System.out.printIn（“x = “ + x + “， y = “ + y）；  
 ） 
 ）  
 ）  
What is the result？（）

A. An error at line 11 causes compilation to fail.
B. Errors at lines 7 and 8 cause compilation to fail.
C. The program prints pairs of values for x and y that might not always be the same on the same line  （for example， “x=2， y=1”）
D. The program prints pairs of values for x and y that are always the same on the same line （forexample， “x=1， y=1”. In addition， each value appears twice （for example， “x=1， y=1” followed by  “x=1， y=1”）
E. The program prints pairs of values for x and y that are always the same on the same line （for example， “x=1， y=1”. In addition， each value appears twice （for example， “x=1， y=1” followed by  “x=2s， y=2”）
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