A licensee asked to clarify the specs. in Thread API and to mention in API document 
if it's specs.

When a thread enters into sleep and an interruption happens to the thread,
an InterruptedException occurs. (This is described in Thread#interrupt() API doc.)
However, as the attached test case shows, sleep interval time is set to 0,
interruption does not seem to occur.


REPRODUCE :
1) Compile the following test case

===== Test Case ======
class SleepTest extends Thread {
    static int sleep_time;
    public static void main( String arg[] ) {
	try {
	    sleep_time = Integer.parseInt( arg[0] );
	    SleepTest st = new SleepTest();
	    st.start();
	    Thread.sleep(1000);

	    System.out.println("Interrupt...");
	    st.interrupt();
	}
	catch( Exception e ) {
	    e.printStackTrace();
	}
    }

    public void run() {
	try {
	    while( true ) {
		Thread.sleep(sleep_time);
	    }
	}
	catch( InterruptedException e ) {
	    e.printStackTrace();
	}
    }
}
=======================

2) Launch "java SleepTest <sleep interval time>"
    for example, if sleep interval is 2[sec], launch "java SleepTest 2000"

    Yo will see the message,

Interrupt...
java.lang.InterruptedException: sleep interrupted
	at java.lang.Thread.sleep(Native Method)
	at SleepTest.run(SleepTest.java:35)


  However, if you specify 0 as interval time
     java SleepTest 0

  You can not see InterruptedException.

REQUEST :
 The licensee requested to mention the above in API document like,
  "When an interruption happens to thread.sleep(0),
  InterruptedException does not appear."

CONFIGURATION :
   OS : WindowsXP(SP1, Japanese)
   JRE : 1.4.2_06/5.0/6.0b11

###@###.### 2004-11-12 02:44:33 GMT