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

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