Virtual Developer Workshop: Containerized Development with Docker
|Bruce Eckel's Thinking in Java||Contents | Prev | Next|
- Inherit a class from Thread and override the run( ) method. Inside run( ), print a message, then call sleep( ). Repeat this three times, then return from run( ). Put a start-up message in the constructor and override finalize( ) to print a shut-down message. Make a separate thread class that calls System.gc( ) and System.runFinalization( ) inside run( ), printing a message as it does so. Make several thread objects of both types and run them to see what happens.
- Modify Counter2.java so that the thread is an inner class and doesn’t need to explicitly store a handle to a Counter2.
- Modify Sharing2.java to add a synchronized block inside the run( ) method of TwoCounter instead of synchronizing the entire run( ) method.
- Create two Thread subclasses, one with a run( ) that starts up, captures the handle of the second Thread object and then calls wait( ). The other class’ run( ) should call notifyAll( ) for the first thread after some number of seconds have passed, so the first thread can print out a message.
- In Counter5.java inside Ticker2, remove the yield( ) and explain the results. Replace the yield( ) with a sleep( ) and explain the results.
- In ThreadGroup1.java, replace the call to sys.suspend( ) with a call to wait( ) for the thread group, causing it to wait for two seconds. For this to work correctly you must acquire the lock for sys inside a synchronized block.
- Change Daemons.java so that main( ) has a sleep( ) instead of a readLine( ). Experiment with different sleep times to see what happens.
- (Intermediate) In Chapter 7, locate the GreenhouseControls.java example, which consists of three files. In Event.java, the class Event is based on watching the time. Change Event so that it is a Thread, and change the rest of the design so that it works with this new Thread-based Event.