org.apache.tools.ant.taskdefs
Class ExecuteWatchdog

java.lang.Object
  |
  +--org.apache.tools.ant.taskdefs.ExecuteWatchdog
All Implemented Interfaces:
java.lang.Runnable

public class ExecuteWatchdog
extends java.lang.Object
implements java.lang.Runnable

Destroys a process running for too long. For example:

 ExecuteWatchdog watchdog = new ExecuteWatchdog(30000);
 Execute exec = new Execute(myloghandler, watchdog);
 exec.setCommandLine(mycmdline);
 int exitvalue = exec.execute();
 if (exitvalue != SUCCESS && watchdog.killedProcess()){
              // it was killed on purpose by the watchdog
 }
 

Author:
thomas.haas@softwired-inc.com, Stephane Bailliez
See Also:
Execute

Constructor Summary
ExecuteWatchdog(int timeout)
          Creates a new watchdog with a given timeout.
 
Method Summary
 void checkException()
          This method will rethrow the exception that was possibly caught during the run of the process.
protected  void cleanUp()
          reset the monitor flag and the process.
 boolean isWatching()
          Indicates whether or not the watchdog is still monitoring the process.
 boolean killedProcess()
          Indicates whether the last process run was killed on timeout or not.
 void run()
          Watches the process and terminates it, if it runs for to long.
 void start(java.lang.Process process)
          Watches the given process and terminates it, if it runs for too long.
 void stop()
          Stops the watcher.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ExecuteWatchdog

public ExecuteWatchdog(int timeout)
Creates a new watchdog with a given timeout.
Parameters:
timeout - the timeout for the process in milliseconds. It must be greather than 0.
Method Detail

start

public void start(java.lang.Process process)
Watches the given process and terminates it, if it runs for too long. All information from the previous run are reset.
Parameters:
process - the process to monitor. It cannot be null
Throws:
java.lang.IllegalStateException - thrown if a process is still being monitored.

stop

public void stop()
Stops the watcher. It will notify all threads possibly waiting on this object.

run

public void run()
Watches the process and terminates it, if it runs for to long.
Specified by:
run in interface java.lang.Runnable

cleanUp

protected void cleanUp()
reset the monitor flag and the process.

checkException

public void checkException()
                    throws BuildException
This method will rethrow the exception that was possibly caught during the run of the process. It will only remains valid once the process has been terminated either by 'error', timeout or manual intervention. Information will be discarded once a new process is ran.
Throws:
BuildException - a wrapped exception over the one that was silently swallowed and stored during the process run.

isWatching

public boolean isWatching()
Indicates whether or not the watchdog is still monitoring the process.
Returns:
true if the process is still running, otherwise false.

killedProcess

public boolean killedProcess()
Indicates whether the last process run was killed on timeout or not.
Returns:
true if the process was killed otherwise false.


Copyright ? 2000 Apache Software Foundation. All Rights Reserved.