Package org.apache.tools.ant.taskdefs

# Class ExecuteWatchdog

java.lang.Object
org.apache.tools.ant.taskdefs.ExecuteWatchdog

All Implemented Interfaces:
  `TimeoutObserver`

public class ExecuteWatchdog extends Object implements TimeoutObserver
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 (Execute.isFailure(exitvalue) && watchdog.killedProcess()) {
                  // it was killed on purpose by the watchdog
     }

Since:
  Ant 1.2
See Also:
  - `Execute`
  - `Watchdog`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ExecuteWatchdog(int timeout)`
  Deprecated.
  since 1.5.x.
  `ExecuteWatchdog(long timeout)`
  Creates a new watchdog with a given timeout.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `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`
  `start(Process process)`
  Watches the given process and terminates it, if it runs for too long.
  `void`
  `stop()`
  Stops the watcher.
  `void`
  `timeoutOccured(Watchdog w)`
  Called after watchdog has finished.

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Constructor Details

  - ### ExecuteWatchdog

    public ExecuteWatchdog(long timeout)
    Creates a new watchdog with a given timeout.
    Parameters:
      `timeout` - the timeout for the process in milliseconds. It must be greater than 0.

  - ### ExecuteWatchdog

    @Deprecated public ExecuteWatchdog(int timeout)
    Deprecated.
    since 1.5.x. Use constructor with a long type instead. (1.4.x compatibility)
    Parameters:
      `timeout` - the timeout value to use in milliseconds.
    See Also:
      - `ExecuteWatchdog(long)`

- ## Method Details

  - ### start

    public void start(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:
      `IllegalStateException` - if a process is still being monitored.

  - ### stop

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

  - ### timeoutOccured

    public void timeoutOccured(Watchdog w)
    Called after watchdog has finished. This can be called in the watchdog thread
    Specified by:
      `timeoutOccured` in interface `TimeoutObserver`
    Parameters:
      `w` - the watchdog

  - ### 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`.