Class ThreadSafeProgressMonitor

  • All Implemented Interfaces:

    public class ThreadSafeProgressMonitor
    extends Object
    implements ProgressMonitor
    Wrapper around the general ProgressMonitor to make it thread safe. Updates to the underlying ProgressMonitor are made only from the thread that allocated this wrapper. Callers are responsible for ensuring the allocating thread uses pollForUpdates() or waitForCompletion() to update the underlying ProgressMonitor. Only update(int), isCancelled(), and endWorker() may be invoked from a worker thread. All other methods of the ProgressMonitor interface can only be called from the thread that allocates this wrapper.
    • Constructor Detail

      • ThreadSafeProgressMonitor

        public ThreadSafeProgressMonitor​(ProgressMonitor pm)
        Wrap a ProgressMonitor to be thread safe.
        pm - the underlying monitor to receive events.
    • Method Detail

      • start

        public void start​(int totalTasks)
        Advise the monitor of the total number of subtasks.

        This should be invoked at most once per progress monitor interface.

        Specified by:
        start in interface ProgressMonitor
        totalTasks - the total number of tasks the caller will need to complete their processing.
      • beginTask

        public void beginTask​(String title,
                              int totalWork)
        Begin processing a single task.
        Specified by:
        beginTask in interface ProgressMonitor
        title - title to describe the task. Callers should publish these as stable string constants that implementations could match against for translation support.
        totalWork - total number of work units the application will perform; ProgressMonitor.UNKNOWN if it cannot be predicted in advance.
      • startWorker

        public void startWorker()
        Notify the monitor a worker is starting.
      • startWorkers

        public void startWorkers​(int count)
        Notify the monitor of workers starting.
        count - the number of worker threads that are starting.
      • endWorker

        public void endWorker()
        Notify the monitor a worker is finished.
      • pollForUpdates

        public void pollForUpdates()
        Non-blocking poll for pending updates. This method can only be invoked by the same thread that allocated this ThreadSafeProgressMonior.
      • waitForCompletion

        public void waitForCompletion()
                               throws InterruptedException
        Process pending updates and wait for workers to finish. This method can only be invoked by the same thread that allocated this ThreadSafeProgressMonior.
        InterruptedException - if the main thread is interrupted while waiting for completion of workers.
      • update

        public void update​(int completed)
        Denote that some work units have been completed.

        This is an incremental update; if invoked once per work unit the correct value for our argument is 1, to indicate a single unit of work has been finished by the caller.

        Specified by:
        update in interface ProgressMonitor
        completed - the number of work units completed since the last call.
      • isCancelled

        public boolean isCancelled()
        Check for user task cancellation.
        Specified by:
        isCancelled in interface ProgressMonitor
        true if the user asked the process to stop working.
      • endTask

        public void endTask()
        Finish the current task, so the next can begin.
        Specified by:
        endTask in interface ProgressMonitor