Merge "Omaha #3668 Give grid a custom job pool." into omaha_14.4.1

Former-commit-id: 5e22943a26 [formerly b98016900319d31c23be96640aa97f7b2efcee5b]
Former-commit-id: e83c1f20bb

cave/com.raytheon.viz.grid/src/com/raytheon/viz/grid/rsc/general/GridDataRequestJobPool.java

@@ -0,0 +1,128 @@
+/**
+ * This software was developed and / or modified by Raytheon Company,
+ * pursuant to Contract DG133W-05-CQ-1067 with the US Government.
+ * 
+ * U.S. EXPORT CONTROLLED TECHNICAL DATA
+ * This software product contains export-restricted data whose
+ * export/transfer/disclosure is restricted by U.S. law. Dissemination
+ * to non-U.S. persons whether in the United States or abroad requires
+ * an export license or other authorization.
+ * 
+ * Contractor Name:        Raytheon Company
+ * Contractor Address:     6825 Pine Street, Suite 340
+ *                         Mail Stop B8
+ *                         Omaha, NE 68106
+ *                         402.291.0100
+ * 
+ * See the AWIPS II Master Rights File ("Master Rights File.pdf") for
+ * further licensing information.
+ **/
+package com.raytheon.viz.grid.rsc.general;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.LinkedBlockingQueue;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.Job;
+
+/**
+ * A pool of {@link Job} that executes {@link GridDataRequestRunner}s with a
+ * scheduling pattern that is ideal for smooth user interaction. This object
+ * expects {@link #schedule(GridDataRequestRunner)} to be called each time data
+ * is needed that is not yet available(primarily when the frame is displayed).
+ * Calling {@link #schedule(GridDataRequestRunner)} causes the runner to be
+ * bumped to the front of the queue so that data will be ready as soon as
+ * possible. This causes runners that are not being displayed to frequently get
+ * bumped to the back of the queue, which is desired since the user does not
+ * need that data yet.
+ * 
+ * <pre>
+ * 
+ * SOFTWARE HISTORY
+ * 
+ * Date          Ticket#  Engineer    Description
+ * ------------- -------- ----------- --------------------------
+ * Oct 29, 2014  3668     bsteffen    Initial creation
+ * 
+ * </pre>
+ * 
+ * @author bsteffen
+ * @version 1.0
+ */
+public class GridDataRequestJobPool {
+
+    private static final int POOL_SIZE = Integer.getInteger(
+            "grid.request.pool.size", 10);
+    
+    private static final GridDataRequestJobPool instance = new GridDataRequestJobPool();
+
+    public static void schedule(GridDataRequestRunner runner) {
+        instance.scheduleRunner(runner);
+    }
+
+    protected LinkedBlockingQueue<Job> jobQueue = new LinkedBlockingQueue<Job>();
+
+    protected List<GridDataRequestRunner> runners = new LinkedList<>();
+    
+    private GridDataRequestJobPool(){
+        for (int i = 0; i <POOL_SIZE; i++) {
+            jobQueue.add(new GridDataRequestJob());
+        }
+    }
+    
+    protected void scheduleRunner(GridDataRequestRunner runner) {
+        synchronized (runners) {
+            if (runners.isEmpty() || !(runners.get(0) == runner)) {
+                runners.remove(runner);
+                runners.add(0, runner);
+            }
+        }
+        Job job = jobQueue.poll();
+        if (job != null) {
+            job.schedule();
+        }
+    }
+    
+    protected void reschedule(GridDataRequestRunner runner){
+        synchronized (runners) {
+            if(!runners.contains(runner)){
+                runners.add(runner);
+            }
+        }
+    }
+    
+    protected GridDataRequestRunner getNextRunner(){
+        synchronized (runners) {
+            if(runners.isEmpty()){
+                return null;
+            }else{
+                return runners.remove(0);
+            }
+        }
+    }
+    
+    
+    private class GridDataRequestJob extends Job{
+
+        public GridDataRequestJob() {
+            super("Requesting Grid Data");
+        }
+
+        @Override
+        protected IStatus run(IProgressMonitor monitor) {
+            jobQueue.offer(this);
+            GridDataRequestRunner runner = getNextRunner();
+            while(runner != null){
+                if(runner.processOneRequest()){
+                    reschedule(runner);
+                }
+                runner = getNextRunner();
+            }
+            return Status.OK_STATUS;
+        }
+    }
+    
+}

cave/com.raytheon.viz.grid/src/com/raytheon/viz/grid/rsc/general/GridDataRequestRunner.java

@@ -29,11 +29,10 @@ import com.raytheon.uf.common.status.UFStatus;
 import com.raytheon.uf.common.status.UFStatus.Priority;
 import com.raytheon.uf.common.time.DataTime;
 import com.raytheon.uf.viz.core.exception.VizException;
-import com.raytheon.uf.viz.core.jobs.JobPool;
 
 /**
  * 
- * Manages asynchronously requesting data for GridResources.
+ * Manages asynchronously requesting data for {@link AbstractGridResource}s.
  * 
  * <pre>
  * 
@@ -47,21 +46,15 @@ import com.raytheon.uf.viz.core.jobs.JobPool;
  * Jun 24, 2013 2140       randerso    Moved safe name code into AbstractVizResource
  * Oct 07, 2014 3668       bclement    uses executor instead of eclipse job
  *                                      renamed to GridDataRequestRunner
- * Oct 23, 2014 3668       bsteffen    replace executor with job pool so user
+ * Oct 29, 2014 3668       bsteffen    replace executor with custom job pool.
- *                                     sees progress.
  * 
  * </pre>
  * 
  * @author bsteffen
  * @version 1.0
+ * @see GridDataRequestJobPool
  */
-class GridDataRequestRunner implements Runnable {
+class GridDataRequestRunner {
-
-    private static final int POOL_SIZE = Integer.getInteger(
-            "grid.request.pool.size", 10);
-
-    private static final JobPool jobPool = new JobPool("Requesting Grid Data",
-            POOL_SIZE);
 
     private static final transient IUFStatusHandler statusHandler = UFStatus
             .getHandler(GridDataRequestRunner.class);
@@ -80,6 +73,8 @@ class GridDataRequestRunner implements Runnable {
         // been notified.)
         public boolean exceptionHandled = false;
 
+        public boolean isRunning = false;
+
         public GridDataRequest(DataTime time, List<PluginDataObject> pdos) {
             this.time = time;
             if (pdos == null) {
@@ -91,21 +86,12 @@ class GridDataRequestRunner implements Runnable {
         }
 
         public boolean shouldRequest() {
-            return (gridData == null) && (exception == null);
+            return (gridData == null) && (exception == null)
+                    && (isRunning == false);
         }
 
     }
 
-    /**
-     * This class is not designed to handle multiple requests concurrently. To
-     * ensure this doesn't happen we track when it is scheduled and do not
-     * schedule again. It would have been simpler to synchronize the run method
-     * but that ties up threads from the pool that other resources should use.
-     * So we don't leave dangling requests this should only be modified while
-     * synchronized on requests.
-     */
-    private volatile boolean scheduled = false;
-
     private AbstractGridResource<?> resource;
 
     private List<GridDataRequest> requests = new ArrayList<GridDataRequest>();
@@ -114,42 +100,49 @@ class GridDataRequestRunner implements Runnable {
         this.resource = resource;
     }
 
-    @Override
+    /**
-    public void run() {
+     * Attempt to process a request if there are any that need to be processed
-        for (GridDataRequest request = getNext(); request != null; request = getNext()) {
+     * 
-            try {
+     * @return true if a request was processed or false if no requests need to
-                request.gridData = resource.getData(request.time, request.pdos);
+     *         be processed.
-                if (request.gridData == null) {
+     */
-                    /*
+    public boolean processOneRequest() {
-                     * need to remove unfulfillable requests to avoid infinite
+        GridDataRequest request = getNext();
-                     * loop.
+        if (request == null) {
-                     */
+            return false;
-                    synchronized (requests) {
+        }
-                        requests.remove(request);
+        try {
-                    }
+            request.gridData = resource.getData(request.time, request.pdos);
-                } else {
+            if (request.gridData == null) {
-                    resource.issueRefresh();
+                /* need to remove unfulfillable requests to avoid infinite loop. */
+                synchronized (requests) {
+                    requests.remove(request);
                 }
-            } catch (VizException e) {
+            } else {
-                request.exception = e;
                 resource.issueRefresh();
             }
+        } catch (VizException e) {
+            request.exception = e;
+            resource.issueRefresh();
+        } finally {
+            request.isRunning = false;
         }
+        return true;
     }
 
     /**
-     * Get the next request that should be sent
+     * Get the next request that should be processed
      * 
-     * @return null if no request should be sent
+     * @return null if no request should be processed
      */
     protected GridDataRequest getNext() {
         synchronized (requests) {
             for (GridDataRequest request : requests) {
                 if (request.shouldRequest()) {
+                    request.isRunning = true;
                     return request;
                 }
             }
-            scheduled = false;
         }
         return null;
     }
@@ -181,9 +174,8 @@ class GridDataRequestRunner implements Runnable {
             if ((request.exception != null) && !request.exceptionHandled) {
                 handleExceptions();
             }
-            if (!scheduled && request.shouldRequest()) {
+            if (request.shouldRequest()) {
-                scheduled = true;
+                GridDataRequestJobPool.schedule(this);
-                jobPool.schedule(this);
             }
         }
         return null;
@@ -268,9 +260,6 @@ class GridDataRequestRunner implements Runnable {
     public void stopAndClear() {
         synchronized (requests) {
             requests.clear();
-            if (jobPool.cancel(this)) {
-                scheduled = false;
-            }
         }
     }