Changeset 11438 in josm for trunk/src

Timestamp:

2017-01-07T09:44:59+01:00 (7 years ago)

Author:

wiktorn

Message:

Fix thread pool for WMS

Because threds in WMS download ThreadPool never died, the unreferenced ThreadPool object (and its threads) was never cleared. To fix this minimum size of ThreadPool was changed to 0.

But due to the fact, that ThreadPoolExecutor spawns new Thread only when workQueue refuses to take a new job, workaround is implemented in HostLimitQueue based on: ​http://stackoverflow.com/questions/9622599/java-threadpoolexecutor-strategy-direct-handoff-with-queue#

WMS Settings was fixed so now WMS has it's own THREAD_LIMIT setting not connected to JCS default setting.

Location:

trunk/src/org/openstreetmap/josm

Files:

• data/cache/HostLimitQueue.java (modified) (3 diffs)
• data/imagery/TMSCachedTileLoader.java (modified) (1 diff)
• data/imagery/WMSCachedTileLoader.java (modified) (2 diffs)
• gui/preferences/imagery/WMSSettingsPanel.java (modified) (4 diffs)

trunk/src/org/openstreetmap/josm/data/cache/HostLimitQueue.java

@@ -9 +9 @@
 import java.util.concurrent.LinkedBlockingDeque;
 import java.util.concurrent.Semaphore;
+import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 
@@ -32 +33 @@
     private final Map<String, Semaphore> hostSemaphores = new ConcurrentHashMap<>();
     private final int hostLimit;
+
+    private ThreadPoolExecutor executor;
+
+    private int corePoolSize;
+
+    private int maximumPoolSize;
 
     /**
@@ -93 +100 @@
     }
 
+    /**
+     * Set the executor for which this queue works. It's needed to spawn new threads.
+     * See: http://stackoverflow.com/questions/9622599/java-threadpoolexecutor-strategy-direct-handoff-with-queue#
+     *
+     * @param executor
+     */
+
+    public void setExecutor(ThreadPoolExecutor executor) {
+        this.executor = executor;
+        this.maximumPoolSize = executor.getMaximumPoolSize();
+        this.corePoolSize = executor.getCorePoolSize();
+    }
+
+    @Override
+    public boolean offer(Runnable e)
+    {
+        if (super.offer(e) == false)
+        {
+            return false;
+        }
+
+        if (executor != null) {
+            // See: http://stackoverflow.com/questions/9622599/java-threadpoolexecutor-strategy-direct-handoff-with-queue#
+            // force spawn of a thread if not reached maximum
+            int currentPoolSize = executor.getPoolSize();
+            if (currentPoolSize < maximumPoolSize
+                    && currentPoolSize >= corePoolSize)
+            {
+                executor.setCorePoolSize(currentPoolSize + 1);
+                executor.setCorePoolSize(corePoolSize);
+            }
+        }
+        return true;
+    }
+
     private Semaphore getSemaphore(JCSCachedTileLoaderJob<?, ?> job) {
         String host;

trunk/src/org/openstreetmap/josm/data/imagery/TMSCachedTileLoader.java

@@ -78 +78 @@
      */
     public static ThreadPoolExecutor getNewThreadPoolExecutor(String nameFormat, int workers) {
-        return new ThreadPoolExecutor(
-                workers, // keep the thread number constant
+        HostLimitQueue workQueue = new HostLimitQueue(HOST_LIMIT.get().intValue());
+        ThreadPoolExecutor executor = new ThreadPoolExecutor(
+                0, // 0 so for unused thread pools threads will eventually die, freeing also the threadpool
                 workers, // do not this number of threads
-                30, // keepalive for thread
+                300, // keepalive for thread
                 TimeUnit.SECONDS,
-                new HostLimitQueue(HOST_LIMIT.get().intValue()),
+                workQueue,
                 Utils.newThreadFactory(nameFormat, Thread.NORM_PRIORITY)
                 );
+        workQueue.setExecutor(executor);
+        return executor;
     }
 

trunk/src/org/openstreetmap/josm/data/imagery/WMSCachedTileLoader.java

@@ -10 +10 @@
 import org.openstreetmap.gui.jmapviewer.interfaces.TileLoaderListener;
 import org.openstreetmap.josm.data.cache.BufferedImageCacheEntry;
+import org.openstreetmap.josm.data.preferences.IntegerProperty;
 
 /**
@@ -20 +21 @@
 public class WMSCachedTileLoader extends TMSCachedTileLoader {
 
+    /**
+     * overrides the THREAD_LIMIT in superclass, as we want to have separate limit and pool for WMS
+     */
+    public static final IntegerProperty THREAD_LIMIT = new IntegerProperty("imagery.wms.loader.maxjobs", 3);
     /**
      * Creates a TileLoader with separate WMS downloader.

trunk/src/org/openstreetmap/josm/gui/preferences/imagery/WMSSettingsPanel.java

@@ -13 +13 @@
 import javax.swing.SpinnerNumberModel;
 
-import org.openstreetmap.josm.data.imagery.WMSCachedTileLoaderJob;
+import org.openstreetmap.josm.data.imagery.WMSCachedTileLoader;
 import org.openstreetmap.josm.gui.layer.WMSLayer;
 import org.openstreetmap.josm.tools.GBC;
@@ -49 +49 @@
         add(Box.createHorizontalGlue(), GBC.eol().fill(GBC.HORIZONTAL));
         JLabel labelSimConn = new JLabel(tr("Simultaneous connections:"));
-        int threadLimitValue = Utils.clamp(WMSCachedTileLoaderJob.THREAD_LIMIT.get(), THREADS_MIN, THREADS_MAX);
+        int threadLimitValue = Utils.clamp(WMSCachedTileLoader.THREAD_LIMIT.get(), THREADS_MIN, THREADS_MAX);
         spinSimConn = new JSpinner(new SpinnerNumberModel(threadLimitValue, THREADS_MIN, THREADS_MAX, 1));
         labelSimConn.setLabelFor(spinSimConn);
@@ -71 +71 @@
     public void loadSettings() {
         this.autozoomActive.setSelected(WMSLayer.PROP_DEFAULT_AUTOZOOM.get());
-        this.spinSimConn.setValue(WMSCachedTileLoaderJob.THREAD_LIMIT.get());
+        this.spinSimConn.setValue(WMSCachedTileLoader.THREAD_LIMIT.get());
         this.tileSize.setValue(WMSLayer.PROP_IMAGE_SIZE.get());
     }
@@ -81 +81 @@
     public boolean saveSettings() {
         WMSLayer.PROP_DEFAULT_AUTOZOOM.put(this.autozoomActive.isSelected());
-        WMSCachedTileLoaderJob.THREAD_LIMIT.put((Integer) spinSimConn.getModel().getValue());
+        WMSCachedTileLoader.THREAD_LIMIT.put((Integer) spinSimConn.getModel().getValue());
         WMSLayer.PROP_IMAGE_SIZE.put((Integer) this.tileSize.getModel().getValue());