simplify decoder pool, just be a ConcurrentLinkedQueue

common-tools/clara-io/src/main/java/org/jlab/io/clara/Clas12Writer.java

@@ -3,8 +3,6 @@
 import java.io.File;
 import java.nio.file.Path;
 import java.util.List;
-import java.util.TreeMap;
-import java.util.TreeSet;
 import org.jlab.clara.std.services.EventWriterException;
 import org.jlab.detector.calib.utils.ConstantsManager;
 import org.jlab.detector.helicity.HelicitySequenceDelayed;

common-tools/clas-detector/src/main/java/org/jlab/detector/decode/CLASDecoderPool.java

@@ -6,16 +6,14 @@
  *
  * @author baltzell
  */
-public class CLASDecoderPool {
+public class CLASDecoderPool extends ConcurrentLinkedQueue<CLASDecoder> {
 
-    ConcurrentLinkedQueue<CLASDecoder> pool;
-
     int sharedConstantsManagers = 64;
 
     public CLASDecoderPool(int size, String variation, String timestamp) {
 
-        pool = new ConcurrentLinkedQueue<>();
-        
+        super();
+
         CLASDecoder d0 = null;
 
         for (int i=0; i<size; i++) {
@@ -30,16 +28,15 @@ public CLASDecoderPool(int size, String variation, String timestamp) {
             }
             else d = new CLASDecoder(d0);
 
-            pool.add(d);
+            add(d);
         }
     }
 
-    public CLASDecoder take() throws InterruptedException {
-        return pool.poll();
-    }
+    volatile static CLASDecoderPool instance = null;
 
-    public void put(CLASDecoder decoder) throws InterruptedException {
-        pool.offer(decoder);
+    public static synchronized CLASDecoderPool getInstance() {
+        if (instance == null) 
+            instance = new CLASDecoderPool(64,"default",null);
+        return instance;
     }
-
 }

common-tools/clas-reco/src/main/java/org/jlab/clas/reco/DecoderEngine.java

@@ -82,9 +82,9 @@ public EngineData execute(EngineData input) {
             }
             HipoDataEvent hipo;
             try {
-                CLASDecoder d = pool.take();
+                CLASDecoder d = pool.poll();
                 hipo = new HipoDataEvent(d.getDecodedEvent(evio),schema);
-                pool.put(d);
+                pool.offer(d);
                 output.setData("binary/data-hipo", hipo.getHipoEvent());
             } catch (Exception e) {
                 String msg = String.format("Error processing input event%n%n%s", ClaraUtil.reportException(e));