add AbstractSpanDisruptor to avoid endless blocking of next()

skywalking-storage-center/skywalking-routing/src/main/java/com/a/eye/skywalking/routing/disruptor/AbstractSpanDisruptor.java

+package com.a.eye.skywalking.routing.disruptor;
+
+import com.lmax.disruptor.InsufficientCapacityException;
+import com.lmax.disruptor.RingBuffer;
+
+/**
+ * Created by wusheng on 2016/12/4.
+ */
+public class AbstractSpanDisruptor {
+    private volatile boolean isRunning = true;
+
+    public long getRingBufferSequence(RingBuffer buffer){
+        long sequence;
+        while(true) {
+            try {
+                if(!isRunning){
+                    return -1;
+                }
+
+                sequence = buffer.tryNext();
+                break;
+            } catch (InsufficientCapacityException e) {
+                try {
+                    Thread.sleep(1L);
+                } catch (InterruptedException e1) {
+                }
+            }
+        }
+        return sequence;
+    }
+
+    protected boolean isShutdown(){
+        return !isRunning;
+    }
+
+    protected void shutdown(){
+        isRunning = false;
+    }
+}

skywalking-storage-center/skywalking-routing/src/main/java/com/a/eye/skywalking/routing/disruptor/NoopSpanDisruptor.java

@@ -7,6 +7,11 @@ import com.a.eye.skywalking.network.grpc.RequestSpan;
  * Created by xin on 2016/11/29.
  */
 public class NoopSpanDisruptor extends SpanDisruptor {
+    public static NoopSpanDisruptor INSTANCE = new NoopSpanDisruptor();
+
+    private NoopSpanDisruptor() {
+
+    }
 
     @Override
     public boolean saveSpan(AckSpan ackSpan) {

skywalking-storage-center/skywalking-routing/src/main/java/com/a/eye/skywalking/routing/disruptor/SpanDisruptor.java

@@ -48,7 +48,7 @@ public class SpanDisruptor {
     }
 
     public void shutdown() {
-        ackSpanDisruptor.shutdown();
+        requestSpanDisruptor.shutdown();
         ackSpanDisruptor.shutdown();
     }
 }

skywalking-storage-center/skywalking-routing/src/main/java/com/a/eye/skywalking/routing/disruptor/ack/AckSpanDisruptor.java

@@ -6,6 +6,8 @@ import com.a.eye.skywalking.logging.api.ILog;
 import com.a.eye.skywalking.logging.api.LogManager;
 import com.a.eye.skywalking.network.grpc.AckSpan;
 import com.a.eye.skywalking.routing.config.Config;
+import com.a.eye.skywalking.routing.disruptor.AbstractSpanDisruptor;
+import com.lmax.disruptor.InsufficientCapacityException;
 import com.lmax.disruptor.RingBuffer;
 import com.lmax.disruptor.dsl.Disruptor;
 import com.lmax.disruptor.util.DaemonThreadFactory;
@@ -13,7 +15,7 @@ import com.lmax.disruptor.util.DaemonThreadFactory;
 /**
  * Created by xin on 2016/11/29.
  */
-public class AckSpanDisruptor {
+public class AckSpanDisruptor extends AbstractSpanDisruptor {
     private static ILog logger = LogManager.getLogger(AckSpanDisruptor.class);
     private Disruptor<AckSpanHolder> ackSpanDisruptor;
     private RingBuffer<AckSpanHolder> ackSpanRingBuffer;
@@ -29,7 +31,11 @@ public class AckSpanDisruptor {
     }
 
     public boolean saveAckSpan(AckSpan ackSpan) {
-        long sequence = ackSpanRingBuffer.next();
+        long sequence = this.getRingBufferSequence(ackSpanRingBuffer);
+        if(this.isShutdown()){
+            return false;
+        }
+
         try {
             AckSpanHolder data = ackSpanRingBuffer.get(sequence);
             data.setAckSpan(ackSpan);
@@ -44,9 +50,10 @@ public class AckSpanDisruptor {
         }
     }
 
+
     public void shutdown() {
+        super.shutdown();
         ackSpanEventHandler.stop();
-
         ackSpanDisruptor.shutdown();
     }
 }

skywalking-storage-center/skywalking-routing/src/main/java/com/a/eye/skywalking/routing/disruptor/request/RequestSpanDisruptor.java

@@ -6,6 +6,8 @@ import com.a.eye.skywalking.logging.api.ILog;
 import com.a.eye.skywalking.logging.api.LogManager;
 import com.a.eye.skywalking.network.grpc.RequestSpan;
 import com.a.eye.skywalking.routing.config.Config;
+import com.a.eye.skywalking.routing.disruptor.AbstractSpanDisruptor;
+import com.lmax.disruptor.InsufficientCapacityException;
 import com.lmax.disruptor.RingBuffer;
 import com.lmax.disruptor.dsl.Disruptor;
 import com.lmax.disruptor.util.DaemonThreadFactory;
@@ -13,7 +15,7 @@ import com.lmax.disruptor.util.DaemonThreadFactory;
 /**
  * Created by xin on 2016/11/29.
  */
-public class RequestSpanDisruptor {
+public class RequestSpanDisruptor extends AbstractSpanDisruptor {
     private static ILog logger = LogManager.getLogger(RequestSpanDisruptor.class);
     private Disruptor<RequestSpanHolder>     requestSpanDisruptor;
     private RingBuffer<RequestSpanHolder>    requestSpanRingBuffer;
@@ -28,8 +30,13 @@ public class RequestSpanDisruptor {
     }
 
     public boolean saveRequestSpan(RequestSpan requestSpan) {
-        long sequence = requestSpanRingBuffer.next();
+        long sequence = this.getRingBufferSequence(requestSpanRingBuffer);
+        if(this.isShutdown()){
+            return false;
+        }
+
         try {
+
             RequestSpanHolder data = requestSpanRingBuffer.get(sequence);
             data.setRequestSpan(requestSpan);
 
@@ -44,7 +51,8 @@ public class RequestSpanDisruptor {
         }
     }
 
-    public void shutDown() {
+    public void shutdown() {
+        super.shutdown();
         eventHandler.stop();
         requestSpanDisruptor.shutdown();
     }

skywalking-storage-center/skywalking-routing/src/main/java/com/a/eye/skywalking/routing/router/Router.java

@@ -19,7 +19,6 @@ public class Router implements NodeChangesListener {
     private static ILog logger = LogManager.getLogger(Router.class);
 
     private SpanDisruptor[] disruptors = new SpanDisruptor[0];
-    private NoopSpanDisruptor noopSpanPool = new NoopSpanDisruptor();
 
     public SpanDisruptor lookup(RequestSpan requestSpan) {
         return getSpanDisruptor(requestSpan.getRouteKey());
@@ -31,7 +30,7 @@ public class Router implements NodeChangesListener {
 
     private SpanDisruptor getSpanDisruptor(long routKey) {
         if (disruptors.length == 0) {
-            return noopSpanPool;
+            return NoopSpanDisruptor.INSTANCE;
         }
 
         while (true) {