add test case for tracer concurrency

Author: David R. MacIver

test/src/com/rabbitmq/examples/TracerConcurrencyTest.java

@@ -0,0 +1,74 @@
+package com.rabbitmq.examples;
+
+import com.rabbitmq.client.*;
+import java.util.concurrent.*;
+import java.util.Random;
+
+/** 
+ * Test that the tracer correctly handles multiple concurrently processing
+ * channels. If it doesn't then this code will cause the tracer to break
+ * and will be disconneted.
+ */
+public class TracerConcurrencyTest{
+
+  public int port = 5673;
+  public String host = "localhost";
+  public int threadCount = 3;
+
+  private final Object lock = new Object();
+
+  public static void main(String[] args) throws Exception{
+    new TracerConcurrencyTest().run();
+  }
+
+  static String EXCHANGE = "tracer-exchange";
+  static String QUEUE = "tracer-queue";
+
+  public void run(){
+
+    final Connection conn;
+    try {
+      conn = new ConnectionFactory().newConnection(host, port);
+      Channel setup = conn.createChannel();
+
+      setup.exchangeDeclare(EXCHANGE, "direct");
+      setup.queueDeclare(QUEUE);
+      setup.queueBind(QUEUE,EXCHANGE, "");
+      
+      setup.close();
+    } catch(Exception e){
+      e.printStackTrace();
+      System.exit(1);
+      throw null; // placate the compiler
+    }
+
+    for(int i = 0; i < threadCount; i++){
+      final int j = i;
+      new Thread(){
+        @Override public void run(){
+          try {
+            Random rnd = new Random();
+            Channel ch = conn.createChannel();
+            while(true){
+                Channel old = ch;
+                ch.close();
+                ch = conn.createChannel(); 
+                ch.basicPublish(
+                  EXCHANGE,
+                  "", null,
+                  new byte[1024 * 1024]
+                );
+                ch.basicGet(QUEUE, true);
+            }
+          } catch(Exception e){
+            synchronized(lock){
+              e.printStackTrace();
+              System.err.println();
+            }
+            System.exit(1);
+          } 
+        }
+      }.start();
+    }
+  }
+}