1 files changed, 127 insertions, 0 deletions
diff --git a/qpid/java/qpid-test-utils/src/main/java/org/apache/qpid/test/utils/PortHelper.java b/qpid/java/qpid-test-utils/src/main/java/org/apache/qpid/test/utils/PortHelper.java
new file mode 100644
index 0000000000..d3586c364f
--- /dev/null
+++ b/qpid/java/qpid-test-utils/src/main/java/org/apache/qpid/test/utils/PortHelper.java
@@ -0,0 +1,127 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.qpid.test.utils;
+
+import java.io.IOException;
+import java.net.DatagramSocket;
+import java.net.ServerSocket;
+import java.util.Set;
+
+import org.apache.log4j.Logger;
+
+public class PortHelper
+{
+    private static final Logger _logger = Logger.getLogger(PortHelper.class);
+
+    private static final int DEFAULT_TIMEOUT_MILLIS = 5000;
+
+    private int timeout = DEFAULT_TIMEOUT_MILLIS;
+
+    public void waitUntilPortsAreFree(Set<Integer> ports)
+    {
+        _logger.debug("Checking if ports " + ports + " are free...");
+
+        for (Integer port : ports)
+        {
+            waitUntilPortIsFree(port);
+        }
+
+        _logger.debug("ports " + ports + " are free");
+    }
+
+    private void waitUntilPortIsFree(int port)
+    {
+        long startTime = System.currentTimeMillis();
+        long deadline = startTime + timeout;
+        boolean alreadyFailed = false;
+
+        while (true)
+        {
+            if (System.currentTimeMillis() > deadline)
+            {
+                throw new RuntimeException("Timed out after " + timeout + " ms waiting for port " + port + " to become available");
+            }
+
+            if (isPortAvailable(port))
+            {
+                if(alreadyFailed)
+                {
+                    _logger.debug("port " + port + " is now available");
+                }
+                return;
+            }
+            else
+            {
+                alreadyFailed = true;
+            }
+
+            try
+            {
+                Thread.sleep(500);
+            }
+            catch (InterruptedException e)
+            {
+                Thread.currentThread().interrupt();
+            }
+        }
+    }
+
+    public boolean isPortAvailable(int port)
+    {
+        ServerSocket serverSocket = null;
+        DatagramSocket datagramSocket = null;
+
+        try
+        {
+            serverSocket = new ServerSocket(port);
+            serverSocket.setReuseAddress(true); // ensures that the port is subsequently usable
+            datagramSocket = new DatagramSocket(port);
+            datagramSocket.setReuseAddress(true);
+            return true;
+        }
+        catch (IOException e)
+        {
+            _logger.debug("port " + port + " is not free");
+            return false;
+        }
+        finally
+        {
+            if (serverSocket != null)
+            {
+                try
+                {
+                    serverSocket.close();
+                }
+                catch (IOException e)
+                {
+                    throw new RuntimeException("Couldn't close port " + port + " that we created to check its availability", e);
+                }
+            }
+            if(datagramSocket != null)
+            {
+                datagramSocket.close();
+            }
+        }
+    }
+
+    public void setTimeout(int timeout)
+    {
+        this.timeout = timeout;
+    }
+}