svn commit: r397899 - in /db/derby/code/trunk/java/client/org/apache/derby/client/net: NetAgent.java NetConnection40.java

[rh...@apache.org]

Author: rhillegas
Date: Fri Apr 28 06:44:29 2006
New Revision: 397899

URL: http://svn.apache.org/viewcvs?rev=397899&view=rev
Log:
DERBY-1090: Commit Olav's client1090_patch2.diff patch, which addresses recovery from hanging servers.

Modified:
    db/derby/code/trunk/java/client/org/apache/derby/client/net/NetAgent.java
    db/derby/code/trunk/java/client/org/apache/derby/client/net/NetConnection40.java

Modified: db/derby/code/trunk/java/client/org/apache/derby/client/net/NetAgent.java
URL: http://svn.apache.org/viewcvs/db/derby/code/trunk/java/client/org/apache/derby/client/net/NetAgent.java?rev=397899&r1=397898&r2=397899&view=diff
==============================================================================
--- db/derby/code/trunk/java/client/org/apache/derby/client/net/NetAgent.java (original)
+++ db/derby/code/trunk/java/client/org/apache/derby/client/net/NetAgent.java Fri Apr 28 06:44:29 2006
@@ -20,10 +20,13 @@
 
 package org.apache.derby.client.net;
 
+import java.net.SocketException;
+
 import org.apache.derby.client.am.Agent;
 import org.apache.derby.client.am.DisconnectException;
 import org.apache.derby.client.am.SqlException;
 import org.apache.derby.client.am.Utils;
+import org.apache.derby.shared.common.sanity.SanityManager;
 
 public class NetAgent extends Agent {
     //---------------------navigational members-----------------------------------
@@ -323,6 +326,60 @@
         }
     }
 
+    /**
+     * Specifies the maximum blocking time that should be used when sending
+     * and receiving messages. The timeout is implemented by using the the 
+     * underlying socket implementation's timeout support. 
+     * 
+     * Note that the support for timeout on sockets is dependent on the OS 
+     * implementation. For the same reason we ignore any exceptions thrown
+     * by the call to the socket layer.
+     * 
+     * @param timeout The timeout value in seconds. A value of 0 corresponds to 
+     * infinite timeout.
+     */
+    protected void setTimeout(int timeout) {
+        try {
+            // Sets a timeout on the socket
+            socket_.setSoTimeout(timeout * 1000); // convert to milliseconds
+        } catch (SocketException se) {
+            // Silently ignore any exceptions from the socket layer
+            if (SanityManager.DEBUG) {
+                System.out.println("NetAgent.setTimeout: ignoring exception: " + 
+                                   se);
+            }
+        }
+    }
+
+    /**
+     * Returns the current timeout value that is set on the socket.
+     * 
+     * Note that the support for timeout on sockets is dependent on the OS 
+     * implementation. For the same reason we ignore any exceptions thrown
+     * by the call to the socket layer.
+     * 
+     * @return The timeout value in seconds. A value of 0 corresponds to
+     * that no timeout is specified on the socket.
+     */
+    protected int getTimeout() {
+        int timeout = 0; // 0 is default timeout for sockets
+
+        // Read the timeout currently set on the socket
+        try {
+            timeout = socket_.getSoTimeout();
+        } catch (SocketException se) {
+            // Silently ignore any exceptions from the socket layer
+            if (SanityManager.DEBUG) {
+                System.out.println("NetAgent.getTimeout: ignoring exception: " + 
+                                   se);
+            }
+        }
+
+        // Convert from milliseconds to seconds (note that this truncates
+        // the results towards zero but that should not be a problem).
+        timeout = timeout / 1000;
+        return timeout;
+    }
 
     protected void sendRequest() throws DisconnectException {
         try {

Modified: db/derby/code/trunk/java/client/org/apache/derby/client/net/NetConnection40.java
URL: http://svn.apache.org/viewcvs/db/derby/code/trunk/java/client/org/apache/derby/client/net/NetConnection40.java?rev=397899&r1=397898&r2=397899&view=diff
==============================================================================
--- db/derby/code/trunk/java/client/org/apache/derby/client/net/NetConnection40.java (original)
+++ db/derby/code/trunk/java/client/org/apache/derby/client/net/NetConnection40.java Fri Apr 28 06:44:29 2006
@@ -130,6 +130,14 @@
      * The validity is checked by running a simple query against the 
      * database.
      *
+     * The timeout specified by the caller is implemented as follows:
+     * On the server: uses the queryTimeout functionality to make the
+     * query time out on the server in case the server has problems or
+     * is highly loaded.
+     * On the client: uses a timeout on the socket to make sure that 
+     * the client is not blocked forever in the cases where the server
+     * is "hanging" or not sending the reply.
+     *
      * @param timeout The time in seconds to wait for the database
      * operation used to validate the connection to complete. If the 
      * timeout period expires before the operation completes, this 
@@ -155,6 +163,12 @@
         // Do a simple query against the database
         synchronized(this) {
             try {
+                // Save the current network timeout value
+                int oldTimeout = netAgent_.getTimeout();
+
+                // Set the required timeout value on the network connection
+                netAgent_.setTimeout(timeout);
+
                 // If this is the first time this method is called on this 
                 // connection we prepare the query 
                 if (isValidStmt == null) {
@@ -167,6 +181,9 @@
                 // Run the query against the database
                 ResultSet rs = isValidStmt.executeQuery();
                 rs.close();
+
+                // Restore the previous timeout value
+                netAgent_.setTimeout(oldTimeout);
             } catch(SQLException e) {
                 // If an SQL exception is thrown the connection is not valid,
                 // we ignore the exception and return false.