pgjdbc · metlos · Oct 2, 2014 · Oct 2, 2014
diff --git a/org/postgresql/Driver.java.in b/org/postgresql/Driver.java.in
@@ -54,7 +54,6 @@ public class Driver implements java.sql.Driver
 
     private static final Logger logger = new Logger();
     private static boolean logLevelSet = false;
-	private static Timer cancelTimer = new Timer(true);
 
     static
     {
@@ -762,15 +761,4 @@ public class Driver implements java.sql.Driver
     {
         throw notImplemented(this.getClass(), "getParentLogger()");
     }
-
-    public static void purgeTimerTasks()
-    {
-        if ( cancelTimer != null ) cancelTimer.purge();
-    }
-
-    public  static void addTimerTask(TimerTask timerTask, long milliSeconds)
-    {
-    	cancelTimer.schedule( timerTask, milliSeconds );
-    }
-
 }
diff --git a/org/postgresql/PGConnection.java b/org/postgresql/PGConnection.java
@@ -8,6 +8,8 @@
 package org.postgresql;
 
 import java.sql.*;
+import java.util.TimerTask;
+
 import org.postgresql.copy.CopyManager;
 import org.postgresql.fastpath.Fastpath;
 import org.postgresql.largeobject.LargeObjectManager;
@@ -116,5 +118,15 @@ public void addDataType(String type, Class klass)
      * @return PID of backend server process. 
      */
     public int getBackendPID();
+
+    /**
+     * Adds the timer task to the {@link org.postgresql.util.SharedTimer} used driver-wide.
+     * This method exists on the connection object because the lifetime of the shared timer is governed by existence
+     * of connections.
+     *
+     * @param timerTask the task to add
+     * @param milliSeconds the delay before the task is executed
+     */
+    public void addTimerTask(TimerTask timerTask, long milliSeconds);
 }
 
diff --git a/org/postgresql/jdbc2/AbstractJdbc2Connection.java b/org/postgresql/jdbc2/AbstractJdbc2Connection.java
@@ -81,6 +81,8 @@ public abstract class AbstractJdbc2Connection implements BaseConnection
     /** Set of oids that use binary transfer when receiving from server. */
     private Set<Integer> useBinaryReceiveForOids;
 
+    private SharedTimer.Loan timerLoan = SharedTimer.loan();
+
     public abstract DatabaseMetaData getMetaData() throws SQLException;
 
     //
@@ -672,6 +674,7 @@ public void close()
     {
         protoConnection.close();
         openStackTrace = null;
+        timerLoan.release();
     }
 
     /*
@@ -1324,4 +1327,10 @@ protected void abort()
     {
        protoConnection.abort();
     }
+
+    @Override
+    public void addTimerTask(TimerTask timerTask, long milliSeconds)
+    {
+        timerLoan.timer().schedule(timerTask, milliSeconds);
+    }
 }
diff --git a/org/postgresql/jdbc2/AbstractJdbc2Statement.java b/org/postgresql/jdbc2/AbstractJdbc2Statement.java
@@ -32,6 +32,7 @@
 import org.postgresql.util.PSQLState;
 import org.postgresql.util.PGobject;
 import org.postgresql.util.GT;
+import org.postgresql.util.SharedTimer;
 
 /**
  * This class defines methods of the jdbc2 specification.
@@ -3439,7 +3440,7 @@ public void run()
 	    }
 	};
 
-	Driver.addTimerTask( cancelTimer, timeout * 1000);
+	getPGConnection().addTimerTask(cancelTimer, timeout * 1000);
     }
 
     private synchronized void killTimer()
@@ -3448,7 +3449,7 @@ private synchronized void killTimer()
         {
             cancelTimer.cancel();
             cancelTimer = null;
-	    Driver.purgeTimerTasks();
+            SharedTimer.purge();
         }
 
     }

diff --git a/org/postgresql/test/TestUtil.java b/org/postgresql/test/TestUtil.java
@@ -14,6 +14,7 @@
 import java.util.Properties;
 
 import org.postgresql.jdbc2.AbstractJdbc2Connection;
+import org.postgresql.util.SharedTimer;
 
 /**
  * Utility class for JDBC tests
@@ -222,6 +223,8 @@ public static void closeDB(Connection con) throws SQLException
     {
         if (con != null)
             con.close();
+
+        assert SharedTimer.getLoanCount() == 0 : "Some connections remain open after the test.";
     }
 
     /*

diff --git a/org/postgresql/util/SharedTimer.java b/org/postgresql/util/SharedTimer.java
@@ -0,0 +1,101 @@
+/*
+ * -------------------------------------------------------------------------
+ *
+ *  Copyright (c) 2003-2014, PostgreSQL Global Development Group
+ *
+ *
+ * -------------------------------------------------------------------------
+ */
+
+package org.postgresql.util;
+
+import java.util.Timer;
+
+/**
+ * @author Lukas Krejci
+ */
+public final class SharedTimer
+{
+    private static Timer timer;
+    private static int loanCount;
+
+    // no instances of this class
+    private SharedTimer() {
+
+    }
+
+    public static synchronized Loan loan()
+    {
+        if (timer == null)
+        {
+            timer = new Timer("Postgresql JDBC shared statement cancellation timer", true);
+        }
+
+        loanCount++;
+
+        return new Loan();
+    }
+
+    /**
+     * @see java.util.Timer#purge()
+     */
+    public static int purge()
+    {
+        return timer == null ? 0 : timer.purge();
+    }
+
+    /**
+     * Just for testing purposes.
+     */
+    public static synchronized int getLoanCount()
+    {
+        return loanCount;
+    }
+
+    private static synchronized void release()
+    {
+        loanCount--;
+
+        // clean out cancelled tasks
+        timer.purge();
+
+        if (loanCount == 0)
+        {
+            timer.cancel();
+            timer = null;
+        }
+    }
+
+    /**
+     * A loan of a shared timer.
+     */
+    public static final class Loan
+    {
+        private boolean returned;
+
+        private Loan() {
+
+        }
+
+        /**
+         * @return the loaned timer. Don't keep a reference to the timer itself because it might be cancelled if this
+         *         loan object is {@link #release()}ed.
+         */
+        public Timer timer()
+        {
+            return returned ? null : timer;
+        }
+
+        /**
+         * Releases the loan making it no longer usable.
+         */
+        public void release()
+        {
+            if (!returned)
+            {
+                returned = true;
+                SharedTimer.release();
+            }
+        }
+    }
+}