Small LeakTask refactor just to make HikariPool.getConnection() a little tighter (and more readable).

CHANGES

@@ -2,16 +2,11 @@ HikariCP Changes
 
 Changes in 2.2.6
 
- * Fix an InvalidStateException thrown from the ConcurrentBag when two separate
-   threads call close() on the same connection by making the isClosed state of
-   the ConnectionProxy visible across threads through volatility.
-
  * Support pool suspend/resume though JMX to support certain failover scenarios.
 
  * Fix theoretical race in JDBC 4.0 detection support.
 
- * Suppress ordinary internal accounting sanity checks when the pool is being
+ * Improve shutdown() semantics to avoid exceptions as connections are forcefully
-   undergoing forced shutdown.  All bets are off when live connections are being
    aborted.
 
 Changes in 2.2.5

hikaricp-java6/src/main/java/com/zaxxer/hikari/pool/HikariPool.java

@@ -92,6 +92,7 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
    private final IConnectionCustomizer connectionCustomizer;
    private final Semaphore acquisitionSemaphore;
 
+   private final LeakTask leakTask;
    private final AtomicInteger totalConnections;
    private final AtomicReference<Throwable> lastConnectionFailure;
    private final ScheduledThreadPoolExecutor houseKeepingExecutorService;
@@ -100,7 +101,6 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
    private final String password;
    private final boolean isRecordMetrics;
    private final boolean isIsolateInternalQueries;
-   private final long leakDetectionThreshold;
 
    private volatile boolean isShutdown;
    private volatile long connectionTimeout;
@@ -143,7 +143,6 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
       this.catalog = configuration.getCatalog();
       this.connectionCustomizer = initializeCustomizer();
       this.transactionIsolation = getTransactionIsolation(configuration.getTransactionIsolation());
-      this.leakDetectionThreshold = configuration.getLeakDetectionThreshold();
       this.isIsolateInternalQueries = configuration.isIsolateInternalQueries();
 
       this.isRecordMetrics = configuration.getMetricRegistry() != null;
@@ -160,6 +159,7 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
          this.houseKeepingExecutorService.setRemoveOnCancelPolicy(true);
       }
       this.houseKeepingExecutorService.scheduleAtFixedRate(new HouseKeeper(), delayPeriod, delayPeriod, TimeUnit.MILLISECONDS);
+      this.leakTask = (configuration.getLeakDetectionThreshold() == 0) ? LeakTask.NO_LEAK : new LeakTask(configuration.getLeakDetectionThreshold(), houseKeepingExecutorService);
 
       setLoginTimeout(dataSource, connectionTimeout, LOGGER);
       registerMBeans(configuration, this);
@@ -193,12 +193,9 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
                continue;
             }
 
-            final LeakTask leakTask = (leakDetectionThreshold == 0) ? LeakTask.NO_LEAK : new LeakTask(leakDetectionThreshold, houseKeepingExecutorService);
-            final IHikariConnectionProxy proxyConnection = ProxyFactory.getProxyConnection(this, bagEntry, leakTask);
-
             metricsContext.setConnectionLastOpen(bagEntry, now);
 
-            return proxyConnection;
+            return ProxyFactory.getProxyConnection(this, bagEntry, leakTask.start());
          }
          while (timeout > 0L);
       }

hikaricp-java6/src/main/java/com/zaxxer/hikari/util/LeakTask.java

@@ -34,28 +34,42 @@ public class LeakTask implements Runnable
    public static final LeakTask NO_LEAK;
    private static final Logger LOGGER = LoggerFactory.getLogger(LeakTask.class);
 
-   private final ScheduledFuture<?> scheduledFuture;
+   private final ScheduledExecutorService executorService;
-   private final Exception exception;
+   private final long leakDetectionThreshold;
+   private ScheduledFuture<?> scheduledFuture;
+   private Exception exception;
 
    static
    {
       NO_LEAK = new LeakTask() {
          @Override
          public void cancel() {};
+
+         @Override
+         public LeakTask start()
+         {
+            return this;
+         }
       };
    }
 
    public LeakTask()
    {
-      scheduledFuture = null;
+      executorService = null;
-      exception = null;
+      leakDetectionThreshold = 0;
    }
 
    public LeakTask(final long leakDetectionThreshold, final ScheduledExecutorService executorService)
    {
-      this.exception = new Exception();
+      this.executorService = executorService;
+      this.leakDetectionThreshold = leakDetectionThreshold;
+   }
 
+   public LeakTask start()
+   {
+      exception = new Exception();
       scheduledFuture = executorService.schedule(this, leakDetectionThreshold, TimeUnit.MILLISECONDS);
+      return this;
    }
 
    /** {@inheritDoc} */

hikaricp/src/main/java/com/zaxxer/hikari/pool/HikariPool.java

@@ -91,6 +91,7 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
    private final IConnectionCustomizer connectionCustomizer;
    private final Semaphore acquisitionSemaphore;
 
+   private final LeakTask leakTask;
    private final AtomicInteger totalConnections;
    private final AtomicReference<Throwable> lastConnectionFailure;
    private final ScheduledThreadPoolExecutor houseKeepingExecutorService;
@@ -99,7 +100,6 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
    private final String password;
    private final boolean isRecordMetrics;
    private final boolean isIsolateInternalQueries;
-   private final long leakDetectionThreshold;
 
    private volatile boolean isShutdown;
    private volatile long connectionTimeout;
@@ -142,7 +142,6 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
       this.catalog = configuration.getCatalog();
       this.connectionCustomizer = initializeCustomizer();
       this.transactionIsolation = getTransactionIsolation(configuration.getTransactionIsolation());
-      this.leakDetectionThreshold = configuration.getLeakDetectionThreshold();
       this.isIsolateInternalQueries = configuration.isIsolateInternalQueries();
 
       this.isRecordMetrics = configuration.getMetricRegistry() != null;
@@ -157,6 +156,7 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
       this.houseKeepingExecutorService = new ScheduledThreadPoolExecutor(1, configuration.getThreadFactory() != null ? configuration.getThreadFactory() : new DefaultThreadFactory("Hikari Housekeeping Timer (pool " + configuration.getPoolName() + ")", true));
       this.houseKeepingExecutorService.setRemoveOnCancelPolicy(true);
       this.houseKeepingExecutorService.scheduleAtFixedRate(new HouseKeeper(), delayPeriod, delayPeriod, TimeUnit.MILLISECONDS);
+      this.leakTask = (configuration.getLeakDetectionThreshold() == 0) ? LeakTask.NO_LEAK : new LeakTask(configuration.getLeakDetectionThreshold(), houseKeepingExecutorService);
 
       setLoginTimeout(dataSource, connectionTimeout, LOGGER);
       registerMBeans(configuration, this);
@@ -190,12 +190,9 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
                continue;
             }
 
-            final LeakTask leakTask = (leakDetectionThreshold == 0) ? LeakTask.NO_LEAK : new LeakTask(leakDetectionThreshold, houseKeepingExecutorService);
-            final IHikariConnectionProxy proxyConnection = ProxyFactory.getProxyConnection(this, bagEntry, leakTask);
-
             metricsContext.setConnectionLastOpen(bagEntry, now);
 
-            return proxyConnection;
+            return ProxyFactory.getProxyConnection(this, bagEntry, leakTask.start());
          }
          while (timeout > 0L);
       }

hikaricp/src/main/java/com/zaxxer/hikari/util/LeakTask.java

@@ -34,28 +34,42 @@ public class LeakTask implements Runnable
    public static final LeakTask NO_LEAK;
    private static final Logger LOGGER = LoggerFactory.getLogger(LeakTask.class);
 
-   private final ScheduledFuture<?> scheduledFuture;
+   private final ScheduledExecutorService executorService;
-   private final Exception exception;
+   private final long leakDetectionThreshold;
+   private ScheduledFuture<?> scheduledFuture;
+   private Exception exception;
 
    static
    {
       NO_LEAK = new LeakTask() {
          @Override
          public void cancel() {};
+
+         @Override
+         public LeakTask start()
+         {
+            return this;
+         }
       };
    }
 
    public LeakTask()
    {
-      scheduledFuture = null;
+      executorService = null;
-      exception = null;
+      leakDetectionThreshold = 0;
    }
 
    public LeakTask(final long leakDetectionThreshold, final ScheduledExecutorService executorService)
    {
-      this.exception = new Exception();
+      this.executorService = executorService;
+      this.leakDetectionThreshold = leakDetectionThreshold;
+   }
 
+   public LeakTask start()
+   {
+      exception = new Exception();
       scheduledFuture = executorService.schedule(this, leakDetectionThreshold, TimeUnit.MILLISECONDS);
+      return this;
    }
 
    /** {@inheritDoc} */