[misc] solving possible race condition

src/main/java/org/mariadb/jdbc/MariaDbConnection.java

@@ -50,8 +50,9 @@ WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWIS
 
 package org.mariadb.jdbc;
 
+import org.mariadb.jdbc.internal.logging.Logger;
+import org.mariadb.jdbc.internal.logging.LoggerFactory;
 import org.mariadb.jdbc.internal.protocol.Protocol;
-import org.mariadb.jdbc.internal.com.read.dao.Results;
 import org.mariadb.jdbc.internal.util.*;
 import org.mariadb.jdbc.internal.util.dao.CallableStatementCacheKey;
 import org.mariadb.jdbc.internal.util.dao.CloneableCallableStatement;
@@ -69,6 +70,7 @@ WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWIS
 
 
 public class MariaDbConnection implements Connection {
+    private static Logger logger = LoggerFactory.getLogger(MariaDbConnection.class);
 
     /**
      * Pattern  to check the correctness of callable statement query string
@@ -100,6 +102,7 @@ public class MariaDbConnection implements Connection {
     private boolean canUseServerTimeout = false;
     private boolean sessionStateAware = true;
 
+
     /**
      * save point count - to generate good names for the savepoints.
      */
@@ -728,6 +731,7 @@ public boolean isReadOnly() throws SQLException {
      */
     public void setReadOnly(final boolean readOnly) throws SQLException {
         try {
+            logger.debug("setReadOnly to value " + readOnly);
             protocol.setReadonly(readOnly);
         } catch (SQLException e) {
             ExceptionMapper.throwException(e, this, null);
@@ -1100,9 +1104,8 @@ public boolean isValid(final int timeout) throws SQLException {
         if (timeout < 0) {
             throw new SQLException("the value supplied for timeout is negative");
         }
-        if (isClosed()) {
-            return false;
-        }
+        if (isClosed()) return false;
+
         try {
             return protocol.ping();
         } catch (SQLException e) {

src/main/java/org/mariadb/jdbc/internal/failover/impl/MastersFailoverListener.java

@@ -130,6 +130,7 @@ public HandleErrorResult primaryFail(Method method, Object[] args) throws Throwa
         boolean alreadyClosed = !currentProtocol.isConnected();
         boolean inTransaction = currentProtocol != null && currentProtocol.inTransaction();
 
+        proxy.lock.lock();
         try {
             if (currentProtocol != null && currentProtocol.isConnected() && currentProtocol.ping()) {
                 //connection re-established
@@ -141,15 +142,12 @@ public HandleErrorResult primaryFail(Method method, Object[] args) throws Throwa
                 return new HandleErrorResult(true);
             }
         } catch (SQLException e) {
-            proxy.lock.lock();
-            try {
-                currentProtocol.close();
-            } finally {
-                proxy.lock.unlock();
-            }
+            currentProtocol.close();
             if (setMasterHostFail()) {
                 addToBlacklist(currentProtocol.getHostAddress());
             }
+        } finally {
+            proxy.lock.unlock();
         }
 
         try {

src/main/java/org/mariadb/jdbc/internal/failover/impl/MastersSlavesListener.java

@@ -441,12 +441,9 @@ public void switchReadOnlyConnection(Boolean mustBeReadOnly) throws SQLException
         if (currentReadOnlyAsked != mustBeReadOnly) {
             proxy.lock.lock();
             try {
-                if (currentReadOnlyAsked == mustBeReadOnly) {
-                    // someone else updated state
-                    return;
-                } else {
-                    currentReadOnlyAsked = mustBeReadOnly;
-                }
+                // another thread updated state
+                if (currentReadOnlyAsked == mustBeReadOnly) return;
+                currentReadOnlyAsked = mustBeReadOnly;
                 if (currentReadOnlyAsked) {
                     if (currentProtocol.isMasterConnection()) {
                         //must change to replica connection
@@ -529,7 +526,9 @@ public void switchReadOnlyConnection(Boolean mustBeReadOnly) throws SQLException
     public HandleErrorResult primaryFail(Method method, Object[] args) throws Throwable {
         boolean alreadyClosed = !masterProtocol.isConnected();
         boolean inTransaction = masterProtocol != null && masterProtocol.inTransaction();
+
         //try to reconnect automatically only time before looping
+        proxy.lock.lock();
         try {
             if (masterProtocol != null && masterProtocol.isConnected() && masterProtocol.ping()) {
                 if (inTransaction) {
@@ -539,16 +538,13 @@ public HandleErrorResult primaryFail(Method method, Object[] args) throws Throwa
                 return relaunchOperation(method, args);
             }
         } catch (SQLException e) {
-            proxy.lock.lock();
-            try {
-                masterProtocol.close();
-            } finally {
-                proxy.lock.unlock();
-            }
+            masterProtocol.close();
 
             if (setMasterHostFail()) {
                 addToBlacklist(masterProtocol.getHostAddress());
             }
+        } finally {
+            proxy.lock.unlock();
         }
 
         //fail on slave if parameter permit so
@@ -634,18 +630,20 @@ public void reconnect() throws SQLException {
         }
     }
 
+    /**
+     * Ping secondary protocol.
+     * ! lock must be set !
+     *
+     * @param protocol socket to ping
+     * @return true if ping is valid.
+     */
     private boolean pingSecondaryProtocol(Protocol protocol) {
         try {
             if (protocol != null && protocol.isConnected() && protocol.ping()) {
                 return true;
             }
         } catch (Exception e) {
-            proxy.lock.lock();
-            try {
-                protocol.close();
-            } finally {
-                proxy.lock.unlock();
-            }
+            protocol.close();
 
             if (setSecondaryHostFail()) {
                 addToBlacklist(protocol.getHostAddress());
@@ -663,10 +661,16 @@ private boolean pingSecondaryProtocol(Protocol protocol) {
      * @throws Throwable if failover has not catch error
      */
     public HandleErrorResult secondaryFail(Method method, Object[] args) throws Throwable {
-        if (pingSecondaryProtocol(this.secondaryProtocol)) {
-            return relaunchOperation(method, args);
+        proxy.lock.lock();
+        try {
+            if (pingSecondaryProtocol(this.secondaryProtocol)) {
+                return relaunchOperation(method, args);
+            }
+        } finally {
+            proxy.lock.unlock();
         }
 
+
         if (!isMasterHostFail()) {
             try {
                 if (masterProtocol != null) {

src/main/java/org/mariadb/jdbc/internal/protocol/AbstractQueryProtocol.java

@@ -780,8 +780,10 @@ public boolean ping() throws SQLException {
         lock.lock();
         try {
 
-            final SendPingPacket pingPacket = new SendPingPacket();
-            pingPacket.send(writer);
+            writer.startPacket(0);
+            writer.write(COM_PING);
+            writer.flush();
+
             Buffer buffer = reader.getPacket(true);
             return buffer.getByteAt(0) == OK;