#124 ownJobThread may made all threads in threadPool are busy

src/main/java/io/mycat/MycatServer.java

@@ -155,6 +155,7 @@ public class MycatServer {
 	private NIOProcessor[] processors;
 	private SocketConnector connector;
 	private NameableExecutor businessExecutor;
+	private NameableExecutor ownJobExecutor;
 	private NameableExecutor timerExecutor;
 	private ListeningExecutorService listeningExecutorService;
 	private  InterProcessMutex dnindexLock;
@@ -219,6 +220,10 @@ public class MycatServer {
 		return catletClassLoader;
 	}
 
+	public NameableExecutor getOwnJobExecutor() {
+		return ownJobExecutor;
+	}
+
 	public String genXATXID() {
 		long seq = this.xaIDInc.incrementAndGet();
 		if (seq < 0) {
@@ -345,8 +350,8 @@ public class MycatServer {
 				LOGGER.error("Error",e);
 			}
 		}
-		businessExecutor = ExecutorUtil.createFixed("BusinessExecutor",
-				threadPoolSize);
+		businessExecutor = ExecutorUtil.createFixed("BusinessExecutor", threadPoolSize);
+		ownJobExecutor = ExecutorUtil.createCached("ownJobExecutor", 1);
 		timerExecutor = ExecutorUtil.createFixed("Timer", 1);
 		listeningExecutorService = MoreExecutors.listeningDecorator(businessExecutor);
 

src/main/java/io/mycat/backend/mysql/nio/handler/query/OwnThreadDMLHandler.java

@@ -2,6 +2,7 @@ package io.mycat.backend.mysql.nio.handler.query;
 
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import io.mycat.MycatServer;
 import io.mycat.server.NonBlockingSession;
 
 /**
@@ -41,7 +42,7 @@ public abstract class OwnThreadDMLHandler extends BaseDMLHandler {
 	 *            有可能会用到的参数
 	 */
 	protected final void startOwnThread(final Object... objects) {
-		session.getSource().getProcessor().getExecutor().execute(new Runnable() {
+		MycatServer.getInstance().getOwnJobExecutor().execute(new Runnable() {
 			@Override
 			public void run() {
 				if (terminate.get())

src/main/java/io/mycat/server/ServerConnection.java

@@ -327,21 +327,6 @@ public class ServerConnection extends FrontendConnection {
 		
 	}
 
-	/**
-	 * 撤销执行中的语句
-	 * 
-	 * @param sponsor
-	 *            发起者为null表示是自己
-	 */
-	public void cancel(final FrontendConnection sponsor) {
-		processor.getExecutor().execute(new Runnable() {
-			@Override
-			public void run() {
-				session.cancel(sponsor);
-			}
-		});
-	}
-
 	@Override
 	public void close(String reason) {