Merge pull request MyCATApache#2222 from codelaw1/1.6

fix issue MyCATApache#2164

src/main/java/io/mycat/memory/unsafe/Platform.java

@@ -17,6 +17,7 @@
 
 package io.mycat.memory.unsafe;
 
+import io.mycat.MycatServer;
 import io.mycat.memory.unsafe.utils.BytesTools;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -61,6 +62,7 @@ public final class Platform {
  public static final boolean littleEndian = ByteOrder.nativeOrder()
  .equals(ByteOrder.LITTLE_ENDIAN);
 
+ public static final long sqlTimeout = MycatServer.getInstance().getConfig().getSystem().getSqlExecuteTimeout() * 1000L;
  static {
  boolean _unaligned;
  // use reflection to access unaligned field
@@ -293,12 +295,19 @@ public static void copyMemory(
  } else {
  srcOffset += length;
  dstOffset += length;
- while (length > 0) {
+ while (length > 0) { // if backend db run time out ,this will be endless loop
  long size = Math.min(length, UNSAFE_COPY_THRESHOLD);
+ long lbegin = System.currentTimeMillis();
  srcOffset -= size;
  dstOffset -= size;
  _UNSAFE.copyMemory(src, srcOffset, dst, dstOffset, size);
  length -= size;
+ long l = System.currentTimeMillis() - lbegin;
+ if(l > sqlTimeout) { // when sql run timeout,break the loop
+ logger.error("copyMemory timeout.loop(seconds):" + String.valueOf(l / 1000));
+
+ break;
+ }
  }
 
  }