[iotdb] branch rel/0.13 updated: [To rel/0.13] [IOTDB-4196] Fix concurrent bug in TsFileSequenceReader (#7125)

[hui]

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hui pushed a commit to branch rel/0.13
in repository https://gitbox.apache.org/repos/asf/iotdb.git


The following commit(s) were added to refs/heads/rel/0.13 by this push:
     new a281fa579a [To rel/0.13] [IOTDB-4196] Fix concurrent bug in 
TsFileSequenceReader (#7125)
a281fa579a is described below

commit a281fa579a9e05c9d6557fb91b7dbb00afc02889
Author: liuminghui233 <36565497+liuminghui...@users.noreply.github.com>
AuthorDate: Thu Aug 25 16:29:52 2022 +0800

    [To rel/0.13] [IOTDB-4196] Fix concurrent bug in TsFileSequenceReader 
(#7125)
---
 .../org/apache/iotdb/tsfile/read/TsFileSequenceReader.java     | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git 
a/tsfile/src/main/java/org/apache/iotdb/tsfile/read/TsFileSequenceReader.java 
b/tsfile/src/main/java/org/apache/iotdb/tsfile/read/TsFileSequenceReader.java
index 81d6c8a63b..619890a74c 100644
--- 
a/tsfile/src/main/java/org/apache/iotdb/tsfile/read/TsFileSequenceReader.java
+++ 
b/tsfile/src/main/java/org/apache/iotdb/tsfile/read/TsFileSequenceReader.java
@@ -100,7 +100,7 @@ public class TsFileSequenceReader implements AutoCloseable {
   protected long fileMetadataPos;
   protected int fileMetadataSize;
   private ByteBuffer markerBuffer = ByteBuffer.allocate(Byte.BYTES);
-  protected TsFileMetadata tsFileMetaData;
+  protected volatile TsFileMetadata tsFileMetaData;
   // device -> measurement -> TimeseriesMetadata
   private Map<String, Map<String, TimeseriesMetadata>> cachedDeviceMetadata =
       new ConcurrentHashMap<>();
@@ -269,8 +269,12 @@ public class TsFileSequenceReader implements AutoCloseable 
{
   public TsFileMetadata readFileMetadata() throws IOException {
     try {
       if (tsFileMetaData == null) {
-        tsFileMetaData =
-            TsFileMetadata.deserializeFrom(readData(fileMetadataPos, 
fileMetadataSize));
+        synchronized (this) {
+          if (tsFileMetaData == null) {
+            tsFileMetaData =
+                TsFileMetadata.deserializeFrom(readData(fileMetadataPos, 
fileMetadataSize));
+          }
+        }
       }
     } catch (Exception e) {
       logger.error("Something error happened while reading file metadata of 
file {}", file);