[iotdb] branch master updated: [IOTDB-4196] Fix concurrent bug in TsFileSequenceReader (#7122)

[qiaojialin]

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qiaojialin pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/iotdb.git


The following commit(s) were added to refs/heads/master by this push:
     new a79cb13aa8 [IOTDB-4196] Fix concurrent bug in TsFileSequenceReader 
(#7122)
a79cb13aa8 is described below

commit a79cb13aa8481a738f83a2eab608a6f77e383193
Author: liuminghui233 <36565497+liuminghui...@users.noreply.github.com>
AuthorDate: Thu Aug 25 13:58:53 2022 +0800

    [IOTDB-4196] Fix concurrent bug in TsFileSequenceReader (#7122)
---
 .../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 5f9aea46cc..452ecb9381 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<>();
@@ -277,8 +277,12 @@ 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);