From a64331d79f04bb9321383269150fe8302289e9b2 Mon Sep 17 00:00:00 2001
From: Anton Popov <pad11rus@gmail.com>
Date: Fri, 11 Sep 2020 16:09:26 +0300
Subject: [PATCH] fix syncing of WAL

---
 src/Storages/MergeTree/MergeTreeWriteAheadLog.cpp | 7 +++++++
 src/Storages/MergeTree/MergeTreeWriteAheadLog.h   | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/src/Storages/MergeTree/MergeTreeWriteAheadLog.cpp b/src/Storages/MergeTree/MergeTreeWriteAheadLog.cpp
index bc6738a8321..35fadb999b4 100644
--- a/src/Storages/MergeTree/MergeTreeWriteAheadLog.cpp
+++ b/src/Storages/MergeTree/MergeTreeWriteAheadLog.cpp
@@ -37,6 +37,13 @@ MergeTreeWriteAheadLog::MergeTreeWriteAheadLog(
     });
 }
 
+MergeTreeWriteAheadLog::~MergeTreeWriteAheadLog()
+{
+    std::unique_lock lock(write_mutex);
+    if (sync_scheduled)
+        sync_cv.wait(lock, [this] { return !sync_scheduled; });
+}
+
 void MergeTreeWriteAheadLog::init()
 {
     out = disk->writeFile(path, DBMS_DEFAULT_BUFFER_SIZE, WriteMode::Append);
diff --git a/src/Storages/MergeTree/MergeTreeWriteAheadLog.h b/src/Storages/MergeTree/MergeTreeWriteAheadLog.h
index c5675eac696..77c7c7e11e7 100644
--- a/src/Storages/MergeTree/MergeTreeWriteAheadLog.h
+++ b/src/Storages/MergeTree/MergeTreeWriteAheadLog.h
@@ -35,6 +35,8 @@ public:
     MergeTreeWriteAheadLog(MergeTreeData & storage_, const DiskPtr & disk_,
         const String & name = DEFAULT_WAL_FILE_NAME);
 
+    ~MergeTreeWriteAheadLog();
+
     void addPart(const Block & block, const String & part_name);
     void dropPart(const String & part_name);
     std::vector<MergeTreeMutableDataPartPtr> restore(const StorageMetadataPtr & metadata_snapshot);