Add unit tests for concurrent CF iteration and drop

improve facebook#6147

HISTORY.md

@@ -7,6 +7,7 @@
 ### Bug Fixes
 * Fix a bug that can cause unnecessary bg thread to be scheduled(#6104).
 * Fix a bug in which a snapshot read could be affected by a DeleteRange after the snapshot (#6062).
+* Fix crash caused by concurrent CF iterations and drops(#6147).
 
 ## 6.6.0 (11/25/2019)
 ### Bug Fixes

db/column_family_test.cc

@@ -2365,6 +2365,45 @@ TEST_P(ColumnFamilyTest, ReadDroppedColumnFamily) {
  }
 }
 
+TEST_P(ColumnFamilyTest, LiveIteratorWithDroppedColumnFamily) {
+ db_options_.create_missing_column_families = true;
+ db_options_.max_open_files = 20;
+ // delete obsolete files always
+ db_options_.delete_obsolete_files_period_micros = 0;
+ Open({"default", "one", "two"});
+ ColumnFamilyOptions options;
+ options.level0_file_num_compaction_trigger = 100;
+ options.level0_slowdown_writes_trigger = 200;
+ options.level0_stop_writes_trigger = 200;
+ options.write_buffer_size = 100000; // small write buffer size
+ Reopen({options, options, options});
+
+ // 1MB should create ~10 files for each CF
+ int kKeysNum = 10000;
+ PutRandomData(1, kKeysNum, 100);
+
+ {
+ std::unique_ptr<Iterator> iterator(
+ db_->NewIterator(ReadOptions(), handles_[1]));
+ iterator->SeekToFirst();
+
+ DropColumnFamilies({1});
+
+ // Make sure iterator created can still be used.
+ int count = 0;
+ for (; iterator->Valid(); iterator->Next()) {
+ ASSERT_OK(iterator->status());
+ ++count;
+ }
+ ASSERT_OK(iterator->status());
+ ASSERT_EQ(count, kKeysNum);
+ }
+
+ Reopen();
+ Close();
+ Destroy();
+}
+
 TEST_P(ColumnFamilyTest, FlushAndDropRaceCondition) {
  db_options_.create_missing_column_families = true;
  Open({"default", "one"});

db/db_iterator_test.cc

@@ -804,6 +804,50 @@ TEST_P(DBIteratorTest, IteratorPinsRef) {
  } while (ChangeCompactOptions());
 }
 
+TEST_P(DBIteratorTest, IteratorDeleteAfterCfDelete) {
+ CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+
+ Put(1, "foo", "delete-cf-then-delete-iter");
+ Put(1, "hello", "value2");
+
+ ColumnFamilyHandle* cf = handles_[1];
+ ReadOptions ro;
+
+ auto* iter = db_->NewIterator(ro, cf);
+ iter->SeekToFirst();
+ ASSERT_EQ(IterStatus(iter), "foo->delete-cf-then-delete-iter");
+
+ // delete CF handle
+ db_->DestroyColumnFamilyHandle(cf);
+ handles_.erase(std::begin(handles_) + 1);
+
+ // delete Iterator after CF handle is deleted
+ iter->Next();
+ ASSERT_EQ(IterStatus(iter), "hello->value2");
+ delete iter;
+}
+
+TEST_P(DBIteratorTest, IteratorDeleteAfterCfDrop) {
+ CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+
+ Put(1, "foo", "drop-cf-then-delete-iter");
+
+ ReadOptions ro;
+ ColumnFamilyHandle* cf = handles_[1];
+
+ auto* iter = db_->NewIterator(ro, cf);
+ iter->SeekToFirst();
+ ASSERT_EQ(IterStatus(iter), "foo->drop-cf-then-delete-iter");
+
+ // drop and delete CF
+ db_->DropColumnFamily(cf);
+ db_->DestroyColumnFamilyHandle(cf);
+ handles_.erase(std::begin(handles_) + 1);
+
+ // delete Iterator after CF handle is dropped
+ delete iter;
+}
+
 // SetOptions not defined in ROCKSDB LITE
 #ifndef ROCKSDB_LITE
 TEST_P(DBIteratorTest, DBIteratorBoundTest) {

java/src/test/java/org/rocksdb/RocksIteratorTest.java

@@ -97,4 +97,55 @@ public void rocksIterator() throws RocksDBException {
  }
  }
  }
+
+ @Test
+ public void rocksIteratorReleaseAfterCfClose() throws RocksDBException {
+ try (final Options options = new Options()
+ .setCreateIfMissing(true)
+ .setCreateMissingColumnFamilies(true);
+ final RocksDB db = RocksDB.open(options,
+ this.dbFolder.getRoot().getAbsolutePath())) {
+ db.put("key".getBytes(), "value".getBytes());
+
+ // Test case: release iterator after default CF close
+ try (final RocksIterator iterator = db.newIterator()) {
+ // In fact, calling close() on default CF has no effect
+ db.getDefaultColumnFamily().close();
+
+ iterator.seekToFirst();
+ assertThat(iterator.isValid()).isTrue();
+ assertThat(iterator.key()).isEqualTo("key".getBytes());
+ assertThat(iterator.value()).isEqualTo("value".getBytes());
+ }
+
+ // Test case: release iterator after custom CF close
+ ColumnFamilyDescriptor cfd1 = new ColumnFamilyDescriptor("cf1".getBytes());
+ ColumnFamilyHandle cfHandle1 = db.createColumnFamily(cfd1);
+ db.put(cfHandle1, "key1".getBytes(), "value1".getBytes());
+
+ try (final RocksIterator iterator = db.newIterator(cfHandle1)) {
+ cfHandle1.close();
+
+ iterator.seekToFirst();
+ assertThat(iterator.isValid()).isTrue();
+ assertThat(iterator.key()).isEqualTo("key1".getBytes());
+ assertThat(iterator.value()).isEqualTo("value1".getBytes());
+ }
+
+ // Test case: release iterator after custom CF drop & close
+ ColumnFamilyDescriptor cfd2 = new ColumnFamilyDescriptor("cf2".getBytes());
+ ColumnFamilyHandle cfHandle2 = db.createColumnFamily(cfd2);
+ db.put(cfHandle2, "key2".getBytes(), "value2".getBytes());
+
+ try (final RocksIterator iterator = db.newIterator(cfHandle2)) {
+ db.dropColumnFamily(cfHandle2);
+ cfHandle2.close();
+
+ iterator.seekToFirst();
+ assertThat(iterator.isValid()).isTrue();
+ assertThat(iterator.key()).isEqualTo("key2".getBytes());
+ assertThat(iterator.value()).isEqualTo("value2".getBytes());
+ }
+ }
+ }
 }