ClickHouse / ClickHouse/clickhouse-java
DataTypeConverter usage has potential thread-safety issues
- 主要言語
- Java
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- 平均マージ
- 2日 23時間
- マージ済み PR(30日)
- 29
説明
## Description
_This is not an explicit bug report in the sense that I haven't experienced a problem (yet?), it is just something I bumped into while browsing the code_.
`DataTypeConverter` has a [javadoc comment stating that it is not thread safe](https://github.com/ClickHouse/clickhouse-java/blob/main/client-v2/src/main/java/com/clickhouse/client/api/internal/DataTypeConverter.java#L25). For what it's worth, I have also confirmed thread safety problems because I ended up using the `DataTypeConverter.INSTANCE` in production (before I realised that it was labelled as non thread safe) which caused some bugs.
After fixing the bugs in my project, I was curious about the fact that a static singleton `DataTypeConverter.INSTANCE` was even declared in the `clickhouse-java` repo (why have a singleton instance if it is not thread safe, in an otherwise thread safe library?). Of course this class is in a package named `internal`, so it's not really my business... :) Still, I did notice that `DataTypeConverter.INSTANCE` is used in [two](https://github.com/ClickHouse/clickhouse-java/blob/8da0b0c9aa7995b9fa839b56861a28047f71076a/client-v2/src/main/java/com/clickhouse/client/api/data_formats/internal/MapBackedRecord.java#L48) [places](https://github.com/ClickHouse/clickhouse-java/blob/8da0b0c9aa7995b9fa839b56861a28047f71076a/client-v2/src/main/java/com/clickhouse/client/api/data_formats/internal/AbstractBinaryFormatReader.java#L90) which makes me wonder if it could be the source of (other / future / not-yet-encountered) problems..
コントリビューションガイド
調査の方向性
Start with the javadoc and implementation of client-v2/src/main/java/com/clickhouse/client/api/internal/DataTypeConverter.java, then inspect its uses in MapBackedRecord.java and AbstractBinaryFormatReader.java. Trace the mutable state and existing tests to establish the intended thread-safety contract; done should include coverage that exercises the shared INSTANCE safely or documents why it cannot be shared.
索引モデルが issue の本文から書いたものです。
評価
- 技術スタック
- java
- 領域
- api, backend
- issue の種類
- バグ
- 難易度
- 4/5
- 見積もり時間
- 3〜5日
- 活発さ
- 静か
- 明瞭さ
- 説明が足りない
- 初心者へのやさしさ
- 38/100