haohao0103 commented on issue #2608: URL: https://github.com/apache/incubator-hugegraph/issues/2608#issuecomment-2261779463
> `ThreadLocal<Txs>` transactions in Tinkerpop solve the problem of data reuse during thread reuse by ensuring that each thread has its own instance of the transaction. This is achieved through the use of `ThreadLocal` variables, which provide thread-local storage. > > In the `TinkerPopTransaction` class, the `transactions` field is defined as: > > ```java > private final ThreadLocal<Txs> transactions; > ``` > > This ensures that each thread accessing the `transactions` field gets its own instance of `Txs`, preventing data from being shared across threads. This isolation is crucial when threads are reused, as it avoids unintended data reuse and potential data corruption. > > The `ThreadLocal` is initialized with: > > ```java > this.transactions = ThreadLocal.withInitial(() -> null); > ``` > > This means that when a thread accesses the `transactions` field for the first time, it will get a `null` value, and subsequent accesses will return the same value unless explicitly set. > > By using `ThreadLocal`, the `TinkerPopTransaction` class ensures that each thread has its own transaction context, thereby solving the problem of data reuse during thread reuse. > > Additionally, HugeGraph's transaction implementation relies on binding transactions to threads using `ThreadLocal` to ensure isolation. This means that the uncommitted content of a transaction is only visible to the thread that created it, and other threads cannot see these changes until the transaction is committed. This approach helps maintain data consistency and integrity, especially in a multi-threaded environment [[1]](https://github.com/apache/incubator-hugegraph/blob/master/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/StandardHugeGraph.java)[[2]](https://github.com/apache/incubator-hugegraph-doc/blob/master/content/en/docs/guides/desgin-concept.md). > > _To continue talking to [Dosu](https://dosu.dev), mention @dosu._ When threads are reused, the transaction field is no longer null when obtained. Will there be a situation where the transaction field is reused? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
