JOTM :: Core's transaction concurrent control strategy analysis

JOTM (Java Open Transaction Manager) is an open source transaction manager written in Java. It uses the JTA (Java Transaction API) specification to provide transaction management functions.JOTM's core framework is based on the JTA specifications in Java, providing a series of transaction complication control strategies to manage the order and resource access between concurrent transactions. Affairs complication control is a very important part of multi -threaded applications. It ensures that multiple transactions can be correctly accessed and updated and shared resources, while maintaining the consistency and integrity of data.JOTM provides the following commonly used transaction complication control strategies: 1. Optimistic Locking: In the optimistic lock control strategy, transactions will not directly lock shared resources during execution.Instead, it marked resources to indicate transactions that are dealing with.If the conflict occurs (that is, two or more transactions to update the same resource), JOTM detects and causes an exception to make the application process the conflict. 2. Pessimistic Locking: Pessimistic lock control means that the transaction directly locks shared resources during execution to prevent other transactions from modifying it.In JOTM, you can use the `javax.transaction.usertransactions'` settransactionTimeout` method to set the pessimistic timeout time.If the transaction fails to lock the resources during the timeout time, it will cause an exception. 3. Two-PHASE Commit: Two stages of submission is an agreement to ensure that transactions across multiple resources remain consistent during execution.In the first stage, the JOTM coordinator will ask all the participating resource managers (such as databases) to prepare to submit transactions.If all resource managers are ready to submit, in the second stage, JOTM will notify all resource managers to submit or roll back. In addition to the above main concurrent control strategies, JOTM also provides other strategies, such as timeout control, deadlock detection and concurrent transaction isolation level configuration options.These strategies can be customized by setting up corresponding properties in the configuration file of JOTM.For example, you can use the `jotm.timeout` property in the` JOTM.PROPERTIES` file to set timeout, or use the `JOTM.LOCKINGMode` property in the` JOTM.PROPERTIES` file to set the concurrent control mode. Below is an example code using JOTM for transaction management: import javax.transaction.Transaction; import javax.transaction.TransactionManager; import org.objectweb.jotm.Current; import org.objectweb.jotm.Jotm; public class TransactionExample { public static void main(String[] args) { try { // Create a JOTM instance Jotm jotm = new Jotm(true, false); // Get the transaction manager TransactionManager tm = Current.getCurrent(jotm.getCoordinator()); // Starting transaction tm.begin(); // Execute transaction operation // ... // Submit a transaction tm.commit(); } catch (Exception e) { e.printStackTrace(); // Roll back transactions tm.rollback(); } } } In the above example code, we first created a JOTM instance and obtained the transaction manager through the `Getcurrent ()` method.Then, we performed some transaction operations between `Begin ()` and `Commit ()`.If abnormalities occur, we will handle it and call the `rollback ()` roll back the transaction. By using JOTM's transaction complication control strategy, we can ensure the correct execution of transactions in the multi -threaded environment to avoid data access conflict and data inconsistent problems.At the same time, we can configure different concurrent control strategies according to actual needs to meet the requirements of the application.