Pessimistic Offline Lock pattern

Description

The Pessimistic Offline Lock design pattern ensures that only one process can access a particular resource at a time, preventing concurrent modifications and ensuring data consistency. This pattern is particularly useful in distributed systems where multiple processes might attempt to modify the same data. By locking resources before making changes, this pattern avoids conflicts and maintains data integrity.

Main elements of the pattern:

• Lock Management: Implement a mechanism to acquire and release locks on resources.
• Transaction Handling: Ensure that the locks are managed within the scope of transactions to avoid deadlocks and ensure that resources are properly released.
• Conflict Resolution: Define strategies to handle situations where a lock cannot be acquired immediately, such as retry mechanisms or user notifications.

References

• Pessimistic Offline Lock - Martin Fowler
• Patterns of Enterprise Application Architecture - Page 303
• Java Design Patterns - Contribution Guidelines

Acceptance Criteria

1. Implement a lock management system that allows resources to be locked and unlocked by processes.
2. Ensure that the lock management is integrated with transaction handling to maintain data consistency and avoid deadlocks.
3. Document the implemented pattern with code examples and usage instructions in accordance with the project's contribution guidelines.

No implementation files, tests, or entry points are named. Start with the project's contribution guidelines and the linked Pessimistic Offline Lock references, then identify the appropriate pattern location and existing transaction conventions. Done means a documented Java implementation with lock acquisition and release, transaction integration, conflict handling, and usage examples.