Tosan Lock Manager is a logical distributed lock library that provides unified locking mechanisms across multiple backend technologies: DBMS (Oracle, DB2, PostgreSQL), Zookeeper, Redis, and Hazelcast.

• Java Version: 17
• Build Tool: Maven
• Key Dependencies: Spring ORM, Hibernate, Hazelcast, Redisson, Apache Curator

The library is built around a single interface LockManagementService (in api/) that defines the contract for all locking operations:

• Read/Write lock acquisition with configurable timeout
• Lock release (explicit or transaction-based via releaseOnCommit flag)
• Lock conversion between read and write modes

Each backend technology has its own implementation package under impl/:

DBMS Implementation (impl/dbms/):

• Uses a factory pattern (DbmsLockServiceFactory) to auto-detect database dialect via Hibernate
• Supports Oracle, DB2, and PostgreSQL through database-specific stored procedures
• Each database has separate DAO and Service layers:
  • DAOs (dao/) handle database-specific SQL/procedure calls
  • Services (service/) implement DbmsLockService interface
• Requires Spring @Transactional context with REQUIRED propagation
• Lock names are prefixed with schema name for uniqueness (max 128 chars: 30 for schema + 96 for lockNameType+lockName)

Distributed Systems (impl/hazelcast/, impl/redis/, impl/zookeeper/):

• Each provides a *LockManagementService implementation
• Redis uses Redisson library for distributed locks
• Zookeeper uses Apache Curator recipes
• Hazelcast uses native distributed lock primitives

For DBMS implementations:

• Total lock name length: max 128 characters
• Schema name: max 30 characters (Oracle constraint)
• Combined lockNameType + lockName: max 96 characters
• Schema name is automatically prepended for uniqueness

• LockManagerTimeoutException: Thrown when lock cannot be acquired within timeout period
• LockManagerRunTimeException: Thrown for internal errors (e.g., unsupported database dialect)

All DBMS lock operations require active Spring transactions with Propagation.REQUIRED. Non-transactional calls will fail.

• DBMS: Pass EntityManager to constructor → factory auto-detects database type
• Redis/Zookeeper/Hazelcast: Each has specific configuration requirements for their respective clients

The releaseOnCommit parameter controls when locks are released:

• true: Lock released automatically on transaction commit/rollback (DBMS only)
• false: Lock held until explicit unlock() call or session/transaction end