# Package org.eclipse.emf.cdo.common.lock

Common concepts for dealing with durable locks and views.

- Interface Summary
  Interface | Description
  --- | ---
  CDOLockChangeInfo | Represents a change in the lock state of a set of objects.
  CDOLockChangeInfoHandler | A call-back interface that indicates the ability to handle `lock-change infos` that are passed from other entities.
  CDOLockOwner | A client-side representation of a view owning locks.
  CDOLockState | A client-side representation of all the locks on a single CDOObject.
  IDurableLockingManager | Manages all persistent aspects of durable CDO views such as `branch point` and acquired locks.
  IDurableLockingManager.LockArea | Encapsulates the persistable information about a single durable CDO view like `branch point` and acquired locks.
  IDurableLockingManager.LockArea.Handler | A call-back interface for handling `lock area` objects.

- Class Summary
  Class | Description
  --- | ---
  CDOLockUtil | Various static methods that may help with classes related to CDO locks.

- Enum Summary
  Enum | Description
  --- | ---
  CDOLockChangeInfo.Operation | Enumerates the possible locking operations.
  IDurableLockingManager.LockGrade | Enumerates the possible combinations of read and write locks on a single CDO object.

- Exception Summary
  Exception | Description
  --- | ---
  IDurableLockingManager.LockAreaAlreadyExistsException | Exception occurs when attempting to create a durable `IDurableLockingManager.LockArea` that already exists.
  IDurableLockingManager.LockAreaNotFoundException | Thrown if a `lock area` is spcified that does not exist in a CDO `repository`.