Package org.apache.openjpa.kernel

Class VersionLockManager

java.lang.Object
org.apache.openjpa.kernel.AbstractLockManager
org.apache.openjpa.kernel.VersionLockManager
All Implemented Interfaces:
LockLevels, LockManager, Closeable
Direct Known Subclasses:
PessimisticLockManager
public class VersionLockManager extends AbstractLockManager
LockManager implementation that provides support for version checking and version updating when locks are acquired. This lock manager may be used standalone or extended for additional locking.
Author:
Marc Prud'hommeaux

  • Constructor Details

    • VersionLockManager

      public VersionLockManager()

  • Method Details

    • getLockLevel

      public int getLockLevel(OpenJPAStateManager sm)
      Returns the given instance's lock level, assuming that the state's lock object is a number. If the given instance is embedded, traverses to its owner. Override if lock is not stored as a number.

    • setLockLevel

      protected void setLockLevel(OpenJPAStateManager sm, int level)
      Sets the given instance's lock level to the given number. Override to store something else as the lock.

    • release

      public void release(OpenJPAStateManager sm)
      Nulls given instance's lock object.
      See Also:

    • lock

      public void lock(OpenJPAStateManager sm, int level, int timeout, Object sdata)
      Delegates to lockInternal(org.apache.openjpa.kernel.OpenJPAStateManager, int, int, java.lang.Object, boolean) after traversing to owning instance (if embedded) and assuring that the instance is persistent, is not new, and is not already locked at a higher level. After locking, calls setLockLevel(org.apache.openjpa.kernel.OpenJPAStateManager, int) with the given level.
      Parameters:
      sm - the object to lock
      level - one of the lock constants defined in LockLevels, or a custom level
      timeout - the timeout in milliseconds, or a negative number for no timeout
      sdata - the context information passed from the store manager to the persistence context, if any; lock managers specific to a certain back end may be able to take advantage of this; others should ignore it
      See Also:

    • refreshLock

      public void refreshLock(OpenJPAStateManager sm, int level, int timeout, Object sdata)
      Description copied from interface: LockManager
      Perform the same function as previous lock method and has the option to perform a version check after the lock function has completed.

    • lockInternal

      protected void lockInternal(OpenJPAStateManager sm, int level, int timeout, Object sdata, boolean postLockVersionCheck)
      Marks the instance's transactional status in accordance with the settings of getVersionCheckOnReadLock() and getVersionUpdateOnWriteLock(). Override to perform additional locking.
      See Also:

    • optimisticLockInternal

      protected void optimisticLockInternal(OpenJPAStateManager sm, int level, int timeout, Object sdata, boolean postLockVersionCheck)

    • setVersionCheckOnReadLock

      public void setVersionCheckOnReadLock(boolean versionCheckOnReadLock)
      Whether or not we should force a version check at commit time when a read lock is requested in order to verify read consistency. Defaults to true.

    • getVersionCheckOnReadLock

      public boolean getVersionCheckOnReadLock()
      Whether or not we should force a version check at commit time when a read lock is requested in order to verify read consistency. Defaults to true.

    • setVersionUpdateOnWriteLock

      public void setVersionUpdateOnWriteLock(boolean versionUpdateOnWriteLock)
      Whether or not we should force an update to the version at commit time when a write lock is requested. Defaults to true.

    • getVersionUpdateOnWriteLock

      public boolean getVersionUpdateOnWriteLock()
      Whether or not we should force an update to the version at commit time when a write lock is requested. Defaults to true.