arlut.csd.ganymede
Class DBDumpLock

java.lang.Object
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  +--arlut.csd.ganymede.DBLock
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        +--arlut.csd.ganymede.DBDumpLock

class DBDumpLock

extends DBLock

DBDumpLock is a DBLock object used to lock the DBStore for the purpose of dumping the database. A DBDumpLock establish request has lower priority than DBWriteLock requests, but once a DBDumpLock establish request is submitted, no new DBWriteLock can be established until the dumping thread has completed the dump and released the lock.

DBReadLock's can be established while a DBDumpLock is active.

Field Summary

(package private) static boolean

debug

Fields inherited from class arlut.csd.ganymede.DBLock

abort, baseSet, inEstablish, key, locked, lockSync

Constructor Summary

DBDumpLock(arlut.csd.ganymede.DBStore store)
constructor to get a dump lock on all the object bases

DBDumpLock(arlut.csd.ganymede.DBStore store, java.util.Vector baseSet)
constructor to get a dump lock on a subset of the object bases.

Method Summary

void	abort() Withdraw this lock.
void	establish(java.lang.Object key) Establish a dump lock on bases specified in this DBDumpLock's constructor.
void	release() Release this lock on all bases locked

Methods inherited from class arlut.csd.ganymede.DBLock

getKey, isLocked, isLocked, isLocked, overlaps, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

debug

static final boolean debug

See Also:

Constant Field Values

Constructor Detail

DBDumpLock

public DBDumpLock(arlut.csd.ganymede.DBStore store)

constructor to get a dump lock on all the object bases

DBDumpLock

public DBDumpLock(arlut.csd.ganymede.DBStore store,
                  java.util.Vector baseSet)

constructor to get a dump lock on a subset of the object bases.

Method Detail

establish

public void establish(java.lang.Object key)
               throws java.lang.InterruptedException

Establish a dump lock on bases specified in this DBDumpLock's constructor. Can throw InterruptedException if another thread orders us to abort() while we're waiting for permission to proceed with reads on the specified baseset.

Specified by:

establish in class DBLock

java.lang.InterruptedException

release

public void release()

Release this lock on all bases locked

Specified by:

release in class DBLock

abort

public void abort()

Withdraw this lock. This method can be called by a thread to interrupt a lock establish that is blocked waiting to get access to the appropriate set of DBObjectBase objects. If this method is called while another thread is blocked in establish(), establish() will throw an InterruptedException.

Once abort() is processed, this lock may never be established. Any subsequent calls to estabish() will always throw InterruptedException.

Specified by:

abort in class DBLock