org.apache.manifoldcf.core.lockmanager
Class LockObject

java.lang.Object
  org.apache.manifoldcf.core.lockmanager.LockObject

public class LockObject
extends java.lang.Object

One instance of this object exists for each lock on each JVM!

Field Summary

static java.lang.String

_rcsid

Constructor Summary

LockObject(LockPool lockPool, java.lang.Object lockKey, java.io.File synchDir)

Method Summary

void	enterNonExWriteLock()
void	enterNonExWriteLockNoWait() Note well: Upgrading a read lock to a non-ex write lock is tricky.
void	enterReadLock()
void	enterReadLockNoWait()
void	enterWriteLock() This method WILL NOT BE CALLED UNLESS we are actually committing a write lock for the first time for a given thread.
void	enterWriteLockNoWait() Note well: Upgrading a read lock to a non-ex write lock is tricky.
void	leaveNonExWriteLock()
void	leaveReadLock()
void	leaveWriteLock()
void	makeInvalid()

Methods inherited from class java.lang.Object

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

Field Detail

_rcsid

public static final java.lang.String _rcsid

See Also:

Constant Field Values

Constructor Detail

LockObject

public LockObject(LockPool lockPool,
                  java.lang.Object lockKey,
                  java.io.File synchDir)

Method Detail

makeInvalid

public void makeInvalid()

enterWriteLock

public void enterWriteLock()
                    throws java.lang.InterruptedException,
                           ExpiredObjectException

This method WILL NOT BE CALLED UNLESS we are actually committing a write lock for the first time for a given thread.

Throws:

java.lang.InterruptedException

ExpiredObjectException

enterWriteLockNoWait

public void enterWriteLockNoWait()
                          throws LockException,
                                 LocalLockException,
                                 java.lang.InterruptedException,
                                 ExpiredObjectException

Note well: Upgrading a read lock to a non-ex write lock is tricky. The code inside the lock should execute only when there are NO threads that are executing in a read-locked area that aren't waiting to enter the non-ex write lock area! This is therefore essentially an illegal codepath, because it will lead inevitably to deadlock, as is going from a read-locked area into a write-locked area, or from a non-ex write area into an exclusive write area.

Throws:

LockException

LocalLockException

java.lang.InterruptedException

ExpiredObjectException

leaveWriteLock

public void leaveWriteLock()
                    throws java.lang.InterruptedException,
                           ExpiredObjectException

Throws:

java.lang.InterruptedException

ExpiredObjectException

enterNonExWriteLock

public void enterNonExWriteLock()
                         throws java.lang.InterruptedException,
                                ExpiredObjectException

Throws:

java.lang.InterruptedException

ExpiredObjectException

enterNonExWriteLockNoWait

public void enterNonExWriteLockNoWait()
                               throws LockException,
                                      LocalLockException,
                                      java.lang.InterruptedException,
                                      ExpiredObjectException

Note well: Upgrading a read lock to a non-ex write lock is tricky. The code inside the lock should execute only when there are NO threads that are executing in a read-locked area that aren't waiting to enter the non-ex write lock area! This is therefore essentially an illegal codepath, because it will lead inevitably to deadlock, as is going from a read-locked area into a write-locked area, or from a non-ex write area into an exclusive write area.

Throws:

LockException

LocalLockException

java.lang.InterruptedException

ExpiredObjectException

leaveNonExWriteLock

public void leaveNonExWriteLock()
                         throws java.lang.InterruptedException,
                                ExpiredObjectException

Throws:

java.lang.InterruptedException

ExpiredObjectException

enterReadLock

public void enterReadLock()
                   throws java.lang.InterruptedException,
                          ExpiredObjectException

Throws:

java.lang.InterruptedException

ExpiredObjectException

enterReadLockNoWait

public void enterReadLockNoWait()
                         throws LockException,
                                LocalLockException,
                                java.lang.InterruptedException,
                                ExpiredObjectException

Throws:

LockException

LocalLockException

java.lang.InterruptedException

ExpiredObjectException

leaveReadLock

public void leaveReadLock()
                   throws java.lang.InterruptedException,
                          ExpiredObjectException

Throws:

java.lang.InterruptedException

ExpiredObjectException