LockManager (ObJectRelationalBridge 1.0.4 API documentation)

All Superinterfaces:

IsolationLevels

All Known Implementing Classes:

LockManagerCommonsImpl, LockManagerInMemoryImpl, LockManagerRemoteImpl
```
public interface LockManager
extends IsolationLevels
```
This interface declares the functionality of the OJB locking-api for support of pessimistic locking.
OJB allows to provide user defined implementations of this interface. To activate a user defined LockManager implementation it must be configured in the OJB.properties file.

All locks have to be reentrant, this means if you already have a lock for writing and you try to acquire write access again you will not be blocked by this first lock.

It's optional to support the lockTimeout and blockTimeout properties.

Version:

$Id: LockManager.java 365232 2005-12-21 22:36:07Z tomdz $

See Also:
LockManagerInMemoryImpl, LockManagerCommonsImpl

Field Summary

Fields
Modifier and Type	Field and Description
`static long`	`DEFAULT_BLOCK_TIMEOUT` Default lock wait time in millisecond - set to 1000 ms;
`static long`	`DEFAULT_LOCK_TIMEOUT` Default lock timeout value - set to 60000 ms.

Fields inherited from interface org.apache.ojb.broker.locking.IsolationLevels
IL_DEFAULT, IL_NONE, IL_OPTIMISTIC, IL_READ_COMMITTED, IL_READ_UNCOMMITTED, IL_REPEATABLE_READ, IL_SERIALIZABLE, LITERAL_IL_NONE, LITERAL_IL_OPTIMISTIC, LITERAL_IL_READ_COMMITTED, LITERAL_IL_READ_UNCOMMITTED, LITERAL_IL_REPEATABLE_READ, LITERAL_IL_SERIALIZABLE

Method Summary

Methods
Modifier and Type	Method and Description
`long`	`getBlockTimeout()` The maximal time to wait for acquire a lock.
`java.lang.String`	`getLockInfo()` Returns info about the used lock manager implementation and the state of the lock manager.
`long`	`getLockTimeout()` Get the current used lock timeout value in milliseconds.
`boolean`	`hasRead(java.lang.Object key, java.lang.Object resourceId)` Checks if there is a read lock for owner key on resource object.
`boolean`	`hasUpgrade(java.lang.Object key, java.lang.Object resourceId)` Checks if there is a upgrade lock for lock key on resource object.
`boolean`	`hasWrite(java.lang.Object key, java.lang.Object resourceId)` Checks if there is a write lock for lock key on resource object.
`boolean`	`readLock(java.lang.Object key, java.lang.Object resourceId, int isolationLevel)` Acquires a readlock for lock key on resource object.
`boolean`	`releaseLock(java.lang.Object key, java.lang.Object resourceId)` Releases a lock for lock key on resource object.
`void`	`releaseLocks(java.lang.Object key)` Release all resource locks hold by the specified owner key.
`void`	`setBlockTimeout(long timeout)` Set the maximal time to wait for acquire a lock in milliseconds.
`void`	`setLockTimeout(long timeout)` Set the lock timeout value in milliseconds.
`boolean`	`upgradeLock(java.lang.Object key, java.lang.Object resourceId, int isolationLevel)` Acquire an upgrade lock.
`boolean`	`writeLock(java.lang.Object key, java.lang.Object resourceId, int isolationLevel)` Acquires a write lock for lock key on resource object.

- Field Detail
  - DEFAULT_LOCK_TIMEOUT
```
static final long DEFAULT_LOCK_TIMEOUT
```
    Default lock timeout value - set to 60000 ms.
    
    See Also:
    Constant Field Values
  - DEFAULT_BLOCK_TIMEOUT
```
static final long DEFAULT_BLOCK_TIMEOUT
```
    Default lock wait time in millisecond - set to 1000 ms;
    
    See Also:
    Constant Field Values
- Method Detail
  - getBlockTimeout
```
long getBlockTimeout()
```
    The maximal time to wait for acquire a lock.
    
    Returns:
  - setBlockTimeout
```
void setBlockTimeout(long timeout)
```
    Set the maximal time to wait for acquire a lock in milliseconds. All so called non-blocking implementation will ignore this setting.
    
    Parameters:
    timeout - The time to wait for acquire a lock.
  - getLockTimeout
```
long getLockTimeout()
```
    Get the current used lock timeout value in milliseconds.
    
    Returns:
    Current used locking timeout value in ms.
  - setLockTimeout
```
void setLockTimeout(long timeout)
```
    Set the lock timeout value in milliseconds. If timeout was set to -1 the never will never timeout.
    
    Parameters:
    timeout - The lock timeout in ms of acquired read/write/upgrade locks.
  - getLockInfo
```
java.lang.String getLockInfo()
```
    Returns info about the used lock manager implementation and the state of the lock manager.
  - readLock
```
boolean readLock(java.lang.Object key,
               java.lang.Object resourceId,
               int isolationLevel)
```
    Acquires a readlock for lock key on resource object. Returns true if successful, else false.
    
    Parameters:
    key - The owner key of the lock.
    resourceId - The resource to lock.
    isolationLevel - The isolation level of the lock.
    
    Returns:
    True if the lock was successfully acquired.
  - writeLock
```
boolean writeLock(java.lang.Object key,
                java.lang.Object resourceId,
                int isolationLevel)
```
    Acquires a write lock for lock key on resource object. Returns true if successful, else false.
    
    Parameters:
    key - The owner key of the lock.
    resourceId - The resource to lock.
    isolationLevel - The isolation level of the lock.
    
    Returns:
    True if the lock was successfully acquired.
  - upgradeLock
```
boolean upgradeLock(java.lang.Object key,
                  java.lang.Object resourceId,
                  int isolationLevel)
```
    Acquire an upgrade lock. (Current implementations always acquire a write lock instead).
    
    Parameters:
    key - The owner key of the lock.
    resourceId - The resource to lock.
    isolationLevel - The isolation level of the lock.
    
    Returns:
    True if the lock was successfully acquired.
  - releaseLock
```
boolean releaseLock(java.lang.Object key,
                  java.lang.Object resourceId)
```
    Releases a lock for lock key on resource object. Returns true if successful, else false.
    
    Parameters:
    key - The owner key of the lock.
    resourceId - The resource to release.
    
    Returns:
    True if the lock was successfully released.
  - releaseLocks
```
void releaseLocks(java.lang.Object key)
```
    Release all resource locks hold by the specified owner key.
    
    Parameters:
    key - The owner key to release all associated locks.
  - hasRead
```
boolean hasRead(java.lang.Object key,
              java.lang.Object resourceId)
```
    Checks if there is a read lock for owner key on resource object. Returns true if so, else false.
    
    Parameters:
    key - The owner key of the lock.
    resourceId - The resource to check.
    
    Returns:
    True if the lock exists.
  - hasWrite
```
boolean hasWrite(java.lang.Object key,
               java.lang.Object resourceId)
```
    Checks if there is a write lock for lock key on resource object. Returns true if so, else false.
    
    Parameters:
    key - The owner key of the lock.
    resourceId - The resource to check.
    
    Returns:
    True if the lock exists.
  - hasUpgrade
```
boolean hasUpgrade(java.lang.Object key,
                 java.lang.Object resourceId)
```
    Checks if there is a upgrade lock for lock key on resource object. Returns true if so, else false.
    
    Parameters:
    key - The owner key of the lock.
    resourceId - The resource to check.
    
    Returns:
    True if the lock exists.

Interface LockManager

Field Summary

Fields inherited from interface org.apache.ojb.broker.locking.IsolationLevels

Method Summary

Field Detail

DEFAULT_LOCK_TIMEOUT

DEFAULT_BLOCK_TIMEOUT

Method Detail

getBlockTimeout

setBlockTimeout

getLockTimeout

setLockTimeout

getLockInfo

readLock

writeLock

upgradeLock

releaseLock

releaseLocks

hasRead

hasWrite

hasUpgrade