com.tibco.ftl

Interface TibLock

public interface TibLock

Cooperating application programs can use locks to implement exclusive access to a map within a persistence store.

To create a lock object, see Realm.createLock.

If a client process exits or disconnects from the persistence server, the library automatically releases all the locks that the process holds.

This file defines the calls that manipulate locks. In addition, map objects and map iterator objects have methods that operate while holding a lock.

Since:

4.2

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	PROPERTY_DOUBLE_LOCK_ACQUIRE_RETRY_DURATION Retry duration for lock requests.

Method Summary

Modifier and Type	Method and Description
void	destroy() Destroy a local lock object and reclaim its resources.
boolean	request() No operation.
void	returnLock() Release a lock.
void	steal() Forcibly acquire a lock, even if another process holds it.

Field Detail

PROPERTY_DOUBLE_LOCK_ACQUIRE_RETRY_DURATION

static final java.lang.String PROPERTY_DOUBLE_LOCK_ACQUIRE_RETRY_DURATION

Retry duration for lock requests. double

Supply this property to Realm.createLock.

This determines the number of seconds the client will attempt to acquire the lock. The client may retry if it can't access the persistence server, or wait if another client owns the lock. If the client does not already own the lock, the client attempts to acquire it when any map operation requiring a lock is called.

This value must be positive or zero. A value of 0 (zero) specifies no wait duration.

See Also:

Constant Field Values

Method Detail

request

boolean request()
         throws FTLException

No operation.

In releases earlier than 5.0, this call requested a lock from its persistence store.

In Release 5.0 and later, this call is no longer necessary; it returns true without any other effect.

Calls that require a lock automatically request it; see:

• TibMap.set(String, Message, TibLock)
• TibMap.get(String, TibLock)
• TibMap.remove(String, TibLock)
• TibMap.createIterator(TibLock, TibProperties)

Programs that correctly used earlier versions of lock calls continue to operate properly.

Returns:

This call returns the boolean value true.

Throws:

FTLException

Since:

4.2

steal

void steal()
    throws FTLException

Forcibly acquire a lock, even if another process holds it.

Throws:

FTLException

Since:

4.2

returnLock

void returnLock()
         throws FTLException

Release a lock.

If the process does not hold the lock, this call has no effect.

Throws:

FTLException

Since:

4.2

destroy

void destroy()
      throws FTLException

Destroy a local lock object and reclaim its resources.

If the process holds the lock, this call returns the lock before destroying the object.

Throws:

FTLException

Since:

4.2