org.vibur.objectpool

Interface HolderValidatingPoolService<T>

Type Parameters:

T - the type of objects held in this object pool

All Superinterfaces:

BasePoolService

All Known Implementing Classes:

ConcurrentHolderLinkedPool

public interface HolderValidatingPoolService<T>
extends BasePoolService

Extends the functionality defined by BasePoolService with take and restore methods which provide validation for whether the restored (returned) object is one which has been taken before that from this object pool, as well as whether the object is currently in taken state.

The object returned by the take methods is enclosed in a thin wrapper class which is created by the object pool and which is implementing the described below Holder interface. The underlying object is accessible via the interface's value() method.

Author:

Simeon Malchev

Method Summary

Methods

Modifier and Type	Method and Description
boolean	restore(Holder<T> holder) Restores (returns) an object to the object pool.
boolean	restore(Holder<T> holder, boolean valid) Restores (returns) an object to the object pool.
Holder<T>	take() Takes an object from the object pool if there is such available.
List<Holder<T>>	takenHolders() Returns list of all Holder objects (i.e the wrappers of the underlying objects) which are currently (at the moment of the call) in taken state in this object pool.
Holder<T>	takeUninterruptibly() Takes an object from the object pool if there is such available.
Holder<T>	tryTake() Tries to take an object from the object pool if there is one which is immediately available.
Holder<T>	tryTake(long timeout, TimeUnit unit) Takes an object from the object pool if there is such available.

Methods inherited from interface org.vibur.objectpool.BasePoolService

createdTotal, drainCreated, initialSize, isFair, isTerminated, maxSize, reduceCreated, remainingCapacity, remainingCreated, taken, terminate

Method Detail

take

Holder<T> take()

Takes an object from the object pool if there is such available. This is a blocking call which waits indefinitely until an object becomes available. If the calling thread is interrupted while waiting this call will return null and the thread's interrupted status will be set to true.

Returns:

an object taken from the object pool and enclosed into a thin wrapper class implementing the Holder interface or null if was interrupted while waiting

takeUninterruptibly

Holder<T> takeUninterruptibly()

Takes an object from the object pool if there is such available. This is a blocking call which waits indefinitely until an object becomes available.

Returns:

an object taken from the object pool and enclosed into a thin wrapper class implementing the Holder interface

tryTake

Holder<T> tryTake(long timeout,
                TimeUnit unit)

Takes an object from the object pool if there is such available. This is a blocking call which waits up to the specified timeout for an object to become available. If the calling thread is interrupted while waiting this call will return null and the thread's interrupted status will be set to true.

Parameters:

timeout - the maximum time to wait for an object to become available in the object pool

unit - the time unit of the timeout argument

Returns:

an object taken from the object pool and enclosed into a thin wrapper class implementing the Holder interface or null if the specified timeout expires or if was interrupted while waiting

tryTake

Holder<T> tryTake()

Tries to take an object from the object pool if there is one which is immediately available. Returns null if no object is available at the moment of the call.

Returns:

an object taken from the object pool and enclosed into a thin wrapper class implementing the Holder interface or null if there is no object available in the object pool

restore

boolean restore(Holder<T> holder)

Restores (returns) an object to the object pool. The object pool validates whether the object restored has been taken before from this object pool and whether it is currently in taken state. If the validation fails, this method will return false otherwise will return true. Equivalent to calling restore(holder, true).

Parameters:

holder - a thin wrapper enclosing the object that is to be restored to the object pool

Returns:

true if the underlying object from the given holder was taken before that from this object pool and if it is currently in taken state, false otherwise

restore

boolean restore(Holder<T> holder,
              boolean valid)

Restores (returns) an object to the object pool. The object pool validates whether the object restored has been taken before from this object pool and whether it is currently in taken state. If the validation fails, this method will return false otherwise will return true. This validation should not be mistaken with the valid status of the object state which is provided by the valid parameter as shown below.

Parameters:

holder - a thin wrapper enclosing the object that is to be restored to the object pool

valid - if true the restored object is presumed to be in valid (healthy) state, otherwise it is treated as invalid

Returns:

true if the underlying object from the given holder was taken before that from this object pool and if it is currently in taken state, false otherwise

takenHolders

List<Holder<T>> takenHolders()

Returns list of all Holder objects (i.e the wrappers of the underlying objects) which are currently (at the moment of the call) in taken state in this object pool. Useful for testing and debugging purposes. The objects in the returned list are in random order, i.e. the list is not sorted.

Returns:

see above