Pool

java.lang.Object
- org.apache.openejb.util.Pool<T>

```
public class Pool<T>
extends java.lang.Object
```
Any successful pop() call requires a corresponding push() or discard() call.
A pop() call that returns null is considered successful. A null indicates that the calling code has a permit to create a poolable object and call push(Object). This is the only situation in which that method may be called.
To simply fill the pool without a corresponding pop(), the add() method must be used. This method will attempt to aquire a permit to add to the pool.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Pool.Builder<T>`
`class`	`Pool.Entry`
`static class`	`Pool.Event`
`static class`	`Pool.HardReference<T>`
`static interface`	`Pool.Supplier<T>`

Constructor Summary

Constructors
Constructor and Description
`Pool(int max, int min, boolean strict)`
`Pool(int max, int min, boolean strict, long maxAge, long idleTimeout, long sweepInterval, java.util.concurrent.Executor executor, Pool.Supplier<T> supplier, boolean replaceAged, double maxAgeOffset, boolean garbageCollection, boolean replaceFlushed)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`add(T obj)` Attempt to aquire a permit to add the object to the pool.
`boolean`	`add(T obj, long offset)` Attempt to aquire a permit to add the object to the pool.
`boolean`	`close(long timeout, java.util.concurrent.TimeUnit unit)`
`void`	`discard()` Used when a call to pop() was made that returned null indicating that the caller has a permit to create an object for this pool, but the caller will not be exercising that permit and wishes intstead to return "null" to the pool.
`void`	`discard(Pool.Entry entry)`
`void`	`flush()`
`Pool.Entry`	`pop(long timeout, java.util.concurrent.TimeUnit unit)` Any successful pop() call requires a corresponding push() or discard() call A pop() call that returns null is considered successful.
`boolean`	`push(Pool.Entry entry)`
`boolean`	`push(T obj)` Never call this method without having successfully called `pop(long, TimeUnit)` beforehand.
`boolean`	`running()`
`Pool`	`start()`
`void`	`stop()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Pool
```
public Pool(int max,
            int min,
            boolean strict)
```
  - Pool
```
public Pool(int max,
            int min,
            boolean strict,
            long maxAge,
            long idleTimeout,
            long sweepInterval,
            java.util.concurrent.Executor executor,
            Pool.Supplier<T> supplier,
            boolean replaceAged,
            double maxAgeOffset,
            boolean garbageCollection,
            boolean replaceFlushed)
```
- Method Detail
  - start
```
public Pool start()
```
  - stop
```
public void stop()
```
  - running
```
public boolean running()
```
  - flush
```
public void flush()
```
  - pop
```
public Pool.Entry pop(long timeout,
                      java.util.concurrent.TimeUnit unit)
               throws java.lang.InterruptedException,
                      java.util.concurrent.TimeoutException
```
    Any successful pop() call requires a corresponding push() or discard() call
    A pop() call that returns null is considered successful.
    
    Parameters:
    
    timeout - time to block while waiting for an instance
    
    unit - unit of time dicated by the timeout
    
    Returns:
    
    an entry from the pool or null indicating permission to create and push() an instance into the pool
    
    Throws:
    
    java.lang.InterruptedException - vm level thread interruption
    
    java.lang.IllegalStateException - if a permit could not be acquired
    
    java.util.concurrent.TimeoutException - if no instance could be obtained within the timeout
  - add
```
public boolean add(T obj)
```
    Attempt to aquire a permit to add the object to the pool.
    
    Parameters:
    
    obj - object to add to the pool
    
    Returns:
    
    true of the item as added
  - add
```
public boolean add(T obj,
                   long offset)
```
    Attempt to aquire a permit to add the object to the pool.
    
    Parameters:
    
    obj - object to add to the pool
    
    offset - creation time offset, used for maxAge
    
    Returns:
    
    true of the item as added
  - push
```
public boolean push(T obj)
```
    Never call this method without having successfully called pop(long, TimeUnit) beforehand.
    Failure to do so will increase the max pool size by one.
    
    Parameters:
    
    obj - object to push onto the pool
    
    Returns:
    
    false if the pool max size was exceeded
  - push
```
public boolean push(Pool.Entry entry)
```
  - discard
```
public void discard()
```
    Used when a call to pop() was made that returned null indicating that the caller has a permit to create an object for this pool, but the caller will not be exercising that permit and wishes intstead to return "null" to the pool.
  - discard
```
public void discard(Pool.Entry entry)
```
  - close
```
public boolean close(long timeout,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.InterruptedException
```
    Throws:
    
    java.lang.InterruptedException

Class Pool<T>

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Pool

Pool

Method Detail

start

stop

running

flush

pop

add

add

push

push

discard

discard

close