BaseGenericObjectPool

Base class that provides common functionality for {@link GenericObjectPool} and {@link GenericKeyedObjectPool}. The primary reason this class exists is reduce code duplication between the two pool implementations.

@param <T> Type of element pooled in this pool.

This class is intended to be thread-safe.

abstract

class BaseGenericObjectPool : BaseObject {

enum int MEAN_TIMING_STATS_CACHE_SIZE;

Object closeLock;

Object evictionLock;

EvictionIterator evictionIterator;

long createdCount;

long destroyedCount;

long destroyedByEvictorCount;

long destroyedByBorrowValidationCount;

this(BaseObjectPoolConfig config, string jmxNameBase, string jmxNamePrefix);

int getMaxTotal();

void setMaxTotal(int maxTotal);

bool getBlockWhenExhausted();

void setBlockWhenExhausted(bool blockWhenExhausted);

void setConfig(BaseObjectPoolConfig conf);

long getMaxWaitMillis();

void setMaxWaitMillis(long maxWaitMillis);

bool getLifo();

bool getFairness();

void setLifo(bool lifo);

bool getTestOnCreate();

void setTestOnCreate(bool testOnCreate);

bool getTestOnBorrow();

void setTestOnBorrow(bool testOnBorrow);

bool getTestOnReturn();

void setTestOnReturn(bool testOnReturn);

bool getTestWhileIdle();

void setTestWhileIdle(bool testWhileIdle);

long getTimeBetweenEvictionRunsMillis();

void setTimeBetweenEvictionRunsMillis(long timeBetweenEvictionRunsMillis);

int getNumTestsPerEvictionRun();

void setNumTestsPerEvictionRun(int numTestsPerEvictionRun);

long getMinEvictableIdleTimeMillis();

void setMinEvictableIdleTimeMillis(long minEvictableIdleTimeMillis);

long getSoftMinEvictableIdleTimeMillis();

void setSoftMinEvictableIdleTimeMillis(long softMinEvictableIdleTimeMillis);

string getEvictionPolicyClassName();

void setEvictionPolicy(EvictionPolicy evictionPolicy);

long getEvictorShutdownTimeoutMillis();

void setEvictorShutdownTimeoutMillis(long evictorShutdownTimeoutMillis);

void close();

bool isClosed();

void evict();

EvictionPolicy getEvictionPolicy();

void assertOpen();

void startEvictor(long delay);

void stopEvitor();

void ensureMinIdle();

string getCreationStackTrace();

long getBorrowedCount();

long getReturnedCount();

long getCreatedCount();

long getDestroyedCount();

long getDestroyedByEvictorCount();

long getDestroyedByBorrowValidationCount();

long getMeanActiveTimeMillis();

long getMeanIdleTimeMillis();

long getMeanBorrowWaitTimeMillis();

long getMaxBorrowWaitTimeMillis();

int getNumIdle();

SwallowedExceptionListener getSwallowedExceptionListener();

void setSwallowedExceptionListener(SwallowedExceptionListener swallowedExceptionListener);

void swallowException(Exception swallowException);

void updateStatsBorrow(IPooledObject p, long waitTime);

void updateStatsReturn(long activeTime);

void markReturningState(IPooledObject pooledObject);

void toStringAppendFields(StringBuilder builder);

}

Constructors

this this(BaseObjectPoolConfig config, string jmxNameBase, string jmxNamePrefix): Handles JMX registration (if required) and the initialization required for monitoring.

Members

Classes

Evictor class Evictor: The idle object evictor {@link TimerTask}.

Functions

assertOpen void assertOpen(): Verifies that the pool is open. @throws IllegalStateException if the pool is closed.
close void close(): Closes the pool, destroys the remaining idle objects and, if registered in JMX, deregisters it.
ensureMinIdle void ensureMinIdle(): Tries to ensure that the configured minimum number of idle instances are available in the pool. @throws Exception if an error occurs creating idle instances
evict void evict(): <p>Perform <code>numTests</code> idle object eviction tests, evicting examined objects that meet the criteria for eviction. If <code>testWhileIdle</code> is true, examined objects are validated when visited (and removed if invalid); otherwise only objects that have been idle for more than <code>minEvicableIdleTimeMillis</code> are removed.</p>
getBlockWhenExhausted bool getBlockWhenExhausted(): Returns whether to block when the <code>borrowObject()</code> method is invoked when the pool is exhausted (the maximum number of "active" objects has been reached).
getBorrowedCount long getBorrowedCount(): The total number of objects successfully borrowed from this pool over the lifetime of the pool. @return the borrowed object count
getCreatedCount long getCreatedCount(): The total number of objects created for this pool over the lifetime of the pool. @return the created object count
getCreationStackTrace string getCreationStackTrace(): Provides the stack trace for the call that created this pool. JMX registration may trigger a memory leak so it is important that pools are deregistered when no longer used by calling the {@link #close()} method. This method is provided to assist with identifying code that creates but does not close it thereby creating a memory leak. @return pool creation stack trace
getDestroyedByBorrowValidationCount long getDestroyedByBorrowValidationCount(): The total number of objects destroyed by this pool as a result of failing validation during <code>borrowObject()</code> over the lifetime of the pool. @return validation destroyed object count
getDestroyedByEvictorCount long getDestroyedByEvictorCount(): The total number of objects destroyed by the evictor associated with this pool over the lifetime of the pool. @return the evictor destroyed object count
getDestroyedCount long getDestroyedCount(): The total number of objects destroyed by this pool over the lifetime of the pool. @return the destroyed object count
getEvictionPolicy EvictionPolicy getEvictionPolicy(): Returns the {@link EvictionPolicy} defined for this pool.
getEvictionPolicyClassName string getEvictionPolicyClassName(): Returns the name of the {@link EvictionPolicy} implementation that is used by this pool.
getEvictorShutdownTimeoutMillis long getEvictorShutdownTimeoutMillis(): Gets the timeout that will be used when waiting for the Evictor to shutdown if this pool is closed and it is the only pool still using the the value for the Evictor.
getFairness bool getFairness(): Returns whether or not the pool serves threads waiting to borrow objects fairly. True means that waiting threads are served as if waiting in a FIFO queue.
getLifo bool getLifo(): Returns whether the pool has LIFO (last in, first out) behaviour with respect to idle objects - always returning the most recently used object from the pool, or as a FIFO (first in, first out) queue, where the pool always returns the oldest object in the idle object pool.
getMaxBorrowWaitTimeMillis long getMaxBorrowWaitTimeMillis(): The maximum time a thread has waited to borrow objects from the pool. @return maximum wait time in milliseconds since the pool was created
getMaxTotal int getMaxTotal(): Returns the maximum number of objects that can be allocated by the pool (checked out to clients, or idle awaiting checkout) at a given time. When negative, there is no limit to the number of objects that can be managed by the pool at one time.
getMaxWaitMillis long getMaxWaitMillis(): Returns the maximum amount of time (in milliseconds) the <code>borrowObject()</code> method should block before throwing an exception when the pool is exhausted and {@link #getBlockWhenExhausted} is true. When less than 0, the <code>borrowObject()</code> method may block indefinitely.
getMeanActiveTimeMillis long getMeanActiveTimeMillis(): The mean time objects are active for based on the last {@link #MEAN_TIMING_STATS_CACHE_SIZE} objects returned to the pool. @return mean time an object has been checked out from the pool among recently returned objects
getMeanBorrowWaitTimeMillis long getMeanBorrowWaitTimeMillis(): The mean time threads wait to borrow an object based on the last {@link #MEAN_TIMING_STATS_CACHE_SIZE} objects borrowed from the pool. @return mean time in milliseconds that a recently served thread has had to wait to borrow an object from the pool
getMeanIdleTimeMillis long getMeanIdleTimeMillis(): The mean time objects are idle for based on the last {@link #MEAN_TIMING_STATS_CACHE_SIZE} objects borrowed from the pool. @return mean time an object has been idle in the pool among recently borrowed objects
getMinEvictableIdleTimeMillis long getMinEvictableIdleTimeMillis(): Returns the minimum amount of time an object may sit idle in the pool before it is eligible for eviction by the idle object evictor (if any - see {@link #setTimeBetweenEvictionRunsMillis(long)}). When non-positive, no objects will be evicted from the pool due to idle time alone.
getNumIdle int getNumIdle(): The number of instances currently idle in this pool. @return count of instances available for checkout from the pool
getNumTestsPerEvictionRun int getNumTestsPerEvictionRun(): Returns the maximum number of objects to examine during each run (if any) of the idle object evictor thread. When positive, the number of tests performed for a run will be the minimum of the configured value and the number of idle instances in the pool. When negative, the number of tests performed will be <code>ceil({@link #getNumIdle}/ abs({@link #getNumTestsPerEvictionRun}))</code> which means that when the value is <code>-n</code> roughly one nth of the idle objects will be tested per run.
getReturnedCount long getReturnedCount(): The total number of objects returned to this pool over the lifetime of the pool. This excludes attempts to return the same object multiple times. @return the returned object count
getSoftMinEvictableIdleTimeMillis long getSoftMinEvictableIdleTimeMillis(): Returns the minimum amount of time an object may sit idle in the pool before it is eligible for eviction by the idle object evictor (if any - see {@link #setTimeBetweenEvictionRunsMillis(long)}), with the extra condition that at least <code>minIdle</code> object instances remain in the pool. This setting is overridden by {@link #getMinEvictableIdleTimeMillis} (that is, if {@link #getMinEvictableIdleTimeMillis} is positive, then {@link #getSoftMinEvictableIdleTimeMillis} is ignored).
getSwallowedExceptionListener SwallowedExceptionListener getSwallowedExceptionListener(): The listener used (if any) to receive notifications of exceptions unavoidably swallowed by the pool.
getTestOnBorrow bool getTestOnBorrow(): Returns whether objects borrowed from the pool will be validated before being returned from the <code>borrowObject()</code> method. Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. If the object fails to validate, it will be removed from the pool and destroyed, and a new attempt will be made to borrow an object from the pool.
getTestOnCreate bool getTestOnCreate(): Returns whether objects created for the pool will be validated before being returned from the <code>borrowObject()</code> method. Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. If the object fails to validate, then <code>borrowObject()</code> will fail.
getTestOnReturn bool getTestOnReturn(): Returns whether objects borrowed from the pool will be validated when they are returned to the pool via the <code>returnObject()</code> method. Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. Returning objects that fail validation are destroyed rather then being returned the pool.
getTestWhileIdle bool getTestWhileIdle(): Returns whether objects sitting idle in the pool will be validated by the idle object evictor (if any - see {@link #setTimeBetweenEvictionRunsMillis(long)}). Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. If the object fails to validate, it will be removed from the pool and destroyed.
getTimeBetweenEvictionRunsMillis long getTimeBetweenEvictionRunsMillis(): Returns the number of milliseconds to sleep between runs of the idle object evictor thread. When non-positive, no idle object evictor thread will be run.
isClosed bool isClosed(): Has this pool instance been closed. @return <code>true</code> when this pool has been closed.
markReturningState void markReturningState(IPooledObject pooledObject): Marks the object as returning to the pool. @param pooledObject instance to return to the keyed pool
setBlockWhenExhausted void setBlockWhenExhausted(bool blockWhenExhausted): Sets whether to block when the <code>borrowObject()</code> method is invoked when the pool is exhausted (the maximum number of "active" objects has been reached).
setConfig void setConfig(BaseObjectPoolConfig conf): Undocumented in source. Be warned that the author may not have intended to support it.
setEvictionPolicy void setEvictionPolicy(EvictionPolicy evictionPolicy): Sets the eviction policy for this pool.
setEvictorShutdownTimeoutMillis void setEvictorShutdownTimeoutMillis(long evictorShutdownTimeoutMillis): Sets the timeout that will be used when waiting for the Evictor to shutdown if this pool is closed and it is the only pool still using the the value for the Evictor.
setLifo void setLifo(bool lifo): Sets whether the pool has LIFO (last in, first out) behaviour with respect to idle objects - always returning the most recently used object from the pool, or as a FIFO (first in, first out) queue, where the pool always returns the oldest object in the idle object pool.
setMaxTotal void setMaxTotal(int maxTotal): Sets the cap on the number of objects that can be allocated by the pool (checked out to clients, or idle awaiting checkout) at a given time. Use a negative value for no limit.
setMaxWaitMillis void setMaxWaitMillis(long maxWaitMillis): Sets the maximum amount of time (in milliseconds) the <code>borrowObject()</code> method should block before throwing an exception when the pool is exhausted and {@link #getBlockWhenExhausted} is true. When less than 0, the <code>borrowObject()</code> method may block indefinitely.
setMinEvictableIdleTimeMillis void setMinEvictableIdleTimeMillis(long minEvictableIdleTimeMillis): Sets the minimum amount of time an object may sit idle in the pool before it is eligible for eviction by the idle object evictor (if any - see {@link #setTimeBetweenEvictionRunsMillis(long)}). When non-positive, no objects will be evicted from the pool due to idle time alone.
setNumTestsPerEvictionRun void setNumTestsPerEvictionRun(int numTestsPerEvictionRun): Sets the maximum number of objects to examine during each run (if any) of the idle object evictor thread. When positive, the number of tests performed for a run will be the minimum of the configured value and the number of idle instances in the pool. When negative, the number of tests performed will be <code>ceil({@link #getNumIdle}/ abs({@link #getNumTestsPerEvictionRun}))</code> which means that when the value is <code>-n</code> roughly one nth of the idle objects will be tested per run.
setSoftMinEvictableIdleTimeMillis void setSoftMinEvictableIdleTimeMillis(long softMinEvictableIdleTimeMillis): Sets the minimum amount of time an object may sit idle in the pool before it is eligible for eviction by the idle object evictor (if any - see {@link #setTimeBetweenEvictionRunsMillis(long)}), with the extra condition that at least <code>minIdle</code> object instances remain in the pool. This setting is overridden by {@link #getMinEvictableIdleTimeMillis} (that is, if {@link #getMinEvictableIdleTimeMillis} is positive, then {@link #getSoftMinEvictableIdleTimeMillis} is ignored).
setSwallowedExceptionListener void setSwallowedExceptionListener(SwallowedExceptionListener swallowedExceptionListener): The listener used (if any) to receive notifications of exceptions unavoidably swallowed by the pool.
setTestOnBorrow void setTestOnBorrow(bool testOnBorrow): Sets whether objects borrowed from the pool will be validated before being returned from the <code>borrowObject()</code> method. Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. If the object fails to validate, it will be removed from the pool and destroyed, and a new attempt will be made to borrow an object from the pool.
setTestOnCreate void setTestOnCreate(bool testOnCreate): Sets whether objects created for the pool will be validated before being returned from the <code>borrowObject()</code> method. Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. If the object fails to validate, then <code>borrowObject()</code> will fail.
setTestOnReturn void setTestOnReturn(bool testOnReturn): Sets whether objects borrowed from the pool will be validated when they are returned to the pool via the <code>returnObject()</code> method. Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. Returning objects that fail validation are destroyed rather then being returned the pool.
setTestWhileIdle void setTestWhileIdle(bool testWhileIdle): Returns whether objects sitting idle in the pool will be validated by the idle object evictor (if any - see {@link #setTimeBetweenEvictionRunsMillis(long)}). Validation is performed by the <code>validateObject()</code> method of the factory associated with the pool. If the object fails to validate, it will be removed from the pool and destroyed. Note that setting this property has no effect unless the idle object evictor is enabled by setting <code>timeBetweenEvictionRunsMillis</code> to a positive value.
setTimeBetweenEvictionRunsMillis void setTimeBetweenEvictionRunsMillis(long timeBetweenEvictionRunsMillis): Sets the number of milliseconds to sleep between runs of the idle object evictor thread. <ul> <li>When positive, the idle object evictor thread starts.</li> <li>When non-positive, no idle object evictor thread runs.</li> </ul>
startEvictor void startEvictor(long delay): <p>Starts the evictor with the given delay. If there is an evictor running when this method is called, it is stopped and replaced with a new evictor with the specified delay.</p>
stopEvitor void stopEvitor(): Stops the evictor.
swallowException void swallowException(Exception swallowException): Swallows an exception and notifies the configured listener for swallowed exceptions queue.
toStringAppendFields void toStringAppendFields(StringBuilder builder): Undocumented in source. Be warned that the author may not have intended to support it.
updateStatsBorrow void updateStatsBorrow(IPooledObject p, long waitTime): Updates statistics after an object is borrowed from the pool. @param p object borrowed from the pool @param waitTime time (in milliseconds) that the borrowing thread had to wait
updateStatsReturn void updateStatsReturn(long activeTime): Updates statistics after an object is returned to the pool. @param activeTime the amount of time (in milliseconds) that the returning object was checked out

Variables

MEAN_TIMING_STATS_CACHE_SIZE enum int MEAN_TIMING_STATS_CACHE_SIZE;: The size of the caches used to store historical data for some attributes so that rolling means may be calculated.
closeLock Object closeLock;: Undocumented in source.
closed bool closed;: Undocumented in source.
createdCount long createdCount;: Undocumented in source.
destroyedByBorrowValidationCount long destroyedByBorrowValidationCount;: Undocumented in source.
destroyedByEvictorCount long destroyedByEvictorCount;: Undocumented in source.
destroyedCount long destroyedCount;: Undocumented in source.
evictionIterator EvictionIterator evictionIterator;: Undocumented in source.
evictionLock Object evictionLock;: Undocumented in source.

Inherited Members

From BaseObject

toString string toString(): Undocumented in source. Be warned that the author may not have intended to support it.
toStringAppendFields void toStringAppendFields(StringBuilder builder): Used by sub-classes to include the fields defined by the sub-class in the {@link #toString()} output.

Meta

Source

See Implementation

hunt pool impl BaseGenericObjectPool classes