/**
* Sets the abandoned object removal configuration.
*
* @param abandonedConfig the new configuration to use. This is used by value.
* @see AbandonedConfig
*/
public void setAbandonedConfig(AbandonedConfig abandonedConfig) {
if (abandonedConfig == null) {
this.abandonedConfig = null;
} else {
this.abandonedConfig = new AbandonedConfig();
this.abandonedConfig.setLogAbandoned(abandonedConfig.getLogAbandoned());
this.abandonedConfig.setLogWriter(abandonedConfig.getLogWriter());
this.abandonedConfig.setRemoveAbandonedOnBorrow(abandonedConfig.getRemoveAbandonedOnBorrow());
this.abandonedConfig.setRemoveAbandonedOnMaintenance(
abandonedConfig.getRemoveAbandonedOnMaintenance());
this.abandonedConfig.setRemoveAbandonedTimeout(abandonedConfig.getRemoveAbandonedTimeout());
this.abandonedConfig.setUseUsageTracking(abandonedConfig.getUseUsageTracking());
}
}
/**
* Borrow an object from the pool using the specific waiting time which only applies if {@link
* #getBlockWhenExhausted()} is true.
*
* <p>If there is one or more idle instance available in the pool, then an idle instance will be
* selected based on the value of {@link #getLifo()}, activated and returned. If activation fails,
* or {@link #getTestOnBorrow() testOnBorrow} is set to <code>true</code> and validation fails,
* the instance is destroyed and the next available instance is examined. This continues until
* either a valid instance is returned or there are no more idle instances available.
*
* <p>If there are no idle instances available in the pool, behavior depends on the {@link
* #getMaxTotal() maxTotal}, (if applicable) {@link #getBlockWhenExhausted()} and the value passed
* in to the <code>borrowMaxWaitMillis</code> parameter. If the number of instances checked out
* from the pool is less than <code>maxTotal,</code> a new instance is created, activated and (if
* applicable) validated and returned to the caller. If validation fails, a <code>
* NoSuchElementException</code> is thrown.
*
* <p>If the pool is exhausted (no available idle instances and no capacity to create new ones),
* this method will either block (if {@link #getBlockWhenExhausted()} is true) or throw a <code>
* NoSuchElementException</code> (if {@link #getBlockWhenExhausted()} is false). The length of
* time that this method will block when {@link #getBlockWhenExhausted()} is true is determined by
* the value passed in to the <code>borrowMaxWaitMillis</code> parameter.
*
* <p>When the pool is exhausted, multiple calling threads may be simultaneously blocked waiting
* for instances to become available. A "fairness" algorithm has been implemented to ensure that
* threads receive available instances in request arrival order.
*
* @param borrowMaxWaitMillis The time to wait in milliseconds for an object to become available
* @return object instance from the pool
* @throws NoSuchElementException if an instance cannot be returned
* @throws Exception if an object instance cannot be returned due to an error
*/
public T borrowObject(long borrowMaxWaitMillis) throws Exception {
assertOpen();
AbandonedConfig ac = this.abandonedConfig;
if (ac != null
&& ac.getRemoveAbandonedOnBorrow()
&& (getNumIdle() < 2)
&& (getNumActive() > getMaxTotal() - 3)) {
removeAbandoned(ac);
}
PooledObject<T> p = null;
// Get local copy of current config so it is consistent for entire
// method execution
boolean blockWhenExhausted = getBlockWhenExhausted();
boolean create;
long waitTime = System.currentTimeMillis();
while (p == null) {
create = false;
if (blockWhenExhausted) {
p = idleObjects.pollFirst();
if (p == null) {
p = create();
if (p != null) {
create = true;
}
}
if (p == null) {
if (borrowMaxWaitMillis < 0) {
p = idleObjects.takeFirst();
} else {
p = idleObjects.pollFirst(borrowMaxWaitMillis, TimeUnit.MILLISECONDS);
}
}
if (p == null) {
throw new NoSuchElementException("Timeout waiting for idle object");
}
if (!p.allocate()) {
p = null;
}
} else {
p = idleObjects.pollFirst();
if (p == null) {
p = create();
if (p != null) {
create = true;
}
}
if (p == null) {
throw new NoSuchElementException("Pool exhausted");
}
if (!p.allocate()) {
p = null;
}
}
if (p != null) {
try {
factory.activateObject(p);
} catch (Exception e) {
try {
destroy(p);
} catch (Exception e1) {
// Ignore - activation failure is more important
}
p = null;
if (create) {
NoSuchElementException nsee = new NoSuchElementException("Unable to activate object");
nsee.initCause(e);
throw nsee;
}
}
if (p != null && (getTestOnBorrow() || create && getTestOnCreate())) {
boolean validate = false;
Throwable validationThrowable = null;
try {
validate = factory.validateObject(p);
} catch (Throwable t) {
PoolUtils.checkRethrow(t);
validationThrowable = t;
}
if (!validate) {
try {
destroy(p);
destroyedByBorrowValidationCount.incrementAndGet();
} catch (Exception e) {
// Ignore - validation failure is more important
}
p = null;
if (create) {
NoSuchElementException nsee = new NoSuchElementException("Unable to validate object");
nsee.initCause(validationThrowable);
throw nsee;
}
}
}
}
}
updateStatsBorrow(p, System.currentTimeMillis() - waitTime);
return p.getObject();
}
/**
* Will a check be made for abandoned objects when an object is borrowed from this pool?
*
* @return {@code true} if abandoned object removal is configured to be activated by borrowObject
* otherwise {@code false}
* @see AbandonedConfig#getRemoveAbandonedOnBorrow()
*/
@Override
public boolean getRemoveAbandonedOnBorrow() {
AbandonedConfig ac = this.abandonedConfig;
return ac != null && ac.getRemoveAbandonedOnBorrow();
}