* @param <T>
*/
public class Pool<T> {
- /**
- * This is a constant which specified the default maximum number of unused
- * objects to be held at any given time.
- */
- private static final int MAX_RANGE = 6; // safety
+ /**
+ * This is a constant which specified the default maximum number of unused
+ * objects to be held at any given time.
+ */
+ private static final int MAX_RANGE = 6; // safety
- /**
- * only Simple List needed.
- *
- * NOTE TO MAINTAINERS: THIS OBJECT DOES IT'S OWN SYNCHRONIZATION. All
- * changes that touch list must account for correctly synchronizing list.
- */
-
private LinkedList<Pooled<T>> list;
+ /**
+ * only Simple List needed.
+ *
+ * NOTE TO MAINTAINERS: THIS OBJECT DOES IT'S OWN SYNCHRONIZATION. All
+ * changes that touch list must account for correctly synchronizing list.
+ */
+ private LinkedList<Pooled<T>> list;
- /**
- * keep track of how many elements exist, to avoid asking list.
- */
- private int count;
+ /**
+ * keep track of how many elements exist, to avoid asking list.
+ */
+ private int count;
- /**
- * Spares are those Object that are primed and ready to go.
- */
- private int spares;
+ /**
+ * Spares are those Object that are primed and ready to go.
+ */
+ private int spares;
- /**
- * Actual MAX number of spares allowed to hang around. Can be set to
- * something besides the default MAX_RANGE.
- */
- private int max_range = MAX_RANGE;
+ /**
+ * Actual MAX number of spares allowed to hang around. Can be set to
+ * something besides the default MAX_RANGE.
+ */
+ private int max_range = MAX_RANGE;
- /**
- * The Creator for this particular pool. It must work for type T.
- */
- private Creator<T> creator;
+ /**
+ * The Creator for this particular pool. It must work for type T.
+ */
+ private Creator<T> creator;
- private Log logger;
+ private Log logger;
- /**
- * Create a new Pool, given the implementation of Creator<T>, which must be
- * able to create/destroy T objects at will.
- *
- * @param creator
- */
- public Pool(Creator<T> creator) {
- count = spares = 0;
- this.creator = creator;
- list = new LinkedList<>();
- logger = Log.NULL;
- }
-
- /**
- * Attach Pool Logging activities to any other Logging Mechanism.
- * @param logger
- */
- public void setLogger(Log logger) {
- this.logger = logger;
- }
-
- public void log(Object ...objects) {
- logger.log(objects);
- }
+ /**
+ * Create a new Pool, given the implementation of Creator<T>, which must be
+ * able to create/destroy T objects at will.
+ *
+ * @param creator
+ */
+ public Pool(Creator<T> creator) {
+ count = spares = 0;
+ this.creator = creator;
+ list = new LinkedList<>();
+ logger = Log.NULL;
+ }
+
+ /**
+ * Attach Pool Logging activities to any other Logging Mechanism.
+ * @param logger
+ */
+ public void setLogger(Log logger) {
+ this.logger = logger;
+ }
+
+ public void log(Object ...objects) {
+ logger.log(objects);
+ }
- /**
- * Preallocate a certain number of T Objects. Useful for services so that
- * the first transactions don't get hit with all the Object creation costs
- *
- * @param lt
- * @param prime
- * @throws CadiException
- */
- public void prime(int prime) throws CadiException {
- for (int i = 0; i < prime; ++i) {
- Pooled<T> pt = new Pooled<T>(creator.create(), this);
- synchronized (list) {
- list.addFirst(pt);
- ++count;
- }
- }
+ /**
+ * Preallocate a certain number of T Objects. Useful for services so that
+ * the first transactions don't get hit with all the Object creation costs
+ *
+ * @param lt
+ * @param prime
+ * @throws CadiException
+ */
+ public void prime(int prime) throws CadiException {
+ for (int i = 0; i < prime; ++i) {
+ Pooled<T> pt = new Pooled<T>(creator.create(), this);
+ synchronized (list) {
+ list.addFirst(pt);
+ ++count;
+ }
+ }
- }
+ }
- /**
- * Destroy and remove all remaining objects. This is valuable for closing
- * down all Allocated objects cleanly for exiting. It is also a good method
- * for removing objects when, for instance, all Objects are invalid because
- * of broken connections, etc.
- */
- public void drain() {
- synchronized (list) {
- for (int i = 0; i < list.size(); ++i) {
- Pooled<T> pt = list.remove();
- creator.destroy(pt.content);
- logger.log("Pool drained ", creator.toString());
- }
- count = spares = 0;
- }
+ /**
+ * Destroy and remove all remaining objects. This is valuable for closing
+ * down all Allocated objects cleanly for exiting. It is also a good method
+ * for removing objects when, for instance, all Objects are invalid because
+ * of broken connections, etc.
+ */
+ public void drain() {
+ synchronized (list) {
+ for (int i = 0; i < list.size(); ++i) {
+ Pooled<T> pt = list.remove();
+ creator.destroy(pt.content);
+ logger.log("Pool drained ", creator.toString());
+ }
+ count = spares = 0;
+ }
- }
+ }
- /**
- * This is the essential function for Pool. Get an Object "T" inside a
- * "Pooled<T>" object. If there is a spare Object, then use it. If not, then
- * create and pass back.
- *
- * This one uses a Null LogTarget
- *
- * IMPORTANT: When the use of this object is done (and the object is still
- * in a valid state), then "done()" should be called immediately to allow
- * the object to be reused. That is the point of the Pool...
- *
- * If the Object is in an invalid state, then "toss()" should be used so the
- * Pool doesn't pass on invalid objects to others.
- *
- * @param lt
- * @return
- * @throws CadiException
- */
- public Pooled<T> get() throws CadiException {
- Pooled<T> pt;
- synchronized (list) {
- if (list.isEmpty()) {
- pt = null;
- } else {
- pt = list.removeLast();
- --count;
- creator.reuse(pt.content);
- }
- }
- if (pt == null) {
- if (spares < max_range)
- ++spares;
- pt = new Pooled<T>(creator.create(), this);
- } else {
- if (spares > 1)
- --spares;
- }
- return pt;
- }
+ /**
+ * This is the essential function for Pool. Get an Object "T" inside a
+ * "Pooled<T>" object. If there is a spare Object, then use it. If not, then
+ * create and pass back.
+ *
+ * This one uses a Null LogTarget
+ *
+ * IMPORTANT: When the use of this object is done (and the object is still
+ * in a valid state), then "done()" should be called immediately to allow
+ * the object to be reused. That is the point of the Pool...
+ *
+ * If the Object is in an invalid state, then "toss()" should be used so the
+ * Pool doesn't pass on invalid objects to others.
+ *
+ * @param lt
+ * @return
+ * @throws CadiException
+ */
+ public Pooled<T> get() throws CadiException {
+ Pooled<T> pt;
+ synchronized (list) {
+ if (list.isEmpty()) {
+ pt = null;
+ } else {
+ pt = list.removeLast();
+ --count;
+ creator.reuse(pt.content);
+ }
+ }
+ if (pt == null) {
+ if (spares < max_range)
+ ++spares;
+ pt = new Pooled<T>(creator.create(), this);
+ } else {
+ if (spares > 1)
+ --spares;
+ }
+ return pt;
+ }
- /**
- * This function will validate whether the Objects are still in a usable
- * state. If not, they are tossed from the Pool. This is valuable to have
- * when Remote Connections go down, and there is a question on whether the
- * Pooled Objects are still functional.
- *
- * @return
- */
- public boolean validate() {
- boolean rv = true;
- synchronized (list) {
-
for (Iterator<Pooled<T>> iter = list.iterator(); iter.hasNext();) {
- Pooled<T> t = iter.next();
- if (!creator.isValid(t.content)) {
- rv = false;
- t.toss();
- iter.remove();
- }
- }
- }
- return rv;
- }
+ /**
+ * This function will validate whether the Objects are still in a usable
+ * state. If not, they are tossed from the Pool. This is valuable to have
+ * when Remote Connections go down, and there is a question on whether the
+ * Pooled Objects are still functional.
+ *
+ * @return
+ */
+ public boolean validate() {
+ boolean rv = true;
+ synchronized (list) {
+ for (Iterator<Pooled<T>> iter = list.iterator(); iter.hasNext();) {
+ Pooled<T> t = iter.next();
+ if (!creator.isValid(t.content)) {
+ rv = false;
+ t.toss();
+ iter.remove();
+ }
+ }
+ }
+ return rv;
+ }
- /**
- * This is an internal method, used only by the Internal Pooled<T> class.
- *
- * The Pooled<T> class "offers" it's Object back after use. It is an
- * "offer", because Pool will simply destroy and remove the object if it has
- * more than enough spares.
- *
- * @param lt
- * @param used
- * @return
- */
- // Used only by Pooled<T>
- private boolean offer(Pooled<T> used) {
- if (count < spares) {
- synchronized (list) {
- list.addFirst(used);
- ++count;
- }
- logger.log("Pool recovered ", creator);
- } else {
- logger.log("Pool destroyed ", creator);
- creator.destroy(used.content);
- }
- return false;
- }
+ /**
+ * This is an internal method, used only by the Internal Pooled<T> class.
+ *
+ * The Pooled<T> class "offers" it's Object back after use. It is an
+ * "offer", because Pool will simply destroy and remove the object if it has
+ * more than enough spares.
+ *
+ * @param lt
+ * @param used
+ * @return
+ */
+ // Used only by Pooled<T>
+ private boolean offer(Pooled<T> used) {
+ if (count < spares) {
+ synchronized (list) {
+ list.addFirst(used);
+ ++count;
+ }
+ logger.log("Pool recovered ", creator);
+ } else {
+ logger.log("Pool destroyed ", creator);
+ creator.destroy(used.content);
+ }
+ return false;
+ }
- /**
- * The Creator Interface give the Pool the ability to Create, Destroy and
- * Validate the Objects it is maintaining. Thus, it is a specially written
- * Implementation for each type.
- *
- * @author Jonathan
- *
- * @param <T>
- */
- public interface Creator<T> {
- public T create() throws CadiException;
+ /**
+ * The Creator Interface give the Pool the ability to Create, Destroy and
+ * Validate the Objects it is maintaining. Thus, it is a specially written
+ * Implementation for each type.
+ *
+ * @author Jonathan
+ *
+ * @param <T>
+ */
+ public interface Creator<T> {
+ public T create() throws CadiException;
- public void destroy(T t);
+ public void destroy(T t);
- public boolean isValid(T t);
+ public boolean isValid(T t);
- public void reuse(T t);
- }
+ public void reuse(T t);
+ }
- public interface Log {
- public void log(Object ... o);
-
- public final static Log NULL = new Log() {
- @Override
- public void log(Object ... o) {
- }
- };
- }
- /**
- * The "Pooled<T>" class is the transient class that wraps the actual Object
- * T for API use/ It gives the ability to return ("done()", or "toss()") the
- * Object to the Pool when processing is finished.
- *
- * For Safety, i.e. to avoid memory leaks and invalid Object States, there
- * is a "finalize" method. It is strictly for when coder forgets to return
- * the object, or perhaps hasn't covered the case during Exceptions or
- * Runtime Exceptions with finally (preferred). This should not be
- * considered normal procedure, as finalize() is called at an undetermined
- * time during garbage collection, and is thus rather useless for a Pool.
- * However, we don't want Coding Mistakes to put the whole program in an
- * invalid state, so if something happened such that "done()" or "toss()"
- * were not called, the resource is still cleaned up as well as possible.
- *
- * @author Jonathan
- *
- * @param <T>
- */
- public static class Pooled<T> {
- public final T content;
- private Pool<T> pool;
+ public interface Log {
+ public void log(Object ... o);
+
+ public final static Log NULL = new Log() {
+ @Override
+ public void log(Object ... o) {
+ }
+ };
+ }
+ /**
+ * The "Pooled<T>" class is the transient class that wraps the actual Object
+ * T for API use/ It gives the ability to return ("done()", or "toss()") the
+ * Object to the Pool when processing is finished.
+ *
+ * For Safety, i.e. to avoid memory leaks and invalid Object States, there
+ * is a "finalize" method. It is strictly for when coder forgets to return
+ * the object, or perhaps hasn't covered the case during Exceptions or
+ * Runtime Exceptions with finally (preferred). This should not be
+ * considered normal procedure, as finalize() is called at an undetermined
+ * time during garbage collection, and is thus rather useless for a Pool.
+ * However, we don't want Coding Mistakes to put the whole program in an
+ * invalid state, so if something happened such that "done()" or "toss()"
+ * were not called, the resource is still cleaned up as well as possible.
+ *
+ * @author Jonathan
+ *
+ * @param <T>
+ */
+ public static class Pooled<T> {
+ public final T content;
+ private Pool<T> pool;
- /**
- * Create the Wrapping Object Pooled<T>.
- *
- * @param t
- * @param pool
- * @param logTarget
- */
- public Pooled(T t, Pool<T> pool) {
- content = t;
- this.pool = pool;
+ /**
+ * Create the Wrapping Object Pooled<T>.
+ *
+ * @param t
+ * @param pool
+ * @param logTarget
+ */
+ public Pooled(T t, Pool<T> pool) {
+ content = t;
+ this.pool = pool;
- }
+ }
- /**
- * This is the key API for the Pool, as calling "done()" offers this
- * object back to the Pool for reuse.
- *
- * Do not use the Pooled<T> object again after calling "done()".
- */
- public void done() {
- if (pool != null) {
- pool.offer(this);
- }
- }
+ /**
+ * This is the key API for the Pool, as calling "done()" offers this
+ * object back to the Pool for reuse.
+ *
+ * Do not use the Pooled<T> object again after calling "done()".
+ */
+ public void done() {
+ if (pool != null) {
+ pool.offer(this);
+ }
+ }
- /**
- * The user of the Object may discover that the Object t is no longer in
- * a valid state. Don't put Garbage back in the Refrigerator... Toss it,
- * if it's no longer valid.
- *
- * toss() is also used for draining the Pool, etc.
- *
- * toss() will attempt to destroy the Object by using the Creator
- * Interface.
- *
- */
- public void toss() {
- if (pool != null) {
- pool.creator.destroy(content);
- }
- // Don't allow finalize to put it back in.
- pool = null;
- }
+ /**
+ * The user of the Object may discover that the Object t is no longer in
+ * a valid state. Don't put Garbage back in the Refrigerator... Toss it,
+ * if it's no longer valid.
+ *
+ * toss() is also used for draining the Pool, etc.
+ *
+ * toss() will attempt to destroy the Object by using the Creator
+ * Interface.
+ *
+ */
+ public void toss() {
+ if (pool != null) {
+ pool.creator.destroy(content);
+ }
+ // Don't allow finalize to put it back in.
+ pool = null;
+ }
- /**
- * Just in case someone neglected to offer back object... Do not rely on
- * this, as there is no specific time when finalize is called, which
- * rather defeats the purpose of a Pool.
- */
- @Override
- protected void finalize() throws Throwable {
- if (pool != null) {
- done();
- pool = null;
- }
- }
- }
+ /**
+ * Just in case someone neglected to offer back object... Do not rely on
+ * this, as there is no specific time when finalize is called, which
+ * rather defeats the purpose of a Pool.
+ */
+ @Override
+ protected void finalize() throws Throwable {
+ if (pool != null) {
+ done();
+ pool = null;
+ }
+ }
+ }
- /**
- * Get the maximum number of spare objects allowed at any moment
- *
- * @return
- */
- public int getMaxRange() {
- return max_range;
- }
+ /**
+ * Get the maximum number of spare objects allowed at any moment
+ *
+ * @return
+ */
+ public int getMaxRange() {
+ return max_range;
+ }
- /**
- * Set a Max Range for numbers of spare objects waiting to be used.
- *
- * No negative numbers are allowed
- *
- * @return
- */
- public void setMaxRange(int max_range) {
- // Do not allow negative numbers
- this.max_range = Math.max(0, max_range);
- }
+ /**
+ * Set a Max Range for numbers of spare objects waiting to be used.
+ *
+ * No negative numbers are allowed
+ *
+ * @return
+ */
+ public void setMaxRange(int max_range) {
+ // Do not allow negative numbers
+ this.max_range = Math.max(0, max_range);
+ }
}
Code Review / aaf / authz.git / blobdiff