--- /dev/null
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package pool107.org.apache.commons.pool;
+
+import java.util.NoSuchElementException;
+
+/**
+ * A pooling interface.
+ * <p>
+ * <code>ObjectPool</code> defines a trivially simple pooling interface. The only
+ * required methods are {@link #borrowObject borrowObject}, {@link #returnObject returnObject}
+ * and {@link #invalidateObject invalidateObject}.
+ * </p>
+ * <p>
+ * Example of use:
+ * <pre style="border:solid thin; padding: 1ex;"
+ * > Object obj = <code style="color:#00C">null</code>;
+ *
+ * <code style="color:#00C">try</code> {
+ * obj = pool.borrowObject();
+ * <code style="color:#0C0">//...use the object...</code>
+ * } <code style="color:#00C">catch</code>(Exception e) {
+ * <code style="color:#0C0">// invalidate the object</code>
+ * pool.invalidateObject(obj);
+ * <code style="color:#0C0">// do not return the object to the pool twice</code>
+ * obj = <code style="color:#00C">null</code>;
+ * } <code style="color:#00C">finally</code> {
+ * <code style="color:#0C0">// make sure the object is returned to the pool</code>
+ * <code style="color:#00C">if</code>(<code style="color:#00C">null</code> != obj) {
+ * pool.returnObject(obj);
+ * }
+ * }</pre>
+ * </p>
+ *
+ * <p>See {@link BaseObjectPool} for a simple base implementation.</p>
+ *
+ * @author Rodney Waldhoff
+ * @author Sandy McArthur
+ * @version $Revision: 480413 $ $Date: 2006-11-29 00:16:05 -0500 (Wed, 29 Nov 2006) $
+ * @see PoolableObjectFactory
+ * @see ObjectPoolFactory
+ * @see KeyedObjectPool
+ * @see BaseObjectPool
+ * @since Pool 1.0
+ */
+public interface ObjectPool {
+ /**
+ * Obtains an instance from this pool.
+ * <p>
+ * Instances returned from this method will have been either newly created with
+ * {@link PoolableObjectFactory#makeObject makeObject} or will be a previously idle object and
+ * have been activated with {@link PoolableObjectFactory#activateObject activateObject} and
+ * then validated with {@link PoolableObjectFactory#validateObject validateObject}.
+ * </p>
+ * <p>
+ * By contract, clients <strong>must</strong> return the borrowed instance using
+ * {@link #returnObject returnObject}, {@link #invalidateObject invalidateObject}, or a related method
+ * as defined in an implementation or sub-interface.
+ * </p>
+ * <p>
+ * The behaviour of this method when the pool has been exhausted
+ * is not strictly specified (although it may be specified by implementations).
+ * Older versions of this method would return <code>null</code> to indicate exhaustion,
+ * newer versions are encouraged to throw a {@link NoSuchElementException}.
+ * </p>
+ *
+ * @return an instance from this pool.
+ * @throws IllegalStateException after {@link #close close} has been called on this pool.
+ * @throws Exception when {@link PoolableObjectFactory#makeObject makeObject} throws an exception.
+ * @throws NoSuchElementException when the pool is exhausted and cannot or will not return another instance.
+ */
+ Object borrowObject() throws Exception, NoSuchElementException, IllegalStateException;
+
+ /**
+ * Return an instance to the pool.
+ * By contract, <code>obj</code> <strong>must</strong> have been obtained
+ * using {@link #borrowObject() borrowObject}
+ * or a related method as defined in an implementation
+ * or sub-interface.
+ *
+ * @param obj a {@link #borrowObject borrowed} instance to be returned.
+ * @throws Exception <b>deprecated</b>: as of Pool 2.0 pool implementations should swallow
+ * exceptions that occur when a poolable object is returned. For future source compatability
+ * implementations of this method should not even declare that they throw any exception.
+ */
+ void returnObject(Object obj) throws Exception;
+
+ /**
+ * Invalidates an object from the pool
+ * By contract, <code>obj</code> <strong>must</strong> have been obtained
+ * using {@link #borrowObject borrowObject}
+ * or a related method as defined in an implementation
+ * or sub-interface.
+ * <p>
+ * This method should be used when an object that has been borrowed
+ * is determined (due to an exception or other problem) to be invalid.
+ * </p>
+ *
+ * @param obj a {@link #borrowObject borrowed} instance to be disposed.
+ * @throws Exception <b>deprecated</b>: as of Pool 2.0 pool implementations should swallow
+ * exceptions that occur when a poolable object is returned. For future source compatability
+ * implementations of this method should not even declare that they throw any exception.
+ */
+ void invalidateObject(Object obj) throws Exception;
+
+ /**
+ * Create an object using the {@link PoolableObjectFactory factory} or other
+ * implementation dependent mechanism, passivate it, and then place it in the idle object pool.
+ * <code>addObject</code> is useful for "pre-loading" a pool with idle objects.
+ * (Optional operation).
+ *
+ * @throws Exception when {@link PoolableObjectFactory#makeObject} fails.
+ * @throws IllegalStateException after {@link #close} has been called on this pool.
+ * @throws UnsupportedOperationException when this pool cannot add new idle objects.
+ */
+ void addObject() throws Exception, IllegalStateException, UnsupportedOperationException;
+
+ /**
+ * Return the number of instances
+ * currently idle in this pool (optional operation).
+ * This may be considered an approximation of the number
+ * of objects that can be {@link #borrowObject borrowed}
+ * without creating any new instances.
+ * Returns a negative value if this information is not available.
+ *
+ * @return the number of instances currently idle in this pool or a negative value if unsupported
+ * @throws UnsupportedOperationException <strong>deprecated</strong>: if this implementation does not support the operation
+ */
+ int getNumIdle() throws UnsupportedOperationException;
+
+ /**
+ * Return the number of instances
+ * currently borrowed from this pool
+ * (optional operation).
+ * Returns a negative value if this information is not available.
+ *
+ * @return the number of instances currently borrowed from this pool or a negative value if unsupported
+ * @throws UnsupportedOperationException <strong>deprecated</strong>: if this implementation does not support the operation
+ */
+ int getNumActive() throws UnsupportedOperationException;
+
+ /**
+ * Clears any objects sitting idle in the pool, releasing any
+ * associated resources (optional operation).
+ * Idle objects cleared must be {@link PoolableObjectFactory#destroyObject(Object) destroyed}.
+ *
+ * @throws UnsupportedOperationException if this implementation does not support the operation
+ */
+ void clear() throws Exception, UnsupportedOperationException;
+
+ /**
+ * Close this pool, and free any resources associated with it.
+ * <p>
+ * Calling {@link #addObject} or {@link #borrowObject} after invoking
+ * this method on a pool will cause them to throw an
+ * {@link IllegalStateException}.
+ * </p>
+ *
+ * @throws Exception <strong>deprecated</strong>: implementations should silently fail if not all resources can be freed.
+ */
+ void close() throws Exception;
+
+ /**
+ * Sets the {@link PoolableObjectFactory factory} this pool uses
+ * to create new instances (optional operation). Trying to change
+ * the <code>factory</code> after a pool has been used will frequently
+ * throw an {@link UnsupportedOperationException}. It is up to the pool
+ * implementation to determine when it is acceptable to call this method.
+ *
+ * @param factory the {@link PoolableObjectFactory} used to create new instances.
+ * @throws IllegalStateException when the factory cannot be set at this time
+ * @throws UnsupportedOperationException if this implementation does not support the operation
+ */
+ void setFactory(PoolableObjectFactory factory) throws IllegalStateException, UnsupportedOperationException;
+}
projects / Benchmarks_CSolver.git / blobdiff