+ * Implementations of this interface must be thread-safe. Access to shared
+ * data must be synchronized as methods of this interface may be executed
+ * from multiple threads.
+ *
+ * @since 4.0
+ */
+public interface ClientConnectionManager {
+
+ /**
+ * Obtains the scheme registry used by this manager.
+ *
+ * @return the scheme registry, never null
+ */
+ SchemeRegistry getSchemeRegistry();
+
+ /**
+ * Returns a new {@link ClientConnectionRequest}, from which a
+ * {@link ManagedClientConnection} can be obtained or the request can be
+ * aborted.
+ */
+ ClientConnectionRequest requestConnection(HttpRoute route, Object state);
+
+ /**
+ * Releases a connection for use by others.
+ * You may optionally specify how long the connection is valid
+ * to be reused. Values <= 0 are considered to be valid forever.
+ * If the connection is not marked as reusable, the connection will
+ * not be reused regardless of the valid duration.
+ *
+ * If the connection has been released before,
+ * the call will be ignored.
+ *
+ * @param conn the connection to release
+ * @param validDuration the duration of time this connection is valid for reuse
+ * @param timeUnit the unit of time validDuration is measured in
+ *
+ * @see #closeExpiredConnections()
+ */
+ void releaseConnection(ManagedClientConnection conn, long validDuration, TimeUnit timeUnit);
+
+ /**
+ * Closes idle connections in the pool.
+ * Open connections in the pool that have not been used for the
+ * timespan given by the argument will be closed.
+ * Currently allocated connections are not subject to this method.
+ * Times will be checked with milliseconds precision
+ *
+ * All expired connections will also be closed.
+ *
+ * @param idletime the idle time of connections to be closed
+ * @param tunit the unit for the idletime
+ *
+ * @see #closeExpiredConnections()
+ */
+ void closeIdleConnections(long idletime, TimeUnit tunit);
+
+ /**
+ * Closes all expired connections in the pool.
+ * Open connections in the pool that have not been used for
+ * the timespan defined when the connection was released will be closed.
+ * Currently allocated connections are not subject to this method.
+ * Times will be checked with milliseconds precision.
+ */
+ void closeExpiredConnections();
+
+ /**
+ * Shuts down this connection manager and releases allocated resources.
+ * This includes closing all connections, whether they are currently
+ * used or not.
+ */
+ void shutdown();
+
+}