* concurrently should synchronize amongst themselves and provide the
 * necessary locking.
 *
 * @author Rosanna Lee
 * @author Scott Seligman
 * @version 1.15 06/01/06
 *
 * @see Context
 * @see NamingManager#setInitialContextFactoryBuilder
 *	NamingManager.setInitialContextFactoryBuilder
 * @since JNDI 1.1 / Java 2 Platform, Standard Edition, v 1.3
 */

public class InitialContext implements Context {

    /**
     * The environment associated with this InitialContext.
     * It is initialized to null and is updated by the constructor
     * that accepts an environment or by the <tt>init()</tt> method.
     * @see #addToEnvironment
     * @see #removeFromEnvironment
     * @see #getEnvironment
     */
    protected Hashtable<Object,Object> myProps = null;

    /**
     * Field holding the result of calling NamingManager.getInitialContext().
     * It is set by getDefaultInitCtx() the first time getDefaultInitCtx()
     * is called. Subsequent invocations of getDefaultInitCtx() return
     * the value of defaultInitCtx.
     * @see #getDefaultInitCtx
     */
    protected Context defaultInitCtx = null;

    /**
     * Field indicating whether the initial context has been obtained
     * by calling NamingManager.getInitialContext().
     * If true, its result is in <code>defaultInitCtx</code>.
     */
    protected boolean gotDefault = false;

    /**
     * Constructs an initial context with the option of not
     * initializing it.  This may be used by a constructor in
     * a subclass when the value of the environment parameter
     * is not yet known at the time the <tt>InitialContext</tt>
     * constructor is called.  The subclass's constructor will
     * call this constructor, compute the value of the environment,
     * and then call <tt>init()</tt> before returning.
     *
     * @param lazy
     *		true means do not initialize the initial context; false
     *		is equivalent to calling <tt>new InitialContext()</tt>
     * @throws	NamingException if a naming exception is encountered
     *
     * @see #init(Hashtable)
     * @since 1.3
     */
    protected InitialContext(boolean lazy) throws NamingException {
	if (!lazy) {
	    init(null);
	}
    }

    /**
     * Constructs an initial context.
     * No environment properties are supplied.
     * Equivalent to <tt>new InitialContext(null)</tt>.
     *
     * @throws	NamingException if a naming exception is encountered
     *
     * @see #InitialContext(Hashtable)
     */
    public InitialContext() throws NamingException {
	init(null);
    }

    /**
     * Constructs an initial context using the supplied environment.
     * Environment properties are discussed in the class description.
     *
     * <p> This constructor will not modify <tt>environment</tt>
     * or save a reference to it, but may save a clone.
     *
     * @param environment
     *		environment used to create the initial context.
     *		Null indicates an empty environment.
     *
     * @throws	NamingException if a naming exception is encountered
     */
    public InitialContext(Hashtable<?,?> environment)
	throws NamingException
    {
	if (environment != null) {
	    environment = (Hashtable)environment.clone();
	}
	init(environment);
    }

    /**