/*
 * Copyright 2009 Yuichiro Moriguchi
 *
 * Licensed 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 net.morilib.lisp;

import java.util.HashMap;
import java.util.Map;

/*package*/ class CodeExecutorFactory {

	//
	private static Map<LispMessage, CodeExecutor> instances =
		new HashMap<LispMessage, CodeExecutor>();

	//
	/*package*/ static CodeExecutor getInstance(LispMessage msg) {
		CodeExecutor r;

		synchronized(CodeExecutorFactory.class) {
			if((r = instances.get(msg)) == null) {
				r = new CodeExecutorImpl(msg);
				instances.put(msg, r);
			}
		}
		return r;
	}

}
