001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017package org.apache.logging.log4j.core.async; 018 019import org.apache.logging.log4j.Level; 020import org.apache.logging.log4j.core.util.Log4jThread; 021 022/** 023 * Default router: enqueue the event for asynchronous logging in the background thread, unless the current thread is the 024 * background thread and the queue is full (enqueueing would cause a deadlock). In that case send the event directly to 025 * the appender (in the current thread). 026 */ 027public class DefaultAsyncQueueFullPolicy implements AsyncQueueFullPolicy { 028 @Override 029 public EventRoute getRoute(final long backgroundThreadId, final Level level) { 030 031 // LOG4J2-471: prevent deadlock when RingBuffer is full and object 032 // being logged calls Logger.log() from its toString() method 033 Thread currentThread = Thread.currentThread(); 034 if (currentThread.getId() == backgroundThreadId 035 // Threads owned by log4j are most likely to result in 036 // deadlocks because they generally consume events. 037 // This prevents deadlocks between AsyncLoggerContext 038 // disruptors. 039 || currentThread instanceof Log4jThread) { 040 return EventRoute.SYNCHRONOUS; 041 } 042 return EventRoute.ENQUEUE; 043 } 044}