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17 package org.apache.logging.log4j.core.appender;
18
19 import java.io.Serializable;
20 import java.util.ArrayList;
21 import java.util.List;
22 import java.util.Map;
23 import java.util.concurrent.ArrayBlockingQueue;
24 import java.util.concurrent.BlockingQueue;
25 import java.util.concurrent.atomic.AtomicLong;
26
27 import org.apache.logging.log4j.core.Appender;
28 import org.apache.logging.log4j.core.Filter;
29 import org.apache.logging.log4j.core.LogEvent;
30 import org.apache.logging.log4j.core.config.AppenderControl;
31 import org.apache.logging.log4j.core.config.AppenderRef;
32 import org.apache.logging.log4j.core.config.Configuration;
33 import org.apache.logging.log4j.core.config.ConfigurationException;
34 import org.apache.logging.log4j.core.config.plugins.Plugin;
35 import org.apache.logging.log4j.core.config.plugins.PluginAliases;
36 import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
37 import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
38 import org.apache.logging.log4j.core.config.plugins.PluginElement;
39 import org.apache.logging.log4j.core.config.plugins.PluginFactory;
40 import org.apache.logging.log4j.core.helpers.Booleans;
41 import org.apache.logging.log4j.core.impl.Log4jLogEvent;
42
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48
49 @Plugin(name = "Async", category = "Core", elementType = "appender", printObject = true)
50 public final class AsyncAppender extends AbstractAppender {
51
52 private static final int DEFAULT_QUEUE_SIZE = 128;
53 private static final String SHUTDOWN = "Shutdown";
54
55 private final BlockingQueue<Serializable> queue;
56 private final int queueSize;
57 private final boolean blocking;
58 private final Configuration config;
59 private final AppenderRef[] appenderRefs;
60 private final String errorRef;
61 private final boolean includeLocation;
62 private AppenderControl errorAppender;
63 private AsyncThread thread;
64 private static final AtomicLong threadSequence = new AtomicLong(1);
65 private static ThreadLocal<Boolean> isAppenderThread = new ThreadLocal<Boolean>();
66
67
68 private AsyncAppender(final String name, final Filter filter, final AppenderRef[] appenderRefs,
69 final String errorRef, final int queueSize, final boolean blocking,
70 final boolean ignoreExceptions, final Configuration config,
71 final boolean includeLocation) {
72 super(name, filter, null, ignoreExceptions);
73 this.queue = new ArrayBlockingQueue<Serializable>(queueSize);
74 this.queueSize = queueSize;
75 this.blocking = blocking;
76 this.config = config;
77 this.appenderRefs = appenderRefs;
78 this.errorRef = errorRef;
79 this.includeLocation = includeLocation;
80 }
81
82 @Override
83 public void start() {
84 final Map<String, Appender> map = config.getAppenders();
85 final List<AppenderControl> appenders = new ArrayList<AppenderControl>();
86 for (final AppenderRef appenderRef : appenderRefs) {
87 if (map.containsKey(appenderRef.getRef())) {
88 appenders.add(new AppenderControl(map.get(appenderRef.getRef()), appenderRef.getLevel(),
89 appenderRef.getFilter()));
90 } else {
91 LOGGER.error("No appender named {} was configured", appenderRef);
92 }
93 }
94 if (errorRef != null) {
95 if (map.containsKey(errorRef)) {
96 errorAppender = new AppenderControl(map.get(errorRef), null, null);
97 } else {
98 LOGGER.error("Unable to set up error Appender. No appender named {} was configured", errorRef);
99 }
100 }
101 if (appenders.size() > 0) {
102 thread = new AsyncThread(appenders, queue);
103 thread.setName("AsyncAppender-" + getName());
104 } else if (errorRef == null) {
105 throw new ConfigurationException("No appenders are available for AsyncAppender " + getName());
106 }
107
108 thread.start();
109 super.start();
110 }
111
112 @Override
113 public void stop() {
114 super.stop();
115 thread.shutdown();
116 try {
117 thread.join();
118 } catch (final InterruptedException ex) {
119 LOGGER.warn("Interrupted while stopping AsyncAppender {}", getName());
120 }
121 }
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128 @Override
129 public void append(final LogEvent evt) {
130 if (!isStarted()) {
131 throw new IllegalStateException("AsyncAppender " + getName() + " is not active");
132 }
133 if (!(evt instanceof Log4jLogEvent)) {
134 return;
135 }
136 Log4jLogEvent event = (Log4jLogEvent) evt;
137 boolean appendSuccessful = false;
138 if (blocking) {
139 if (isAppenderThread.get() == Boolean.TRUE && queue.remainingCapacity() == 0) {
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142 event.setEndOfBatch(false);
143 appendSuccessful = thread.callAppenders(event);
144 } else {
145 try {
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147 queue.put(Log4jLogEvent.serialize(event, includeLocation));
148 appendSuccessful = true;
149 } catch (final InterruptedException e) {
150 LOGGER.warn("Interrupted while waiting for a free slot in the AsyncAppender LogEvent-queue {}",
151 getName());
152 }
153 }
154 } else {
155 appendSuccessful = queue.offer(Log4jLogEvent.serialize(event, includeLocation));
156 if (!appendSuccessful) {
157 error("Appender " + getName() + " is unable to write primary appenders. queue is full");
158 }
159 }
160 if (!appendSuccessful && errorAppender != null) {
161 errorAppender.callAppender(event);
162 }
163 }
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179 @PluginFactory
180 public static AsyncAppender createAppender(@PluginElement("AppenderRef") final AppenderRef[] appenderRefs,
181 @PluginAttribute("errorRef") @PluginAliases("error-ref") final String errorRef,
182 @PluginAttribute("blocking") final String blocking,
183 @PluginAttribute("bufferSize") final String size,
184 @PluginAttribute("name") final String name,
185 @PluginAttribute("includeLocation") final String includeLocation,
186 @PluginElement("Filter") final Filter filter,
187 @PluginConfiguration final Configuration config,
188 @PluginAttribute("ignoreExceptions") final String ignore) {
189 if (name == null) {
190 LOGGER.error("No name provided for AsyncAppender");
191 return null;
192 }
193 if (appenderRefs == null) {
194 LOGGER.error("No appender references provided to AsyncAppender {}", name);
195 }
196
197 final boolean isBlocking = Booleans.parseBoolean(blocking, true);
198 final int queueSize = AbstractAppender.parseInt(size, DEFAULT_QUEUE_SIZE);
199 final boolean isIncludeLocation = Boolean.parseBoolean(includeLocation);
200 final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
201
202 return new AsyncAppender(name, filter, appenderRefs, errorRef,
203 queueSize, isBlocking, ignoreExceptions, config, isIncludeLocation);
204 }
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208
209 private class AsyncThread extends Thread {
210
211 private volatile boolean shutdown = false;
212 private final List<AppenderControl> appenders;
213 private final BlockingQueue<Serializable> queue;
214
215 public AsyncThread(final List<AppenderControl> appenders, final BlockingQueue<Serializable> queue) {
216 this.appenders = appenders;
217 this.queue = queue;
218 setDaemon(true);
219 setName("AsyncAppenderThread" + threadSequence.getAndIncrement());
220 }
221
222 @Override
223 public void run() {
224 isAppenderThread.set(Boolean.TRUE);
225 while (!shutdown) {
226 Serializable s;
227 try {
228 s = queue.take();
229 if (s != null && s instanceof String && SHUTDOWN.equals(s.toString())) {
230 shutdown = true;
231 continue;
232 }
233 } catch (final InterruptedException ex) {
234
235 continue;
236 }
237 final Log4jLogEvent event = Log4jLogEvent.deserialize(s);
238 event.setEndOfBatch(queue.isEmpty());
239 boolean success = callAppenders(event);
240 if (!success && errorAppender != null) {
241 try {
242 errorAppender.callAppender(event);
243 } catch (final Exception ex) {
244
245 }
246 }
247 }
248
249 while (!queue.isEmpty()) {
250 try {
251 final Serializable s = queue.take();
252 if (s instanceof Log4jLogEvent) {
253 final Log4jLogEvent event = Log4jLogEvent.deserialize(s);
254 event.setEndOfBatch(queue.isEmpty());
255 callAppenders(event);
256 }
257 } catch (final InterruptedException ex) {
258
259 }
260 }
261 }
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272 boolean callAppenders(final Log4jLogEvent event) {
273 boolean success = false;
274 for (final AppenderControl control : appenders) {
275 try {
276 control.callAppender(event);
277 success = true;
278 } catch (final Exception ex) {
279
280 }
281 }
282 return success;
283 }
284
285 public void shutdown() {
286 shutdown = true;
287 if (queue.isEmpty()) {
288 queue.offer(SHUTDOWN);
289 }
290 }
291 }
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298 public String[] getAppenderRefStrings() {
299 final String[] result = new String[appenderRefs.length];
300 for (int i = 0; i < result.length; i++) {
301 result[i] = appenderRefs[i].getRef();
302 }
303 return result;
304 }
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312 public boolean isIncludeLocation() {
313 return includeLocation;
314 }
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321 public boolean isBlocking() {
322 return blocking;
323 }
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329 public String getErrorRef() {
330 return errorRef;
331 }
332
333 public int getQueueCapacity() {
334 return queueSize;
335 }
336
337 public int getQueueRemainingCapacity() {
338 return queue.remainingCapacity();
339 }
340 }