/**
* Actual writing occurs here.
*
* @param logEvent The LogEvent.
*/
@Override
public void append(LogEvent logEvent) {
if (!isStarted()) {
throw new IllegalStateException("AsyncAppender " + getName() + " is not active");
}
if (!(logEvent instanceof Log4jLogEvent)) {
if (!(logEvent instanceof RingBufferLogEvent)) {
return; // only know how to Serialize Log4jLogEvents and RingBufferLogEvents
}
logEvent = ((RingBufferLogEvent) logEvent).createMemento();
}
logEvent.getMessage().getFormattedMessage(); // LOG4J2-763: ask message to freeze parameters
final Log4jLogEvent coreEvent = (Log4jLogEvent) logEvent;
boolean appendSuccessful = false;
if (blocking) {
if (isAppenderThread.get() == Boolean.TRUE && queue.remainingCapacity() == 0) {
// LOG4J2-485: avoid deadlock that would result from trying
// to add to a full queue from appender thread
coreEvent.setEndOfBatch(false); // queue is definitely not empty!
appendSuccessful = thread.callAppenders(coreEvent);
} else {
final Serializable serialized = Log4jLogEvent.serialize(coreEvent, includeLocation);
try {
// wait for free slots in the queue
queue.put(serialized);
appendSuccessful = true;
} catch (final InterruptedException e) {
// LOG4J2-1049: Some applications use Thread.interrupt() to send
// messages between application threads. This does not necessarily
// mean that the queue is full. To prevent dropping a log message,
// quickly try to offer the event to the queue again.
// (Yes, this means there is a possibility the same event is logged twice.)
//
// Finally, catching the InterruptedException means the
// interrupted flag has been cleared on the current thread.
// This may interfere with the application's expectation of
// being interrupted, so when we are done, we set the interrupted
// flag again.
appendSuccessful = queue.offer(serialized);
if (!appendSuccessful) {
LOGGER.warn(
"Interrupted while waiting for a free slot in the AsyncAppender LogEvent-queue {}",
getName());
}
// set the interrupted flag again.
Thread.currentThread().interrupt();
}
}
} else {
appendSuccessful = queue.offer(Log4jLogEvent.serialize(coreEvent, includeLocation));
if (!appendSuccessful) {
error("Appender " + getName() + " is unable to write primary appenders. queue is full");
}
}
if (!appendSuccessful && errorAppender != null) {
errorAppender.callAppender(coreEvent);
}
}
/**
* FOR INTERNAL USE ONLY.
*
* @param logEvent the event to log
*/
public void logMessageInCurrentThread(final LogEvent logEvent) {
logEvent.setEndOfBatch(queue.isEmpty());
final boolean appendSuccessful = thread.callAppenders(logEvent);
logToErrorAppenderIfNecessary(appendSuccessful, logEvent);
}
