public void DoAppend()

in src/log4net/Appender/AppenderSkeleton.cs [290:340]
37 lines of code
9 McCabe index (conditional complexity)

		public void DoAppend(LoggingEvent loggingEvent) 
		{
			// This lock is absolutely critical for correct formatting
			// of the message in a multi-threaded environment.  Without
			// this, the message may be broken up into elements from
			// multiple thread contexts (like get the wrong thread ID).

			lock(this)
			{
				if (m_closed)
				{
					ErrorHandler.Error("Attempted to append to closed appender named ["+m_name+"].");
					return;
				}

				// prevent re-entry
				if (m_recursiveGuard)
				{
					return;
				}

				try
				{
					m_recursiveGuard = true;

					if (FilterEvent(loggingEvent) && PreAppendCheck())
					{
						this.Append(loggingEvent);
					}
				}
				catch(Exception ex)
				{
					ErrorHandler.Error("Failed in DoAppend", ex);
				}
#if !MONO && !NET_2_0 && !NETSTANDARD
				// on .NET 2.0 (and higher) and Mono (all profiles), 
				// exceptions that do not derive from System.Exception will be
				// wrapped in a RuntimeWrappedException by the runtime, and as
				// such will be catched by the catch clause above
				catch
				{
					// Catch handler for non System.Exception types
					ErrorHandler.Error("Failed in DoAppend (unknown exception)");
				}
#endif
				finally
				{
					m_recursiveGuard = false;
				}
			}
		}