logging and unit test updates

[debian/openrocket] / src / net / sf / openrocket / logging / DelegatorLogger.java

diff --git a/src/net/sf/openrocket/logging/DelegatorLogger.java b/src/net/sf/openrocket/logging/DelegatorLogger.java
index 10a8daa7ec22b74eb9ddb05ca408e6321f4721e0..45ff9e55b963fa0699d920e8c4dd121eeac2a103 100644 (file)
--- a/src/net/sf/openrocket/logging/DelegatorLogger.java
+++ b/src/net/sf/openrocket/logging/DelegatorLogger.java
@@ -12,23 +12,42 @@ import java.util.List;
  */
 public class DelegatorLogger extends LogHelper {
 
-       private List<LogHelper> loggers = new ArrayList<LogHelper>();
+       /**
+        * List of loggers.  This list must not be modified, instead it should be
+        * replaced every time the list is changed.
+        */
+       private volatile ArrayList<LogHelper> loggers = new ArrayList<LogHelper>();
        
        @Override
        public void log(LogLine line) {
-               LogHelper[] array = loggers.toArray(new LogHelper[0]);
-               for (LogHelper l: array) {
+               // Must create local reference for thread safety
+               List<LogHelper> list = loggers;
+               for (LogHelper l: list) {
                        l.log(line);
                }
        }
        
        
-       public void addLogger(LogHelper logger) {
-               this.loggers.add(logger);
+       /**
+        * Add a logger from the delegation list.
+        * @param logger        the logger to add.
+        */
+       @SuppressWarnings("unchecked")
+       public synchronized void addLogger(LogHelper logger) {
+               ArrayList<LogHelper> newList = (ArrayList<LogHelper>) loggers.clone();
+               newList.add(logger);
+               this.loggers = newList;
        }
        
-       public void removeLogger(LogHelper logger) {
-               this.loggers.remove(logger);
+       /**
+        * Remove a logger from the delegation list.
+        * @param logger        the logger to be removed.
+        */
+       @SuppressWarnings("unchecked")
+       public synchronized void removeLogger(LogHelper logger) {
+               ArrayList<LogHelper> newList = (ArrayList<LogHelper>) loggers.clone();
+               newList.remove(logger);
+               this.loggers = newList;
        }
 
 }