fix exceptions when reloading the server (#1689)

src/main/java/com/comphenix/protocol/injector/netty/manager/ListeningList.java

@@ -4,10 +4,14 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import java.util.Collection;
+import java.util.Comparator;
 import java.util.Iterator;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.NoSuchElementException;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
 
 @SuppressWarnings("NullableProblems")
 final class ListeningList implements List<Object> {
@@ -25,17 +29,23 @@ final class ListeningList implements List<Object> {
 
 	@Override
 	public int size() {
-		return this.original.size();
+		synchronized (this) {
+			return this.original.size();
+		}
 	}
 
 	@Override
 	public boolean isEmpty() {
-		return this.original.isEmpty();
+		synchronized (this) {
+			return this.original.isEmpty();
+		}
 	}
 
 	@Override
 	public boolean contains(Object o) {
-		return this.original.contains(o);
+		synchronized (this) {
+			return this.original.contains(o);
+		}
 	}
 
 	@Override
@@ -43,81 +53,113 @@ final class ListeningList implements List<Object> {
 		return this.original.iterator();
 	}
 
+	@Override
+	public void forEach(Consumer<? super Object> action) {
+		synchronized (this) {
+			this.original.forEach(action);
+		}
+	}
+
 	@Override
 	public Object[] toArray() {
-		return this.original.toArray();
+		synchronized (this) {
+			return this.original.toArray();
+		}
 	}
 
 	@Override
 	public <T> T[] toArray(T[] a) {
-		//noinspection SuspiciousToArrayCall
-		return this.original.toArray(a);
+		synchronized (this) {
+			//noinspection SuspiciousToArrayCall
+			return this.original.toArray(a);
+		}
 	}
 
 	@Override
 	public boolean add(Object o) {
-		this.processInsert(o);
-		return this.original.add(o);
+		synchronized (this) {
+			this.processInsert(o);
+			return this.original.add(o);
+		}
 	}
 
 	@Override
 	public void add(int index, Object element) {
-		this.processInsert(element);
-		this.original.add(index, element);
+		synchronized (this) {
+			this.processInsert(element);
+			this.original.add(index, element);
+		}
 	}
 
 	@Override
 	public boolean addAll(Collection<?> c) {
-		c.forEach(this::processInsert);
-		return this.original.addAll(c);
+		synchronized (this) {
+			c.forEach(this::processInsert);
+			return this.original.addAll(c);
+		}
 	}
 
 	@Override
 	public boolean addAll(int index, Collection<?> c) {
-		c.forEach(this::processInsert);
-		return this.original.addAll(index, c);
+		synchronized (this) {
+			c.forEach(this::processInsert);
+			return this.original.addAll(index, c);
+		}
 	}
 
 	@Override
 	public Object set(int index, Object element) {
-		this.processInsert(element);
+		synchronized (this) {
+			this.processInsert(element);
 
-		Object prev = this.original.set(index, element);
-		this.processRemove(prev);
+			Object prev = this.original.set(index, element);
+			this.processRemove(prev);
 
-		return prev;
+			return prev;
+		}
 	}
 
 	@Override
 	public boolean remove(Object o) {
-		if (this.original.remove(o)) {
-			this.processRemove(o);
-			return true;
-		}
+		synchronized (this) {
+			if (this.original.remove(o)) {
+				this.processRemove(o);
+				return true;
+			}
 
-		return false;
+			return false;
+		}
 	}
 
 	@Override
 	public boolean containsAll(Collection<?> c) {
-		return this.original.containsAll(c);
+		synchronized (this) {
+			//noinspection SlowListContainsAll
+			return this.original.containsAll(c);
+		}
 	}
 
 	@Override
 	public Object remove(int index) {
-		Object removed = this.original.remove(index);
-		this.processRemove(removed);
-		return removed;
+		synchronized (this) {
+			Object removed = this.original.remove(index);
+			this.processRemove(removed);
+			return removed;
+		}
 	}
 
 	@Override
 	public int indexOf(Object o) {
-		return this.original.indexOf(o);
+		synchronized (this) {
+			return this.original.indexOf(o);
+		}
 	}
 
 	@Override
 	public int lastIndexOf(Object o) {
-		return this.original.lastIndexOf(o);
+		synchronized (this) {
+			return this.original.lastIndexOf(o);
+		}
 	}
 
 	@Override
@@ -132,33 +174,77 @@ final class ListeningList implements List<Object> {
 
 	@Override
 	public List<Object> subList(int fromIndex, int toIndex) {
-		return this.original.subList(fromIndex, toIndex);
+		synchronized (this) {
+			return this.original.subList(fromIndex, toIndex);
+		}
 	}
 
 	@Override
 	public boolean removeAll(Collection<?> c) {
-		c.forEach(element -> {
-			if (this.original.contains(element)) {
-				this.processRemove(element);
-			}
-		});
-		return this.original.removeAll(c);
+		synchronized (this) {
+			c.forEach(element -> {
+				if (this.original.contains(element)) {
+					this.processRemove(element);
+				}
+			});
+			return this.original.removeAll(c);
+		}
+	}
+
+	@Override
+	public boolean removeIf(Predicate<? super Object> filter) {
+		synchronized (this) {
+			return this.original.removeIf(object -> {
+				boolean shouldRemove = filter.test(object);
+				if (shouldRemove) {
+					this.processRemove(object);
+				}
+				return shouldRemove;
+			});
+		}
 	}
 
 	@Override
 	public boolean retainAll(Collection<?> c) {
-		return this.original.retainAll(c);
+		synchronized (this) {
+			return this.original.retainAll(c);
+		}
+	}
+
+	@Override
+	public void replaceAll(UnaryOperator<Object> operator) {
+		synchronized (this) {
+			this.original.replaceAll(value -> {
+				Object newValue = operator.apply(value);
+				if (newValue != value) {
+					this.processRemove(value);
+					this.processInsert(newValue);
+				}
+				return newValue;
+			});
+		}
+	}
+
+	@Override
+	public void sort(Comparator<? super Object> c) {
+		synchronized (this) {
+			this.original.sort(c);
+		}
 	}
 
 	@Override
 	public void clear() {
-		this.original.forEach(this::processRemove);
-		this.original.clear();
+		synchronized (this) {
+			this.original.forEach(this::processRemove);
+			this.original.clear();
+		}
 	}
 
 	@Override
 	public Object get(int index) {
-		return this.original.get(index);
+		synchronized (this) {
+			return this.original.get(index);
+		}
 	}
 
 	private void processInsert(Object element) {

src/main/java/com/comphenix/protocol/injector/netty/manager/NetworkManagerInjector.java

@@ -26,7 +26,6 @@ import io.netty.channel.ChannelFuture;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -205,7 +204,7 @@ public class NetworkManagerInjector implements ChannelListener {
 				//noinspection SynchronizationOnLocalVariableOrMethodParameter
 				synchronized (value) {
 					// override the list field with our list
-					List<Object> newList = Collections.synchronizedList(new ListeningList(value, this.pipelineInjectorHandler));
+					List<Object> newList = new ListeningList(value, this.pipelineInjectorHandler);
 					accessor.set(serverConnection, newList);
 				}
 			}
@@ -215,7 +214,6 @@ public class NetworkManagerInjector implements ChannelListener {
 		this.injected = true;
 	}
 
-	@SuppressWarnings("unchecked")
 	public void close() {
 		if (this.closed || !this.injected) {
 			return;
@@ -229,10 +227,10 @@ public class NetworkManagerInjector implements ChannelListener {
 		for (Pair<Object, FieldAccessor> list : this.overriddenLists) {
 			// get the value of the field we've overridden, if it is no longer a ListeningList someone probably jumped in
 			// and replaced the field himself - we are out safely as the other person needs to clean the mess...
-			List<Object> value = (List<Object>) list.getSecond().get(list.getFirst());
-			if (value instanceof ListeningList) {
+			Object currentFieldValue = list.getSecond().get(list.getFirst());
+			if (currentFieldValue instanceof ListeningList) {
 				// just reset to the list we wrapped originally
-				ListeningList ourList = (ListeningList) value;
+				ListeningList ourList = (ListeningList) currentFieldValue;
 				List<Object> original = ourList.getOriginal();
 				//noinspection SynchronizationOnLocalVariableOrMethodParameter
 				synchronized (original) {