diff --git a/src/ddebug/common/queue.d b/src/ddebug/common/queue.d
index 1a5ebf0..2e2a643 100644
--- a/src/ddebug/common/queue.d
+++ b/src/ddebug/common/queue.d
@@ -10,6 +10,7 @@ class BlockingQueue(T) {
 	private T[] _buffer;
 	private int _readPos;
 	private int _writePos;
+	private shared bool _closed;
 
 	this() {
 		_mutex = new Mutex();
@@ -19,6 +20,15 @@ class BlockingQueue(T) {
 	}
 
 	void close() {
+		if (_mutex && !_closed) {
+			synchronized(_mutex) {
+				_closed = true;
+				if (_condition !is null)
+					_condition.notifyAll();
+			}
+		} else {
+			_closed = true;
+		}
 		if (_condition) {
 			destroy(_condition);
 			_condition = null;
@@ -53,14 +63,22 @@ class BlockingQueue(T) {
 	}
 
 	void put(T item) {
+		if (_closed)
+			return;
 		synchronized(_mutex) {
+			if (_closed)
+				return;
 			append(item);
 			_condition.notifyAll();
 		}
 	}
 
 	void put(T[] items) {
+		if (_closed)
+			return;
 		synchronized(_mutex) {
+			if (_closed)
+				return;
 			foreach(ref item; items) {
 				append(item);
 			}
@@ -70,7 +88,11 @@ class BlockingQueue(T) {
 	}
 	
 	bool get(ref T value, int timeoutMillis) {
+		if (_closed)
+			return false;
 		synchronized(_mutex) {
+			if (_closed)
+				return false;
 			if (_readPos < _writePos) {
 				value = _buffer[_readPos++];
 				return true;
@@ -88,7 +110,11 @@ class BlockingQueue(T) {
 	}
 
 	bool getAll(ref T[] values, int timeoutMillis) {
+		if (_closed)
+			return false;
 		synchronized(_mutex) {
+			if (_closed)
+				return false;
 			values.length = 0;
 			while (_readPos < _writePos)
 				values ~= _buffer[_readPos++];