diff --git a/briar-api/src/org/briarproject/api/db/DatabaseComponent.java b/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
index c1dfc0072419a3b80b1ead10f4222926de3fb0d4..48a67fb1dfa5d58b5f225eab09946f863d4973a0 100644
--- a/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
+++ b/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
@@ -30,6 +30,10 @@ import java.util.Map;
 /**
  * Encapsulates the database implementation and exposes high-level operations
  * to other components.
+ * <p>
+ * This interface's methods are blocking, but they do not call out into other
+ * components except to broadcast {@link org.briarproject.api.event.Event
+ * Events}, so they can safely be called while holding locks.
  */
 public interface DatabaseComponent {
 
diff --git a/briar-api/src/org/briarproject/api/event/EventListener.java b/briar-api/src/org/briarproject/api/event/EventListener.java
index 8ab59aa04ba33559475784b2a96606b2ce2e912f..89598d79e1e4bbdccf702da3edc35feed070acb5 100644
--- a/briar-api/src/org/briarproject/api/event/EventListener.java
+++ b/briar-api/src/org/briarproject/api/event/EventListener.java
@@ -3,5 +3,9 @@ package org.briarproject.api.event;
 /** An interface for receiving notifications when events occur. */
 public interface EventListener {
 
+	/**
+	 * Called when an event is broadcast. Implementations of this method must
+	 * not block.
+	 */
 	void eventOccurred(Event e);
 }