Don't start transactions while holding locks. #272

briar-api/src/org/briarproject/api/db/DatabaseComponent.java

@@ -26,10 +26,6 @@ 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 {
 
@@ -45,6 +41,9 @@ public interface DatabaseComponent {
 
 	/**
 	 * Starts a new transaction and returns an object representing it.
+	 * <p/>
+	 * This method acquires locks, so it must not be called while holding a
+	 * lock.
 	 * @param readOnly true if the transaction will only be used for reading.
 	 */
 	Transaction startTransaction(boolean readOnly) throws DbException;

briar-api/src/org/briarproject/api/transport/KeyManager.java

@@ -26,12 +26,14 @@ public interface KeyManager {
 	 * contact over the given transport, or null if an error occurs or the
 	 * contact does not support the transport.
 	 */
-	StreamContext getStreamContext(ContactId c, TransportId t);
+	StreamContext getStreamContext(ContactId c, TransportId t)
+			throws DbException;
 
 	/**
 	 * Looks up the given tag and returns a {@link StreamContext} for reading
 	 * from the corresponding stream, or null if an error occurs or the tag was
 	 * unexpected.
 	 */
-	StreamContext getStreamContext(TransportId t, byte[] tag);
+	StreamContext getStreamContext(TransportId t, byte[] tag)
+			throws DbException;
 }