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diff --git a/bundles/org.eclipse.equinox.logstream/src/org/osgi/util/pushstream/PushEventSource.java b/bundles/org.eclipse.equinox.logstream/src/org/osgi/util/pushstream/PushEventSource.java
new file mode 100644
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+++ b/bundles/org.eclipse.equinox.logstream/src/org/osgi/util/pushstream/PushEventSource.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) OSGi Alliance (2015, 2016). All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.osgi.util.pushstream;
+
+import org.osgi.annotation.versioning.ConsumerType;
+
+/**
+ * An event source. An event source can open a channel between a source and a
+ * consumer. Once the channel is opened (even before it returns) the source can
+ * send events to the consumer.
+ *
+ * A source should stop sending and automatically close the channel when sending
+ * an event returns a negative value, see {@link PushEventConsumer#ABORT}.
+ * Values that are larger than 0 should be treated as a request to delay the
+ * next events with those number of milliseconds.
+ * 
+ * @param <T>
+ *            The payload type
+ */
+@ConsumerType
+@FunctionalInterface
+public interface PushEventSource<T> {
+
+	/**
+	 * Open the asynchronous channel between the source and the consumer. The
+	 * call returns an {@link AutoCloseable}. This can be closed, and should
+	 * close the channel, including sending a Close event if the channel was not
+	 * already closed. The returned object must be able to be closed multiple
+	 * times without sending more than one Close events.
+	 * 
+	 * @param aec the consumer (not null)
+	 * @return a {@link AutoCloseable} that can be used to close the stream
+	 * @throws Exception
+	 */
+	AutoCloseable open(PushEventConsumer< ? super T> aec) throws Exception;
+}