diff --git a/services/audioflinger/MmapTracks.h b/services/audioflinger/MmapTracks.h
new file mode 100644
index 0000000..e4fe8ac
--- /dev/null
+++ b/services/audioflinger/MmapTracks.h
@@ -0,0 +1,60 @@
+/*
+**
+** Copyright 2017, The Android Open Source Project
+**
+** 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.
+*/
+
+#ifndef INCLUDING_FROM_AUDIOFLINGER_H
+    #error This header file should only be included from AudioFlinger.h
+#endif
+
+// playback track
+class MmapTrack : public TrackBase {
+public:
+                MmapTrack(ThreadBase *thread,
+                            uint32_t sampleRate,
+                            audio_format_t format,
+                            audio_channel_mask_t channelMask,
+                            audio_session_t sessionId,
+                            uid_t uid,
+                            audio_port_handle_t portId = AUDIO_PORT_HANDLE_NONE);
+    virtual             ~MmapTrack();
+
+                        // TrackBase virtual
+    virtual status_t    initCheck() const;
+    virtual status_t    start(AudioSystem::sync_event_t event,
+                              audio_session_t triggerSession);
+    virtual void        stop();
+    virtual bool        isFastTrack() const { return false; }
+
+     static void        appendDumpHeader(String8& result);
+            void        dump(char* buffer, size_t size);
+
+protected:
+    friend class MmapThread;
+
+                MmapTrack(const MmapTrack&);
+                MmapTrack& operator = (const MmapTrack&);
+
+    // AudioBufferProvider interface
+    virtual status_t getNextBuffer(AudioBufferProvider::Buffer* buffer);
+    // releaseBuffer() not overridden
+
+    // ExtendedAudioBufferProvider interface
+    virtual size_t framesReady() const;
+    virtual int64_t framesReleased() const;
+    virtual void onTimestamp(const ExtendedTimestamp &timestamp);
+
+};  // end of Track
+