Merge "USB MIDI: Multijack MIDI 1.0 for MIDI 2.0 devices" into udc-dev

core/java/com/android/internal/midi/EventScheduler.java

@@ -16,7 +16,6 @@
 
 package com.android.internal.midi;
 
-import java.util.Iterator;
 import java.util.SortedMap;
 import java.util.TreeMap;
 
@@ -26,11 +25,11 @@ import java.util.TreeMap;
  * And only one Thread can read from the buffer.
  */
 public class EventScheduler {
-    private static final long NANOS_PER_MILLI = 1000000;
+    public static final long NANOS_PER_MILLI = 1000000;
 
     private final Object mLock = new Object();
-    volatile private SortedMap<Long, FastEventQueue> mEventBuffer;
+    protected volatile SortedMap<Long, FastEventQueue> mEventBuffer;
-    private FastEventQueue mEventPool = null;
+    protected FastEventQueue mEventPool = null;
     private int mMaxPoolSize = 200;
     private boolean mClosed;
 
@@ -38,9 +37,13 @@ public class EventScheduler {
         mEventBuffer = new TreeMap<Long, FastEventQueue>();
     }
 
-    // If we keep at least one node in the list then it can be atomic
+    /**
-    // and non-blocking.
+     * Class for a fast event queue.
-    private class FastEventQueue {
+     *
+     * If we keep at least one node in the list then it can be atomic
+     * and non-blocking.
+     */
+    public static class FastEventQueue {
         // One thread takes from the beginning of the list.
         volatile SchedulableEvent mFirst;
         // A second thread returns events to the end of the list.
@@ -48,7 +51,7 @@ public class EventScheduler {
         volatile long mEventsAdded;
         volatile long mEventsRemoved;
 
-        FastEventQueue(SchedulableEvent event) {
+        public FastEventQueue(SchedulableEvent event) {
             mFirst = event;
             mLast = mFirst;
             mEventsAdded = 1;
@@ -149,7 +152,8 @@ public class EventScheduler {
      * @param event
      */
     public void add(SchedulableEvent event) {
-        synchronized (mLock) {
+        Object lock = getLock();
+        synchronized (lock) {
             FastEventQueue list = mEventBuffer.get(event.getTimestamp());
             if (list == null) {
                 long lowestTime = mEventBuffer.isEmpty() ? Long.MAX_VALUE
@@ -159,7 +163,7 @@ public class EventScheduler {
                 // If the event we added is earlier than the previous earliest
                 // event then notify any threads waiting for the next event.
                 if (event.getTimestamp() < lowestTime) {
-                    mLock.notify();
+                    lock.notify();
                 }
             } else {
                 list.add(event);
@@ -167,7 +171,7 @@ public class EventScheduler {
         }
     }
 
-    private SchedulableEvent removeNextEventLocked(long lowestTime) {
+    protected SchedulableEvent removeNextEventLocked(long lowestTime) {
         SchedulableEvent event;
         FastEventQueue list = mEventBuffer.get(lowestTime);
         // Remove list from tree if this is the last node.
@@ -186,7 +190,8 @@ public class EventScheduler {
      */
     public SchedulableEvent getNextEvent(long time) {
         SchedulableEvent event = null;
-        synchronized (mLock) {
+        Object lock = getLock();
+        synchronized (lock) {
             if (!mEventBuffer.isEmpty()) {
                 long lowestTime = mEventBuffer.firstKey();
                 // Is it time for this list to be processed?
@@ -209,7 +214,8 @@ public class EventScheduler {
      */
     public SchedulableEvent waitNextEvent() throws InterruptedException {
         SchedulableEvent event = null;
-        synchronized (mLock) {
+        Object lock = getLock();
+        synchronized (lock) {
             while (!mClosed) {
                 long millisToWait = Integer.MAX_VALUE;
                 if (!mEventBuffer.isEmpty()) {
@@ -231,7 +237,7 @@ public class EventScheduler {
                         }
                     }
                 }
-                mLock.wait((int) millisToWait);
+                lock.wait((int) millisToWait);
             }
         }
         return event;
@@ -242,10 +248,25 @@ public class EventScheduler {
         mEventBuffer = new TreeMap<Long, FastEventQueue>();
     }
 
+    /**
+     * Stops the EventScheduler.
+     * The subscriber calling waitNextEvent() will get one final SchedulableEvent returning null.
+     */
     public void close() {
-        synchronized (mLock) {
+        Object lock = getLock();
+        synchronized (lock) {
             mClosed = true;
-            mLock.notify();
+            lock.notify();
         }
     }
+
+    /**
+     * Gets the lock. This doesn't lock it in anyway.
+     * Subclasses can override this.
+     *
+     * @return Object
+     */
+    protected Object getLock() {
+        return mLock;
+    }
 }

core/java/com/android/internal/midi/MidiEventMultiScheduler.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+package com.android.internal.midi;
+
+/**
+ * Uses multiple MidiEventSchedulers for waiting for events.
+ *
+ */
+public class MidiEventMultiScheduler {
+    private MultiLockMidiEventScheduler[] mMidiEventSchedulers;
+    private int mNumEventSchedulers;
+    private int mNumClosedSchedulers = 0;
+    private final Object mMultiLock = new Object();
+
+    private class MultiLockMidiEventScheduler extends MidiEventScheduler {
+        @Override
+        public void close() {
+            synchronized (mMultiLock) {
+                mNumClosedSchedulers++;
+            }
+            super.close();
+        }
+
+        @Override
+        protected Object getLock() {
+            return mMultiLock;
+        }
+
+        public boolean isEventBufferEmptyLocked() {
+            return mEventBuffer.isEmpty();
+        }
+
+        public long getLowestTimeLocked() {
+            return mEventBuffer.firstKey();
+        }
+    }
+
+    /**
+     * MidiEventMultiScheduler constructor
+     *
+     * @param numSchedulers the number of schedulers to create
+     */
+    public MidiEventMultiScheduler(int numSchedulers) {
+        mNumEventSchedulers = numSchedulers;
+        mMidiEventSchedulers = new MultiLockMidiEventScheduler[numSchedulers];
+        for (int i = 0; i < numSchedulers; i++) {
+            mMidiEventSchedulers[i] = new MultiLockMidiEventScheduler();
+        }
+    }
+
+    /**
+     * Waits for the next MIDI event. This will return true when it receives it.
+     * If all MidiEventSchedulers have been closed, this will return false.
+     *
+     * @return true if a MIDI event is received and false if all schedulers are closed.
+     */
+    public boolean waitNextEvent() throws InterruptedException {
+        synchronized (mMultiLock) {
+            while (true) {
+                if (mNumClosedSchedulers >= mNumEventSchedulers) {
+                    return false;
+                }
+                long lowestTime = Long.MAX_VALUE;
+                long now = System.nanoTime();
+                for (MultiLockMidiEventScheduler eventScheduler : mMidiEventSchedulers) {
+                    if (!eventScheduler.isEventBufferEmptyLocked()) {
+                        lowestTime = Math.min(lowestTime,
+                                eventScheduler.getLowestTimeLocked());
+                    }
+                }
+                if (lowestTime <= now) {
+                    return true;
+                }
+                long nanosToWait = lowestTime - now;
+                // Add 1 millisecond so we don't wake up before it is
+                // ready.
+                long millisToWait = 1 + (nanosToWait / EventScheduler.NANOS_PER_MILLI);
+                // Clip 64-bit value to 32-bit max.
+                if (millisToWait > Integer.MAX_VALUE) {
+                    millisToWait = Integer.MAX_VALUE;
+                }
+                mMultiLock.wait(millisToWait);
+            }
+        }
+    }
+
+    /**
+     * Gets the number of MidiEventSchedulers.
+     *
+     * @return the number of MidiEventSchedulers.
+     */
+    public int getNumEventSchedulers() {
+        return mNumEventSchedulers;
+    }
+
+    /**
+     * Gets a specific MidiEventScheduler based on the index.
+     *
+     * @param index the zero indexed index of a MIDI event scheduler
+     * @return a MidiEventScheduler
+     */
+    public MidiEventScheduler getEventScheduler(int index) {
+        return mMidiEventSchedulers[index];
+    }
+
+    /**
+     * Closes all event schedulers.
+     */
+    public void close() {
+        for (MidiEventScheduler eventScheduler : mMidiEventSchedulers) {
+            eventScheduler.close();
+        }
+    }
+}

core/java/com/android/internal/midi/MidiEventScheduler.java

@@ -79,7 +79,7 @@ public class MidiEventScheduler extends EventScheduler {
     /**
      * Create an event that contains the message.
      */
-    private MidiEvent createScheduledEvent(byte[] msg, int offset, int count,
+    public MidiEvent createScheduledEvent(byte[] msg, int offset, int count,
             long timestamp) {
         MidiEvent event;
         if (count > POOL_EVENT_SIZE) {

services/usb/java/com/android/server/usb/UsbDirectMidiDevice.java

@@ -19,7 +19,6 @@ package com.android.server.usb;
 import android.annotation.NonNull;
 import android.content.Context;
 import android.hardware.usb.UsbConfiguration;
-import android.hardware.usb.UsbConstants;
 import android.hardware.usb.UsbDevice;
 import android.hardware.usb.UsbDeviceConnection;
 import android.hardware.usb.UsbEndpoint;
@@ -35,9 +34,12 @@ import android.os.Bundle;
 import android.service.usb.UsbDirectMidiDeviceProto;
 import android.util.Log;
 
+import com.android.internal.midi.MidiEventMultiScheduler;
 import com.android.internal.midi.MidiEventScheduler;
 import com.android.internal.midi.MidiEventScheduler.MidiEvent;
 import com.android.internal.util.dump.DualDumpOutputStream;
+import com.android.server.usb.descriptors.UsbACMidi10Endpoint;
+import com.android.server.usb.descriptors.UsbDescriptor;
 import com.android.server.usb.descriptors.UsbDescriptorParser;
 import com.android.server.usb.descriptors.UsbEndpointDescriptor;
 import com.android.server.usb.descriptors.UsbInterfaceDescriptor;
@@ -45,6 +47,7 @@ import com.android.server.usb.descriptors.UsbMidiBlockParser;
 
 import libcore.io.IoUtils;
 
+import java.io.ByteArrayOutputStream;
 import java.io.Closeable;
 import java.io.IOException;
 import java.nio.ByteBuffer;
@@ -56,7 +59,7 @@ import java.util.ArrayList;
  */
 public final class UsbDirectMidiDevice implements Closeable {
     private static final String TAG = "UsbDirectMidiDevice";
-    private static final boolean DEBUG = false;
+    private static final boolean DEBUG = true;
 
     private Context mContext;
     private String mName;
@@ -74,9 +77,6 @@ public final class UsbDirectMidiDevice implements Closeable {
 
     private MidiDeviceServer mServer;
 
-    // event schedulers for each input port of the physical device
-    private MidiEventScheduler[] mEventSchedulers;
-
     // Timeout for sending a packet to a device.
     // If bulkTransfer times out, retry sending the packet up to 20 times.
     private static final int BULK_TRANSFER_TIMEOUT_MILLISECONDS = 50;
@@ -86,8 +86,21 @@ public final class UsbDirectMidiDevice implements Closeable {
     private static final int THREAD_JOIN_TIMEOUT_MILLISECONDS = 200;
 
     private ArrayList<UsbDeviceConnection> mUsbDeviceConnections;
+
+    // Array of endpoints by device connection.
     private ArrayList<ArrayList<UsbEndpoint>> mInputUsbEndpoints;
     private ArrayList<ArrayList<UsbEndpoint>> mOutputUsbEndpoints;
+
+    // Array of cable counts by device connection.
+    // Each number here maps to an entry in mInputUsbEndpoints or mOutputUsbEndpoints.
+    // This is needed because this info is part of UsbEndpointDescriptor but not UsbEndpoint.
+    private ArrayList<ArrayList<Integer>> mInputUsbEndpointCableCounts;
+    private ArrayList<ArrayList<Integer>> mOutputUsbEndpointCableCounts;
+
+    // Array of event schedulers by device connection.
+    // Each number here maps to an entry in mOutputUsbEndpoints.
+    private ArrayList<ArrayList<MidiEventMultiScheduler>> mMidiEventMultiSchedulers;
+
     private ArrayList<Thread> mThreads;
 
     private UsbMidiBlockParser mMidiBlockParser = new UsbMidiBlockParser();
@@ -97,8 +110,6 @@ public final class UsbDirectMidiDevice implements Closeable {
     private boolean mIsOpen;
     private boolean mServerAvailable;
 
-    private UsbMidiPacketConverter mUsbMidiPacketConverter;
-
     private PowerBoostSetter mPowerBoostSetter = null;
 
     private static final byte MESSAGE_TYPE_MIDI_1_CHANNEL_VOICE = 0x02;
@@ -238,9 +249,9 @@ public final class UsbDirectMidiDevice implements Closeable {
                         interfaceDescriptor.getEndpointDescriptor(endpointIndex);
                 // 0 is output, 1 << 7 is input.
                 if (endpoint.getDirection() == 0) {
-                    numOutputs++;
+                    numOutputs += getNumJacks(endpoint);
                 } else {
-                    numInputs++;
+                    numInputs += getNumJacks(endpoint);
                 }
             }
         }
@@ -307,19 +318,21 @@ public final class UsbDirectMidiDevice implements Closeable {
         Log.d(TAG, "openLocked()");
         UsbManager manager = mContext.getSystemService(UsbManager.class);
 
-        // Converting from raw MIDI to USB MIDI is not thread-safe.
-        // UsbMidiPacketConverter creates a converter from raw MIDI
-        // to USB MIDI for each USB output.
-        mUsbMidiPacketConverter = new UsbMidiPacketConverter(mNumOutputs);
-
         mUsbDeviceConnections = new ArrayList<UsbDeviceConnection>();
         mInputUsbEndpoints = new ArrayList<ArrayList<UsbEndpoint>>();
         mOutputUsbEndpoints = new ArrayList<ArrayList<UsbEndpoint>>();
+        mInputUsbEndpointCableCounts = new ArrayList<ArrayList<Integer>>();
+        mOutputUsbEndpointCableCounts = new ArrayList<ArrayList<Integer>>();
+        mMidiEventMultiSchedulers = new ArrayList<ArrayList<MidiEventMultiScheduler>>();
         mThreads = new ArrayList<Thread>();
 
         for (int interfaceIndex = 0; interfaceIndex < mUsbInterfaces.size(); interfaceIndex++) {
             ArrayList<UsbEndpoint> inputEndpoints = new ArrayList<UsbEndpoint>();
             ArrayList<UsbEndpoint> outputEndpoints = new ArrayList<UsbEndpoint>();
+            ArrayList<Integer> inputEndpointCableCounts = new ArrayList<Integer>();
+            ArrayList<Integer> outputEndpointCableCounts = new ArrayList<Integer>();
+            ArrayList<MidiEventMultiScheduler> midiEventMultiSchedulers =
+                    new ArrayList<MidiEventMultiScheduler>();
             UsbInterfaceDescriptor interfaceDescriptor = mUsbInterfaces.get(interfaceIndex);
             for (int endpointIndex = 0; endpointIndex < interfaceDescriptor.getNumEndpoints();
                     endpointIndex++) {
@@ -328,8 +341,13 @@ public final class UsbDirectMidiDevice implements Closeable {
                 // 0 is output, 1 << 7 is input.
                 if (endpoint.getDirection() == 0) {
                     outputEndpoints.add(endpoint.toAndroid(mParser));
+                    outputEndpointCableCounts.add(getNumJacks(endpoint));
+                    MidiEventMultiScheduler scheduler =
+                            new MidiEventMultiScheduler(getNumJacks(endpoint));
+                    midiEventMultiSchedulers.add(scheduler);
                 } else {
                     inputEndpoints.add(endpoint.toAndroid(mParser));
+                    inputEndpointCableCounts.add(getNumJacks(endpoint));
                 }
             }
             if (!outputEndpoints.isEmpty() || !inputEndpoints.isEmpty()) {
@@ -341,40 +359,69 @@ public final class UsbDirectMidiDevice implements Closeable {
                 mUsbDeviceConnections.add(connection);
                 mInputUsbEndpoints.add(inputEndpoints);
                 mOutputUsbEndpoints.add(outputEndpoints);
+                mInputUsbEndpointCableCounts.add(inputEndpointCableCounts);
+                mOutputUsbEndpointCableCounts.add(outputEndpointCableCounts);
+                mMidiEventMultiSchedulers.add(midiEventMultiSchedulers);
             }
         }
 
-        mEventSchedulers = new MidiEventScheduler[mNumOutputs];
+        // Set up event schedulers
-
+        int outputIndex = 0;
-        for (int i = 0; i < mNumOutputs; i++) {
+        for (int connectionIndex = 0; connectionIndex < mMidiEventMultiSchedulers.size();
-            MidiEventScheduler scheduler = new MidiEventScheduler();
+                connectionIndex++) {
-            mEventSchedulers[i] = scheduler;
+            for (int endpointIndex = 0;
-            mMidiInputPortReceivers[i].setReceiver(scheduler.getReceiver());
+                    endpointIndex < mMidiEventMultiSchedulers.get(connectionIndex).size();
+                    endpointIndex++) {
+                int cableCount =
+                        mOutputUsbEndpointCableCounts.get(connectionIndex).get(endpointIndex);
+                MidiEventMultiScheduler multiScheduler =
+                        mMidiEventMultiSchedulers.get(connectionIndex).get(endpointIndex);
+                for (int cableNumber = 0; cableNumber < cableCount; cableNumber++) {
+                    MidiEventScheduler scheduler = multiScheduler.getEventScheduler(cableNumber);
+                    mMidiInputPortReceivers[outputIndex].setReceiver(scheduler.getReceiver());
+                    outputIndex++;
+                }
+            }
         }
 
         final MidiReceiver[] outputReceivers = mServer.getOutputPortReceivers();
 
         // Create input thread for each input port of the physical device
-        int portNumber = 0;
+        int portStartNumber = 0;
         for (int connectionIndex = 0; connectionIndex < mInputUsbEndpoints.size();
                 connectionIndex++) {
             for (int endpointIndex = 0;
                     endpointIndex < mInputUsbEndpoints.get(connectionIndex).size();
                     endpointIndex++) {
+                // Each USB endpoint maps to one or more outputReceivers. USB MIDI data from an
+                // endpoint should be sent to the appropriate outputReceiver. A new thread is
+                // created and waits for incoming USB data. Once the data is received, it is added
+                // to the packet converter. The packet converter acts as an inverse multiplexer.
+                // With a for loop, data is pulled per cable and sent to the correct output
+                // receiver. The first byte of each legacy MIDI 1.0 USB message indicates which
+                // cable the data should be used and is how the reverse multiplexer directs data.
+                // For MIDI UMP endpoints, a multiplexer is not needed as we are just swapping
+                // the endianness of the packets.
                 final UsbDeviceConnection connectionFinal =
                         mUsbDeviceConnections.get(connectionIndex);
                 final UsbEndpoint endpointFinal =
                         mInputUsbEndpoints.get(connectionIndex).get(endpointIndex);
-                final int portFinal = portNumber;
+                final int portStartFinal = portStartNumber;
+                final int cableCountFinal =
+                        mInputUsbEndpointCableCounts.get(connectionIndex).get(endpointIndex);
 
-                Thread newThread = new Thread("UsbDirectMidiDevice input thread " + portFinal) {
+                Thread newThread = new Thread("UsbDirectMidiDevice input thread "
+                        + portStartFinal) {
                     @Override
                     public void run() {
                         final UsbRequest request = new UsbRequest();
+                        final UsbMidiPacketConverter packetConverter = new UsbMidiPacketConverter();
+                        packetConverter.createDecoders(cableCountFinal);
                         try {
                             request.initialize(connectionFinal, endpointFinal);
                             byte[] inputBuffer = new byte[endpointFinal.getMaxPacketSize()];
-                            while (true) {
+                            boolean keepGoing = true;
+                            while (keepGoing) {
                                 if (Thread.currentThread().interrupted()) {
                                     Log.w(TAG, "input thread interrupted");
                                     break;
@@ -404,42 +451,56 @@ public final class UsbDirectMidiDevice implements Closeable {
                                         logByteArray("Input before conversion ", inputBuffer,
                                                 0, bytesRead);
                                     }
+
+                                    // Add packets into the packet decoder.
+                                    if (!mIsUniversalMidiDevice) {
+                                        packetConverter.decodeMidiPackets(inputBuffer, bytesRead);
+                                    }
+
                                     byte[] convertedArray;
-                                    if (mIsUniversalMidiDevice) {
+                                    for (int cableNumber = 0; cableNumber < cableCountFinal;
-                                        // For USB, each 32 bit word of a UMP is
+                                            cableNumber++) {
-                                        // sent with the least significant byte first.
+                                        if (mIsUniversalMidiDevice) {
-                                        convertedArray = swapEndiannessPerWord(inputBuffer,
+                                            // For USB, each 32 bit word of a UMP is
-                                                bytesRead);
+                                            // sent with the least significant byte first.
-                                    } else {
+                                            convertedArray = swapEndiannessPerWord(inputBuffer,
-                                        if (mUsbMidiPacketConverter == null) {
+                                                    bytesRead);
-                                            Log.w(TAG, "mUsbMidiPacketConverter is null");
+                                        } else {
+                                            convertedArray =
+                                                    packetConverter.pullDecodedMidiPackets(
+                                                            cableNumber);
+                                        }
+
+                                        if (DEBUG) {
+                                            logByteArray("Input " + cableNumber
+                                                    + " after conversion ", convertedArray, 0,
+                                                    convertedArray.length);
+                                        }
+
+                                        if (convertedArray.length == 0) {
+                                            continue;
+                                        }
+
+                                        if ((outputReceivers == null)
+                                                || (outputReceivers[portStartFinal + cableNumber]
+                                                == null)) {
+                                            Log.w(TAG, "outputReceivers is null");
+                                            keepGoing = false;
                                             break;
                                         }
-                                        convertedArray =
+                                        outputReceivers[portStartFinal + cableNumber].send(
-                                                mUsbMidiPacketConverter.usbMidiToRawMidi(
+                                                convertedArray, 0, convertedArray.length,
-                                                         inputBuffer, bytesRead);
+                                                timestamp);
-                                    }
 
-                                    if (DEBUG) {
+                                        // Boost power if there seems to be a voice message.
-                                        logByteArray("Input after conversion ", convertedArray,
+                                        // For legacy devices, boost if message length > 1.
-                                                0, convertedArray.length);
+                                        // For UMP devices, boost for channel voice messages.
-                                    }
+                                        if ((mPowerBoostSetter != null
-
+                                                && convertedArray.length > 1)
-                                    if ((outputReceivers == null)
+                                                && (!mIsUniversalMidiDevice
-                                            || (outputReceivers[portFinal] == null)) {
+                                                || isChannelVoiceMessage(convertedArray))) {
-                                        Log.w(TAG, "outputReceivers is null");
+                                            mPowerBoostSetter.boostPower();
-                                        break;
+                                        }
-                                    }
-                                    outputReceivers[portFinal].send(convertedArray, 0,
-                                            convertedArray.length, timestamp);
-
-                                    // Boost power if there seems to be a voice message.
-                                    // For legacy devices, boost when message is more than size 1.
-                                    // For UMP devices, boost for channel voice messages.
-                                    if ((mPowerBoostSetter != null && convertedArray.length > 1)
-                                            && (!mIsUniversalMidiDevice
-                                            || isChannelVoiceMessage(convertedArray))) {
-                                        mPowerBoostSetter.boostPower();
                                     }
                                 }
                             }
@@ -455,64 +516,93 @@ public final class UsbDirectMidiDevice implements Closeable {
                 };
                 newThread.start();
                 mThreads.add(newThread);
-                portNumber++;
+                portStartNumber += cableCountFinal;
             }
         }
 
         // Create output thread for each output port of the physical device
-        portNumber = 0;
+        portStartNumber = 0;
         for (int connectionIndex = 0; connectionIndex < mOutputUsbEndpoints.size();
                 connectionIndex++) {
             for (int endpointIndex = 0;
                     endpointIndex < mOutputUsbEndpoints.get(connectionIndex).size();
                     endpointIndex++) {
+                // Each USB endpoint maps to one or more MIDI ports. Each port has an event
+                // scheduler that is used to pull incoming raw MIDI bytes from Android apps.
+                // With a MidiEventMultiScheduler, data can be pulled if any of the schedulers
+                // have new incoming data. This data is then packaged as USB MIDI packets before
+                // getting sent through USB. One thread will be created per endpoint that pulls
+                // data from all relevant event schedulers. Raw MIDI from the event schedulers
+                // will be converted to the correct USB MIDI format before getting sent through
+                // USB.
+
                 final UsbDeviceConnection connectionFinal =
                         mUsbDeviceConnections.get(connectionIndex);
                 final UsbEndpoint endpointFinal =
                         mOutputUsbEndpoints.get(connectionIndex).get(endpointIndex);
-                final int portFinal = portNumber;
+                final int portStartFinal = portStartNumber;
-                final MidiEventScheduler eventSchedulerFinal = mEventSchedulers[portFinal];
+                final int cableCountFinal =
+                        mOutputUsbEndpointCableCounts.get(connectionIndex).get(endpointIndex);
+                final MidiEventMultiScheduler multiSchedulerFinal =
+                            mMidiEventMultiSchedulers.get(connectionIndex).get(endpointIndex);
 
-                Thread newThread = new Thread("UsbDirectMidiDevice output thread " + portFinal) {
+                Thread newThread = new Thread("UsbDirectMidiDevice output write thread "
+                        + portStartFinal) {
                     @Override
                     public void run() {
                         try {
-                            while (true) {
+                            final ByteArrayOutputStream midi2ByteStream =
-                                if (Thread.currentThread().interrupted()) {
+                                    new ByteArrayOutputStream();
-                                    Log.w(TAG, "output thread interrupted");
+                            final UsbMidiPacketConverter packetConverter =
+                                    new UsbMidiPacketConverter();
+                            packetConverter.createEncoders(cableCountFinal);
+                            boolean isInterrupted = false;
+                            while (!isInterrupted) {
+                                boolean wasSuccessful = multiSchedulerFinal.waitNextEvent();
+                                if (!wasSuccessful) {
+                                    Log.d(TAG, "output thread closed");
                                     break;
                                 }
-                                MidiEvent event;
+                                long now = System.nanoTime();
-                                try {
+                                for (int cableNumber = 0; cableNumber < cableCountFinal;
-                                    event = (MidiEvent) eventSchedulerFinal.waitNextEvent();
+                                        cableNumber++) {
-                                } catch (InterruptedException e) {
+                                    MidiEventScheduler eventScheduler =
-                                    Log.w(TAG, "event scheduler interrupted");
+                                            multiSchedulerFinal.getEventScheduler(cableNumber);
-                                    break;
+                                    MidiEvent event =
-                                }
+                                            (MidiEvent) eventScheduler.getNextEvent(now);
-                                if (event == null) {
+                                    while (event != null) {
-                                    Log.w(TAG, "event is null");
+                                        if (DEBUG) {
-                                    break;
+                                            logByteArray("Output before conversion ",
-                                }
+                                                    event.data, 0, event.count);
-
+                                        }
-                                if (DEBUG) {
+                                        if (mIsUniversalMidiDevice) {
-                                    logByteArray("Output before conversion ", event.data, 0,
+                                            // For USB, each 32 bit word of a UMP is
-                                            event.count);
+                                            // sent with the least significant byte first.
-                                }
+                                            byte[] convertedArray = swapEndiannessPerWord(
-
+                                                    event.data, event.count);
-                                byte[] convertedArray;
+                                            midi2ByteStream.write(convertedArray, 0,
-                                if (mIsUniversalMidiDevice) {
+                                                    convertedArray.length);
-                                    // For USB, each 32 bit word of a UMP is
+                                        } else {
-                                    // sent with the least significant byte first.
+                                            packetConverter.encodeMidiPackets(event.data,
-                                    convertedArray = swapEndiannessPerWord(event.data,
+                                                    event.count, cableNumber);
-                                            event.count);
+                                        }
-                                } else {
+                                        eventScheduler.addEventToPool(event);
-                                    if (mUsbMidiPacketConverter == null) {
+                                        event = (MidiEvent) eventScheduler.getNextEvent(now);
-                                        Log.w(TAG, "mUsbMidiPacketConverter is null");
-                                        break;
                                     }
+                                }
+
+                                if (Thread.currentThread().interrupted()) {
+                                    Log.d(TAG, "output thread interrupted");
+                                    break;
+                                }
+
+                                byte[] convertedArray = new byte[0];
+                                if (mIsUniversalMidiDevice) {
+                                    convertedArray = midi2ByteStream.toByteArray();
+                                    midi2ByteStream.reset();
+                                } else {
                                     convertedArray =
-                                            mUsbMidiPacketConverter.rawMidiToUsbMidi(
+                                            packetConverter.pullEncodedMidiPackets();
-                                                     event.data, event.count, portFinal);
                                 }
 
                                 if (DEBUG) {
@@ -520,7 +610,6 @@ public final class UsbDirectMidiDevice implements Closeable {
                                             convertedArray.length);
                                 }
 
-                                boolean isInterrupted = false;
                                 // Split the packet into multiple if they are greater than the
                                 // endpoint's max packet size.
                                 for (int curPacketStart = 0;
@@ -558,11 +647,9 @@ public final class UsbDirectMidiDevice implements Closeable {
                                         }
                                     }
                                 }
-                                if (isInterrupted == true) {
-                                    break;
-                                }
-                                eventSchedulerFinal.addEventToPool(event);
                             }
+                        } catch (InterruptedException e) {
+                            Log.w(TAG, "output thread: ", e);
                         } catch (NullPointerException e) {
                             Log.e(TAG, "output thread: ", e);
                         }
@@ -571,7 +658,7 @@ public final class UsbDirectMidiDevice implements Closeable {
                 };
                 newThread.start();
                 mThreads.add(newThread);
-                portNumber++;
+                portStartNumber += cableCountFinal;
             }
         }
 
@@ -667,11 +754,21 @@ public final class UsbDirectMidiDevice implements Closeable {
         }
         mThreads = null;
 
-        for (int i = 0; i < mEventSchedulers.length; i++) {
+        for (int i = 0; i < mMidiInputPortReceivers.length; i++) {
             mMidiInputPortReceivers[i].setReceiver(null);
-            mEventSchedulers[i].close();
         }
-        mEventSchedulers = null;
+
+        for (int connectionIndex = 0; connectionIndex < mMidiEventMultiSchedulers.size();
+                connectionIndex++) {
+            for (int endpointIndex = 0;
+                    endpointIndex < mMidiEventMultiSchedulers.get(connectionIndex).size();
+                    endpointIndex++) {
+                MidiEventMultiScheduler multiScheduler =
+                        mMidiEventMultiSchedulers.get(connectionIndex).get(endpointIndex);
+                multiScheduler.close();
+            }
+        }
+        mMidiEventMultiSchedulers = null;
 
         for (UsbDeviceConnection connection : mUsbDeviceConnections) {
             connection.close();
@@ -679,8 +776,8 @@ public final class UsbDirectMidiDevice implements Closeable {
         mUsbDeviceConnections = null;
         mInputUsbEndpoints = null;
         mOutputUsbEndpoints = null;
-
+        mInputUsbEndpointCableCounts = null;
-        mUsbMidiPacketConverter = null;
+        mOutputUsbEndpointCableCounts = null;
 
         mIsOpen = false;
     }
@@ -788,4 +885,19 @@ public final class UsbDirectMidiDevice implements Closeable {
         return messageType == MESSAGE_TYPE_MIDI_1_CHANNEL_VOICE
                 || messageType == MESSAGE_TYPE_MIDI_2_CHANNEL_VOICE;
     }
+
+    // Returns the number of jacks for MIDI 1.0 endpoints.
+    // For MIDI 2.0 endpoints, this concept does not exist and each endpoint should be treated as
+    // one port.
+    private int getNumJacks(UsbEndpointDescriptor usbEndpointDescriptor) {
+        UsbDescriptor classSpecificEndpointDescriptor =
+                usbEndpointDescriptor.getClassSpecificEndpointDescriptor();
+        if (classSpecificEndpointDescriptor != null
+                && (classSpecificEndpointDescriptor instanceof UsbACMidi10Endpoint)) {
+            UsbACMidi10Endpoint midiEndpoint =
+                    (UsbACMidi10Endpoint) classSpecificEndpointDescriptor;
+            return midiEndpoint.getNumJacks();
+        }
+        return 1;
+    }
 }

services/usb/java/com/android/server/usb/UsbMidiPacketConverter.java

@@ -16,12 +16,17 @@
 
 package com.android.server.usb;
 
+import android.util.Log;
+
 import java.io.ByteArrayOutputStream;
 
 /**
- * Converts between MIDI packets and USB MIDI 1.0 packets.
+ * Converts between raw MIDI packets and USB MIDI 1.0 packets.
+ * This is NOT thread-safe. Please handle locking outside this function for multiple threads.
+ * For data mapping to an invalid cable number, this converter will use the first cable.
  */
 public class UsbMidiPacketConverter {
+    private static final String TAG = "UsbMidiPacketConverter";
 
     // Refer to Table 4-1 in USB MIDI 1.0 spec.
     private static final int[] PAYLOAD_SIZE = new int[]{
@@ -74,54 +79,133 @@ public class UsbMidiPacketConverter {
     private static final byte SYSEX_START_EXCLUSIVE = (byte) 0xF0;
     private static final byte SYSEX_END_EXCLUSIVE = (byte) 0xF7;
 
-    private UsbMidiDecoder mUsbMidiDecoder = new UsbMidiDecoder();
     private UsbMidiEncoder[] mUsbMidiEncoders;
+    private ByteArrayOutputStream mEncoderOutputStream = new ByteArrayOutputStream();
 
-    public UsbMidiPacketConverter(int numEncoders) {
+    private UsbMidiDecoder mUsbMidiDecoder;
-        mUsbMidiEncoders = new UsbMidiEncoder[numEncoders];
-        for (int i = 0; i < numEncoders; i++) {
-            mUsbMidiEncoders[i] = new UsbMidiEncoder();
-        }
-    }
 
     /**
-     * Converts a USB MIDI array into a raw MIDI array.
+     * Creates encoders.
      *
-     * @param usbMidiBytes the USB MIDI bytes to convert
+     * createEncoders() must be called before raw MIDI can be converted to USB MIDI.
-     * @param size the size of usbMidiBytes
+     *
-     * @return byte array of raw MIDI packets
+     * @param size the number of encoders to create
      */
-    public byte[] usbMidiToRawMidi(byte[] usbMidiBytes, int size) {
+    public void createEncoders(int size) {
-        return mUsbMidiDecoder.decode(usbMidiBytes, size);
+        mUsbMidiEncoders = new UsbMidiEncoder[size];
+        for (int i = 0; i < size; i++) {
+            mUsbMidiEncoders[i] = new UsbMidiEncoder(i);
+        }
     }
 
     /**
      * Converts a raw MIDI array into a USB MIDI array.
      *
+     * Call pullEncodedMidiPackets to retrieve the byte array.
+     *
      * @param midiBytes the raw MIDI bytes to convert
      * @param size the size of usbMidiBytes
      * @param encoderId which encoder to use
+     */
+    public void encodeMidiPackets(byte[] midiBytes, int size, int encoderId) {
+        // Use the first encoder if the encoderId is invalid.
+        if (encoderId >= mUsbMidiEncoders.length) {
+            Log.w(TAG, "encoderId " + encoderId + " invalid");
+            encoderId = 0;
+        }
+        byte[] encodedPacket = mUsbMidiEncoders[encoderId].encode(midiBytes, size);
+        mEncoderOutputStream.write(encodedPacket, 0, encodedPacket.length);
+    }
+
+    /**
+     * Returns the encoded MIDI packets from encodeMidiPackets
+     *
      * @return byte array of USB MIDI packets
      */
-    public byte[] rawMidiToUsbMidi(byte[] midiBytes, int size, int encoderId) {
+    public byte[] pullEncodedMidiPackets() {
-        return mUsbMidiEncoders[encoderId].encode(midiBytes, size);
+        byte[] output = mEncoderOutputStream.toByteArray();
+        mEncoderOutputStream.reset();
+        return output;
+    }
+
+    /**
+     * Creates decoders.
+     *
+     * createDecoders() must be called before USB MIDI can be converted to raw MIDI.
+     *
+     * @param size the number of decoders to create
+     */
+    public void createDecoders(int size) {
+        mUsbMidiDecoder = new UsbMidiDecoder(size);
+    }
+
+    /**
+     * Converts a USB MIDI array into a multiple MIDI arrays, one per cable.
+     *
+     * Call pullDecodedMidiPackets to retrieve the byte array.
+     *
+     * @param usbMidiBytes the USB MIDI bytes to convert
+     * @param size the size of usbMidiBytes
+     */
+    public void decodeMidiPackets(byte[] usbMidiBytes, int size) {
+        mUsbMidiDecoder.decode(usbMidiBytes, size);
+    }
+
+    /**
+     * Returns the decoded MIDI packets from decodeMidiPackets
+     *
+     * @param cableNumber the cable to pull data from
+     * @return byte array of raw MIDI packets
+     */
+    public byte[] pullDecodedMidiPackets(int cableNumber) {
+        return mUsbMidiDecoder.pullBytes(cableNumber);
     }
 
     private class UsbMidiDecoder {
+        int mNumJacks;
+        ByteArrayOutputStream[] mDecodedByteArrays;
+
+        UsbMidiDecoder(int numJacks) {
+            mNumJacks = numJacks;
+            mDecodedByteArrays = new ByteArrayOutputStream[numJacks];
+            for (int i = 0; i < numJacks; i++) {
+                mDecodedByteArrays[i] = new ByteArrayOutputStream();
+            }
+        }
+
         // Decodes the data from USB MIDI to raw MIDI.
         // Each valid 4 byte input maps to a 1-3 byte output.
         // Reference the USB MIDI 1.0 spec for more info.
-        public byte[] decode(byte[] usbMidiBytes, int size) {
+        public void decode(byte[] usbMidiBytes, int size) {
             ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+            if (size % 4 != 0) {
+                Log.w(TAG, "size " + size + " not multiple of 4");
+            }
             for (int i = 0; i + 3 < size; i += 4) {
+                int cableNumber = (usbMidiBytes[i] >> 4) & 0x0f;
                 int codeIndex = usbMidiBytes[i] & 0x0f;
                 int numPayloadBytes = PAYLOAD_SIZE[codeIndex];
                 if (numPayloadBytes < 0) {
                     continue;
                 }
-                outputStream.write(usbMidiBytes, i + 1, numPayloadBytes);
+                // Use the first cable if the cable number is invalid.
+                if (cableNumber >= mNumJacks) {
+                    Log.w(TAG, "cableNumber " + cableNumber + " invalid");
+                    cableNumber = 0;
+                }
+                mDecodedByteArrays[cableNumber].write(usbMidiBytes, i + 1, numPayloadBytes);
             }
-            return outputStream.toByteArray();
+        }
+
+        public byte[] pullBytes(int cableNumber) {
+            // Use the first cable if the cable number is invalid.
+            if (cableNumber >= mNumJacks) {
+                Log.w(TAG, "cableNumber " + cableNumber + " invalid");
+                cableNumber = 0;
+            }
+            byte[] output = mDecodedByteArrays[cableNumber].toByteArray();
+            mDecodedByteArrays[cableNumber].reset();
+            return output;
         }
     }
 
@@ -135,6 +219,13 @@ public class UsbMidiPacketConverter {
 
         private byte[] mEmptyBytes = new byte[3]; // Used to fill out extra data
 
+        private byte mShiftedCableNumber;
+
+        UsbMidiEncoder(int cableNumber) {
+            // Jack Id is always the left nibble of every byte so shift this now.
+            mShiftedCableNumber = (byte) (cableNumber << 4);
+        }
+
         // Encodes the data from raw MIDI to USB MIDI.
         // Each valid 1-3 byte input maps to a 4 byte output.
         // Reference the USB MIDI 1.0 spec for more info.
@@ -153,7 +244,8 @@ public class UsbMidiPacketConverter {
                                 midiBytes[curLocation];
                         mNumStoredSystemExclusiveBytes++;
                         if (mNumStoredSystemExclusiveBytes == 3) {
-                            outputStream.write(CODE_INDEX_NUMBER_SYSEX_STARTS_OR_CONTINUES);
+                            outputStream.write(CODE_INDEX_NUMBER_SYSEX_STARTS_OR_CONTINUES
+                                    | mShiftedCableNumber);
                             outputStream.write(mStoredSystemExclusiveBytes, 0, 3);
                             mNumStoredSystemExclusiveBytes = 0;
                         }
@@ -179,7 +271,7 @@ public class UsbMidiPacketConverter {
                     byte codeIndexNumber = (byte) ((midiBytes[curLocation] >> 4) & 0x0f);
                     int channelMessageSize = PAYLOAD_SIZE[codeIndexNumber];
                     if (curLocation + channelMessageSize <= size) {
-                        outputStream.write(codeIndexNumber);
+                        outputStream.write(codeIndexNumber | mShiftedCableNumber);
                         outputStream.write(midiBytes, curLocation, channelMessageSize);
                         // Fill in the rest of the bytes with 0.
                         outputStream.write(mEmptyBytes, 0, 3 - channelMessageSize);
@@ -197,8 +289,8 @@ public class UsbMidiPacketConverter {
                     curLocation++;
                 } else if (midiBytes[curLocation] == SYSEX_END_EXCLUSIVE) {
                     // 1 byte is 0x05, 2 bytes is 0x06, and 3 bytes is 0x07
-                    outputStream.write(CODE_INDEX_NUMBER_SYSEX_END_SINGLE_BYTE
+                    outputStream.write((CODE_INDEX_NUMBER_SYSEX_END_SINGLE_BYTE
-                            + mNumStoredSystemExclusiveBytes);
+                            + mNumStoredSystemExclusiveBytes) | mShiftedCableNumber);
                     mStoredSystemExclusiveBytes[mNumStoredSystemExclusiveBytes] =
                             midiBytes[curLocation];
                     mNumStoredSystemExclusiveBytes++;
@@ -218,7 +310,7 @@ public class UsbMidiPacketConverter {
                     } else {
                         int systemMessageSize = PAYLOAD_SIZE[codeIndexNumber];
                         if (curLocation + systemMessageSize <= size) {
-                            outputStream.write(codeIndexNumber);
+                            outputStream.write(codeIndexNumber | mShiftedCableNumber);
                             outputStream.write(midiBytes, curLocation, systemMessageSize);
                             // Fill in the rest of the bytes with 0.
                             outputStream.write(mEmptyBytes, 0, 3 - systemMessageSize);
@@ -236,7 +328,7 @@ public class UsbMidiPacketConverter {
         }
 
         private void writeSingleByte(ByteArrayOutputStream outputStream, byte byteToWrite) {
-            outputStream.write(CODE_INDEX_NUMBER_SINGLE_BYTE);
+            outputStream.write(CODE_INDEX_NUMBER_SINGLE_BYTE | mShiftedCableNumber);
             outputStream.write(byteToWrite);
             outputStream.write(0);
             outputStream.write(0);

services/usb/java/com/android/server/usb/descriptors/UsbEndpointDescriptor.java

@@ -118,7 +118,7 @@ public class UsbEndpointDescriptor extends UsbDescriptor {
         mClassSpecificEndpointDescriptor = descriptor;
     }
 
-    UsbDescriptor getClassSpecificEndpointDescriptor() {
+    public UsbDescriptor getClassSpecificEndpointDescriptor() {
         return mClassSpecificEndpointDescriptor;
     }