USB MIDI: Multijack MIDI 1.0 for MIDI 2.0 devices (88e10487) · Commits · e / os / android_frameworks_base

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

+37 −16

Original line number	Diff line number	Diff line
		@@ -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;
		private FastEventQueue mEventPool = null;
		protected volatile SortedMap<Long, FastEventQueue> mEventBuffer;
		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.
		private class FastEventQueue {
		/**
		* Class for a fast event queue.
		*
		* 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 → 100644

+128 −0

Original line number	Diff line number	Diff line
		/*
		* 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

+1 −1

Original line number	Diff line number	Diff line
		@@ -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

+212 −100

File changed.

Preview size limit exceeded, changes collapsed.

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

+117 −25

Original line number	Diff line number	Diff line
		@@ -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) {
		mUsbMidiEncoders = new UsbMidiEncoder[numEncoders];
		for (int i = 0; i < numEncoders; i++) {
		mUsbMidiEncoders[i] = new UsbMidiEncoder();
		}
		}
		private UsbMidiDecoder mUsbMidiDecoder;

		/**
		* Converts a USB MIDI array into a raw MIDI array.
		* Creates encoders.
		*
		* @param usbMidiBytes the USB MIDI bytes to convert
		* @param size the size of usbMidiBytes
		* @return byte array of raw MIDI packets
		* createEncoders() must be called before raw MIDI can be converted to USB MIDI.
		*
		* @param size the number of encoders to create
		*/
		public byte[] usbMidiToRawMidi(byte[] usbMidiBytes, int size) {
		return mUsbMidiDecoder.decode(usbMidiBytes, size);
		public void createEncoders(int 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) {
		return mUsbMidiEncoders[encoderId].encode(midiBytes, size);
		public byte[] pullEncodedMidiPackets() {
		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
		+ mNumStoredSystemExclusiveBytes);
		outputStream.write((CODE_INDEX_NUMBER_SYSEX_END_SINGLE_BYTE
		+ 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);