CEC: Buffer Cec messages while allocating logical address

CEC messages arriving before logical address allocation was being
discarded. Handles them by introducing a message buffer class
to keep them till the address allocation is finished.

Also updated per-device message buffer to use copied version of
messages list for iterating to avoid the possible concurrent
modification exception.

Bug: 18896770
Change-Id: Ifb74fd265510de6dde322e0b3bc5b504fecb4daa

services/core/java/com/android/server/hdmi/DelayedMessageBuffer.java

@@ -77,11 +77,13 @@ final class DelayedMessageBuffer {
     }
 
     void processAllMessages() {
-        for (HdmiCecMessage message : mBuffer) {
+        // Use the copied buffer.
+        ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<HdmiCecMessage>(mBuffer);
+        mBuffer.clear();
+        for (HdmiCecMessage message : copiedBuffer) {
             mDevice.onMessage(message);
             HdmiLogger.debug("Processing message:" + message);
         }
-        mBuffer.clear();
     }
 
     /**
@@ -95,15 +97,21 @@ final class DelayedMessageBuffer {
      *        are associated with
      */
     void processMessagesForDevice(int address) {
+        ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<HdmiCecMessage>(mBuffer);
+        mBuffer.clear();
         HdmiLogger.debug("Checking message for address:" + address);
-        for (Iterator<HdmiCecMessage> iter = mBuffer.iterator(); iter.hasNext(); ) {
+        for (HdmiCecMessage message : copiedBuffer) {
-            HdmiCecMessage message = iter.next();
+            if (message.getSource() != address) {
-            if (message.getSource() != address) continue;
+                mBuffer.add(message);
+                continue;
+            }
             if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE
-                    && !mDevice.isInputReady(HdmiDeviceInfo.idForCecDevice(address))) continue;
+                    && !mDevice.isInputReady(HdmiDeviceInfo.idForCecDevice(address))) {
+                mBuffer.add(message);
+                continue;
+            }
             mDevice.onMessage(message);
             HdmiLogger.debug("Processing message:" + message);
-            iter.remove();
         }
     }
 
@@ -119,13 +127,15 @@ final class DelayedMessageBuffer {
      * @param address logical address of the device to be the active source
      */
     void processActiveSource(int address) {
-        for (Iterator<HdmiCecMessage> iter = mBuffer.iterator(); iter.hasNext(); ) {
+        ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<HdmiCecMessage>(mBuffer);
-            HdmiCecMessage message = iter.next();
+        mBuffer.clear();
+        for (HdmiCecMessage message : copiedBuffer) {
             if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE
                     && message.getSource() == address) {
                 mDevice.onMessage(message);
                 HdmiLogger.debug("Processing message:" + message);
-                iter.remove();
+            } else {
+                mBuffer.add(message);
             }
         }
     }

services/core/java/com/android/server/hdmi/HdmiControlService.java

@@ -286,6 +286,69 @@ public final class HdmiControlService extends SystemService {
     @ServiceThreadOnly
     private int mLastInputMhl = Constants.INVALID_PORT_ID;
 
+    // Set to true if the logical address allocation is completed.
+    private boolean mAddressAllocated = false;
+
+    // Buffer for processing the incoming cec messages while allocating logical addresses.
+    private final class CecMessageBuffer {
+        private List<HdmiCecMessage> mBuffer = new ArrayList<>();
+
+        public void bufferMessage(HdmiCecMessage message) {
+            switch (message.getOpcode()) {
+                case Constants.MESSAGE_ACTIVE_SOURCE:
+                    bufferActiveSource(message);
+                    break;
+                case Constants.MESSAGE_IMAGE_VIEW_ON:
+                case Constants.MESSAGE_TEXT_VIEW_ON:
+                    bufferImageOrTextViewOn(message);
+                    break;
+                    // Add here if new message that needs to buffer
+                default:
+                    // Do not need to buffer messages other than above
+                    break;
+            }
+        }
+
+        public void processMessages() {
+            for (final HdmiCecMessage message : mBuffer) {
+                runOnServiceThread(new Runnable() {
+                    @Override
+                    public void run() {
+                        handleCecCommand(message);
+                    }
+                });
+            }
+            mBuffer.clear();
+        }
+
+        private void bufferActiveSource(HdmiCecMessage message) {
+            if (!replaceMessageIfBuffered(message, Constants.MESSAGE_ACTIVE_SOURCE)) {
+                mBuffer.add(message);
+            }
+        }
+
+        private void bufferImageOrTextViewOn(HdmiCecMessage message) {
+            if (!replaceMessageIfBuffered(message, Constants.MESSAGE_IMAGE_VIEW_ON) &&
+                !replaceMessageIfBuffered(message, Constants.MESSAGE_TEXT_VIEW_ON)) {
+                mBuffer.add(message);
+            }
+        }
+
+        // Returns true if the message is replaced
+        private boolean replaceMessageIfBuffered(HdmiCecMessage message, int opcode) {
+            for (int i = 0; i < mBuffer.size(); i++) {
+                HdmiCecMessage bufferedMessage = mBuffer.get(i);
+                if (bufferedMessage.getOpcode() == opcode) {
+                    mBuffer.set(i, message);
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
+
+    private CecMessageBuffer mCecMessageBuffer = new CecMessageBuffer();
+
     public HdmiControlService(Context context) {
         super(context);
         mLocalDevices = getIntList(SystemProperties.get(Constants.PROPERTY_DEVICE_TYPE));
@@ -474,6 +537,7 @@ public final class HdmiControlService extends SystemService {
     }
 
     private void initializeCec(int initiatedBy) {
+        mAddressAllocated = false;
         mCecController.setOption(OPTION_CEC_SERVICE_CONTROL, ENABLED);
         initializeLocalDevices(initiatedBy);
     }
@@ -504,6 +568,8 @@ public final class HdmiControlService extends SystemService {
         mCecController.clearLogicalAddress();
         final ArrayList<HdmiCecLocalDevice> allocatedDevices = new ArrayList<>();
         final int[] finished = new int[1];
+        mAddressAllocated = allocatingDevices.isEmpty();
+
         for (final HdmiCecLocalDevice localDevice : allocatingDevices) {
             mCecController.allocateLogicalAddress(localDevice.getType(),
                     localDevice.getPreferredAddress(), new AllocateAddressCallback() {
@@ -524,12 +590,14 @@ public final class HdmiControlService extends SystemService {
 
                     // Address allocation completed for all devices. Notify each device.
                     if (allocatingDevices.size() == ++finished[0]) {
+                        mAddressAllocated = true;
                         if (initiatedBy != INITIATED_BY_HOTPLUG) {
                             // In case of the hotplug we don't call onInitializeCecComplete()
                             // since we reallocate the logical address only.
                             onInitializeCecComplete(initiatedBy);
                         }
                         notifyAddressAllocated(allocatedDevices, initiatedBy);
+                        mCecMessageBuffer.processMessages();
                     }
                 }
             });
@@ -762,6 +830,10 @@ public final class HdmiControlService extends SystemService {
     @ServiceThreadOnly
     boolean handleCecCommand(HdmiCecMessage message) {
         assertRunOnServiceThread();
+        if (!mAddressAllocated) {
+            mCecMessageBuffer.bufferMessage(message);
+            return true;
+        }
         int errorCode = mMessageValidator.isValid(message);
         if (errorCode != HdmiCecMessageValidator.OK) {
             // We'll not response on the messages with the invalid source or destination
@@ -1990,6 +2062,7 @@ public final class HdmiControlService extends SystemService {
             device.onStandby(mStandbyMessageReceived);
         }
         mStandbyMessageReceived = false;
+        mAddressAllocated = false;
         mCecController.setOption(OPTION_CEC_SERVICE_CONTROL, DISABLED);
     }