Pebble: remove the legacy countdownlatch on Pebble GATT server code

The GATTServer code is now in line with the new GATTClient code.

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/pebble/ble/PebbleGATTServer.java

@@ -30,6 +30,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
 
 class PebbleGATTServer extends BluetoothGattServerCallback {
     private static final Logger LOG = LoggerFactory.getLogger(PebbleGATTServer.class);
@@ -43,6 +44,7 @@ class PebbleGATTServer extends BluetoothGattServerCallback {
     private Context mContext;
     private BluetoothGattServer mBluetoothGattServer;
     private BluetoothGattCharacteristic writeCharacteristics;
+    private CountDownLatch mWaitWriteCompleteLatch;
 
     PebbleGATTServer(PebbleLESupport pebbleLESupport, Context context, BluetoothDevice btDevice) {
         mContext = context;
@@ -73,9 +75,20 @@ class PebbleGATTServer extends BluetoothGattServerCallback {
     }
 
     synchronized void sendDataToPebble(byte[] data) {
+        mWaitWriteCompleteLatch = new CountDownLatch(1);
         writeCharacteristics.setValue(data.clone());
 
-        mBluetoothGattServer.notifyCharacteristicChanged(mBtDevice, writeCharacteristics, false);
+        boolean success = mBluetoothGattServer.notifyCharacteristicChanged(mBtDevice, writeCharacteristics, false);
+        if (!success) {
+            LOG.error("could not send data to pebble (error writing characteristic)");
+        } else {
+            try {
+                mWaitWriteCompleteLatch.await();
+            } catch (InterruptedException e) {
+                LOG.warn("interrupted while waiting for write complete latch");
+            }
+        }
+        mWaitWriteCompleteLatch = null;
     }
 
     public void onCharacteristicReadRequest(BluetoothDevice device, int requestId, int offset, BluetoothGattCharacteristic characteristic) {
@@ -157,7 +170,19 @@ class PebbleGATTServer extends BluetoothGattServerCallback {
     }
 
     public void onNotificationSent(BluetoothDevice bluetoothDevice, int status) {
-        //LOG.info("onNotificationSent() status = " + status + " to device " + mmBtDevice.getAddress());
+
+        if (!mPebbleLESupport.isExpectedDevice(bluetoothDevice)) {
+            return;
+        }
+        if (status != BluetoothGatt.GATT_SUCCESS) {
+            LOG.error("something went wrong when writing to PPoGATT characteristics");
+        }
+        if (mWaitWriteCompleteLatch != null) {
+            mWaitWriteCompleteLatch.countDown();
+        } else {
+            LOG.warn("mWaitWriteCompleteLatch is null!");
+        }
+//        LOG.info("onNotificationSent() status = " + status + " to device " + bluetoothDevice.getAddress());
     }
 
     void close() {

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/pebble/ble/PebbleLESupport.java

@@ -27,7 +27,6 @@ import org.slf4j.LoggerFactory;
 import java.io.IOException;
 import java.io.PipedInputStream;
 import java.io.PipedOutputStream;
-import java.util.concurrent.CountDownLatch;
 
 import nodomain.freeyourgadget.gadgetbridge.GBApplication;
 
@@ -43,7 +42,6 @@ public class PebbleLESupport {
     private int mMTULimit = Integer.MAX_VALUE;
     public boolean clientOnly = false; // currently experimental, and only possible for Pebble 2
     private boolean mIsConnected = false;
-    private CountDownLatch mPPAck;
     private HandlerThread mWriteHandlerThread;
     private Handler mWriteHandler;
 
@@ -156,13 +154,6 @@ public class PebbleLESupport {
         int serial = header >> 3;
         if (command == 0x01) {
             LOG.info("got ACK for serial = " + serial);
-            if (!clientOnly) {
-                if (mPPAck != null) {
-                    mPPAck.countDown();
-                } else {
-                    LOG.warn("mPPAck countdownlatch is not present but it probably should");
-                }
-            }
         }
         if (command == 0x02) { // some request?
             LOG.info("got command 0x02");
@@ -187,7 +178,12 @@ public class PebbleLESupport {
 
     private synchronized void sendDataToPebble(final byte[] bytes) {
         if (mPebbleGATTServer != null) {
-            mPebbleGATTServer.sendDataToPebble(bytes);
+            mWriteHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mPebbleGATTServer.sendDataToPebble(bytes);
+                }
+            });
         } else {
             // For now only in experimental client only code
             mWriteHandler.post(new Runnable() {
@@ -226,9 +222,6 @@ public class PebbleLESupport {
 
                     int payloadToSend = bytesRead + 4;
                     int srcPos = 0;
-                    if (!clientOnly) {
-                        mPPAck = new CountDownLatch(1);
-                    }
                     while (payloadToSend > 0) {
                         int chunkSize = (payloadToSend < (mMTU - 4)) ? payloadToSend : mMTU - 4;
                         byte[] outBuf = new byte[chunkSize + 1];
@@ -238,11 +231,7 @@ public class PebbleLESupport {
                         srcPos += chunkSize;
                         payloadToSend -= chunkSize;
                     }
-                    if (!clientOnly) {
+                } catch (IOException e) {
-                        mPPAck.await();
-                        mPPAck = null;
-                    }
-                } catch (IOException | InterruptedException e) {
                     LOG.info(e.getMessage());
                     Thread.currentThread().interrupt();
                     break;