From 6f90cf7bb6111753c4f1744c588e698911719915 Mon Sep 17 00:00:00 2001
From: Koen <koen@pop-os.localdomain>
Date: Sun, 7 Jan 2024 14:16:03 +0100
Subject: [PATCH] Added synchronization to sender.

---
 .../com/futo/fcast/receiver/FCastSession.kt   | 57 ++++++++++---------
 .../com/futo/fcast/receiver/NetworkService.kt |  2 +-
 2 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/receivers/android/app/src/main/java/com/futo/fcast/receiver/FCastSession.kt b/receivers/android/app/src/main/java/com/futo/fcast/receiver/FCastSession.kt
index 40b5369..8102cd8 100644
--- a/receivers/android/app/src/main/java/com/futo/fcast/receiver/FCastSession.kt
+++ b/receivers/android/app/src/main/java/com/futo/fcast/receiver/FCastSession.kt
@@ -62,37 +62,40 @@ class FCastSession(outputStream: OutputStream, private val _remoteSocketAddress:
     private var _packetLength = 0
     private var _state = SessionState.WaitingForLength
     private var _outputStream: DataOutputStream? = DataOutputStream(outputStream)
+    private var _outputStreamLock = Object()
     val id = UUID.randomUUID()
 
     fun send(opcode: Opcode, message: String? = null) {
-        try {
-            val data: ByteArray = message?.encodeToByteArray() ?: ByteArray(0)
-            val size = 1 + data.size
-            val outputStream = _outputStream
-            if (outputStream == null) {
-                Log.w(TAG, "Failed to send $size bytes, output stream is null.")
-                return
+        synchronized(_outputStreamLock) {
+            try {
+                val data: ByteArray = message?.encodeToByteArray() ?: ByteArray(0)
+                val size = 1 + data.size
+                val outputStream = _outputStream
+                if (outputStream == null) {
+                    Log.w(TAG, "Failed to send $size bytes, output stream is null.")
+                    return
+                }
+
+                val serializedSizeLE = ByteArray(4)
+                serializedSizeLE[0] = (size and 0xff).toByte()
+                serializedSizeLE[1] = (size shr 8 and 0xff).toByte()
+                serializedSizeLE[2] = (size shr 16 and 0xff).toByte()
+                serializedSizeLE[3] = (size shr 24 and 0xff).toByte()
+                outputStream.write(serializedSizeLE)
+
+                val opcodeBytes = ByteArray(1)
+                opcodeBytes[0] = opcode.value
+                outputStream.write(opcodeBytes)
+
+                if (data.isNotEmpty()) {
+                    outputStream.write(data)
+                }
+
+                Log.d(TAG, "Sent $size bytes: (opcode: $opcode, body: $message).")
+            } catch (e: Throwable) {
+                Log.i(TAG, "Failed to send message ${id}.", e)
+                throw e
             }
-
-            val serializedSizeLE = ByteArray(4)
-            serializedSizeLE[0] = (size and 0xff).toByte()
-            serializedSizeLE[1] = (size shr 8 and 0xff).toByte()
-            serializedSizeLE[2] = (size shr 16 and 0xff).toByte()
-            serializedSizeLE[3] = (size shr 24 and 0xff).toByte()
-            outputStream.write(serializedSizeLE)
-
-            val opcodeBytes = ByteArray(1)
-            opcodeBytes[0] = opcode.value
-            outputStream.write(opcodeBytes)
-
-            if (data.isNotEmpty()) {
-                outputStream.write(data)
-            }
-
-            Log.d(TAG, "Sent $size bytes: (opcode: $opcode, body: $message).")
-        } catch (e: Throwable) {
-            Log.i(TAG, "Failed to send message ${id}.", e)
-            throw e
         }
     }
 
diff --git a/receivers/android/app/src/main/java/com/futo/fcast/receiver/NetworkService.kt b/receivers/android/app/src/main/java/com/futo/fcast/receiver/NetworkService.kt
index 5ebfb9c..0820057 100644
--- a/receivers/android/app/src/main/java/com/futo/fcast/receiver/NetworkService.kt
+++ b/receivers/android/app/src/main/java/com/futo/fcast/receiver/NetworkService.kt
@@ -142,7 +142,7 @@ class NetworkService : Service() {
                     session.send(opcode, message)
                     Log.i(TAG, "Opcode sent (opcode = $opcode) ${session.id}")
                 } catch (e: Throwable) {
-                    Log.w(TAG, "Failed to send playback error", e)
+                    Log.w(TAG, "Failed to send opcode (opcode = $opcode) ${session.id}", e)
                 }
             }
         }