diff --git a/examples/llama.android/llama/src/main/java/android/llama/cpp/LLamaAndroid.kt b/examples/llama.android/llama/src/main/java/android/llama/cpp/LLamaAndroid.kt
index ed46c16713..e84259422f 100644
--- a/examples/llama.android/llama/src/main/java/android/llama/cpp/LLamaAndroid.kt
+++ b/examples/llama.android/llama/src/main/java/android/llama/cpp/LLamaAndroid.kt
@@ -57,7 +57,7 @@ class LLamaAndroid {
     /**
      * Load the LLM, then process the formatted system prompt if provided
      */
-    suspend fun load(pathToModel: String, formattedSystemPrompt: String? = null) {
+    suspend fun load(pathToModel: String, formattedSystemPrompt: String? = null) =
         withContext(runLoop) {
             when (threadLocalState.get()) {
                 is State.NotInitialized -> {
@@ -72,7 +72,7 @@ class LLamaAndroid {
 
                     formattedSystemPrompt?.let {
                         initWithSystemPrompt(formattedSystemPrompt)
-                    } ?: {
+                    } ?: run {
                         Log.w(TAG, "No system prompt to process.")
                         threadLocalState.set(State.AwaitingUserPrompt)
                     }
@@ -80,12 +80,11 @@ class LLamaAndroid {
                 else -> throw IllegalStateException("Model already loaded")
             }
         }
-    }
 
     /**
      * Helper method to process system prompt and update [State]
      */
-    private suspend fun initWithSystemPrompt(formattedMessage: String) {
+    private suspend fun initWithSystemPrompt(formattedMessage: String) =
         withContext(runLoop) {
             when (threadLocalState.get()) {
                 is State.EnvReady -> {
@@ -104,7 +103,6 @@ class LLamaAndroid {
                 )
             }
         }
-    }
 
     /**
      * Send formatted user prompt to LLM
@@ -113,6 +111,10 @@ class LLamaAndroid {
         formattedMessage: String,
         nPredict: Int = DEFAULT_PREDICT_LENGTH,
     ): Flow<String> = flow {
+        require(formattedMessage.isNotEmpty()) {
+            Log.w(TAG, "User prompt discarded due to being empty!")
+        }
+
         when (val state = threadLocalState.get()) {
             is State.AwaitingUserPrompt -> {
                 Log.i(TAG, "Sending user prompt...")
@@ -143,26 +145,28 @@ class LLamaAndroid {
     /**
      * Benchmark the model
      */
-    suspend fun bench(pp: Int, tg: Int, pl: Int, nr: Int = 1): String {
-        return withContext(runLoop) {
-            when (val state = threadLocalState.get()) {
-                is State.EnvReady -> {
-                    Log.d(TAG, "bench(): $state")
-                    benchModel(pp, tg, pl, nr)
+    suspend fun bench(pp: Int, tg: Int, pl: Int, nr: Int = 1): String =
+        withContext(runLoop) {
+            when (threadLocalState.get()) {
+                is State.AwaitingUserPrompt -> {
+                    threadLocalState.set(State.Processing)
+                    Log.d(TAG, "Start benchmark (pp: $pp, tg: $tg, pl: $pl, nr: $nr)")
+                    benchModel(pp, tg, pl, nr).also {
+                        threadLocalState.set(State.AwaitingUserPrompt)
+                    }
                 }
 
-                // TODO-hyin: catch exception in ViewController; disable button when state incorrect
+                // TODO-hyin: disable button when state incorrect
                 else -> throw IllegalStateException("No model loaded")
             }
         }
-    }
 
     /**
      * Unloads the model and frees resources.
      *
      * This is a no-op if there's no model loaded.
      */
-    suspend fun unload() {
+    suspend fun unload() =
         withContext(runLoop) {
             when (val state = threadLocalState.get()) {
                 is State.EnvReady, State.AwaitingUserPrompt -> {
@@ -174,10 +178,9 @@ class LLamaAndroid {
                 }
             }
         }
-    }
 
     companion object {
-        private val TAG = this::class.simpleName
+        private val TAG = LLamaAndroid::class.simpleName
 
         private const val LIB_LLAMA_ANDROID = "llama-android"
         private const val LLAMA_THREAD = "llama-thread"