From d20f8d5095aa87c8ea4acdcfae1fe1d004c1ac6f Mon Sep 17 00:00:00 2001
From: Atneya Nair <atneya@google.com>
Date: Thu, 27 Apr 2023 17:21:52 -0700
Subject: [PATCH] Cache dropped callbacks in STInstrumentation

Sessions can receive callbacks before the client attaches their
callback. To avoid flake, if there is no callback registered, save the
messages in order, and dispatch them when the callback is registered.

Bug: 279774505
Test: AlwaysOnHotwordDetectorTest --iterations 20
Test: SoundTriggerManagerTest --iterations 20
Change-Id: I2dc96e0a3d52149eb0bad75ffd45869b16460057
---
 .../SoundTriggerInstrumentation.java          | 33 ++++++++++++++++---
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/media/java/android/media/soundtrigger/SoundTriggerInstrumentation.java b/media/java/android/media/soundtrigger/SoundTriggerInstrumentation.java
index 80bc5c07dd667..3dfc58788e8a5 100644
--- a/media/java/android/media/soundtrigger/SoundTriggerInstrumentation.java
+++ b/media/java/android/media/soundtrigger/SoundTriggerInstrumentation.java
@@ -231,9 +231,17 @@ public final class SoundTriggerInstrumentation {
          */
         public void setModelCallback(@NonNull @CallbackExecutor Executor executor, @NonNull
                 ModelCallback callback) {
+            Objects.requireNonNull(callback);
+            Objects.requireNonNull(executor);
             synchronized (SoundTriggerInstrumentation.this.mLock) {
-                mModelCallback = Objects.requireNonNull(callback);
-                mModelExecutor = Objects.requireNonNull(executor);
+                if (mModelCallback == null) {
+                    for (var droppedConsumer : mDroppedConsumerList) {
+                        executor.execute(() -> droppedConsumer.accept(callback));
+                    }
+                    mDroppedConsumerList.clear();
+                }
+                mModelCallback = callback;
+                mModelExecutor = executor;
             }
         }
 
@@ -267,9 +275,11 @@ public final class SoundTriggerInstrumentation {
 
         private void wrap(Consumer<ModelCallback> consumer) {
             synchronized (SoundTriggerInstrumentation.this.mLock) {
-                if (mModelCallback != null && mModelExecutor != null) {
+                if (mModelCallback != null) {
                     final ModelCallback callback = mModelCallback;
                     mModelExecutor.execute(() -> consumer.accept(callback));
+                } else {
+                    mDroppedConsumerList.add(consumer);
                 }
             }
         }
@@ -282,6 +292,8 @@ public final class SoundTriggerInstrumentation {
         private ModelCallback mModelCallback = null;
         @GuardedBy("SoundTriggerInstrumentation.this.mLock")
         private Executor mModelExecutor = null;
+        @GuardedBy("SoundTriggerInstrumentation.this.mLock")
+        private final List<Consumer<ModelCallback>> mDroppedConsumerList = new ArrayList<>();
     }
 
     /**
@@ -374,9 +386,18 @@ public final class SoundTriggerInstrumentation {
          */
         public void setRecognitionCallback(@NonNull @CallbackExecutor Executor executor,
                 @NonNull RecognitionCallback callback) {
+            Objects.requireNonNull(callback);
+            Objects.requireNonNull(executor);
             synchronized (SoundTriggerInstrumentation.this.mLock) {
+                if (mRecognitionCallback == null) {
+                    for (var droppedConsumer : mDroppedConsumerList) {
+                        executor.execute(() -> droppedConsumer.accept(callback));
+                    }
+                    mDroppedConsumerList.clear();
+                }
                 mRecognitionCallback = callback;
                 mRecognitionExecutor = executor;
+
             }
         }
 
@@ -401,9 +422,11 @@ public final class SoundTriggerInstrumentation {
 
         private void wrap(Consumer<RecognitionCallback> consumer) {
             synchronized (SoundTriggerInstrumentation.this.mLock) {
-                if (mRecognitionCallback != null && mRecognitionExecutor != null) {
+                if (mRecognitionCallback != null) {
                     final RecognitionCallback callback = mRecognitionCallback;
                     mRecognitionExecutor.execute(() -> consumer.accept(callback));
+                } else {
+                    mDroppedConsumerList.add(consumer);
                 }
             }
         }
@@ -416,6 +439,8 @@ public final class SoundTriggerInstrumentation {
         private Executor mRecognitionExecutor = null;
         @GuardedBy("SoundTriggerInstrumentation.this.mLock")
         private RecognitionCallback mRecognitionCallback = null;
+        @GuardedBy("SoundTriggerInstrumentation.this.mLock")
+        private final List<Consumer<RecognitionCallback>> mDroppedConsumerList = new ArrayList<>();
     }
 
     // Implementation of injection interface passed to the HAL.