Merge "Revert "Remove flag `message_queue_force_legacy`"" into main

2 files changed, 15 insertions, 0 deletions

diff --git a/core/java/android/os/CombinedMessageQueue/MessageQueue.java b/core/java/android/os/CombinedMessageQueue/MessageQueue.java
index c3ec96d17437..c21959b16fbb 100644
--- a/core/java/android/os/CombinedMessageQueue/MessageQueue.java
+++ b/core/java/android/os/CombinedMessageQueue/MessageQueue.java
@@ -144,6 +144,12 @@ public final class MessageQueue {
             return;
         }
 
+        // Holdback study.
+        if (Flags.messageQueueForceLegacy()) {
+            sIsProcessAllowedToUseConcurrent = false;
+            return;
+        }
+
         if (Flags.forceConcurrentMessageQueue()) {
             // b/379472827: Robolectric tests use reflection to access MessageQueue.mMessages.
             // This is a hack to allow Robolectric tests to use the legacy implementation.
diff --git a/core/java/android/os/flags.aconfig b/core/java/android/os/flags.aconfig
index 0150d171d51c..b52a454ea956 100644
--- a/core/java/android/os/flags.aconfig
+++ b/core/java/android/os/flags.aconfig
@@ -4,6 +4,15 @@ container: "system"
 
 # keep-sorted start block=yes newline_separated=yes
 flag {
+     # Holdback study for concurrent MessageQueue.
+     # Do not promote beyond trunkfood.
+     namespace: "system_performance"
+     name: "message_queue_force_legacy"
+     description: "Whether to holdback concurrent MessageQueue (force legacy)."
+     bug: "336880969"
+}
+
+flag {
     name: "adpf_gpu_report_actual_work_duration"
     is_exported: true
     namespace: "game"