From a8ec0f5d0e0bd2932f759decd0aa1ad7c56a77d2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Wilczy=C5=84ski?= <wilczynskip@google.com>
Date: Fri, 8 Apr 2022 13:59:25 +0000
Subject: [PATCH] Move the call to flush() to avoid a race condition

Bug: 221393932
Test: atest PersistentDataStoreTest
Test: Manually change brightness, run 'adb shell dumpsys display | grep -A30 PersistentDataStore' and check that the brightness value has updated. Also reboot the device and check that the brightness value stays the same.
Change-Id: I6f0b958a7db832a0ebe5e9f2ebc434ac92f47a8a
---
 .../java/com/android/server/display/PersistentDataStore.java   | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/display/PersistentDataStore.java b/services/core/java/com/android/server/display/PersistentDataStore.java
index 4b93d8f42da39..59daee9ea2ff5 100644
--- a/services/core/java/com/android/server/display/PersistentDataStore.java
+++ b/services/core/java/com/android/server/display/PersistentDataStore.java
@@ -463,6 +463,7 @@ final class PersistentDataStore {
 
             TypedXmlSerializer serializer = Xml.resolveSerializer(os);
             saveToXml(serializer);
+            serializer.flush();
 
             mHandler.removeCallbacksAndMessages(/* token */ null);
             mHandler.post(() -> {
@@ -481,8 +482,6 @@ final class PersistentDataStore {
                     }
                 }
             });
-
-            serializer.flush();
         } catch (IOException ex) {
             Slog.w(TAG, "Failed to process the XML serializer.", ex);
         }