From c181d60bac646e8b8f09196b63e898a41ccd4599 Mon Sep 17 00:00:00 2001
From: Chaohui Wang <chaohuiw@google.com>
Date: Thu, 25 Jul 2024 10:23:21 +0800
Subject: [PATCH] Fix race condition when requestNetworkScan

requestNetworkScan() could call callbacks concurrently, so we use a
single thread to avoid racing conditions.

Fix: 345494692
Flag: EXEMPT bug fix
Test: manual - do network scan
Change-Id: Ibf38442bbd9cfbbd0762b31347645810aca1113b
---
 .../network/telephony/scan/NetworkScanRepository.kt         | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/com/android/settings/network/telephony/scan/NetworkScanRepository.kt b/src/com/android/settings/network/telephony/scan/NetworkScanRepository.kt
index 0e1503326bd..caf8549d53d 100644
--- a/src/com/android/settings/network/telephony/scan/NetworkScanRepository.kt
+++ b/src/com/android/settings/network/telephony/scan/NetworkScanRepository.kt
@@ -30,8 +30,8 @@ import com.android.settings.R
 import com.android.settings.network.telephony.CellInfoUtil.getNetworkTitle
 import com.android.settings.network.telephony.telephonyManager
 import com.android.settingslib.spa.framework.util.collectLatestWithLifecycle
+import java.util.concurrent.Executors
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.asExecutor
 import kotlinx.coroutines.channels.awaitClose
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.callbackFlow
@@ -96,7 +96,9 @@ class NetworkScanRepository(private val context: Context, subId: Int) {
 
         val networkScan = telephonyManager.requestNetworkScan(
             createNetworkScan(),
-            Dispatchers.Default.asExecutor(),
+            // requestNetworkScan() could call callbacks concurrently, so we use a single thread
+            // to avoid racing conditions.
+            Executors.newSingleThreadExecutor(),
             callback,
         )