From 5564cddbd70a3745e516c39f5299de3886fdf936 Mon Sep 17 00:00:00 2001
From: Jeff Sharkey <jsharkey@android.com>
Date: Fri, 28 Oct 2022 14:47:06 -0600
Subject: [PATCH] BroadcastQueue: fix subtle OOM adjustment bug.

updateOomAdjPendingTargetsLocked() only takes effect for processes
that are already running as warm; it doesn't work on a process that
is still being cold started.

This change fixes the bug by making an explicit update call once
a pending cold start has become a warm process.

Bug: 255985948
Test: atest CtsAppTestCases:ActivityManagerProcessStateTest#testBackgroundCheckBroadcastService
Change-Id: I7e42984c7b7fd6e496fc9245304f1eff8ad71075
---
 .../server/am/BroadcastQueueModernImpl.java     | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java b/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java
index 9e9eb71db4e52..822294859f3a3 100644
--- a/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java
+++ b/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java
@@ -412,21 +412,24 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
             queue.runningTraceTrackName = TAG + ".mRunning[" + queueIndex + "]";
             queue.runningOomAdjusted = queue.isPendingManifest();
 
+            // If already warm, we can make OOM adjust request immediately;
+            // otherwise we need to wait until process becomes warm
+            if (processWarm) {
+                notifyStartedRunning(queue);
+                updateOomAdj |= queue.runningOomAdjusted;
+            }
+
             // If we're already warm, schedule next pending broadcast now;
             // otherwise we'll wait for the cold start to circle back around
             queue.makeActiveNextPending();
             if (processWarm) {
                 queue.traceProcessRunningBegin();
-                notifyStartedRunning(queue);
                 scheduleReceiverWarmLocked(queue);
             } else {
                 queue.traceProcessStartingBegin();
                 scheduleReceiverColdLocked(queue);
             }
 
-            // Only kick off an OOM adjustment pass if needed
-            updateOomAdj |= queue.runningOomAdjusted;
-
             // Move to considering next runnable queue
             queue = nextQueue;
         }
@@ -464,9 +467,13 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
             // now; dispatch its next broadcast and clear the slot
             mRunningColdStart = null;
 
+            // Now that we're running warm, we can finally request that OOM
+            // adjust we've been waiting for
+            notifyStartedRunning(queue);
+            mService.updateOomAdjPendingTargetsLocked(OOM_ADJ_REASON_START_RECEIVER);
+
             queue.traceProcessEnd();
             queue.traceProcessRunningBegin();
-            notifyStartedRunning(queue);
             scheduleReceiverWarmLocked(queue);
 
             // We might be willing to kick off another cold start