From d2aa4e1913c05d8c21e81eef3ad941565aded7d6 Mon Sep 17 00:00:00 2001
From: Amith Yamasani <yamasani@google.com>
Date: Mon, 9 Jul 2018 12:07:35 -0700
Subject: [PATCH] Fix for incorrect cycle evaluation in computeOomAdj DO NOT
 MERGE

Use the conservative value of adj and procstate if at least
one evaluation pass was completed, even if the value is not
final. The later iterations through the procs that have
cycles will elevate the apps if necessary. Otherwise the
dependencies will just get stuck in a low state.

Bug: 79643956
Test: Manual test of connecting to AA and turning off screen
      atest CtsAppTestCases:ActivityManagerProcessStateTest

Change-Id: If520eb239935782e2487b16e8bb650ded775f184
---
 .../server/am/ActivityManagerService.java     | 36 +++++++++++++------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index d8d63927f5e13..e032afb408e10 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -23042,6 +23042,7 @@ public class ActivityManagerService extends IActivityManager.Stub
                 // The process is being computed, so there is a cycle. We cannot
                 // rely on this process's state.
                 app.containsCycle = true;
+
                 return false;
             }
         }
@@ -23066,6 +23067,7 @@ public class ActivityManagerService extends IActivityManager.Stub
         final int logUid = mCurOomAdjUid;
 
         int prevAppAdj = app.curAdj;
+        int prevProcState = app.curProcState;
 
         if (app.maxAdj <= ProcessList.FOREGROUND_APP_ADJ) {
             // The max adjustment doesn't allow this app to be anything
@@ -23544,11 +23546,16 @@ public class ActivityManagerService extends IActivityManager.Stub
                         ProcessRecord client = cr.binding.client;
                         computeOomAdjLocked(client, cachedAdj, TOP_APP, doingAll, now);
                         if (client.containsCycle) {
-                            // We've detected a cycle. We should ignore this connection and allow
-                            // this process to retry computeOomAdjLocked later in case a later-checked
-                            // connection from a client  would raise its priority legitimately.
+                            // We've detected a cycle. We should retry computeOomAdjLocked later in
+                            // case a later-checked connection from a client  would raise its
+                            // priority legitimately.
                             app.containsCycle = true;
-                            continue;
+                            // If the client has not been completely evaluated, skip using its
+                            // priority. Else use the conservative value for now and look for a
+                            // better state in the next iteration.
+                            if (client.completedAdjSeq < mAdjSeq) {
+                                continue;
+                            }
                         }
                         int clientAdj = client.curRawAdj;
                         int clientProcState = client.curProcState;
@@ -23771,11 +23778,16 @@ public class ActivityManagerService extends IActivityManager.Stub
                 }
                 computeOomAdjLocked(client, cachedAdj, TOP_APP, doingAll, now);
                 if (client.containsCycle) {
-                    // We've detected a cycle. We should ignore this connection and allow
-                    // this process to retry computeOomAdjLocked later in case a later-checked
-                    // connection from a client  would raise its priority legitimately.
+                    // We've detected a cycle. We should retry computeOomAdjLocked later in
+                    // case a later-checked connection from a client  would raise its
+                    // priority legitimately.
                     app.containsCycle = true;
-                    continue;
+                    // If the client has not been completely evaluated, skip using its
+                    // priority. Else use the conservative value for now and look for a
+                    // better state in the next iteration.
+                    if (client.completedAdjSeq < mAdjSeq) {
+                        continue;
+                    }
                 }
                 int clientAdj = client.curRawAdj;
                 int clientProcState = client.curProcState;
@@ -24007,8 +24019,8 @@ public class ActivityManagerService extends IActivityManager.Stub
         app.foregroundActivities = foregroundActivities;
         app.completedAdjSeq = mAdjSeq;
 
-        // if curAdj is less than prevAppAdj, then this process was promoted
-        return app.curAdj < prevAppAdj;
+        // if curAdj or curProcState improved, then this process was promoted
+        return app.curAdj < prevAppAdj || app.curProcState < prevProcState;
     }
 
     /**
@@ -25061,7 +25073,7 @@ public class ActivityManagerService extends IActivityManager.Stub
         // - Continue retrying until no process was promoted.
         // - Iterate from least important to most important.
         int cycleCount = 0;
-        while (retryCycles) {
+        while (retryCycles && cycleCount < 10) {
             cycleCount++;
             retryCycles = false;
 
@@ -25076,12 +25088,14 @@ public class ActivityManagerService extends IActivityManager.Stub
             for (int i=0; i<N; i++) {
                 ProcessRecord app = mLruProcesses.get(i);
                 if (!app.killedByAm && app.thread != null && app.containsCycle == true) {
+
                     if (computeOomAdjLocked(app, ProcessList.UNKNOWN_ADJ, TOP_APP, true, now)) {
                         retryCycles = true;
                     }
                 }
             }
         }
+
         for (int i=N-1; i>=0; i--) {
             ProcessRecord app = mLruProcesses.get(i);
             if (!app.killedByAm && app.thread != null) {