From ca7b4a149ae37f3b0e6817dca21910dc222363fc Mon Sep 17 00:00:00 2001
From: Hui Yu <huiyu@google.com>
Date: Wed, 20 Jan 2021 10:01:20 -0800
Subject: [PATCH] Add param isCheckingForFgsStart to
 areBackgroundActivityStartsAllowed().

If isCheckingForFgsStart is true, this checking is for FGS start, it
won't invoke the mBackgroundActivityStartCallback.

Bug: 177642703
Test: atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java
Change-Id: Ie6d58b8886e8477a9dbc524d43ccda930139a460
---
 .../com/android/server/am/ActiveServices.java |  2 +-
 .../server/wm/WindowProcessController.java    | 27 ++++++++++++++-----
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/services/core/java/com/android/server/am/ActiveServices.java b/services/core/java/com/android/server/am/ActiveServices.java
index fcb32a1677b19..e476ca908b5da 100644
--- a/services/core/java/com/android/server/am/ActiveServices.java
+++ b/services/core/java/com/android/server/am/ActiveServices.java
@@ -5373,7 +5373,7 @@ public final class ActiveServices {
             for (int i = mAm.mProcessList.mLruProcesses.size() - 1; i >= 0; i--) {
                 final ProcessRecord pr = mAm.mProcessList.mLruProcesses.get(i);
                 if (pr.uid == callingUid) {
-                    if (pr.getWindowProcessController().areBackgroundActivityStartsAllowed()) {
+                    if (pr.getWindowProcessController().areBackgroundFgsStartsAllowed()) {
                         ret = FGS_FEATURE_ALLOWED_BY_ACTIVITY_STARTER;
                         break;
                     }
diff --git a/services/core/java/com/android/server/wm/WindowProcessController.java b/services/core/java/com/android/server/wm/WindowProcessController.java
index 389f428a41389..66b6616ea28ff 100644
--- a/services/core/java/com/android/server/wm/WindowProcessController.java
+++ b/services/core/java/com/android/server/wm/WindowProcessController.java
@@ -519,13 +519,21 @@ public class WindowProcessController extends ConfigurationContainer<Configuratio
         }
     }
 
-    public boolean areBackgroundActivityStartsAllowed() {
+    /**
+     * Is this WindowProcessController in the state of allowing background FGS start?
+     */
+    public boolean areBackgroundFgsStartsAllowed() {
         synchronized (mAtm.mGlobalLock) {
-            return areBackgroundActivityStartsAllowed(mAtm.getBalAppSwitchesAllowed());
+            return areBackgroundActivityStartsAllowed(mAtm.getBalAppSwitchesAllowed(), true);
         }
     }
 
     boolean areBackgroundActivityStartsAllowed(boolean appSwitchAllowed) {
+        return areBackgroundActivityStartsAllowed(appSwitchAllowed, false);
+    }
+
+    boolean areBackgroundActivityStartsAllowed(boolean appSwitchAllowed,
+            boolean isCheckingForFgsStart) {
         // If app switching is not allowed, we ignore all the start activity grace period
         // exception so apps cannot start itself in onPause() after pressing home button.
         if (appSwitchAllowed) {
@@ -579,7 +587,7 @@ public class WindowProcessController extends ConfigurationContainer<Configuratio
             return true;
         }
         // allow if the flag was explicitly set
-        if (isBackgroundStartAllowedByToken()) {
+        if (isBackgroundStartAllowedByToken(isCheckingForFgsStart)) {
             if (DEBUG_ACTIVITY_STARTS) {
                 Slog.d(TAG, "[WindowProcessController(" + mPid
                         + ")] Activity start allowed: process allowed by token");
@@ -590,13 +598,20 @@ public class WindowProcessController extends ConfigurationContainer<Configuratio
     }
 
     /**
-     * If there are no tokens, we don't allow *by token*. If there are tokens, we ask the callback
-     * if the start is allowed for these tokens, otherwise if there is no callback we allow.
+     * If there are no tokens, we don't allow *by token*. If there are tokens and
+     * isCheckingForFgsStart is false, we ask the callback if the start is allowed for these tokens,
+     * otherwise if there is no callback we allow.
      */
-    private boolean isBackgroundStartAllowedByToken() {
+    private boolean isBackgroundStartAllowedByToken(boolean isCheckingForFgsStart) {
         if (mBackgroundActivityStartTokens.isEmpty()) {
             return false;
         }
+
+        if (isCheckingForFgsStart) {
+            /// The checking is for BG-FGS-start.
+            return true;
+        }
+
         if (mBackgroundActivityStartCallback == null) {
             // We have tokens but no callback to decide => allow
             return true;