From ac7b17b98d56ecc6dfac434f63bd9979c24b60df Mon Sep 17 00:00:00 2001
From: Gavin Corkery <gavincorkery@google.com>
Date: Mon, 1 Jun 2020 23:06:23 +0100
Subject: Unbind explicit health check controller when possible

Ensure that calls to sync requests with the explicit health
check controller are always sent if the list of packages
pending health checks is empty, so that the controller can
unbind. This will allow extservices to be killed by lmkd
on low memory devices.

Test: atest PackageWatchdogTest
Test: atest NetworkStagedRollbackTest
Test: check logcat to see that the service is unbound
Bug: 156323728
Change-Id: If615a337760b2057b962284bde8565b593d82a50
---
 services/core/java/com/android/server/PackageWatchdog.java       | 9 ++++++---
 .../src/com/android/server/PackageWatchdogTest.java              | 1 +
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/services/core/java/com/android/server/PackageWatchdog.java b/services/core/java/com/android/server/PackageWatchdog.java
index e77458cc955a..fd7abfa65c86 100644
--- a/services/core/java/com/android/server/PackageWatchdog.java
+++ b/services/core/java/com/android/server/PackageWatchdog.java
@@ -239,7 +239,10 @@ public class PackageWatchdog {
             mIsPackagesReady = true;
             mHealthCheckController.setCallbacks(packageName -> onHealthCheckPassed(packageName),
                     packages -> onSupportedPackages(packages),
-                    () -> syncRequestsAsync());
+                    () -> {
+                            syncRequestsAsync();
+                            mSyncRequired = true;
+                    });
             setPropertyChangedListenerLocked();
             updateConfigs();
             registerConnectivityModuleHealthListener();
@@ -255,7 +258,6 @@ public class PackageWatchdog {
      */
     public void registerHealthObserver(PackageHealthObserver observer) {
         synchronized (mLock) {
-            mSyncRequired = true;
             ObserverInternal internalObserver = mAllObservers.get(observer.getName());
             if (internalObserver != null) {
                 internalObserver.registeredObserver = observer;
@@ -642,7 +644,8 @@ public class PackageWatchdog {
         synchronized (mLock) {
             if (mIsPackagesReady) {
                 Set<String> packages = getPackagesPendingHealthChecksLocked();
-                if (!packages.equals(mRequestedHealthCheckPackages) || mSyncRequired) {
+                if (mSyncRequired || !packages.equals(mRequestedHealthCheckPackages)
+                        || packages.isEmpty()) {
                     syncRequired = true;
                     mRequestedHealthCheckPackages = packages;
                 }
diff --git a/tests/PackageWatchdog/src/com/android/server/PackageWatchdogTest.java b/tests/PackageWatchdog/src/com/android/server/PackageWatchdogTest.java
index d011dbbbe5db..ae93a81f274e 100644
--- a/tests/PackageWatchdog/src/com/android/server/PackageWatchdogTest.java
+++ b/tests/PackageWatchdog/src/com/android/server/PackageWatchdogTest.java
@@ -1113,6 +1113,7 @@ public class PackageWatchdogTest {
         mTestLooper.dispatchAll();
 
         List<Set> expectedSyncRequests = List.of(
+                Set.of(),
                 Set.of(APP_A),
                 Set.of(APP_A, APP_B),
                 Set.of(APP_A, APP_B, APP_C),
-- 
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