Allow non-user packages to be kept in the use data list

By default, we clean up the data from the package-dex-use.list at
every boot. The clean up will remove any obsolete or uninstalled
packages.

Since system server will not show up as a regular app, we need
to add a mechanism to ensure that its dex files are not cleaned up.

Test: atest DexManagerTests PackageManagerTests
Bug: 148774920
Change-Id: I0788163b066af5713b8763f1875338add2d49aa9

services/core/java/com/android/server/pm/dex/DexManager.java

@@ -45,6 +45,7 @@ import dalvik.system.VMRuntime;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -353,7 +354,9 @@ public class DexManager {
 
         try {
             mPackageDexUsage.read();
-            mPackageDexUsage.syncData(packageToUsersMap, packageToCodePaths);
+            List<String> packagesToKeepDataAbout = new ArrayList<>();
+            mPackageDexUsage.syncData(
+                    packageToUsersMap, packageToCodePaths, packagesToKeepDataAbout);
         } catch (Exception e) {
             mPackageDexUsage.clear();
             Slog.w(TAG, "Exception while loading package dex usage. "

services/core/java/com/android/server/pm/dex/PackageDexUsage.java

@@ -474,13 +474,19 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
      * Syncs the existing data with the set of available packages by removing obsolete entries.
      */
     /*package*/ void syncData(Map<String, Set<Integer>> packageToUsersMap,
-            Map<String, Set<String>> packageToCodePaths) {
+            Map<String, Set<String>> packageToCodePaths,
+            List<String> packagesToKeepDataAbout) {
         synchronized (mPackageUseInfoMap) {
             Iterator<Map.Entry<String, PackageUseInfo>> pIt =
                     mPackageUseInfoMap.entrySet().iterator();
             while (pIt.hasNext()) {
                 Map.Entry<String, PackageUseInfo> pEntry = pIt.next();
                 String packageName = pEntry.getKey();
+                if (packagesToKeepDataAbout.contains(packageName)) {
+                    // This is a package for which we should keep the data even if it's not
+                    // in the list of user packages.
+                    continue;
+                }
                 PackageUseInfo packageUseInfo = pEntry.getValue();
                 Set<Integer> users = packageToUsersMap.get(packageName);
                 if (users == null) {
@@ -501,11 +507,27 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
 
                     // Sync the code paths.
                     Set<String> codePaths = packageToCodePaths.get(packageName);
-                    Iterator<Map.Entry<String, Set<String>>> codeIt =
+
+                    Iterator<Map.Entry<String, Set<String>>> recordedIt =
                             packageUseInfo.mPrimaryCodePaths.entrySet().iterator();
-                    while (codeIt.hasNext()) {
-                        if (!codePaths.contains(codeIt.next().getKey())) {
-                            codeIt.remove();
+                    while (recordedIt.hasNext()) {
+                        Map.Entry<String, Set<String>> entry = recordedIt.next();
+                        String recordedCodePath = entry.getKey();
+                        if (!codePaths.contains(recordedCodePath)) {
+                            // Clean up a non existing code path.
+                            recordedIt.remove();
+                        } else {
+                            // Clean up a non existing loading package.
+                            Set<String> recordedLoadingPackages = entry.getValue();
+                            Iterator<String> recordedLoadingPackagesIt =
+                                    recordedLoadingPackages.iterator();
+                            while (recordedLoadingPackagesIt.hasNext()) {
+                                String recordedLoadingPackage = recordedLoadingPackagesIt.next();
+                                if (!packagesToKeepDataAbout.contains(recordedLoadingPackage)
+                                        && !packageToUsersMap.containsKey(recordedLoadingPackage)) {
+                                    recordedLoadingPackagesIt.remove();
+                                }
+                            }
                         }
                     }
 

services/tests/servicestests/src/com/android/server/pm/dex/PackageDexUsageTests.java

@@ -282,13 +282,48 @@ public class PackageDexUsageTests {
         Map<String, Set<String>> packageToCodePaths = new HashMap<>();
         packageToCodePaths.put(mBarBaseUser0.mPackageName,
                 new HashSet<>(Arrays.asList(mBarBaseUser0.mDexFile)));
-        mPackageDexUsage.syncData(packageToUsersMap, packageToCodePaths);
+        mPackageDexUsage.syncData(packageToUsersMap, packageToCodePaths, new ArrayList<String>());
 
         // Assert that only user 1 files are there.
         assertPackageDexUsage(mBarBaseUser0, mBarSecondary2User1);
         assertNull(mPackageDexUsage.getPackageUseInfo(mFooBaseUser0.mPackageName));
     }
 
+    @Test
+    public void testSyncDataKeepPackages() {
+        PackageDexUsage packageDexUsage = new PackageDexUsage();
+        // Write the record we want to keep and which won't be keep by default.
+        Set<String> fooUsers = new HashSet<>(Arrays.asList(
+                new String[] {mFooBaseUser0.mPackageName}));
+        assertTrue(record(packageDexUsage, mFooBaseUser0, fooUsers));
+        // Write a record that would be kept by default.
+        Set<String> barUsers = new HashSet<>(Arrays.asList(
+                new String[] {"another.package", mFooBaseUser0.mPackageName}));
+        assertTrue(record(packageDexUsage, mBarBaseUser0, barUsers));
+
+        // Construct the user packages and their code paths (things that will be
+        // kept by default during sync).
+        Map<String, Set<Integer>> packageToUsersMap = new HashMap<>();
+        packageToUsersMap.put(mBarBaseUser0.mPackageName,
+                new HashSet<>(Arrays.asList(mBarBaseUser0.mOwnerUserId)));
+        Map<String, Set<String>> packageToCodePaths = new HashMap<>();
+        packageToCodePaths.put(mBarBaseUser0.mPackageName,
+                new HashSet<>(Arrays.asList(mBarBaseUser0.mDexFile)));
+
+        // Sync data.
+        List<String> keepData = new ArrayList<String>();
+        keepData.add(mFooBaseUser0.mPackageName);
+        packageDexUsage.syncData(packageToUsersMap, packageToCodePaths, keepData);
+
+        // Assert that both packages are kept
+        assertPackageDexUsage(packageDexUsage, fooUsers, mFooBaseUser0);
+        // "another.package" should not be in the loading packages after sync.
+        Set<String> expectedBarUsers = new HashSet<>(Arrays.asList(
+                new String[] {mFooBaseUser0.mPackageName}));
+        assertPackageDexUsage(packageDexUsage, expectedBarUsers,
+                mBarBaseUser0.updateUsedBy(mFooBaseUser0.mPackageName));
+    }
+
     @Test
     public void testRemovePackage() {
         // Record Bar secondaries for two different users.
@@ -501,7 +536,7 @@ public class PackageDexUsageTests {
                 new HashSet<>(Arrays.asList(mFooSplit2UsedByOtherApps0.mOwnerUserId)));
 
         // Sync the data.
-        packageDexUsage.syncData(packageToUsersMap, packageToCodePaths);
+        packageDexUsage.syncData(packageToUsersMap, packageToCodePaths, new ArrayList<>());
 
         // Assert foo code paths.
         assertPackageDexUsage(
@@ -654,9 +689,9 @@ public class PackageDexUsageTests {
                     mPrimaryOrSplit, mUsedBy, newContext);
         }
 
-        private TestData updateUseByOthers(boolean newUsedByOthers) {
+        private TestData updateUsedBy(String newUsedBy) {
             return new TestData(mPackageName, mDexFile, mOwnerUserId, mLoaderIsa,
-                mPrimaryOrSplit, mUsedBy, mClassLoaderContext);
+                mPrimaryOrSplit, newUsedBy, mClassLoaderContext);
         }
 
         private boolean isUsedByOtherApps() {