Merge changes Ie8b78c7c,If02081d2

am: fe177b78d7

Change-Id: I2720d1e1433367e9f584451408951dce0b61e0da

10 files changed, 583 insertions, 81 deletions

diff --git a/core/java/android/app/DexLoadReporter.java b/core/java/android/app/DexLoadReporter.java
index fc697a30e6ae..d15dd6d71f94 100644
--- a/core/java/android/app/DexLoadReporter.java
+++ b/core/java/android/app/DexLoadReporter.java
@@ -31,7 +31,7 @@ import libcore.io.Libcore;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.Arrays;
+import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -116,13 +116,18 @@ import java.util.Set;
         registerSecondaryDexForProfiling(dexPathsForRegistration);
     }
 
-    private void notifyPackageManager(List<BaseDexClassLoader> ignored,
+    private void notifyPackageManager(List<BaseDexClassLoader> classLoadersChain,
             List<String> classPaths) {
+        // Get the class loader names for the binder call.
+        List<String> classLoadersNames = new ArrayList<>(classPaths.size());
+        for (BaseDexClassLoader bdc : classLoadersChain) {
+            classLoadersNames.add(bdc.getClass().getName());
+        }
         String packageName = ActivityThread.currentPackageName();
         try {
             // Notify only the paths of the first class loader for now.
             ActivityThread.getPackageManager().notifyDexLoad(
-                    packageName, Arrays.asList(classPaths.get(0).split(File.pathSeparator)),
+                    packageName, classLoadersNames, classPaths,
                     VMRuntime.getRuntime().vmInstructionSet());
         } catch (RemoteException re) {
             Slog.e(TAG, "Failed to notify PM about dex load for package " + packageName, re);
diff --git a/core/java/android/content/pm/IPackageManager.aidl b/core/java/android/content/pm/IPackageManager.aidl
index 64d687e9d3de..c9afd6b7e930 100644
--- a/core/java/android/content/pm/IPackageManager.aidl
+++ b/core/java/android/content/pm/IPackageManager.aidl
@@ -469,11 +469,19 @@ interface IPackageManager {
      * Notify the package manager that a list of dex files have been loaded.
      *
      * @param loadingPackageName the name of the package who performs the load
-     * @param dexPats the list of the dex files paths that have been loaded
+     * @param classLoadersNames the names of the class loaders present in the loading chain. The
+     *    list encodes the class loader chain in the natural order. The first class loader has
+     *    the second one as its parent and so on. The dex files present in the class path of the
+     *    first class loader will be recorded in the usage file.
+     * @param classPaths the class paths corresponding to the class loaders names from
+     *     {@param classLoadersNames}. The the first element corresponds to the first class loader
+     *     and so on. A classpath is represented as a list of dex files separated by
+     *     {@code File.pathSeparator}.
+     *     The dex files found in the first class path will be recorded in the usage file.
      * @param loaderIsa the ISA of the loader process
      */
-    oneway void notifyDexLoad(String loadingPackageName, in List<String> dexPaths,
-            String loaderIsa);
+    oneway void notifyDexLoad(String loadingPackageName, in List<String> classLoadersNames,
+            in List<String> classPaths, String loaderIsa);
 
     /**
      * Register an application dex module with the package manager.
diff --git a/services/core/java/com/android/server/pm/PackageDexOptimizer.java b/services/core/java/com/android/server/pm/PackageDexOptimizer.java
index 68d9227ece43..817fc903c39d 100644
--- a/services/core/java/com/android/server/pm/PackageDexOptimizer.java
+++ b/services/core/java/com/android/server/pm/PackageDexOptimizer.java
@@ -34,12 +34,12 @@ import com.android.internal.util.IndentingPrintWriter;
 import com.android.server.pm.Installer.InstallerException;
 import com.android.server.pm.dex.DexoptOptions;
 import com.android.server.pm.dex.DexoptUtils;
+import com.android.server.pm.dex.PackageDexUsage;
 
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Set;
 
 import dalvik.system.DexFile;
 
@@ -263,13 +263,12 @@ public class PackageDexOptimizer {
      * throwing exceptions). Or maybe make a separate call to installd to get DexOptNeeded, though
      * that seems wasteful.
      */
-    public int dexOptSecondaryDexPath(ApplicationInfo info, String path, Set<String> isas,
-            String compilerFilter, boolean isUsedByOtherApps, boolean downgrade) {
+    public int dexOptSecondaryDexPath(ApplicationInfo info, String path,
+            PackageDexUsage.DexUseInfo dexUseInfo, DexoptOptions options) {
         synchronized (mInstallLock) {
             final long acquireTime = acquireWakeLockLI(info.uid);
             try {
-                return dexOptSecondaryDexPathLI(info, path, isas, compilerFilter,
-                        isUsedByOtherApps, downgrade);
+                return dexOptSecondaryDexPathLI(info, path, dexUseInfo, options);
             } finally {
                 releaseWakeLockLI(acquireTime);
             }
@@ -310,9 +309,16 @@ public class PackageDexOptimizer {
     }
 
     @GuardedBy("mInstallLock")
-    private int dexOptSecondaryDexPathLI(ApplicationInfo info, String path, Set<String> isas,
-            String compilerFilter, boolean isUsedByOtherApps, boolean downgrade) {
-        compilerFilter = getRealCompilerFilter(info, compilerFilter, isUsedByOtherApps);
+    private int dexOptSecondaryDexPathLI(ApplicationInfo info, String path,
+            PackageDexUsage.DexUseInfo dexUseInfo, DexoptOptions options) {
+        if (options.isDexoptOnlySharedDex() && !dexUseInfo.isUsedByOtherApps()) {
+            // We are asked to optimize only the dex files used by other apps and this is not
+            // on of them: skip it.
+            return DEX_OPT_SKIPPED;
+        }
+
+        String compilerFilter = getRealCompilerFilter(info, options.getCompilerFilter(),
+                dexUseInfo.isUsedByOtherApps());
         // Get the dexopt flags after getRealCompilerFilter to make sure we get the correct flags.
         // Secondary dex files are currently not compiled at boot.
         int dexoptFlags = getDexFlags(info, compilerFilter, /* bootComplete */ true)
@@ -329,20 +335,32 @@ public class PackageDexOptimizer {
             return DEX_OPT_FAILED;
         }
         Log.d(TAG, "Running dexopt on: " + path
-                + " pkg=" + info.packageName + " isa=" + isas
+                + " pkg=" + info.packageName + " isa=" + dexUseInfo.getLoaderIsas()
                 + " dexoptFlags=" + printDexoptFlags(dexoptFlags)
                 + " target-filter=" + compilerFilter);
 
+        String classLoaderContext;
+        if (dexUseInfo.isUnknownClassLoaderContext() ||
+                dexUseInfo.isUnsupportedClassLoaderContext() ||
+                dexUseInfo.isVariableClassLoaderContext()) {
+            // If we have an unknown (not yet set), unsupported (custom class loaders), or a
+            // variable class loader chain, compile without a context and mark the oat file with
+            // SKIP_SHARED_LIBRARY_CHECK. Note that his might lead to a incorrect compilation.
+            // TODO(calin): We should just extract in this case.
+            classLoaderContext = SKIP_SHARED_LIBRARY_CHECK;
+        } else {
+            classLoaderContext = dexUseInfo.getClassLoaderContext();
+        }
         try {
-            for (String isa : isas) {
+            for (String isa : dexUseInfo.getLoaderIsas()) {
                 // Reuse the same dexopt path as for the primary apks. We don't need all the
                 // arguments as some (dexopNeeded and oatDir) will be computed by installd because
                 // system server cannot read untrusted app content.
                 // TODO(calin): maybe add a separate call.
                 mInstaller.dexopt(path, info.uid, info.packageName, isa, /*dexoptNeeded*/ 0,
                         /*oatDir*/ null, dexoptFlags,
-                        compilerFilter, info.volumeUuid, SKIP_SHARED_LIBRARY_CHECK, info.seInfoUser,
-                        downgrade);
+                        compilerFilter, info.volumeUuid, classLoaderContext, info.seInfoUser,
+                        options.isDowngrade());
             }
 
             return DEX_OPT_PERFORMED;
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 8f4e8de987e9..946f6cacd6af 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -9461,7 +9461,8 @@ public class PackageManagerService extends IPackageManager.Stub
     }
 
     @Override
-    public void notifyDexLoad(String loadingPackageName, List<String> dexPaths, String loaderIsa) {
+    public void notifyDexLoad(String loadingPackageName, List<String> classLoaderNames,
+            List<String> classPaths, String loaderIsa) {
         int userId = UserHandle.getCallingUserId();
         ApplicationInfo ai = getApplicationInfo(loadingPackageName, /*flags*/ 0, userId);
         if (ai == null) {
@@ -9469,7 +9470,7 @@ public class PackageManagerService extends IPackageManager.Stub
                 + loadingPackageName + ", user=" + userId);
             return;
         }
-        mDexManager.notifyDexLoad(ai, dexPaths, loaderIsa, userId);
+        mDexManager.notifyDexLoad(ai, classLoaderNames, classPaths, loaderIsa, userId);
     }
 
     @Override
diff --git a/services/core/java/com/android/server/pm/dex/DexManager.java b/services/core/java/com/android/server/pm/dex/DexManager.java
index b2851d7cbeab..947e01c49c59 100644
--- a/services/core/java/com/android/server/pm/dex/DexManager.java
+++ b/services/core/java/com/android/server/pm/dex/DexManager.java
@@ -97,29 +97,55 @@ public class DexManager {
      * return as fast as possible.
      *
      * @param loadingAppInfo the package performing the load
-     * @param dexPaths the list of dex files being loaded
+     * @param classLoadersNames the names of the class loaders present in the loading chain. The
+     *    list encodes the class loader chain in the natural order. The first class loader has
+     *    the second one as its parent and so on. The dex files present in the class path of the
+     *    first class loader will be recorded in the usage file.
+     * @param classPaths the class paths corresponding to the class loaders names from
+     *     {@param classLoadersNames}. The the first element corresponds to the first class loader
+     *     and so on. A classpath is represented as a list of dex files separated by
+     *     {@code File.pathSeparator}.
+     *     The dex files found in the first class path will be recorded in the usage file.
      * @param loaderIsa the ISA of the app loading the dex files
      * @param loaderUserId the user id which runs the code loading the dex files
      */
-    public void notifyDexLoad(ApplicationInfo loadingAppInfo, List<String> dexPaths,
-            String loaderIsa, int loaderUserId) {
+    public void notifyDexLoad(ApplicationInfo loadingAppInfo, List<String> classLoadersNames,
+            List<String> classPaths, String loaderIsa, int loaderUserId) {
         try {
-            notifyDexLoadInternal(loadingAppInfo, dexPaths, loaderIsa, loaderUserId);
+            notifyDexLoadInternal(loadingAppInfo, classLoadersNames, classPaths, loaderIsa,
+                    loaderUserId);
         } catch (Exception e) {
             Slog.w(TAG, "Exception while notifying dex load for package " +
                     loadingAppInfo.packageName, e);
         }
     }
 
-    private void notifyDexLoadInternal(ApplicationInfo loadingAppInfo, List<String> dexPaths,
-            String loaderIsa, int loaderUserId) {
+    private void notifyDexLoadInternal(ApplicationInfo loadingAppInfo,
+            List<String> classLoaderNames, List<String> classPaths, String loaderIsa,
+            int loaderUserId) {
+        if (classLoaderNames.size() != classPaths.size()) {
+            Slog.wtf(TAG, "Bad call to noitfyDexLoad: args have different size");
+            return;
+        }
+        if (classLoaderNames.isEmpty()) {
+            Slog.wtf(TAG, "Bad call to notifyDexLoad: class loaders list is empty");
+            return;
+        }
         if (!PackageManagerServiceUtils.checkISA(loaderIsa)) {
-            Slog.w(TAG, "Loading dex files " + dexPaths + " in unsupported ISA: " +
+            Slog.w(TAG, "Loading dex files " + classPaths + " in unsupported ISA: " +
                     loaderIsa + "?");
             return;
         }
 
-        for (String dexPath : dexPaths) {
+        // The classpath is represented as a list of dex files separated by File.pathSeparator.
+        String[] dexPathsToRegister = classPaths.get(0).split(File.pathSeparator);
+
+        // Encode the class loader contexts for the dexPathsToRegister.
+        String[] classLoaderContexts = DexoptUtils.processContextForDexLoad(
+                classLoaderNames, classPaths);
+
+        int dexPathIndex = 0;
+        for (String dexPath : dexPathsToRegister) {
             // Find the owning package name.
             DexSearchResult searchResult = getDexPackage(loadingAppInfo, dexPath, loaderUserId);
 
@@ -147,24 +173,25 @@ public class DexManager {
                 // Record dex file usage. If the current usage is a new pattern (e.g. new secondary,
                 // or UsedBytOtherApps), record will return true and we trigger an async write
                 // to disk to make sure we don't loose the data in case of a reboot.
+
+                // A null classLoaderContexts means that there are unsupported class loaders in the
+                // chain.
+                String classLoaderContext = classLoaderContexts == null
+                        ? PackageDexUsage.UNSUPPORTED_CLASS_LOADER_CONTEXT
+                        : classLoaderContexts[dexPathIndex];
                 if (mPackageDexUsage.record(searchResult.mOwningPackageName,
                         dexPath, loaderUserId, loaderIsa, isUsedByOtherApps, primaryOrSplit,
-                        loadingAppInfo.packageName)) {
+                        loadingAppInfo.packageName, classLoaderContext)) {
                     mPackageDexUsage.maybeWriteAsync();
                 }
             } else {
-                // This can happen in a few situations:
-                // - bogus dex loads
-                // - recent installs/uninstalls that we didn't detect.
-                // - new installed splits
                 // If we can't find the owner of the dex we simply do not track it. The impact is
                 // that the dex file will not be considered for offline optimizations.
-                // TODO(calin): add hooks for move/uninstall notifications to
-                // capture package moves or obsolete packages.
                 if (DEBUG) {
                     Slog.i(TAG, "Could not find owning package for dex file: " + dexPath);
                 }
             }
+            dexPathIndex++;
         }
     }
 
@@ -328,10 +355,8 @@ public class DexManager {
         for (Map.Entry<String, DexUseInfo> entry : useInfo.getDexUseInfoMap().entrySet()) {
             String dexPath = entry.getKey();
             DexUseInfo dexUseInfo = entry.getValue();
-            if (options.isDexoptOnlySharedDex() && !dexUseInfo.isUsedByOtherApps()) {
-                continue;
-            }
-            PackageInfo pkg = null;
+
+            PackageInfo pkg;
             try {
                 pkg = mPackageManager.getPackageInfo(packageName, /*flags*/0,
                     dexUseInfo.getOwnerUserId());
@@ -350,8 +375,7 @@ public class DexManager {
             }
 
             int result = pdo.dexOptSecondaryDexPath(pkg.applicationInfo, dexPath,
-                    dexUseInfo.getLoaderIsas(), options.getCompilerFilter(),
-                    dexUseInfo.isUsedByOtherApps(), options.isDowngrade());
+                    dexUseInfo, options);
             success = success && (result != PackageDexOptimizer.DEX_OPT_FAILED);
         }
         return success;
@@ -434,6 +458,8 @@ public class DexManager {
         }
     }
 
+    // TODO(calin): questionable API in the presence of class loaders context. Needs amends as the
+    // compilation happening here will use a pessimistic context.
     public RegisterDexModuleResult registerDexModule(ApplicationInfo info, String dexPath,
             boolean isUsedByOtherApps, int userId) {
         // Find the owning package record.
@@ -452,12 +478,11 @@ public class DexManager {
 
         // We found the package. Now record the usage for all declared ISAs.
         boolean update = false;
-        Set<String> isas = new HashSet<>();
         for (String isa : getAppDexInstructionSets(info)) {
-            isas.add(isa);
             boolean newUpdate = mPackageDexUsage.record(searchResult.mOwningPackageName,
                     dexPath, userId, isa, isUsedByOtherApps, /*primaryOrSplit*/ false,
-                    searchResult.mOwningPackageName);
+                    searchResult.mOwningPackageName,
+                    PackageDexUsage.UNKNOWN_CLASS_LOADER_CONTEXT);
             update |= newUpdate;
         }
         if (update) {
@@ -467,8 +492,13 @@ public class DexManager {
         // Try to optimize the package according to the install reason.
         String compilerFilter = PackageManagerServiceCompilerMapping.getCompilerFilterForReason(
                 PackageManagerService.REASON_INSTALL);
-        int result = mPackageDexOptimizer.dexOptSecondaryDexPath(info, dexPath, isas,
-                compilerFilter, isUsedByOtherApps, /* downgrade */ false);
+        DexUseInfo dexUseInfo = mPackageDexUsage.getPackageUseInfo(searchResult.mOwningPackageName)
+                .getDexUseInfoMap().get(dexPath);
+
+        DexoptOptions options = new DexoptOptions(info.packageName, compilerFilter, /*flags*/0);
+
+        int result = mPackageDexOptimizer.dexOptSecondaryDexPath(info, dexPath, dexUseInfo,
+                options);
 
         // If we fail to optimize the package log an error but don't propagate the error
         // back to the app. The app cannot do much about it and the background job
diff --git a/services/core/java/com/android/server/pm/dex/DexoptUtils.java b/services/core/java/com/android/server/pm/dex/DexoptUtils.java
index abac52f7a8da..bc8bf5e1fc4c 100644
--- a/services/core/java/com/android/server/pm/dex/DexoptUtils.java
+++ b/services/core/java/com/android/server/pm/dex/DexoptUtils.java
@@ -21,6 +21,8 @@ import android.util.Slog;
 import android.util.SparseArray;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public final class DexoptUtils {
@@ -225,7 +227,81 @@ public final class DexoptUtils {
      * dependencies {@see encodeClassLoader} separated by ';'.
      */
     private static String encodeClassLoaderChain(String cl1, String cl2) {
-        return cl1.isEmpty() ? cl2 : (cl1 + ";" + cl2);
+        if (cl1.isEmpty()) return cl2;
+        if (cl2.isEmpty()) return cl1;
+        return cl1 + ";" + cl2;
+    }
+
+    /**
+     * Compute the class loader context for the dex files present in the classpath of the first
+     * class loader from the given list (referred in the code as the {@code loadingClassLoader}).
+     * Each dex files gets its own class loader context in the returned array.
+     *
+     * Example:
+     *    If classLoadersNames = {"dalvik.system.DelegateLastClassLoader",
+     *    "dalvik.system.PathClassLoader"} and classPaths = {"foo.dex:bar.dex", "other.dex"}
+     *    The output will be
+     *    {"DLC[];PCL[other.dex]", "DLC[foo.dex];PCL[other.dex]"}
+     *    with "DLC[];PCL[other.dex]" being the context for "foo.dex"
+     *    and "DLC[foo.dex];PCL[other.dex]" the context for "bar.dex".
+     *
+     * If any of the class loaders names is unsupported the method will return null.
+     *
+     * The argument lists must be non empty and of the same size.
+     *
+     * @param classLoadersNames the names of the class loaders present in the loading chain. The
+     *    list encodes the class loader chain in the natural order. The first class loader has
+     *    the second one as its parent and so on.
+     * @param classPaths the class paths for the elements of {@param classLoadersNames}. The
+     *     the first element corresponds to the first class loader and so on. A classpath is
+     *     represented as a list of dex files separated by {@code File.pathSeparator}.
+     *     The return context will be for the dex files found in the first class path.
+     */
+    /*package*/ static String[] processContextForDexLoad(List<String> classLoadersNames,
+            List<String> classPaths) {
+        if (classLoadersNames.size() != classPaths.size()) {
+            throw new IllegalArgumentException(
+                    "The size of the class loader names and the dex paths do not match.");
+        }
+        if (classLoadersNames.isEmpty()) {
+            throw new IllegalArgumentException("Empty classLoadersNames");
+        }
+
+        // Compute the context for the parent class loaders.
+        String parentContext = "";
+        // We know that these lists are actually ArrayLists so getting the elements by index
+        // is fine (they come over binder). Even if something changes we expect the sizes to be
+        // very small and it shouldn't matter much.
+        for (int i = 1; i < classLoadersNames.size(); i++) {
+            if (!isValidClassLoaderName(classLoadersNames.get(i))) {
+                return null;
+            }
+            String classpath = encodeClasspath(classPaths.get(i).split(File.pathSeparator));
+            parentContext = encodeClassLoaderChain(parentContext,
+                    encodeClassLoader(classpath, classLoadersNames.get(i)));
+        }
+
+        // Now compute the class loader context for each dex file from the first classpath.
+        String loadingClassLoader = classLoadersNames.get(0);
+        if (!isValidClassLoaderName(loadingClassLoader)) {
+            return null;
+        }
+        String[] loadedDexPaths = classPaths.get(0).split(File.pathSeparator);
+        String[] loadedDexPathsContext = new String[loadedDexPaths.length];
+        String currentLoadedDexPathClasspath = "";
+        for (int i = 0; i < loadedDexPaths.length; i++) {
+            String dexPath = loadedDexPaths[i];
+            String currentContext = encodeClassLoader(
+                    currentLoadedDexPathClasspath, loadingClassLoader);
+            loadedDexPathsContext[i] = encodeClassLoaderChain(currentContext, parentContext);
+            currentLoadedDexPathClasspath = encodeClasspath(currentLoadedDexPathClasspath, dexPath);
+        }
+        return loadedDexPathsContext;
+    }
+
+    // AOSP-only hack.
+    private static boolean isValidClassLoaderName(String name) {
+        return "dalvik.system.PathClassLoader".equals(name) || "dalvik.system.DexClassLoader".equals(name);
     }
 
     /**
diff --git a/services/core/java/com/android/server/pm/dex/PackageDexUsage.java b/services/core/java/com/android/server/pm/dex/PackageDexUsage.java
index be7f7320889f..6ee26d32f0e0 100644
--- a/services/core/java/com/android/server/pm/dex/PackageDexUsage.java
+++ b/services/core/java/com/android/server/pm/dex/PackageDexUsage.java
@@ -26,7 +26,6 @@ import com.android.server.pm.AbstractStatsBase;
 import com.android.server.pm.PackageManagerServiceUtils;
 
 import java.io.BufferedReader;
-import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.InputStreamReader;
@@ -36,7 +35,6 @@ import java.io.Reader;
 import java.io.StringWriter;
 import java.io.Writer;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.HashMap;
@@ -55,10 +53,12 @@ import libcore.util.Objects;
 public class PackageDexUsage extends AbstractStatsBase<Void> {
     private final static String TAG = "PackageDexUsage";
 
-    // The last version update: add the list of packages that load the dex files.
-    private final static int PACKAGE_DEX_USAGE_VERSION = 2;
-    // We support VERSION 1 to ensure that the usage list remains valid cross OTAs.
+    // The last version update: add class loader contexts for secondary dex files.
+    private final static int PACKAGE_DEX_USAGE_VERSION = 3;
+    // We support previous version to ensure that the usage list remains valid cross OTAs.
     private final static int PACKAGE_DEX_USAGE_SUPPORTED_VERSION_1 = 1;
+    // Version 2 added the list of packages that load the dex files.
+    private final static int PACKAGE_DEX_USAGE_SUPPORTED_VERSION_2 = 2;
 
     private final static String PACKAGE_DEX_USAGE_VERSION_HEADER =
             "PACKAGE_MANAGER__PACKAGE_DEX_USAGE__";
@@ -66,6 +66,21 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
     private final static String SPLIT_CHAR = ",";
     private final static String DEX_LINE_CHAR = "#";
     private final static String LOADING_PACKAGE_CHAR = "@";
+
+    // One of the things we record about dex files is the class loader context that was used to
+    // load them. That should be stable but if it changes we don't keep track of variable contexts.
+    // Instead we put a special marker in the dex usage file in order to recognize the case and
+    // skip optimizations on that dex files.
+    /*package*/ static final String VARIABLE_CLASS_LOADER_CONTEXT =
+            "=VariableClassLoaderContext=";
+    // The marker used for unsupported class loader contexts.
+    /*package*/ static final String UNSUPPORTED_CLASS_LOADER_CONTEXT =
+            "=UnsupportedClassLoaderContext=";
+    // The markers used for unknown class loader contexts. This can happen if the dex file was
+    // recorded in a previous version and we didn't have a chance to update its usage.
+    /*package*/ static final String UNKNOWN_CLASS_LOADER_CONTEXT =
+            "=UnknownClassLoaderContext=";
+
     // Map which structures the information we have on a package.
     // Maps package name to package data (which stores info about UsedByOtherApps and
     // secondary dex files.).
@@ -98,10 +113,14 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
      */
     public boolean record(String owningPackageName, String dexPath, int ownerUserId,
             String loaderIsa, boolean isUsedByOtherApps, boolean primaryOrSplit,
-            String loadingPackageName) {
+            String loadingPackageName, String classLoaderContext) {
         if (!PackageManagerServiceUtils.checkISA(loaderIsa)) {
             throw new IllegalArgumentException("loaderIsa " + loaderIsa + " is unsupported");
         }
+        if (classLoaderContext == null) {
+            throw new IllegalArgumentException("Null classLoaderContext");
+        }
+
         synchronized (mPackageUseInfoMap) {
             PackageUseInfo packageUseInfo = mPackageUseInfoMap.get(owningPackageName);
             if (packageUseInfo == null) {
@@ -117,7 +136,8 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
                 } else {
                     // For secondary dex files record the loaderISA and the owner. We'll need
                     // to know under which user to compile and for what ISA.
-                    DexUseInfo newData = new DexUseInfo(isUsedByOtherApps, ownerUserId, loaderIsa);
+                    DexUseInfo newData = new DexUseInfo(isUsedByOtherApps, ownerUserId,
+                            classLoaderContext, loaderIsa);
                     packageUseInfo.mDexUseInfoMap.put(dexPath, newData);
                     maybeAddLoadingPackage(owningPackageName, loadingPackageName,
                             newData.mLoadingPackages);
@@ -134,7 +154,7 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
                     return packageUseInfo.merge(isUsedByOtherApps) || updateLoadingPackages;
                 } else {
                     DexUseInfo newData = new DexUseInfo(
-                            isUsedByOtherApps, ownerUserId, loaderIsa);
+                            isUsedByOtherApps, ownerUserId, classLoaderContext, loaderIsa);
                     boolean updateLoadingPackages = maybeAddLoadingPackage(owningPackageName,
                             loadingPackageName, newData.mLoadingPackages);
 
@@ -253,8 +273,9 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
                 String dexPath = dEntry.getKey();
                 DexUseInfo dexUseInfo = dEntry.getValue();
                 fpw.println(DEX_LINE_CHAR + dexPath);
-                    fpw.println(LOADING_PACKAGE_CHAR +
-                            String.join(SPLIT_CHAR, dexUseInfo.mLoadingPackages));
+                fpw.println(LOADING_PACKAGE_CHAR +
+                        String.join(SPLIT_CHAR, dexUseInfo.mLoadingPackages));
+                fpw.println(dexUseInfo.getClassLoaderContext());
 
                 fpw.print(String.join(SPLIT_CHAR, Integer.toString(dexUseInfo.mOwnerUserId),
                         writeBoolean(dexUseInfo.mIsUsedByOtherApps)));
@@ -314,8 +335,10 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
         while ((s = in.readLine()) != null) {
             if (s.startsWith(DEX_LINE_CHAR)) {
                 // This is the start of the the dex lines.
-                // We expect two lines for each dex entry:
+                // We expect 4 lines for each dex entry:
                 // #dexPaths
+                // @loading_package_1,loading_package_2,...
+                // class_loader_context
                 // onwerUserId,isUsedByOtherApps,isa1,isa2
                 if (currentPackage == null) {
                     throw new IllegalStateException(
@@ -327,11 +350,13 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
 
                 // In version 2 the second line contains the list of packages that loaded the file.
                 List<String> loadingPackages = maybeReadLoadingPackages(in, version);
+                // In version 3 the third line contains the class loader context.
+                String classLoaderContext = maybeReadClassLoaderContext(in, version);
 
                 // Next line is the dex data.
                 s = in.readLine();
                 if (s == null) {
-                    throw new IllegalStateException("Could not find dexUseInfo for line: " + s);
+                    throw new IllegalStateException("Could not find dexUseInfo line");
                 }
 
                 // We expect at least 3 elements (isUsedByOtherApps, userId, isa).
@@ -341,9 +366,9 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
                 }
                 int ownerUserId = Integer.parseInt(elems[0]);
                 boolean isUsedByOtherApps = readBoolean(elems[1]);
-                DexUseInfo dexUseInfo = new DexUseInfo(isUsedByOtherApps, ownerUserId);
+                DexUseInfo dexUseInfo = new DexUseInfo(isUsedByOtherApps, ownerUserId,
+                        classLoaderContext, /*isa*/ null);
                 dexUseInfo.mLoadingPackages.addAll(loadingPackages);
-
                 for (int i = 2; i < elems.length; i++) {
                     String isa = elems[i];
                     if (supportedIsas.contains(isa)) {
@@ -383,12 +408,30 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
     }
 
     /**
-     * Reads the list of loading packages from the buffer {@parm in} if
+     * Reads the class loader context encoding from the buffer {@code in} if
      * {@code version} is at least {PACKAGE_DEX_USAGE_VERSION}.
      */
+    private String maybeReadClassLoaderContext(BufferedReader in, int version) throws IOException {
+        String context = null;
+        if (version == PACKAGE_DEX_USAGE_VERSION) {
+            context = in.readLine();
+            if (context == null) {
+                throw new IllegalStateException("Could not find the classLoaderContext line.");
+            }
+        }
+        // The context might be empty if we didn't have the chance to update it after a version
+        // upgrade. In this case return the special marker so that we recognize this is an unknown
+        // context.
+        return context == null ? UNKNOWN_CLASS_LOADER_CONTEXT : context;
+    }
+
+    /**
+     * Reads the list of loading packages from the buffer {@code in} if
+     * {@code version} is at least {PACKAGE_DEX_USAGE_SUPPORTED_VERSION_2}.
+     */
     private List<String> maybeReadLoadingPackages(BufferedReader in, int version)
             throws IOException {
-        if (version == PACKAGE_DEX_USAGE_VERSION) {
+        if (version >= PACKAGE_DEX_USAGE_SUPPORTED_VERSION_2) {
             String line = in.readLine();
             if (line == null) {
                 throw new IllegalStateException("Could not find the loadingPackages line.");
@@ -664,17 +707,20 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
     public static class DexUseInfo {
         private boolean mIsUsedByOtherApps;
         private final int mOwnerUserId;
+        // The class loader context for the dex file. This encodes the class loader chain
+        // (class loader type + class path) in a format compatible to dex2oat.
+        // See {@code DexoptUtils.processContextForDexLoad}.
+        private String mClassLoaderContext;
+        // The instructions sets of the applications loading the dex file.
         private final Set<String> mLoaderIsas;
         // Packages who load this dex file.
         private final Set<String> mLoadingPackages;
 
-        public DexUseInfo(boolean isUsedByOtherApps, int ownerUserId) {
-            this(isUsedByOtherApps, ownerUserId, null);
-        }
-
-        public DexUseInfo(boolean isUsedByOtherApps, int ownerUserId, String loaderIsa) {
+        public DexUseInfo(boolean isUsedByOtherApps, int ownerUserId, String classLoaderContext,
+                String loaderIsa) {
             mIsUsedByOtherApps = isUsedByOtherApps;
             mOwnerUserId = ownerUserId;
+            mClassLoaderContext = classLoaderContext;
             mLoaderIsas = new HashSet<>();
             if (loaderIsa != null) {
                 mLoaderIsas.add(loaderIsa);
@@ -686,6 +732,7 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
         public DexUseInfo(DexUseInfo other) {
             mIsUsedByOtherApps = other.mIsUsedByOtherApps;
             mOwnerUserId = other.mOwnerUserId;
+            mClassLoaderContext = other.mClassLoaderContext;
             mLoaderIsas = new HashSet<>(other.mLoaderIsas);
             mLoadingPackages = new HashSet<>(other.mLoadingPackages);
         }
@@ -695,8 +742,24 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
             mIsUsedByOtherApps = mIsUsedByOtherApps || dexUseInfo.mIsUsedByOtherApps;
             boolean updateIsas = mLoaderIsas.addAll(dexUseInfo.mLoaderIsas);
             boolean updateLoadingPackages = mLoadingPackages.addAll(dexUseInfo.mLoadingPackages);
-            return updateIsas || (oldIsUsedByOtherApps != mIsUsedByOtherApps) ||
-                    updateLoadingPackages;
+
+            String oldClassLoaderContext = mClassLoaderContext;
+            if (UNKNOWN_CLASS_LOADER_CONTEXT.equals(mClassLoaderContext)) {
+                // Can happen if we read a previous version.
+                mClassLoaderContext = dexUseInfo.mClassLoaderContext;
+            } else if (UNSUPPORTED_CLASS_LOADER_CONTEXT.equals(dexUseInfo.mClassLoaderContext)) {
+                // We detected an unsupported context.
+                mClassLoaderContext = UNSUPPORTED_CLASS_LOADER_CONTEXT;
+            } else if (!UNSUPPORTED_CLASS_LOADER_CONTEXT.equals(mClassLoaderContext) &&
+                    !Objects.equal(mClassLoaderContext, dexUseInfo.mClassLoaderContext)) {
+                // We detected a context change.
+                mClassLoaderContext = VARIABLE_CLASS_LOADER_CONTEXT;
+            }
+
+            return updateIsas ||
+                    (oldIsUsedByOtherApps != mIsUsedByOtherApps) ||
+                    updateLoadingPackages
+                    || !Objects.equal(oldClassLoaderContext, mClassLoaderContext);
         }
 
         public boolean isUsedByOtherApps() {
@@ -714,5 +777,21 @@ public class PackageDexUsage extends AbstractStatsBase<Void> {
         public Set<String> getLoadingPackages() {
             return mLoadingPackages;
         }
+
+        public String getClassLoaderContext() { return mClassLoaderContext; }
+
+        public boolean isUnsupportedClassLoaderContext() {
+            return UNSUPPORTED_CLASS_LOADER_CONTEXT.equals(mClassLoaderContext);
+        }
+
+        public boolean isUnknownClassLoaderContext() {
+            // The class loader context may be unknown if we loaded the data from a previous version
+            // which didn't save the context.
+            return UNKNOWN_CLASS_LOADER_CONTEXT.equals(mClassLoaderContext);
+        }
+
+        public boolean isVariableClassLoaderContext() {
+            return VARIABLE_CLASS_LOADER_CONTEXT.equals(mClassLoaderContext);
+        }
     }
 }
diff --git a/services/tests/servicestests/src/com/android/server/pm/dex/DexManagerTests.java b/services/tests/servicestests/src/com/android/server/pm/dex/DexManagerTests.java
index afc0f67fe993..e2dfb29be561 100644
--- a/services/tests/servicestests/src/com/android/server/pm/dex/DexManagerTests.java
+++ b/services/tests/servicestests/src/com/android/server/pm/dex/DexManagerTests.java
@@ -23,10 +23,14 @@ import android.os.UserHandle;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
 
+import dalvik.system.DelegateLastClassLoader;
+import dalvik.system.PathClassLoader;
 import dalvik.system.VMRuntime;
 
+import java.io.File;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -48,6 +52,10 @@ import static com.android.server.pm.dex.PackageDexUsage.DexUseInfo;
 @RunWith(AndroidJUnit4.class)
 @SmallTest
 public class DexManagerTests {
+    private static final String PATH_CLASS_LOADER_NAME = PathClassLoader.class.getName();
+    private static final String DELEGATE_LAST_CLASS_LOADER_NAME =
+            DelegateLastClassLoader.class.getName();
+
     private DexManager mDexManager;
 
     private TestData mFooUser0;
@@ -56,6 +64,9 @@ public class DexManagerTests {
     private TestData mInvalidIsa;
     private TestData mDoesNotExist;
 
+    private TestData mBarUser0UnsupportedClassLoader;
+    private TestData mBarUser0DelegateLastClassLoader;
+
     private int mUser0;
     private int mUser1;
 
@@ -68,12 +79,17 @@ public class DexManagerTests {
         String foo = "foo";
         String bar = "bar";
 
-        mFooUser0 = new TestData(foo, isa, mUser0);
-        mBarUser0 = new TestData(bar, isa, mUser0);
-        mBarUser1 = new TestData(bar, isa, mUser1);
+        mFooUser0 = new TestData(foo, isa, mUser0, PATH_CLASS_LOADER_NAME);
+        mBarUser0 = new TestData(bar, isa, mUser0, PATH_CLASS_LOADER_NAME);
+        mBarUser1 = new TestData(bar, isa, mUser1, PATH_CLASS_LOADER_NAME);
         mInvalidIsa = new TestData("INVALID", "INVALID_ISA", mUser0);
         mDoesNotExist = new TestData("DOES.NOT.EXIST", isa, mUser1);
 
+        mBarUser0UnsupportedClassLoader = new TestData(bar, isa, mUser0,
+                "unsupported.class_loader");
+        mBarUser0DelegateLastClassLoader = new TestData(bar, isa, mUser0,
+                DELEGATE_LAST_CLASS_LOADER_NAME);
+
         mDexManager = new DexManager(null, null, null, null);
 
         // Foo and Bar are available to user0.
@@ -373,8 +389,82 @@ public class DexManagerTests {
         assertSecondaryUse(mFooUser0, pui, fooSecondaries, /*isUsedByOtherApps*/false, mUser0);
     }
 
+    @Test
+    public void testNotifyUnsupportedClassLoader() {
+        List<String> secondaries = mBarUser0UnsupportedClassLoader.getSecondaryDexPaths();
+        notifyDexLoad(mBarUser0UnsupportedClassLoader, secondaries, mUser0);
+
+        PackageUseInfo pui = getPackageUseInfo(mBarUser0UnsupportedClassLoader);
+        assertNotNull(pui);
+        assertFalse(pui.isUsedByOtherApps());
+        assertEquals(secondaries.size(), pui.getDexUseInfoMap().size());
+        // We expect that all the contexts are unsupported.
+        String[] expectedContexts =
+                Collections.nCopies(secondaries.size(),
+                        PackageDexUsage.UNSUPPORTED_CLASS_LOADER_CONTEXT).toArray(new String[0]);
+        assertSecondaryUse(mBarUser0UnsupportedClassLoader, pui, secondaries,
+                /*isUsedByOtherApps*/false, mUser0, expectedContexts);
+    }
+
+    @Test
+    public void testNotifyVariableClassLoader() {
+        // Record bar secondaries with the default PathClassLoader.
+        List<String> secondaries = mBarUser0.getSecondaryDexPaths();
+
+        notifyDexLoad(mBarUser0, secondaries, mUser0);
+        PackageUseInfo pui = getPackageUseInfo(mBarUser0);
+        assertNotNull(pui);
+        assertFalse(pui.isUsedByOtherApps());
+        assertEquals(secondaries.size(), pui.getDexUseInfoMap().size());
+        assertSecondaryUse(mFooUser0, pui, secondaries, /*isUsedByOtherApps*/false, mUser0);
+
+        // Record bar secondaries again with a different class loader. This will change the context.
+        notifyDexLoad(mBarUser0DelegateLastClassLoader, secondaries, mUser0);
+
+        pui = getPackageUseInfo(mBarUser0);
+        assertNotNull(pui);
+        assertFalse(pui.isUsedByOtherApps());
+        assertEquals(secondaries.size(), pui.getDexUseInfoMap().size());
+        // We expect that all the contexts to be changed to variable now.
+        String[] expectedContexts =
+                Collections.nCopies(secondaries.size(),
+                        PackageDexUsage.VARIABLE_CLASS_LOADER_CONTEXT).toArray(new String[0]);
+        assertSecondaryUse(mFooUser0, pui, secondaries, /*isUsedByOtherApps*/false, mUser0,
+                expectedContexts);
+    }
+
+    @Test
+    public void testNotifyUnsupportedClassLoaderDoesNotChange() {
+        List<String> secondaries = mBarUser0UnsupportedClassLoader.getSecondaryDexPaths();
+        notifyDexLoad(mBarUser0UnsupportedClassLoader, secondaries, mUser0);
+
+        PackageUseInfo pui = getPackageUseInfo(mBarUser0UnsupportedClassLoader);
+        assertNotNull(pui);
+        assertFalse(pui.isUsedByOtherApps());
+        assertEquals(secondaries.size(), pui.getDexUseInfoMap().size());
+        // We expect that all the contexts are unsupported.
+        String[] expectedContexts =
+                Collections.nCopies(secondaries.size(),
+                        PackageDexUsage.UNSUPPORTED_CLASS_LOADER_CONTEXT).toArray(new String[0]);
+        assertSecondaryUse(mBarUser0UnsupportedClassLoader, pui, secondaries,
+                /*isUsedByOtherApps*/false, mUser0, expectedContexts);
+
+        // Record bar secondaries again with a different class loader. This will change the context.
+        // However, because the context was already marked as unsupported we should not chage it.
+        notifyDexLoad(mBarUser0DelegateLastClassLoader, secondaries, mUser0);
+        pui = getPackageUseInfo(mBarUser0UnsupportedClassLoader);
+        assertSecondaryUse(mBarUser0UnsupportedClassLoader, pui, secondaries,
+                /*isUsedByOtherApps*/false, mUser0, expectedContexts);
+
+    }
+
+
     private void assertSecondaryUse(TestData testData, PackageUseInfo pui,
-            List<String> secondaries, boolean isUsedByOtherApps, int ownerUserId) {
+            List<String> secondaries, boolean isUsedByOtherApps, int ownerUserId,
+            String[] expectedContexts) {
+        assertNotNull(expectedContexts);
+        assertEquals(expectedContexts.length, secondaries.size());
+        int index = 0;
         for (String dex : secondaries) {
             DexUseInfo dui = pui.getDexUseInfoMap().get(dex);
             assertNotNull(dui);
@@ -382,11 +472,29 @@ public class DexManagerTests {
             assertEquals(ownerUserId, dui.getOwnerUserId());
             assertEquals(1, dui.getLoaderIsas().size());
             assertTrue(dui.getLoaderIsas().contains(testData.mLoaderIsa));
+            assertEquals(expectedContexts[index++], dui.getClassLoaderContext());
         }
     }
+    private void assertSecondaryUse(TestData testData, PackageUseInfo pui,
+            List<String> secondaries, boolean isUsedByOtherApps, int ownerUserId) {
+        String[] expectedContexts = DexoptUtils.processContextForDexLoad(
+                Arrays.asList(testData.mClassLoader),
+                Arrays.asList(String.join(File.pathSeparator, secondaries)));
+        assertSecondaryUse(testData, pui, secondaries, isUsedByOtherApps, ownerUserId,
+                expectedContexts);
+    }
 
     private void notifyDexLoad(TestData testData, List<String> dexPaths, int loaderUserId) {
-        mDexManager.notifyDexLoad(testData.mPackageInfo.applicationInfo, dexPaths,
+        // By default, assume a single class loader in the chain.
+        // This makes writing tests much easier.
+        List<String> classLoaders = Arrays.asList(testData.mClassLoader);
+        List<String> classPaths = Arrays.asList(String.join(File.pathSeparator, dexPaths));
+        notifyDexLoad(testData, classLoaders, classPaths, loaderUserId);
+    }
+
+    private void notifyDexLoad(TestData testData, List<String> classLoader, List<String> classPaths,
+            int loaderUserId) {
+        mDexManager.notifyDexLoad(testData.mPackageInfo.applicationInfo, classLoader, classPaths,
                 testData.mLoaderIsa, loaderUserId);
     }
 
@@ -416,10 +524,16 @@ public class DexManagerTests {
     private static class TestData {
         private final PackageInfo mPackageInfo;
         private final String mLoaderIsa;
+        private final String mClassLoader;
 
-        private TestData(String  packageName, String loaderIsa, int userId) {
+        private TestData(String packageName, String loaderIsa, int userId, String classLoader) {
             mPackageInfo = getMockPackageInfo(packageName, userId);
             mLoaderIsa = loaderIsa;
+            mClassLoader = classLoader;
+        }
+
+        private TestData(String packageName, String loaderIsa, int userId) {
+            this(packageName, loaderIsa, userId, PATH_CLASS_LOADER_NAME);
         }
 
         private String getPackageName() {
diff --git a/services/tests/servicestests/src/com/android/server/pm/dex/DexoptUtilsTest.java b/services/tests/servicestests/src/com/android/server/pm/dex/DexoptUtilsTest.java
index 21b286e68adf..ff7bd723d23d 100644
--- a/services/tests/servicestests/src/com/android/server/pm/dex/DexoptUtilsTest.java
+++ b/services/tests/servicestests/src/com/android/server/pm/dex/DexoptUtilsTest.java
@@ -17,6 +17,9 @@
 package com.android.server.pm.dex;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
 import android.content.pm.ApplicationInfo;
 import android.support.test.filters.SmallTest;
@@ -24,14 +27,21 @@ import android.support.test.runner.AndroidJUnit4;
 import android.util.SparseArray;
 
 import dalvik.system.DelegateLastClassLoader;
+import dalvik.system.DexClassLoader;
 import dalvik.system.PathClassLoader;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import java.io.File;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
 @RunWith(AndroidJUnit4.class)
 @SmallTest
 public class DexoptUtilsTest {
+    private static final String DEX_CLASS_LOADER_NAME = DexClassLoader.class.getName();
     private static final String PATH_CLASS_LOADER_NAME = PathClassLoader.class.getName();
     private static final String DELEGATE_LAST_CLASS_LOADER_NAME =
             DelegateLastClassLoader.class.getName();
@@ -202,4 +212,68 @@ public class DexoptUtilsTest {
         assertEquals(1, contexts.length);
         assertEquals("PCL[]", contexts[0]);
     }
+
+    @Test
+    public void testProcessContextForDexLoad() {
+        List<String> classLoaders = Arrays.asList(
+                DELEGATE_LAST_CLASS_LOADER_NAME,
+                PATH_CLASS_LOADER_NAME,
+                PATH_CLASS_LOADER_NAME);
+        List<String> classPaths = Arrays.asList(
+                String.join(File.pathSeparator, "foo.dex", "bar.dex"),
+                String.join(File.pathSeparator, "parent1.dex"),
+                String.join(File.pathSeparator, "parent2.dex", "parent3.dex"));
+        String[] context = DexoptUtils.processContextForDexLoad(classLoaders, classPaths);
+        assertNotNull(context);
+        assertEquals(2, context.length);
+        assertEquals("DLC[];PCL[parent1.dex];PCL[parent2.dex:parent3.dex]", context[0]);
+        assertEquals("DLC[foo.dex];PCL[parent1.dex];PCL[parent2.dex:parent3.dex]", context[1]);
+    }
+
+    @Test
+    public void testProcessContextForDexLoadSingleElement() {
+        List<String> classLoaders = Arrays.asList(PATH_CLASS_LOADER_NAME);
+        List<String> classPaths = Arrays.asList(
+                String.join(File.pathSeparator, "foo.dex", "bar.dex", "zoo.dex"));
+        String[] context = DexoptUtils.processContextForDexLoad(classLoaders, classPaths);
+        assertNotNull(context);
+        assertEquals(3, context.length);
+        assertEquals("PCL[]", context[0]);
+        assertEquals("PCL[foo.dex]", context[1]);
+        assertEquals("PCL[foo.dex:bar.dex]", context[2]);
+    }
+
+    @Test
+    public void testProcessContextForDexLoadUnsupported() {
+        List<String> classLoaders = Arrays.asList(
+                DELEGATE_LAST_CLASS_LOADER_NAME,
+                "unsupported.class.loader");
+        List<String> classPaths = Arrays.asList(
+                String.join(File.pathSeparator, "foo.dex", "bar.dex"),
+                String.join(File.pathSeparator, "parent1.dex"));
+        String[] context = DexoptUtils.processContextForDexLoad(classLoaders, classPaths);
+        assertNull(context);
+    }
+
+    @Test
+    public void testProcessContextForDexLoadIllegalCallEmptyList() {
+        boolean gotException = false;
+        try {
+            DexoptUtils.processContextForDexLoad(Collections.emptyList(), Collections.emptyList());
+        } catch (IllegalArgumentException ignore) {
+            gotException = true;
+        }
+        assertTrue(gotException);
+    }
+
+    @Test
+    public void testProcessContextForDexLoadIllegalCallDifferentSize() {
+        boolean gotException = false;
+        try {
+            DexoptUtils.processContextForDexLoad(Collections.emptyList(), Arrays.asList("a"));
+        } catch (IllegalArgumentException ignore) {
+            gotException = true;
+        }
+        assertTrue(gotException);
+    }
 }
diff --git a/services/tests/servicestests/src/com/android/server/pm/dex/PackageDexUsageTests.java b/services/tests/servicestests/src/com/android/server/pm/dex/PackageDexUsageTests.java
index e1ef41e71c34..3fc12b473429 100644
--- a/services/tests/servicestests/src/com/android/server/pm/dex/PackageDexUsageTests.java
+++ b/services/tests/servicestests/src/com/android/server/pm/dex/PackageDexUsageTests.java
@@ -359,7 +359,7 @@ public class PackageDexUsageTests {
     public void testRecordDexFileUsersNotTheOwningPackage() {
         PackageDexUsage packageDexUsageRecordUsers = new PackageDexUsage();
         Set<String> users = new HashSet<>(Arrays.asList(
-                new String[] {mFooBaseUser0.mPackageName,}));
+                new String[] {mFooBaseUser0.mPackageName}));
         Set<String> usersExtra = new HashSet<>(Arrays.asList(
                 new String[] {"another.package.2", "another.package.3"}));
 
@@ -375,6 +375,89 @@ public class PackageDexUsageTests {
                 mFooSecondary1User0);
     }
 
+    @Test
+    public void testRecordClassLoaderContextVariableContext() {
+        // Record a secondary dex file.
+        assertTrue(record(mFooSecondary1User0));
+        // Now update its context.
+        TestData fooSecondary1User0NewContext = mFooSecondary1User0.updateClassLoaderContext(
+                "PCL[new_context.dex]");
+        assertTrue(record(fooSecondary1User0NewContext));
+
+        // Not check that the context was switch to variable.
+        TestData expectedContext = mFooSecondary1User0.updateClassLoaderContext(
+                PackageDexUsage.VARIABLE_CLASS_LOADER_CONTEXT);
+
+        assertPackageDexUsage(null, expectedContext);
+        writeAndReadBack();
+        assertPackageDexUsage(null, expectedContext);
+    }
+
+    @Test
+    public void testRecordClassLoaderContextUnsupportedContext() {
+        // Record a secondary dex file.
+        assertTrue(record(mFooSecondary1User0));
+        // Now update its context.
+        TestData unsupportedContext = mFooSecondary1User0.updateClassLoaderContext(
+                PackageDexUsage.UNSUPPORTED_CLASS_LOADER_CONTEXT);
+        assertTrue(record(unsupportedContext));
+
+        assertPackageDexUsage(null, unsupportedContext);
+        writeAndReadBack();
+        assertPackageDexUsage(null, unsupportedContext);
+    }
+
+    @Test
+    public void testRecordClassLoaderContextTransitionFromUnknown() {
+        // Record a secondary dex file.
+        TestData unknownContext = mFooSecondary1User0.updateClassLoaderContext(
+                PackageDexUsage.UNKNOWN_CLASS_LOADER_CONTEXT);
+        assertTrue(record(unknownContext));
+
+        assertPackageDexUsage(null, unknownContext);
+        writeAndReadBack();
+        assertPackageDexUsage(null, unknownContext);
+
+        // Now update the secondary dex record with a class loader context. This simulates the
+        // version 2 to version 3 upgrade.
+
+        assertTrue(record(mFooSecondary1User0));
+
+        assertPackageDexUsage(null, mFooSecondary1User0);
+        writeAndReadBack();
+        assertPackageDexUsage(null, mFooSecondary1User0);
+    }
+
+
+    @Test
+    public void testDexUsageClassLoaderContext() {
+        final boolean isUsedByOtherApps = false;
+        final int userId = 0;
+        PackageDexUsage.DexUseInfo validContext = new DexUseInfo(isUsedByOtherApps, userId,
+                "valid_context", "arm");
+        assertFalse(validContext.isUnknownClassLoaderContext());
+        assertFalse(validContext.isUnsupportedClassLoaderContext());
+        assertFalse(validContext.isVariableClassLoaderContext());
+
+        PackageDexUsage.DexUseInfo unsupportedContext = new DexUseInfo(isUsedByOtherApps, userId,
+                PackageDexUsage.UNSUPPORTED_CLASS_LOADER_CONTEXT, "arm");
+        assertFalse(unsupportedContext.isUnknownClassLoaderContext());
+        assertTrue(unsupportedContext.isUnsupportedClassLoaderContext());
+        assertFalse(unsupportedContext.isVariableClassLoaderContext());
+
+        PackageDexUsage.DexUseInfo variableContext = new DexUseInfo(isUsedByOtherApps, userId,
+                PackageDexUsage.VARIABLE_CLASS_LOADER_CONTEXT, "arm");
+        assertFalse(variableContext.isUnknownClassLoaderContext());
+        assertFalse(variableContext.isUnsupportedClassLoaderContext());
+        assertTrue(variableContext.isVariableClassLoaderContext());
+
+        PackageDexUsage.DexUseInfo unknownContext = new DexUseInfo(isUsedByOtherApps, userId,
+                PackageDexUsage.UNKNOWN_CLASS_LOADER_CONTEXT, "arm");
+        assertTrue(unknownContext.isUnknownClassLoaderContext());
+        assertFalse(unknownContext.isUnsupportedClassLoaderContext());
+        assertFalse(unknownContext.isVariableClassLoaderContext());
+    }
+
     private void assertPackageDexUsage(TestData primary, TestData... secondaries) {
         assertPackageDexUsage(mPackageDexUsage, null, primary, secondaries);
     }
@@ -382,7 +465,7 @@ public class PackageDexUsageTests {
     private void assertPackageDexUsage(PackageDexUsage packageDexUsage, Set<String> users,
             TestData primary, TestData... secondaries) {
         String packageName = primary == null ? secondaries[0].mPackageName : primary.mPackageName;
-        boolean primaryUsedByOtherApps = primary == null ? false : primary.mUsedByOtherApps;
+        boolean primaryUsedByOtherApps = primary != null && primary.mUsedByOtherApps;
         PackageUseInfo pInfo = packageDexUsage.getPackageUseInfo(packageName);
 
         // Check package use info
@@ -406,13 +489,15 @@ public class PackageDexUsageTests {
             if (users != null) {
                  assertEquals(dInfo.getLoadingPackages(), users);
             }
+
+            assertEquals(testData.mClassLoaderContext, dInfo.getClassLoaderContext());
         }
     }
 
     private boolean record(TestData testData) {
         return mPackageDexUsage.record(testData.mPackageName, testData.mDexFile,
                testData.mOwnerUserId, testData.mLoaderIsa, testData.mUsedByOtherApps,
-               testData.mPrimaryOrSplit, testData.mUsedBy);
+               testData.mPrimaryOrSplit, testData.mUsedBy, testData.mClassLoaderContext);
     }
 
     private boolean record(PackageDexUsage packageDexUsage, TestData testData, Set<String> users) {
@@ -420,7 +505,7 @@ public class PackageDexUsageTests {
         for (String user : users) {
             result = result && packageDexUsage.record(testData.mPackageName, testData.mDexFile,
                     testData.mOwnerUserId, testData.mLoaderIsa, testData.mUsedByOtherApps,
-                    testData.mPrimaryOrSplit, user);
+                    testData.mPrimaryOrSplit, user, testData.mClassLoaderContext);
         }
         return result;
     }
@@ -451,9 +536,16 @@ public class PackageDexUsageTests {
         private final boolean mUsedByOtherApps;
         private final boolean mPrimaryOrSplit;
         private final String mUsedBy;
+        private final String mClassLoaderContext;
 
         private TestData(String packageName, String dexFile, int ownerUserId,
-                 String loaderIsa, boolean isUsedByOtherApps, boolean primaryOrSplit, String usedBy) {
+                String loaderIsa, boolean isUsedByOtherApps, boolean primaryOrSplit, String usedBy) {
+            this(packageName, dexFile, ownerUserId, loaderIsa, isUsedByOtherApps, primaryOrSplit,
+                    usedBy, "DefaultClassLoaderContextFor_" + dexFile);
+        }
+        private TestData(String packageName, String dexFile, int ownerUserId,
+                String loaderIsa, boolean isUsedByOtherApps, boolean primaryOrSplit, String usedBy,
+                String classLoaderContext) {
             mPackageName = packageName;
             mDexFile = dexFile;
             mOwnerUserId = ownerUserId;
@@ -461,7 +553,12 @@ public class PackageDexUsageTests {
             mUsedByOtherApps = isUsedByOtherApps;
             mPrimaryOrSplit = primaryOrSplit;
             mUsedBy = usedBy;
+            mClassLoaderContext = classLoaderContext;
         }
 
+        private TestData updateClassLoaderContext(String newContext) {
+            return new TestData(mPackageName, mDexFile, mOwnerUserId, mLoaderIsa, mUsedByOtherApps,
+                    mPrimaryOrSplit, mUsedBy, newContext);
+        }
     }
 }