Load app images

Support in-place patching of the app image based on boot image
location and app oat location. Only loads for art run test so far
since we do not automatically generate app images for app installs.

N5 maps launch time (~200 runs):
Before: 930ms
After: 878.18ms
After + image class table: 864.57ms

TODO:
Oatdump support.
Store class loaders as class roots in image.

Bug: 22858531

Change-Id: I9cbc645645e62ea2ed1ad8e139e91af7d88514c1

1 files changed, 25 insertions, 3 deletions

diff --git a/runtime/class_linker.h b/runtime/class_linker.h
index f1fd0c38f1..d503dd4704 100644
--- a/runtime/class_linker.h
+++ b/runtime/class_linker.h
@@ -120,11 +120,25 @@ class ClassLinker {
       SHARED_REQUIRES(Locks::mutator_lock_)
       REQUIRES(!dex_lock_);
 
-  // Initialize class linker from one or more images.
-  bool InitFromImage(std::string* error_msg)
+  // Initialize class linker from one or more boot images.
+  bool InitFromBootImage(std::string* error_msg)
       SHARED_REQUIRES(Locks::mutator_lock_)
       REQUIRES(!dex_lock_);
 
+  // Add an image space to the class linker, may fix up classloader fields and dex cache fields.
+  // The dex files that were newly opened for the space are placed in the out argument
+  // out_dex_files. Returns true if the operation succeeded.
+  // The space must be already added to the heap before calling AddImageSpace since we need to
+  // properly handle read barriers and object marking.
+  bool AddImageSpace(gc::space::ImageSpace* space,
+                     Handle<mirror::ClassLoader> class_loader,
+                     jobjectArray dex_elements,
+                     const char* dex_location,
+                     std::vector<std::unique_ptr<const DexFile>>* out_dex_files,
+                     std::string* error_msg)
+      REQUIRES(!dex_lock_)
+      SHARED_REQUIRES(Locks::mutator_lock_);
+
   // Finds a class by its descriptor, loading it if necessary.
   // If class_loader is null, searches boot_class_path_.
   mirror::Class* FindClass(Thread* self,
@@ -985,8 +999,16 @@ class ClassLinker {
       SHARED_REQUIRES(Locks::mutator_lock_)
       REQUIRES(!Locks::classlinker_classes_lock_);
 
+  void UpdateAppImageClassLoadersAndDexCaches(
+      gc::space::ImageSpace* space,
+      Handle<mirror::ClassLoader> class_loader,
+      Handle<mirror::ObjectArray<mirror::DexCache>> dex_caches,
+      bool added_class_table)
+      REQUIRES(!dex_lock_)
+      SHARED_REQUIRES(Locks::mutator_lock_);
+
   std::vector<const DexFile*> boot_class_path_;
-  std::vector<std::unique_ptr<const DexFile>> opened_dex_files_;
+  std::vector<std::unique_ptr<const DexFile>> boot_dex_files_;
 
   mutable ReaderWriterMutex dex_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
   // JNI weak globals and side data to allow dex caches to get unloaded. We lazily delete weak