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, 29 insertions, 0 deletions

diff --git a/runtime/oat_file_assistant.cc b/runtime/oat_file_assistant.cc
index d6b08684b9..2bd5c76c00 100644
--- a/runtime/oat_file_assistant.cc
+++ b/runtime/oat_file_assistant.cc
@@ -38,6 +38,7 @@
 #include "os.h"
 #include "profiler.h"
 #include "runtime.h"
+#include "scoped_thread_state_change.h"
 #include "ScopedFd.h"
 #include "utils.h"
 
@@ -326,6 +327,17 @@ bool OatFileAssistant::OdexFileIsUpToDate() {
   return cached_odex_file_is_up_to_date_;
 }
 
+std::string OatFileAssistant::ArtFileName(const OatFile* oat_file) const {
+  const std::string oat_file_location = oat_file->GetLocation();
+  // Replace extension with .art
+  const size_t last_ext = oat_file_location.find_last_of('.');
+  if (last_ext == std::string::npos) {
+    LOG(ERROR) << "No extension in oat file " << oat_file_location;
+    return std::string();
+  }
+  return oat_file_location.substr(0, last_ext) + ".art";
+}
+
 const std::string* OatFileAssistant::OatFileName() {
   if (!cached_oat_file_name_attempted_) {
     cached_oat_file_name_attempted_ = true;
@@ -1003,5 +1015,22 @@ ProfileFile* OatFileAssistant::GetOldProfile() {
   return old_profile_load_succeeded_ ? &cached_old_profile_ : nullptr;
 }
 
+gc::space::ImageSpace* OatFileAssistant::OpenImageSpace(const OatFile* oat_file) {
+  DCHECK(oat_file != nullptr);
+  std::string art_file = ArtFileName(oat_file);
+  if (art_file.empty()) {
+    return nullptr;
+  }
+  std::string error_msg;
+  ScopedObjectAccess soa(Thread::Current());
+  gc::space::ImageSpace* ret = gc::space::ImageSpace::CreateFromAppImage(art_file.c_str(),
+                                                                         oat_file,
+                                                                         &error_msg);
+  if (ret == nullptr) {
+    LOG(INFO) << "Failed to open app image " << art_file.c_str() << " " << error_msg;
+  }
+  return ret;
+}
+
 }  // namespace art