Reland "Use reference counted pointers for ApkAssets"

This reverts commit cf6e79f809034386b04ae551db815ab087f76c0a

Updates:
    Prepare the shared pointers for the whole operation at once
    instead of re-locking them on each iteration.
    Still a regression of about 5% for changing theme's
    AssetManager object, vs the original 40%

    + change the log message to a warning as it doesn't break
      the app

Original comment:

    Use reference counted pointers for ApkAssets

    The primary reason for memory corruption is freed ApkAssets
    Java expected them to only be freed in the finalizers, but
    there are explicit close() calls now, destroying objects that
    are still in use in some AssetManager2 objects

    This CL makes sure those AssetManagers don't assume ApkAssets
    always exist, but instead tries to lock them in memory for any
    access

    It also adds logging in case of deleting an assets object with
    any weak pointers still existing. Those will get into the
    bugreports attached to related bugs to help with investigation.

    Benchmarks don't regress, and the device appears to be working.
    Given that the crashes used to be pretty rare, let's wait for
    any new reports or lack of those.

    + add a missing .clang-format file to the jni directory
    + enabled C++23 in the project that uses AssetManager headers

    Bug: 197260547
    Bug: 276922628
    Test: unit tests + boot + benchmarks
    Old change id: I495fd9e012fe370a1f725dbb0265b4ee1be8d805
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:b3455190124b41e2deb1774d9c05b396b73b41a2)
Merged-In: Id668fbcf07db17b09691a344c04e98df83006f97
Change-Id: Id668fbcf07db17b09691a344c04e98df83006f97

1 files changed, 175 insertions, 130 deletions

diff --git a/libs/androidfw/AssetManager2.cpp b/libs/androidfw/AssetManager2.cpp
index 68f5e4a88c7e..3a7c91ef5b08 100644
--- a/libs/androidfw/AssetManager2.cpp
+++ b/libs/androidfw/AssetManager2.cpp
@@ -91,13 +91,14 @@ struct FindEntryResult {
   StringPoolRef entry_string_ref;
 };
 
-AssetManager2::AssetManager2() {
-  memset(&configuration_, 0, sizeof(configuration_));
+AssetManager2::AssetManager2(ApkAssetsList apk_assets, const ResTable_config& configuration)
+    : configuration_(configuration) {
+  // Don't invalidate caches here as there's nothing cached yet.
+  SetApkAssets(apk_assets, false);
 }
 
-bool AssetManager2::SetApkAssets(std::vector<const ApkAssets*> apk_assets, bool invalidate_caches) {
-  apk_assets_ = std::move(apk_assets);
-  BuildDynamicRefTable();
+bool AssetManager2::SetApkAssets(ApkAssetsList apk_assets, bool invalidate_caches) {
+  BuildDynamicRefTable(apk_assets);
   RebuildFilterList();
   if (invalidate_caches) {
     InvalidateCaches(static_cast<uint32_t>(-1));
@@ -105,7 +106,13 @@ bool AssetManager2::SetApkAssets(std::vector<const ApkAssets*> apk_assets, bool
   return true;
 }
 
-void AssetManager2::BuildDynamicRefTable() {
+bool AssetManager2::SetApkAssets(std::initializer_list<ApkAssetsPtr> apk_assets,
+                                 bool invalidate_caches) {
+  return SetApkAssets(ApkAssetsList(apk_assets.begin(), apk_assets.size()), invalidate_caches);
+}
+
+void AssetManager2::BuildDynamicRefTable(ApkAssetsList apk_assets) {
+  apk_assets_.assign(apk_assets.begin(), apk_assets.end());
   package_groups_.clear();
   package_ids_.fill(0xff);
 
@@ -116,16 +123,19 @@ void AssetManager2::BuildDynamicRefTable() {
 
   // Overlay resources are not directly referenced by an application so their resource ids
   // can change throughout the application's lifetime. Assign overlay package ids last.
-  std::vector<const ApkAssets*> sorted_apk_assets(apk_assets_);
-  std::stable_partition(sorted_apk_assets.begin(), sorted_apk_assets.end(), [](const ApkAssets* a) {
-    return !a->IsOverlay();
-  });
+  std::vector<const ApkAssets*> sorted_apk_assets;
+  sorted_apk_assets.reserve(apk_assets_.size());
+  for (auto& asset : apk_assets) {
+    sorted_apk_assets.push_back(asset.get());
+  }
+  std::stable_partition(sorted_apk_assets.begin(), sorted_apk_assets.end(),
+                        [](auto a) { return !a->IsOverlay(); });
 
   // The assets cookie must map to the position of the apk assets in the unsorted apk assets list.
   std::unordered_map<const ApkAssets*, ApkAssetsCookie> apk_assets_cookies;
-  apk_assets_cookies.reserve(apk_assets_.size());
-  for (size_t i = 0, n = apk_assets_.size(); i < n; i++) {
-    apk_assets_cookies[apk_assets_[i]] = static_cast<ApkAssetsCookie>(i);
+  apk_assets_cookies.reserve(apk_assets.size());
+  for (size_t i = 0, n = apk_assets.size(); i < n; i++) {
+    apk_assets_cookies[apk_assets[i].get()] = static_cast<ApkAssetsCookie>(i);
   }
 
   // 0x01 is reserved for the android package.
@@ -242,7 +252,8 @@ void AssetManager2::DumpToLog() const {
 
   std::string list;
   for (const auto& apk_assets : apk_assets_) {
-    base::StringAppendF(&list, "%s,", apk_assets->GetDebugName().c_str());
+    auto assets = apk_assets.promote();
+    base::StringAppendF(&list, "%s,", assets ? assets->GetDebugName().c_str() : "nullptr");
   }
   LOG(INFO) << "ApkAssets: " << list;
 
@@ -279,7 +290,8 @@ const ResStringPool* AssetManager2::GetStringPoolForCookie(ApkAssetsCookie cooki
   if (cookie < 0 || static_cast<size_t>(cookie) >= apk_assets_.size()) {
     return nullptr;
   }
-  return apk_assets_[cookie]->GetLoadedArsc()->GetStringPool();
+  auto assets = apk_assets_[cookie].promote();
+  return assets ? assets->GetLoadedArsc()->GetStringPool() : nullptr;
 }
 
 const DynamicRefTable* AssetManager2::GetDynamicRefTableForPackage(uint32_t package_id) const {
@@ -331,7 +343,11 @@ bool AssetManager2::GetOverlayablesToString(android::StringPiece package_name,
                                             std::string* out) const {
   uint8_t package_id = 0U;
   for (const auto& apk_assets : apk_assets_) {
-    const LoadedArsc* loaded_arsc = apk_assets->GetLoadedArsc();
+    auto assets = apk_assets.promote();
+    if (!assets) {
+      continue;
+    }
+    const LoadedArsc* loaded_arsc = assets->GetLoadedArsc();
     if (loaded_arsc == nullptr) {
       continue;
     }
@@ -384,8 +400,10 @@ bool AssetManager2::GetOverlayablesToString(android::StringPiece package_name,
 }
 
 bool AssetManager2::ContainsAllocatedTable() const {
-  return std::find_if(apk_assets_.begin(), apk_assets_.end(),
-                      std::mem_fn(&ApkAssets::IsTableAllocated)) != apk_assets_.end();
+  return std::find_if(apk_assets_.begin(), apk_assets_.end(), [](auto&& assets_weak) {
+           auto assets = assets_weak.promote();
+           return assets && assets->IsTableAllocated();
+         }) != apk_assets_.end();
 }
 
 void AssetManager2::SetConfiguration(const ResTable_config& configuration) {
@@ -398,8 +416,8 @@ void AssetManager2::SetConfiguration(const ResTable_config& configuration) {
   }
 }
 
-std::set<const ApkAssets*> AssetManager2::GetNonSystemOverlays() const {
-  std::set<const ApkAssets*> non_system_overlays;
+std::set<AssetManager2::ApkAssetsPtr> AssetManager2::GetNonSystemOverlays() const {
+  std::set<ApkAssetsPtr> non_system_overlays;
   for (const PackageGroup& package_group : package_groups_) {
     bool found_system_package = false;
     for (const ConfiguredPackage& package : package_group.packages_) {
@@ -411,7 +429,9 @@ std::set<const ApkAssets*> AssetManager2::GetNonSystemOverlays() const {
 
     if (!found_system_package) {
       for (const ConfiguredOverlay& overlay : package_group.overlays_) {
-        non_system_overlays.insert(apk_assets_[overlay.cookie]);
+        if (auto asset = apk_assets_[overlay.cookie].promote()) {
+          non_system_overlays.insert(std::move(asset));
+        }
       }
     }
   }
@@ -423,21 +443,24 @@ base::expected<std::set<ResTable_config>, IOError> AssetManager2::GetResourceCon
     bool exclude_system, bool exclude_mipmap) const {
   ATRACE_NAME("AssetManager::GetResourceConfigurations");
   const auto non_system_overlays =
-      (exclude_system) ? GetNonSystemOverlays() : std::set<const ApkAssets*>();
+      exclude_system ? GetNonSystemOverlays() : std::set<ApkAssetsPtr>();
 
   std::set<ResTable_config> configurations;
   for (const PackageGroup& package_group : package_groups_) {
     for (size_t i = 0; i < package_group.packages_.size(); i++) {
       const ConfiguredPackage& package = package_group.packages_[i];
-      if (exclude_system && package.loaded_package_->IsSystem()) {
-        continue;
-      }
-
-      auto apk_assets = apk_assets_[package_group.cookies_[i]];
-      if (exclude_system && apk_assets->IsOverlay() &&
-          non_system_overlays.find(apk_assets) == non_system_overlays.end()) {
-        // Exclude overlays that target system resources.
-        continue;
+      if (exclude_system) {
+        if (package.loaded_package_->IsSystem()) {
+          continue;
+        }
+        if (!non_system_overlays.empty()) {
+          // Exclude overlays that target only system resources.
+          auto apk_assets = apk_assets_[package_group.cookies_[i]].promote();
+          if (apk_assets && apk_assets->IsOverlay() &&
+              non_system_overlays.find(apk_assets) == non_system_overlays.end()) {
+            continue;
+          }
+        }
       }
 
       auto result = package.loaded_package_->CollectConfigurations(exclude_mipmap, &configurations);
@@ -454,20 +477,23 @@ std::set<std::string> AssetManager2::GetResourceLocales(bool exclude_system,
   ATRACE_NAME("AssetManager::GetResourceLocales");
   std::set<std::string> locales;
   const auto non_system_overlays =
-      (exclude_system) ? GetNonSystemOverlays() : std::set<const ApkAssets*>();
+      exclude_system ? GetNonSystemOverlays() : std::set<ApkAssetsPtr>();
 
   for (const PackageGroup& package_group : package_groups_) {
     for (size_t i = 0; i < package_group.packages_.size(); i++) {
       const ConfiguredPackage& package = package_group.packages_[i];
-      if (exclude_system && package.loaded_package_->IsSystem()) {
-        continue;
-      }
-
-      auto apk_assets = apk_assets_[package_group.cookies_[i]];
-      if (exclude_system && apk_assets->IsOverlay() &&
-          non_system_overlays.find(apk_assets) == non_system_overlays.end()) {
-        // Exclude overlays that target system resources.
-        continue;
+      if (exclude_system) {
+        if (package.loaded_package_->IsSystem()) {
+          continue;
+        }
+        if (!non_system_overlays.empty()) {
+          // Exclude overlays that target only system resources.
+          auto apk_assets = apk_assets_[package_group.cookies_[i]].promote();
+          if (apk_assets && apk_assets->IsOverlay() &&
+              non_system_overlays.find(apk_assets) == non_system_overlays.end()) {
+            continue;
+          }
+        }
       }
 
       package.loaded_package_->CollectLocales(merge_equivalent_languages, &locales);
@@ -492,13 +518,12 @@ std::unique_ptr<AssetDir> AssetManager2::OpenDir(const std::string& dirname) con
   ATRACE_NAME("AssetManager::OpenDir");
 
   std::string full_path = "assets/" + dirname;
-  std::unique_ptr<SortedVector<AssetDir::FileInfo>> files =
-      util::make_unique<SortedVector<AssetDir::FileInfo>>();
+  auto files = util::make_unique<SortedVector<AssetDir::FileInfo>>();
 
   // Start from the back.
   for (auto iter = apk_assets_.rbegin(); iter != apk_assets_.rend(); ++iter) {
-    const ApkAssets* apk_assets = *iter;
-    if (apk_assets->IsOverlay()) {
+    auto apk_assets = iter->promote();
+    if (!apk_assets || apk_assets->IsOverlay()) {
       continue;
     }
 
@@ -527,14 +552,15 @@ std::unique_ptr<Asset> AssetManager2::OpenNonAsset(const std::string& filename,
                                                    Asset::AccessMode mode,
                                                    ApkAssetsCookie* out_cookie) const {
   for (int32_t i = apk_assets_.size() - 1; i >= 0; i--) {
+    const auto assets = apk_assets_[i].promote();
     // Prevent RRO from modifying assets and other entries accessed by file
     // path. Explicitly asking for a path in a given package (denoted by a
     // cookie) is still OK.
-    if (apk_assets_[i]->IsOverlay()) {
+    if (!assets || assets->IsOverlay()) {
       continue;
     }
 
-    std::unique_ptr<Asset> asset = apk_assets_[i]->GetAssetsProvider()->Open(filename, mode);
+    std::unique_ptr<Asset> asset = assets->GetAssetsProvider()->Open(filename, mode);
     if (asset) {
       if (out_cookie != nullptr) {
         *out_cookie = i;
@@ -555,7 +581,8 @@ std::unique_ptr<Asset> AssetManager2::OpenNonAsset(const std::string& filename,
   if (cookie < 0 || static_cast<size_t>(cookie) >= apk_assets_.size()) {
     return {};
   }
-  return apk_assets_[cookie]->GetAssetsProvider()->Open(filename, mode);
+  auto assets = apk_assets_[cookie].promote();
+  return assets ? assets->GetAssetsProvider()->Open(filename, mode) : nullptr;
 }
 
 base::expected<FindEntryResult, NullOrIOError> AssetManager2::FindEntry(
@@ -603,90 +630,97 @@ base::expected<FindEntryResult, NullOrIOError> AssetManager2::FindEntry(
   }
 
   bool overlaid = false;
-  if (!stop_at_first_match && !ignore_configuration && !apk_assets_[result->cookie]->IsLoader()) {
-    for (const auto& id_map : package_group.overlays_) {
-      auto overlay_entry = id_map.overlay_res_maps_.Lookup(resid);
-      if (!overlay_entry) {
-        // No id map entry exists for this target resource.
-        continue;
-      }
-      if (overlay_entry.IsInlineValue()) {
-        // The target resource is overlaid by an inline value not represented by a resource.
-        ConfigDescription best_frro_config;
-        Res_value best_frro_value;
-        bool frro_found = false;
-        for( const auto& [config, value] : overlay_entry.GetInlineValue()) {
-          if ((!frro_found || config.isBetterThan(best_frro_config, desired_config))
-              && config.match(*desired_config)) {
-            frro_found = true;
-            best_frro_config = config;
-            best_frro_value = value;
-          }
-        }
-        if (!frro_found) {
+  if (!stop_at_first_match && !ignore_configuration) {
+    auto assets = apk_assets_[result->cookie].promote();
+    if (!assets) {
+      ALOGE("Found expired ApkAssets #%d for resource ID 0x%08x.", result->cookie, resid);
+      return base::unexpected(std::nullopt);
+    }
+    if (!assets->IsLoader()) {
+      for (const auto& id_map : package_group.overlays_) {
+        auto overlay_entry = id_map.overlay_res_maps_.Lookup(resid);
+        if (!overlay_entry) {
+          // No id map entry exists for this target resource.
           continue;
         }
-        result->entry = best_frro_value;
-        result->dynamic_ref_table = id_map.overlay_res_maps_.GetOverlayDynamicRefTable();
-        result->cookie = id_map.cookie;
-
-        if (UNLIKELY(logging_enabled)) {
-          last_resolution_.steps.push_back(
-              Resolution::Step{Resolution::Step::Type::OVERLAID_INLINE, String8(), result->cookie});
-          if (auto path = apk_assets_[result->cookie]->GetPath()) {
-            const std::string overlay_path = path->data();
-            if (IsFabricatedOverlay(overlay_path)) {
-              // FRRO don't have package name so we use the creating package here.
-              String8 frro_name = String8("FRRO");
-              // Get the first part of it since the expected one should be like
-              // {overlayPackageName}-{overlayName}-{4 alphanumeric chars}.frro
-              // under /data/resource-cache/.
-              const std::string name = overlay_path.substr(overlay_path.rfind('/') + 1);
-              const size_t end = name.find('-');
-              if (frro_name.size() != overlay_path.size() && end != std::string::npos) {
-                frro_name.append(base::StringPrintf(" created by %s",
-                                                    name.substr(0 /* pos */,
-                                                                end).c_str()).c_str());
+        if (overlay_entry.IsInlineValue()) {
+          // The target resource is overlaid by an inline value not represented by a resource.
+          ConfigDescription best_frro_config;
+          Res_value best_frro_value;
+          bool frro_found = false;
+          for( const auto& [config, value] : overlay_entry.GetInlineValue()) {
+            if ((!frro_found || config.isBetterThan(best_frro_config, desired_config))
+                && config.match(*desired_config)) {
+              frro_found = true;
+              best_frro_config = config;
+              best_frro_value = value;
+            }
+          }
+          if (!frro_found) {
+            continue;
+          }
+          result->entry = best_frro_value;
+          result->dynamic_ref_table = id_map.overlay_res_maps_.GetOverlayDynamicRefTable();
+          result->cookie = id_map.cookie;
+
+          if (UNLIKELY(logging_enabled)) {
+            last_resolution_.steps.push_back(
+                Resolution::Step{Resolution::Step::Type::OVERLAID_INLINE, String8(), result->cookie});
+            if (auto path = assets->GetPath()) {
+              const std::string overlay_path = path->data();
+              if (IsFabricatedOverlay(overlay_path)) {
+                // FRRO don't have package name so we use the creating package here.
+                String8 frro_name = String8("FRRO");
+                // Get the first part of it since the expected one should be like
+                // {overlayPackageName}-{overlayName}-{4 alphanumeric chars}.frro
+                // under /data/resource-cache/.
+                const std::string name = overlay_path.substr(overlay_path.rfind('/') + 1);
+                const size_t end = name.find('-');
+                if (frro_name.size() != overlay_path.size() && end != std::string::npos) {
+                  frro_name.append(base::StringPrintf(" created by %s",
+                                                      name.substr(0 /* pos */,
+                                                                  end).c_str()).c_str());
+                }
+                last_resolution_.best_package_name = frro_name;
+              } else {
+                last_resolution_.best_package_name = result->package_name->c_str();
               }
-              last_resolution_.best_package_name = frro_name;
-            } else {
-              last_resolution_.best_package_name = result->package_name->c_str();
             }
+            overlaid = true;
           }
-          overlaid = true;
+          continue;
         }
-        continue;
-      }
 
-      auto overlay_result = FindEntry(overlay_entry.GetResourceId(), density_override,
-                                      false /* stop_at_first_match */,
-                                      false /* ignore_configuration */);
-      if (UNLIKELY(IsIOError(overlay_result))) {
-        return base::unexpected(overlay_result.error());
-      }
-      if (!overlay_result.has_value()) {
-        continue;
-      }
+        auto overlay_result = FindEntry(overlay_entry.GetResourceId(), density_override,
+                                        false /* stop_at_first_match */,
+                                        false /* ignore_configuration */);
+        if (UNLIKELY(IsIOError(overlay_result))) {
+          return base::unexpected(overlay_result.error());
+        }
+        if (!overlay_result.has_value()) {
+          continue;
+        }
 
-      if (!overlay_result->config.isBetterThan(result->config, desired_config)
-          && overlay_result->config.compare(result->config) != 0) {
-        // The configuration of the entry for the overlay must be equal to or better than the target
-        // configuration to be chosen as the better value.
-        continue;
-      }
+        if (!overlay_result->config.isBetterThan(result->config, desired_config)
+            && overlay_result->config.compare(result->config) != 0) {
+          // The configuration of the entry for the overlay must be equal to or better than the target
+          // configuration to be chosen as the better value.
+          continue;
+        }
 
-      result->cookie = overlay_result->cookie;
-      result->entry = overlay_result->entry;
-      result->config = overlay_result->config;
-      result->dynamic_ref_table = id_map.overlay_res_maps_.GetOverlayDynamicRefTable();
+        result->cookie = overlay_result->cookie;
+        result->entry = overlay_result->entry;
+        result->config = overlay_result->config;
+        result->dynamic_ref_table = id_map.overlay_res_maps_.GetOverlayDynamicRefTable();
 
-      if (UNLIKELY(logging_enabled)) {
-        last_resolution_.steps.push_back(
-            Resolution::Step{Resolution::Step::Type::OVERLAID, overlay_result->config.toString(),
-                             overlay_result->cookie});
-        last_resolution_.best_package_name =
-            overlay_result->package_name->c_str();
-        overlaid = true;
+        if (UNLIKELY(logging_enabled)) {
+          last_resolution_.steps.push_back(
+              Resolution::Step{Resolution::Step::Type::OVERLAID, overlay_result->config.toString(),
+                               overlay_result->cookie});
+          last_resolution_.best_package_name =
+              overlay_result->package_name->c_str();
+          overlaid = true;
+        }
       }
     }
   }
@@ -868,7 +902,9 @@ std::string AssetManager2::GetLastResourceResolution() const {
   }
 
   const uint32_t resid = last_resolution_.resid;
-  const auto package = apk_assets_[cookie]->GetLoadedArsc()->GetPackageById(get_package_id(resid));
+  auto assets = apk_assets_[cookie].promote();
+  const auto package =
+      assets ? assets->GetLoadedArsc()->GetPackageById(get_package_id(resid)) : nullptr;
 
   std::string resource_name_string;
   if (package != nullptr) {
@@ -898,8 +934,9 @@ std::string AssetManager2::GetLastResourceResolution() const {
     if (prefix == kStepStrings.end()) {
       continue;
     }
-
-    log_stream << "\n\t" << prefix->second << ": " << apk_assets_[step.cookie]->GetDebugName();
+    auto assets = apk_assets_[step.cookie].promote();
+    log_stream << "\n\t" << prefix->second << ": " 
+               << (assets ? assets->GetDebugName() : "<null>") << " #" << step.cookie;
     if (!step.config_name.isEmpty()) {
       log_stream << " - " << step.config_name;
     }
@@ -1563,12 +1600,20 @@ base::expected<std::monostate, IOError> Theme::SetTo(const Theme& source) {
 
     // Determine which ApkAssets are loaded in both theme AssetManagers.
     const auto& src_assets = source.asset_manager_->GetApkAssets();
-    for (size_t i = 0; i < src_assets.size(); i++) {
-      const ApkAssets* src_asset = src_assets[i];
+    const auto& dest_assets = asset_manager_->GetApkAssets();
+    std::vector<AssetManager2::ApkAssetsPtr> promoted_src_assets;
+    promoted_src_assets.reserve(src_assets.size());
+    for (const auto& src_asset : src_assets) {
+      promoted_src_assets.emplace_back(src_asset.promote());
+    }
 
-      const auto& dest_assets = asset_manager_->GetApkAssets();
-      for (size_t j = 0; j < dest_assets.size(); j++) {
-        const ApkAssets* dest_asset = dest_assets[j];
+    for (size_t j = 0; j < dest_assets.size(); j++) {
+      auto dest_asset = dest_assets[j].promote();
+      if (!dest_asset) {
+        continue;
+      }
+      for (size_t i = 0; i < promoted_src_assets.size(); i++) {
+        const auto& src_asset = promoted_src_assets[i];
         if (src_asset != dest_asset) {
           // ResourcesManager caches and reuses ApkAssets when the same apk must be present in
           // multiple AssetManagers. Two ApkAssets point to the same version of the same resources