share font collections between spawn engines

runtime/runtime_controller.h

@@ -560,7 +560,7 @@ class RuntimeController : public PlatformConfigurationClient {
   void RequestDartDeferredLibrary(intptr_t loading_unit_id) override;
   const fml::WeakPtr<IOManager>& GetIOManager() const { return io_manager_; }
 
-  DartVM* GetDartVM() const { return vm_; }
+  virtual DartVM* GetDartVM() const { return vm_; }
 
   const fml::RefPtr<const DartSnapshot>& GetIsolateSnapshot() const {
     return isolate_snapshot_;

shell/common/BUILD.gn

@@ -256,6 +256,7 @@ if (enable_unittests) {
       "//flutter/common/graphics",
       "//flutter/shell/profiling:profiling_unittests",
       "//flutter/shell/version",
+      "//flutter/testing:fixture_test",
       "//third_party/googletest:gmock",
     ]
 

shell/common/engine.cc

@@ -43,13 +43,15 @@ Engine::Engine(
     Settings settings,
     std::unique_ptr<Animator> animator,
     fml::WeakPtr<IOManager> io_manager,
+    const std::shared_ptr<FontCollection>& font_collection,
     std::unique_ptr<RuntimeController> runtime_controller)
     : delegate_(delegate),
       settings_(std::move(settings)),
       animator_(std::move(animator)),
       runtime_controller_(std::move(runtime_controller)),
       activity_running_(true),
       have_surface_(false),
+      font_collection_(font_collection),
       image_decoder_(task_runners, image_decoder_task_runner, io_manager),
       task_runners_(std::move(task_runners)),
       weak_factory_(this) {
@@ -75,6 +77,7 @@ Engine::Engine(Delegate& delegate,
              settings,
              std::move(animator),
              io_manager,
+             std::make_shared<FontCollection>(),
              nullptr) {
   runtime_controller_ = std::make_unique<RuntimeController>(
       *this,                                 // runtime delegate
@@ -111,6 +114,7 @@ std::unique_ptr<Engine> Engine::Spawn(
       /*settings=*/settings,
       /*animator=*/std::move(animator),
       /*io_manager=*/runtime_controller_->GetIOManager(),
+      /*font_collection=*/font_collection_,
       /*runtime_controller=*/nullptr);
   result->runtime_controller_ = runtime_controller_->Spawn(
       *result,                               // runtime delegate
@@ -132,7 +136,7 @@ fml::WeakPtr<Engine> Engine::GetWeakPtr() const {
 
 void Engine::SetupDefaultFontManager() {
   TRACE_EVENT0("flutter", "Engine::SetupDefaultFontManager");
-  font_collection_.SetupDefaultFontManager();
+  font_collection_->SetupDefaultFontManager();
 }
 
 std::shared_ptr<AssetManager> Engine::GetAssetManager() {
@@ -152,10 +156,10 @@ bool Engine::UpdateAssetManager(
   }
 
   // Using libTXT as the text engine.
-  font_collection_.RegisterFonts(asset_manager_);
+  font_collection_->RegisterFonts(asset_manager_);
 
   if (settings_.use_test_fonts) {
-    font_collection_.RegisterTestFonts();
+    font_collection_->RegisterTestFonts();
   }
 
   return true;
@@ -492,7 +496,7 @@ void Engine::SetNeedsReportTimings(bool needs_reporting) {
 }
 
 FontCollection& Engine::GetFontCollection() {
-  return font_collection_;
+  return *font_collection_;
 }
 
 void Engine::DoDispatchPacket(std::unique_ptr<PointerDataPacket> packet,

shell/common/engine.h

@@ -297,6 +297,7 @@ class Engine final : public RuntimeDelegate,
          Settings settings,
          std::unique_ptr<Animator> animator,
          fml::WeakPtr<IOManager> io_manager,
+         const std::shared_ptr<FontCollection>& font_collection,
          std::unique_ptr<RuntimeController> runtime_controller);
 
   //----------------------------------------------------------------------------
@@ -888,7 +889,7 @@ class Engine final : public RuntimeDelegate,
   std::shared_ptr<AssetManager> asset_manager_;
   bool activity_running_;
   bool have_surface_;
-  FontCollection font_collection_;
+  std::shared_ptr<FontCollection> font_collection_;
   ImageDecoder image_decoder_;
   TaskRunners task_runners_;
   size_t hint_freed_bytes_since_last_idle_ = 0;

shell/common/engine_unittests.cc

@@ -8,6 +8,7 @@
 
 #include "flutter/runtime/dart_vm_lifecycle.h"
 #include "flutter/shell/common/thread_host.h"
+#include "flutter/testing/fixture_test.h"
 #include "flutter/testing/testing.h"
 #include "gmock/gmock.h"
 #include "rapidjson/document.h"
@@ -67,6 +68,7 @@ class MockRuntimeController : public RuntimeController {
   MOCK_METHOD1(DispatchPlatformMessage, bool(fml::RefPtr<PlatformMessage>));
   MOCK_METHOD3(LoadDartDeferredLibraryError,
                void(intptr_t, const std::string, bool));
+  MOCK_CONST_METHOD0(GetDartVM, DartVM*());
 };
 
 fml::RefPtr<PlatformMessage> MakePlatformMessage(
@@ -95,7 +97,7 @@ fml::RefPtr<PlatformMessage> MakePlatformMessage(
   return message;
 }
 
-class EngineTest : public ::testing::Test {
+class EngineTest : public testing::FixtureTest {
  public:
   EngineTest()
       : thread_host_("EngineTest",
@@ -120,6 +122,7 @@ class EngineTest : public ::testing::Test {
 
  protected:
   void SetUp() override {
+    settings_ = CreateSettingsForFixture();
     dispatcher_maker_ = [](PointerDataDispatcher::Delegate&) {
       return nullptr;
     };
@@ -147,6 +150,7 @@ TEST_F(EngineTest, Create) {
         /*settings=*/settings_,
         /*animator=*/std::move(animator_),
         /*io_manager=*/io_manager_,
+        /*font_collection=*/std::make_shared<FontCollection>(),
         /*runtime_controller=*/std::move(runtime_controller_));
     EXPECT_TRUE(engine);
   });
@@ -167,6 +171,7 @@ TEST_F(EngineTest, DispatchPlatformMessageUnknown) {
         /*settings=*/settings_,
         /*animator=*/std::move(animator_),
         /*io_manager=*/io_manager_,
+        /*font_collection=*/std::make_shared<FontCollection>(),
         /*runtime_controller=*/std::move(mock_runtime_controller));
 
     fml::RefPtr<PlatformMessageResponse> response =
@@ -192,6 +197,7 @@ TEST_F(EngineTest, DispatchPlatformMessageInitialRoute) {
         /*settings=*/settings_,
         /*animator=*/std::move(animator_),
         /*io_manager=*/io_manager_,
+        /*font_collection=*/std::make_shared<FontCollection>(),
         /*runtime_controller=*/std::move(mock_runtime_controller));
 
     fml::RefPtr<PlatformMessageResponse> response =
@@ -224,6 +230,7 @@ TEST_F(EngineTest, DispatchPlatformMessageInitialRouteIgnored) {
         /*settings=*/settings_,
         /*animator=*/std::move(animator_),
         /*io_manager=*/io_manager_,
+        /*font_collection=*/std::make_shared<FontCollection>(),
         /*runtime_controller=*/std::move(mock_runtime_controller));
 
     fml::RefPtr<PlatformMessageResponse> response =
@@ -239,6 +246,32 @@ TEST_F(EngineTest, DispatchPlatformMessageInitialRouteIgnored) {
   });
 }
 
+TEST_F(EngineTest, SpawnSharesFontLibrary) {
+  PostUITaskSync([this] {
+    MockRuntimeDelegate client;
+    auto mock_runtime_controller =
+        std::make_unique<MockRuntimeController>(client, task_runners_);
+    auto vm_ref = DartVMRef::Create(settings_);
+    EXPECT_CALL(*mock_runtime_controller, GetDartVM())
+        .WillRepeatedly(::testing::Return(vm_ref.get()));
+    auto engine = std::make_unique<Engine>(
+        /*delegate=*/delegate_,
+        /*dispatcher_maker=*/dispatcher_maker_,
+        /*image_decoder_task_runner=*/image_decoder_task_runner_,
+        /*task_runners=*/task_runners_,
+        /*settings=*/settings_,
+        /*animator=*/std::move(animator_),
+        /*io_manager=*/io_manager_,
+        /*font_collection=*/std::make_shared<FontCollection>(),
+        /*runtime_controller=*/std::move(mock_runtime_controller));
+
+    auto spawn =
+        engine->Spawn(delegate_, dispatcher_maker_, settings_, nullptr);
+    EXPECT_TRUE(spawn != nullptr);
+    EXPECT_EQ(&engine->GetFontCollection(), &spawn->GetFontCollection());
+  });
+}
+
 TEST_F(EngineTest, PassesLoadDartDeferredLibraryErrorToRuntime) {
   PostUITaskSync([this] {
     intptr_t error_id = 123;
@@ -259,6 +292,7 @@ TEST_F(EngineTest, PassesLoadDartDeferredLibraryErrorToRuntime) {
         /*settings=*/settings_,
         /*animator=*/std::move(animator_),
         /*io_manager=*/io_manager_,
+        /*font_collection=*/std::make_shared<FontCollection>(),
         /*runtime_controller=*/std::move(mock_runtime_controller));
 
     engine->LoadDartDeferredLibraryError(error_id, error_message, true);