Migrate flutter_runner from flutter_runner::{Thread,Loop} to fml::{Thread,MessageLoop} (#15118)

Author: George Wright

ci/licenses_golden/licenses_flutter

@@ -1020,8 +1020,6 @@ FILE: ../../../flutter/shell/platform/fuchsia/flutter/kernel/extract_far.dart
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/kernel/framework_shim.dart
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/kernel/libraries.json
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/logging.h
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/loop.cc
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/loop.h
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/main.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/meta/aot_product_runtime
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/meta/aot_runtime
@@ -1044,12 +1042,6 @@ FILE: ../../../flutter/shell/platform/fuchsia/flutter/session_connection.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/session_connection.h
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/surface.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/surface.h
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/task_observers.cc
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/task_observers.h
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/task_runner_adapter.cc
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/task_runner_adapter.h
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/thread.cc
-FILE: ../../../flutter/shell/platform/fuchsia/flutter/thread.h
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/unique_fdio_ns.h
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/vsync_recorder.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/vsync_recorder.h

fml/thread.cc

@@ -10,6 +10,8 @@
 
 #if defined(OS_WIN)
 #include <windows.h>
+#elif defined(OS_FUCHSIA)
+#include <lib/zx/thread.h>
 #else
 #include <pthread.h>
 #endif
@@ -85,6 +87,8 @@ void Thread::SetCurrentThreadName(const std::string& name) {
                    reinterpret_cast<DWORD_PTR*>(&info));
   } __except (EXCEPTION_CONTINUE_EXECUTION) {
   }
+#elif OS_FUCHSIA
+  zx::thread::self()->set_property(ZX_PROP_NAME, name.c_str(), name.size());
 #else
   FML_DLOG(INFO) << "Could not set the thread name to '" << name
                  << "' on this platform.";

shell/platform/fuchsia/flutter/BUILD.gn

@@ -303,8 +303,6 @@ executable("flutter_runner_unittests") {
     "fuchsia_intl.h",
     "fuchsia_intl_unittest.cc",
     "logging.h",
-    "loop.cc",
-    "loop.h",
     "platform_view.cc",
     "platform_view.h",
     "platform_view_unittest.cc",
@@ -313,12 +311,6 @@ executable("flutter_runner_unittests") {
     "runner_unittest.cc",
     "surface.cc",
     "surface.h",
-    "task_observers.cc",
-    "task_observers.h",
-    "task_runner_adapter.cc",
-    "task_runner_adapter.h",
-    "thread.cc",
-    "thread.h",
     "vsync_recorder.cc",
     "vsync_recorder.h",
     "vsync_waiter.cc",

shell/platform/fuchsia/flutter/component.cc

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#define FML_USED_ON_EMBEDDER
+
 #include "component.h"
 
 #include <dlfcn.h>
@@ -36,10 +38,6 @@
 #include "runtime/dart/utils/tempfs.h"
 #include "runtime/dart/utils/vmo.h"
 
-#include "task_observers.h"
-#include "task_runner_adapter.h"
-#include "thread.h"
-
 // TODO(kaushikiska): Use these constants from ::llcpp::fuchsia::io
 // Can read from target object.
 constexpr uint32_t OPEN_RIGHT_READABLE = 1u;
@@ -59,11 +57,11 @@ ActiveApplication Application::Create(
     fuchsia::sys::StartupInfo startup_info,
     std::shared_ptr<sys::ServiceDirectory> runner_incoming_services,
     fidl::InterfaceRequest<fuchsia::sys::ComponentController> controller) {
-  std::unique_ptr<Thread> thread = std::make_unique<Thread>();
+  std::unique_ptr<fml::Thread> thread = std::make_unique<fml::Thread>();
   std::unique_ptr<Application> application;
 
   fml::AutoResetWaitableEvent latch;
-  async::PostTask(thread->dispatcher(), [&]() mutable {
+  fml::TaskRunner::RunNowOrPostTask(thread->GetTaskRunner(), [&]() mutable {
     application.reset(
         new Application(std::move(termination_callback), std::move(package),
                         std::move(startup_info), runner_incoming_services,
@@ -347,12 +345,12 @@ Application::Application(
   settings_.disable_dart_asserts = true;
 #endif
 
-  settings_.task_observer_add =
-      std::bind(&CurrentMessageLoopAddAfterTaskObserver, std::placeholders::_1,
-                std::placeholders::_2);
-
-  settings_.task_observer_remove = std::bind(
-      &CurrentMessageLoopRemoveAfterTaskObserver, std::placeholders::_1);
+  settings_.task_observer_add = [](intptr_t key, fml::closure callback) {
+    fml::MessageLoop::GetCurrent().AddTaskObserver(key, std::move(callback));
+  };
+  settings_.task_observer_remove = [](intptr_t key) {
+    fml::MessageLoop::GetCurrent().RemoveTaskObserver(key);
+  };
 
   // TODO(FL-117): Re-enable causal async stack traces when this issue is
   // addressed.
@@ -379,8 +377,7 @@ Application::Application(
 #endif  // defined(__aarch64__)
 
   auto weak_application = weak_factory_.GetWeakPtr();
-  auto platform_task_runner =
-      CreateFMLTaskRunner(async_get_default_dispatcher());
+  auto platform_task_runner = fml::MessageLoop::GetCurrent().GetTaskRunner();
   const std::string component_url = package.resolved_url;
   settings_.unhandled_exception_callback = [weak_application,
                                             platform_task_runner,

shell/platform/fuchsia/flutter/component.h

@@ -24,16 +24,16 @@
 #include "engine.h"
 #include "flutter/common/settings.h"
 #include "flutter/fml/macros.h"
+#include "flutter/fml/thread.h"
 
-#include "thread.h"
 #include "unique_fdio_ns.h"
 
 namespace flutter_runner {
 
 class Application;
 
 struct ActiveApplication {
-  std::unique_ptr<Thread> thread;
+  std::unique_ptr<fml::Thread> thread;
   std::unique_ptr<Application> application;
 
   ActiveApplication& operator=(ActiveApplication&& other) noexcept {

shell/platform/fuchsia/flutter/engine.cc

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#define FML_USED_ON_EMBEDDER
+
 #include "engine.h"
 
 #include <lib/async/cpp/task.h>
@@ -18,9 +20,7 @@
 #include "fuchsia_intl.h"
 #include "platform_view.h"
 #include "runtime/dart/utils/files.h"
-#include "task_runner_adapter.h"
 #include "third_party/skia/include/ports/SkFontMgr_fuchsia.h"
-#include "thread.h"
 
 namespace flutter_runner {
 
@@ -60,19 +60,17 @@ Engine::Engine(Delegate& delegate,
                fidl::InterfaceRequest<fuchsia::io::Directory> directory_request)
     : delegate_(delegate),
       thread_label_(std::move(thread_label)),
+      thread_host_(thread_label_ + ".",
+                   flutter::ThreadHost::Type::IO |
+                       flutter::ThreadHost::Type::UI |
+                       flutter::ThreadHost::Type::GPU),
       settings_(std::move(settings)),
       weak_factory_(this) {
   if (zx::event::create(0, &vsync_event_) != ZX_OK) {
     FML_DLOG(ERROR) << "Could not create the vsync event.";
     return;
   }
 
-  // Launch the threads that will be used to run the shell. These threads will
-  // be joined in the destructor.
-  for (auto& thread : threads_) {
-    thread.reset(new Thread());
-  }
-
   // Set up the session connection.
   auto scenic = svc->Connect<fuchsia::ui::scenic::Scenic>();
   fidl::InterfaceHandle<fuchsia::ui::scenic::Session> session;
@@ -167,12 +165,14 @@ Engine::Engine(Delegate& delegate,
 
   // Get the task runners from the managed threads. The current thread will be
   // used as the "platform" thread.
+  fml::MessageLoop::EnsureInitializedForCurrentThread();
+
   const flutter::TaskRunners task_runners(
-      thread_label_,  // Dart thread labels
-      CreateFMLTaskRunner(async_get_default_dispatcher()),  // platform
-      CreateFMLTaskRunner(threads_[0]->dispatcher()),       // gpu
-      CreateFMLTaskRunner(threads_[1]->dispatcher()),       // ui
-      CreateFMLTaskRunner(threads_[2]->dispatcher())        // io
+      thread_label_,                                   // Dart thread labels
+      fml::MessageLoop::GetCurrent().GetTaskRunner(),  // platform
+      thread_host_.gpu_thread->GetTaskRunner(),        // gpu
+      thread_host_.ui_thread->GetTaskRunner(),         // ui
+      thread_host_.io_thread->GetTaskRunner()          // io
   );
 
   // Setup the callback that will instantiate the rasterizer.
@@ -353,12 +353,6 @@ Engine::Engine(Delegate& delegate,
 
 Engine::~Engine() {
   shell_.reset();
-  for (const auto& thread : threads_) {
-    thread->Quit();
-  }
-  for (const auto& thread : threads_) {
-    thread->Join();
-  }
 }
 
 std::pair<bool, uint32_t> Engine::GetEngineReturnCode() const {

shell/platform/fuchsia/flutter/engine.h

@@ -16,8 +16,8 @@
 
 #include "flutter/fml/macros.h"
 #include "flutter/shell/common/shell.h"
+#include "flutter/shell/common/thread_host.h"
 #include "isolate_configurator.h"
-#include "thread.h"
 
 namespace flutter_runner {
 
@@ -53,8 +53,8 @@ class Engine final {
  private:
   Delegate& delegate_;
   const std::string thread_label_;
+  flutter::ThreadHost thread_host_;
   flutter::Settings settings_;
-  std::array<std::unique_ptr<Thread>, 3> threads_;
   std::unique_ptr<IsolateConfigurator> isolate_configurator_;
   std::unique_ptr<flutter::Shell> shell_;
   zx::event vsync_event_;

shell/platform/fuchsia/flutter/engine_flutter_runner.gni

@@ -55,8 +55,6 @@ template("flutter_runner") {
       "isolate_configurator.cc",
       "isolate_configurator.h",
       "logging.h",
-      "loop.cc",
-      "loop.h",
       "main.cc",
       "platform_view.cc",
       "platform_view.h",
@@ -66,12 +64,6 @@ template("flutter_runner") {
       "session_connection.h",
       "surface.cc",
       "surface.h",
-      "task_observers.cc",
-      "task_observers.h",
-      "task_runner_adapter.cc",
-      "task_runner_adapter.h",
-      "thread.cc",
-      "thread.h",
       "unique_fdio_ns.h",
       "vsync_recorder.cc",
       "vsync_recorder.h",

shell/platform/fuchsia/flutter/fuchsia_intl.cc

@@ -8,7 +8,6 @@
 #include <string>
 #include <vector>
 
-#include "loop.h"
 #include "rapidjson/document.h"
 #include "rapidjson/stringbuffer.h"
 #include "rapidjson/writer.h"