From 12b9039eb8b3b8c9ac5fba1e21ba3bd22d7c4c32 Mon Sep 17 00:00:00 2001
From: Dan Field <dnfield@google.com>
Date: Tue, 28 Mar 2023 20:42:54 -0700
Subject: [PATCH 1/2] Use NSAutoReleasePool for Metal playgrounds

Fixes https://github.com/flutter/flutter/issues/117339

Avoids creating a new parallel ObjC++ TU
---
 impeller/playground/playground.cc | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/impeller/playground/playground.cc b/impeller/playground/playground.cc
index 1f1c5930ff864..692755d61ff6e 100644
--- a/impeller/playground/playground.cc
+++ b/impeller/playground/playground.cc
@@ -18,18 +18,23 @@
 
 #include "flutter/fml/paths.h"
 #include "impeller/base/validation.h"
+#include "impeller/core/allocator.h"
+#include "impeller/core/formats.h"
 #include "impeller/image/compressed_image.h"
 #include "impeller/playground/imgui/imgui_impl_impeller.h"
 #include "impeller/playground/playground.h"
 #include "impeller/playground/playground_impl.h"
-#include "impeller/renderer/allocator.h"
 #include "impeller/renderer/context.h"
-#include "impeller/renderer/formats.h"
 #include "impeller/renderer/render_pass.h"
 #include "impeller/renderer/renderer.h"
 #include "third_party/imgui/backends/imgui_impl_glfw.h"
 #include "third_party/imgui/imgui.h"
 
+#if FML_OS_MACOSX
+#include <objc/message.h>
+#include <objc/runtime.h>
+#endif
+
 namespace impeller {
 
 std::string PlaygroundBackendToString(PlaygroundBackend backend) {
@@ -178,6 +183,23 @@ void Playground::SetCursorPosition(Point pos) {
   cursor_position_ = pos;
 }
 
+#if FML_OS_MACOSX
+class AutoReleasePool {
+ public:
+  AutoReleasePool() {
+    pool_ = reinterpret_cast<msg_send>(objc_msgSend)(
+        objc_getClass("NSAutoreleasePool"), sel_getUid("new"));
+  }
+  ~AutoReleasePool() {
+    reinterpret_cast<msg_send>(objc_msgSend)(pool_, sel_getUid("drain"));
+  }
+
+ private:
+  typedef id (*msg_send)(void*, SEL);
+  id pool_;
+};
+#endif
+
 bool Playground::OpenPlaygroundHere(
     const Renderer::RenderCallback& render_callback) {
   if (!is_enabled()) {
@@ -239,6 +261,9 @@ bool Playground::OpenPlaygroundHere(
   ::glfwShowWindow(window);
 
   while (true) {
+#if FML_OS_MACOSX
+    AutoReleasePool pool;
+#endif
     ::glfwPollEvents();
 
     if (::glfwWindowShouldClose(window)) {

From f9ec3fb2f57c0ad14bad1f298873e30fd30f09a2 Mon Sep 17 00:00:00 2001
From: Dan Field <dnfield@google.com>
Date: Tue, 28 Mar 2023 20:43:42 -0700
Subject: [PATCH 2/2] Update playground.cc

---
 impeller/playground/playground.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/impeller/playground/playground.cc b/impeller/playground/playground.cc
index 692755d61ff6e..3df9001bc753d 100644
--- a/impeller/playground/playground.cc
+++ b/impeller/playground/playground.cc
@@ -18,13 +18,13 @@
 
 #include "flutter/fml/paths.h"
 #include "impeller/base/validation.h"
-#include "impeller/core/allocator.h"
-#include "impeller/core/formats.h"
 #include "impeller/image/compressed_image.h"
 #include "impeller/playground/imgui/imgui_impl_impeller.h"
 #include "impeller/playground/playground.h"
 #include "impeller/playground/playground_impl.h"
+#include "impeller/renderer/allocator.h"
 #include "impeller/renderer/context.h"
+#include "impeller/renderer/formats.h"
 #include "impeller/renderer/render_pass.h"
 #include "impeller/renderer/renderer.h"
 #include "third_party/imgui/backends/imgui_impl_glfw.h"