From 3ba2e3aa36b5cbc12ee6f5e46537c0f5f2fc255a Mon Sep 17 00:00:00 2001
From: Jelle Foks <jfoks@google.com>
Date: Thu, 25 Apr 2024 10:29:04 -0700
Subject: [PATCH] [Android] Stop calling eglSwapBuffers immediately.

Since we're seeing ANRs at SCREEN_OFF where the rasterizer thread appears to
be hanging during eglSwapBuffers, this change attempts to avoid those ANRs
by immediately skip calls to eglSwapBuffers when a surfaceDestroyed event is
received, until a the next SurfaceCreated.  Since Cobalt uses GameActivity,
those are received in calls to OnNativeWindowDestroyed respectively
OnNativeWindowCreated.

b/225209442
---
 starboard/android/shared/android_main.cc     |  5 +++++
 starboard/android/shared/egl_swap_buffers.cc | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/starboard/android/shared/android_main.cc b/starboard/android/shared/android_main.cc
index ce7e75ae9ea3..514bc8d28f39 100644
--- a/starboard/android/shared/android_main.cc
+++ b/starboard/android/shared/android_main.cc
@@ -38,6 +38,9 @@
 namespace starboard {
 namespace android {
 namespace shared {
+
+atomic_bool g_block_swapbuffers;
+
 namespace {
 
 using ::starboard::shared::starboard::CommandLine;
@@ -314,6 +317,7 @@ void OnWindowFocusChanged(GameActivity* activity, bool focused) {
 }
 
 void OnNativeWindowCreated(GameActivity* activity, ANativeWindow* window) {
+  g_block_swapbuffers.store(false);
   if (g_app_running.load()) {
     ApplicationAndroid::Get()->SendAndroidCommand(
         AndroidCommand::kNativeWindowCreated, window);
@@ -321,6 +325,7 @@ void OnNativeWindowCreated(GameActivity* activity, ANativeWindow* window) {
 }
 
 void OnNativeWindowDestroyed(GameActivity* activity, ANativeWindow* window) {
+  g_block_swapbuffers.store(true);
   if (g_app_running.load()) {
     ApplicationAndroid::Get()->SendAndroidCommand(
         AndroidCommand::kNativeWindowDestroyed);
diff --git a/starboard/android/shared/egl_swap_buffers.cc b/starboard/android/shared/egl_swap_buffers.cc
index ed9d8fc1b259..8cc824127f3b 100644
--- a/starboard/android/shared/egl_swap_buffers.cc
+++ b/starboard/android/shared/egl_swap_buffers.cc
@@ -16,14 +16,25 @@
 #include <GLES2/gl2.h>
 
 #include "starboard/android/shared/video_window.h"
+#include "starboard/common/atomic.h"
 #include "starboard/shared/gles/gl_call.h"
 
+namespace starboard {
+namespace android {
+namespace shared {
+extern atomic_bool g_block_swapbuffers;
+}  // namespace shared
+}  // namespace android
+}  // namespace starboard
+
 extern "C" {
 EGLBoolean __real_eglSwapBuffers(EGLDisplay dpy, EGLSurface surface);
 
 // This needs to be exported to ensure shared_library targets include it.
 SB_EXPORT_PLATFORM EGLBoolean __wrap_eglSwapBuffers(EGLDisplay dpy,
                                                     EGLSurface surface) {
+  if (starboard::android::shared::g_block_swapbuffers.load())
+    return;
   // Kick off the GPU while waiting for new player bounds to take effect.
   GL_CALL(glFlush());