From 0c9caa06154cbeba501d08a8fe7860fc4ffdcd70 Mon Sep 17 00:00:00 2001
From: Emre Kultursay <emrekultursay@google.com>
Date: Wed, 11 Mar 2026 16:28:49 -0700
Subject: [PATCH] Do not let the CPUTiming .so be unloaded

Android Vulkan loader calls dlopen/dlclose/dlopen during the loading
proces. This doesn't play nicely with Perfetto, so we get a crash.

This change adds a keep-alive mechanism (taken from AGI) that prevents
the unloading of the .so file.
---
 layersvt/CMakeLists.txt       |  1 +
 layersvt/cputiming.cpp        | 12 ++++++++++
 layersvt/layer_keep_alive.cpp | 45 +++++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+)
 create mode 100644 layersvt/layer_keep_alive.cpp

diff --git a/layersvt/CMakeLists.txt b/layersvt/CMakeLists.txt
index 393baef525..974a3e354c 100644
--- a/layersvt/CMakeLists.txt
+++ b/layersvt/CMakeLists.txt
@@ -133,6 +133,7 @@ if(BUILD_CPUTIMING)
         ../scripts/generators/cputiming_generator.py
         vk_layer_table.cpp
         vk_layer_table.h
+        layer_keep_alive.cpp
         json/VkLayer_CPUTiming.json.in
     )
 
diff --git a/layersvt/cputiming.cpp b/layersvt/cputiming.cpp
index f6a07b503a..806a94f76a 100644
--- a/layersvt/cputiming.cpp
+++ b/layersvt/cputiming.cpp
@@ -17,6 +17,18 @@
 
 #include "cputiming.h"
 
+#if defined(__ANDROID__)
+#include <android/log.h>
+
+__attribute__((constructor)) static void cputiming_layer_init() {
+    __android_log_print(ANDROID_LOG_WARN, "CPUTiming", "dlopen: CPUTiming library");
+}
+
+__attribute__((destructor)) static void cputiming_layer_finish() {
+    __android_log_print(ANDROID_LOG_WARN, "CPUTiming", "dlclose: CPUTiming library");
+}
+#endif
+
 CpuTiming& CpuTiming::Get() {
     static CpuTiming instance;
     return instance;
diff --git a/layersvt/layer_keep_alive.cpp b/layersvt/layer_keep_alive.cpp
new file mode 100644
index 0000000000..c375f0b637
--- /dev/null
+++ b/layersvt/layer_keep_alive.cpp
@@ -0,0 +1,45 @@
+/* Copyright (c) 2015-2023 The Khronos Group Inc.
+ * Copyright (c) 2015-2023 Valve Corporation
+ * Copyright (c) 2015-2023 LunarG, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if defined(__ANDROID__)
+#include <dlfcn.h>
+
+namespace {
+
+// Anonymous namespace function is NOT exported, keeping it local to each shared object.
+// We use a constructor attribute to trigger it when the library is loaded/opened.
+void layer_keep_alive_func();
+
+class KeepAlive {
+  public:
+    KeepAlive() {
+        Dl_info info;
+        // Attempt to find the filename of the library containing this code.
+        if (dladdr((void*)&layer_keep_alive_func, &info)) {
+            // Re-open with RTLD_NODELETE to force the library to stay resident.
+            dlopen(info.dli_fname, RTLD_NODELETE);
+        }
+    }
+};
+
+__attribute__((constructor)) void layer_keep_alive_func() {
+    static KeepAlive k;
+    (void)k;
+}
+
+}  // namespace
+#endif