Buildbot test to see if we can properly unload vulkan using atexit().…

… super hacky Proof-of-concept.

apps/CMakeLists.txt

@@ -51,7 +51,7 @@ add_app(hist)
 add_app(iir_blur)
 add_app(interpolate)
 add_app(lens_blur)
-add_app(linear_algebra)
+# add_app(linear_algebra)
 # add_app(linear_blur)  # TODO(#5374): missing CMake build
 add_app(local_laplacian)
 add_app(max_filter)

src/runtime/vulkan.cpp

@@ -1397,20 +1397,6 @@ WEAK __attribute__((constructor)) void register_vulkan_allocation_pool() {
     halide_register_device_allocation_pool(&vulkan_allocation_pool);
 }
 
-WEAK __attribute__((destructor)) void halide_vulkan_cleanup() {
-    // FIXME: When the VK_LAYER_KHRONOS_validation is intercepting calls to the API, it will
-    //        cause a segfault if it's invoked inside the destructor since it uses it's own global
-    //        state to track object usage which is no longer valid once this call is invoked.
-    //        Calling this destructor with the validator hooks in place will cause an uncaught
-    //        exception for an uninitialized mutex lock. We can avoid the crash on exit by \
-    //        bypassing the device release call and leak (!!!!)
-    // ISSUE: https://github.com/halide/Halide/issues/8290
-    const char *layer_names = vk_get_layer_names_internal(nullptr);
-    bool has_validation_layer = strstr(layer_names, "VK_LAYER_KHRONOS_validation");
-    if (!has_validation_layer) {
-        halide_vulkan_device_release(nullptr);
-    }
-}
 
 // --------------------------------------------------------------------------
 
@@ -1472,3 +1458,7 @@ WEAK halide_device_interface_t vulkan_device_interface = {
 }  // namespace Internal
 }  // namespace Runtime
 }  // namespace Halide
+
+WEAK void halide_vulkan_cleanup() {
+    halide_vulkan_device_release(nullptr);
+}

src/runtime/vulkan_interface.h

@@ -30,6 +30,9 @@
 // Vulkan API Definition
 // --------------------------------------------------------------------------
 
+extern "C" WEAK void atexit(void (*fn)());
+WEAK void halide_vulkan_cleanup();
+
 namespace Halide {
 namespace Runtime {
 namespace Internal {
@@ -46,6 +49,7 @@ extern WEAK halide_device_interface_t vulkan_device_interface;
 // the Vulkan loader shared library/DLL, and then get the symbol from it.
 WEAK void *lib_vulkan = nullptr;
 
+
 extern "C" WEAK void *halide_vulkan_get_symbol(void *user_context, const char *name) {
     // Only try to load the library if the library isn't already
     // loaded, or we can't load the symbol from the process already.
@@ -66,6 +70,7 @@ extern "C" WEAK void *halide_vulkan_get_symbol(void *user_context, const char *n
         lib_vulkan = halide_load_library(lib_name);
         if (lib_vulkan) {
             debug(user_context) << "    Loaded Vulkan loader library: " << lib_name << "\n";
+            atexit(halide_vulkan_cleanup);
             break;
         } else {
             debug(user_context) << "    Missing Vulkan loader library: " << lib_name << "\n";