diff --git a/Cargo.toml b/Cargo.toml
index 9d10dea..cf5a4ce 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,6 +20,7 @@ paste = "1.0.14"
 serde = "1.0.192"
 serde_json = "1.0.108"
 ringbuf = "0.3.3"
+lazy_static = "1.4.0"
 
 [profile.release-lto]
 inherits = "release"
diff --git a/src/lib.rs b/src/lib.rs
index 74ac621..234447d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,13 +5,39 @@ use std::{
     fs::{self, File, OpenOptions},
     io::Write,
     path::Path,
+    sync::{RwLock, RwLockReadGuard, RwLockWriteGuard},
 };
 
+use lazy_static::lazy_static;
 use overlay::{Overlay, OverlayConfig};
 
 static mut LOG_ENABLED: bool = true;
 static mut LOG_FILE: String = String::new();
-static mut OVERLAY: Overlay = Overlay::new();
+lazy_static! {
+    static ref OVERLAY: RwLock<Overlay> = RwLock::new(Overlay::new());
+}
+
+pub(crate) fn overlay() -> RwLockReadGuard<'static, Overlay> {
+    match OVERLAY.try_read() {
+        Ok(overlay) => overlay,
+        Err(_) => {
+            write_log!("failed to get read handle from OVERLAY");
+            write_log!(std::backtrace::Backtrace::force_capture());
+            panic!();
+        }
+    }
+}
+
+pub(crate) fn overlay_mut() -> RwLockWriteGuard<'static, Overlay> {
+    match OVERLAY.try_write() {
+        Ok(overlay) => overlay,
+        Err(_) => {
+            write_log!("failed to get write handle from OVERLAY");
+            write_log!(std::backtrace::Backtrace::force_capture());
+            panic!();
+        }
+    }
+}
 
 pub(crate) fn logging() -> bool {
     unsafe { LOG_ENABLED }
@@ -96,7 +122,11 @@ pub fn check_logging(home: &str) {
             LOG_FILE = format!("{}/rf2_vk_hud.log", home);
         }
 
-        if let Err(_) = File::create(unsafe { &LOG_FILE }) {}
+        if let Err(_) = OpenOptions::new()
+            .append(true)
+            .create(true)
+            .open(unsafe { &LOG_FILE })
+        {}
 
         write_log!(" ==================================================================");
         write_log!(" ======================= New Negotiation ==========================");
diff --git a/src/overlay/mod.rs b/src/overlay/mod.rs
index e11e641..15b0dfa 100644
--- a/src/overlay/mod.rs
+++ b/src/overlay/mod.rs
@@ -12,8 +12,7 @@ mod rfactor_data;
 use anyhow::Result;
 use assetpath::AssetPath;
 use std::{
-    cell::RefCell,
-    rc::Rc,
+    collections::HashMap,
     sync::{Arc, Mutex},
 };
 use ui::{guihandler::guihandler::Font, prelude::*};
@@ -62,28 +61,38 @@ impl OverlayConfig {
     }
 }
 
+#[derive(Debug)]
+pub struct InstanceCollection {
+    pub instance: Arc<Instance>,
+    pub physical_devices: Vec<VkPhysicalDevice>,
+    pub device_collection: HashMap<VkDevice, DeviceCollection>,
+}
+
+#[derive(Debug)]
+pub struct DeviceCollection {
+    pub device: Arc<Device>,
+    pub queues: HashMap<VkQueue, Arc<Mutex<Queue>>>,
+    pub swapchains: HashMap<VkSwapchainKHR, Arc<Swapchain>>,
+}
+
 pub struct Overlay {
     config: OverlayConfig,
 
-    instance: Option<Arc<Instance>>,
-    device: Option<Arc<Device>>,
-    queue: Option<Arc<Mutex<Queue>>>,
+    pub(crate) instances: HashMap<VkInstance, InstanceCollection>,
     rendering: Option<Rendering>,
     gui_handler: Option<Arc<GuiHandler>>,
 
-    ui_elements: Vec<Rc<RefCell<dyn UiOverlay>>>,
+    ui_elements: Vec<Arc<Mutex<dyn UiOverlay>>>,
 
     rfactor_data: Option<RFactorData>,
 }
 
 impl Overlay {
-    pub const fn new() -> Self {
+    pub fn new() -> Self {
         Self {
             config: OverlayConfig::new(),
 
-            instance: None,
-            device: None,
-            queue: None,
+            instances: HashMap::new(),
             rendering: None,
             gui_handler: None,
             ui_elements: Vec::new(),
@@ -96,28 +105,132 @@ impl Overlay {
         self.config = config;
     }
 
-    pub fn set_instance(&mut self, instance: Arc<Instance>) {
-        self.instance = Some(instance);
+    pub fn add_instance(&mut self, instance: Arc<Instance>) {
+        let physical_devices = match instance.enumerate_physical_devices() {
+            Ok(devices) => devices,
+            Err(err) => {
+                write_log!(format!("failed to enumerate physical devices {err:?}"));
+                panic!();
+            }
+        };
+
+        self.instances.insert(
+            instance.vk_handle(),
+            InstanceCollection {
+                instance,
+                physical_devices,
+                device_collection: HashMap::new(),
+            },
+        );
     }
 
-    pub fn instance(&self) -> Arc<Instance> {
-        self.instance.as_ref().unwrap().clone()
+    pub fn remove_instance(&mut self, handle: VkInstance) {
+        self.instances.remove(&handle);
+    }
+
+    pub fn instance_by_physical_device(&self, physical_device: VkPhysicalDevice) -> Arc<Instance> {
+        match self
+            .instances
+            .values()
+            .find(|collection| {
+                collection
+                    .physical_devices
+                    .iter()
+                    .find(|&&phys_dev| phys_dev == physical_device)
+                    .is_some()
+            })
+            .map(|collection| &collection.instance)
+        {
+            Some(instance) => instance.clone(),
+            None => {
+                write_log!(format!(
+                    "failed to find instance with physical device ({physical_device:?})"
+                ));
+                panic!();
+            }
+        }
     }
 
     pub fn set_device(&mut self, device: Arc<Device>) {
-        self.device = Some(device);
+        if let Some(instance_collection) = self
+            .instances
+            .get_mut(&device.physical_device().instance().vk_handle())
+        {
+            instance_collection.device_collection.insert(
+                device.vk_handle(),
+                DeviceCollection {
+                    device,
+                    queues: HashMap::new(),
+                    swapchains: HashMap::new(),
+                },
+            );
+        }
     }
 
-    pub fn device(&self) -> Arc<Device> {
-        self.device.as_ref().unwrap().clone()
+    fn device_collection(&self, device: VkDevice) -> &DeviceCollection {
+        for instance_collection in self.instances.values() {
+            if let Some(device_collection) = instance_collection.device_collection.get(&device) {
+                return device_collection;
+            }
+        }
+
+        write_log!(format!("device ({device:?}) not found"));
+        panic!();
+    }
+
+    fn device_collection_mut(&mut self, device: &Arc<Device>) -> &mut DeviceCollection {
+        if let Some(instance_collection) = self
+            .instances
+            .get_mut(&device.physical_device().instance().vk_handle())
+        {
+            if let Some(device_collection) = instance_collection
+                .device_collection
+                .get_mut(&device.vk_handle())
+            {
+                return device_collection;
+            }
+        }
+
+        write_log!(format!("device ({device:?}) not found"));
+        panic!();
+    }
+
+    pub fn device(&self, handle: VkDevice) -> Arc<Device> {
+        self.device_collection(handle).device.clone()
     }
 
     pub fn set_queue(&mut self, queue: Arc<Mutex<Queue>>) {
-        self.queue = Some(queue);
+        let handle = queue.lock().unwrap().vk_handle();
+        let device = queue.lock().unwrap().device().clone();
+
+        self.device_collection_mut(&device)
+            .queues
+            .insert(handle, queue);
     }
 
-    pub fn queue(&self) -> Arc<Mutex<Queue>> {
-        self.queue.as_ref().unwrap().clone()
+    pub fn queue(&self, device: VkDevice, queue: VkQueue) -> Arc<Mutex<Queue>> {
+        match self.device_collection(device).queues.get(&queue) {
+            Some(queue) => queue.clone(),
+            None => {
+                write_log!(format!("queue ({queue:?} not found)"));
+                panic!();
+            }
+        }
+    }
+
+    pub fn device_queue(&self, device: VkDevice) -> Arc<Mutex<Queue>> {
+        self.device_collection(device)
+            .queues
+            .values()
+            .next()
+            .expect(&format!("no queue for device ({device:?}) present"))
+            .clone()
+    }
+
+    pub fn insert_swapchain(&mut self, swapchain: Arc<Swapchain>) {
+        self.device_collection_mut(swapchain.device())
+            .swapchains
+            .insert(swapchain.vk_handle(), swapchain);
     }
 
     pub fn swapchain(&self, swapchain: VkSwapchainKHR) -> Option<&Arc<Swapchain>> {
@@ -130,14 +243,32 @@ impl Overlay {
         }
     }
 
-    pub fn create_rendering(&mut self, swapchain: Arc<Swapchain>) -> Result<()> {
+    pub fn create_rendering(&mut self, device: VkDevice) -> Result<()> {
         write_log!("-> create rendering: start");
 
         self.rendering = None;
 
         write_log!("-> create rendering: old cleared");
 
-        let mut rendering = Rendering::new(self.queue(), swapchain.clone())?;
+        let device_collection = self.device_collection(device);
+
+        let device = &device_collection.device.clone();
+        let queue = match device_collection.queues.values().next() {
+            Some(queue) => queue.clone(),
+            None => {
+                write_log!(format!("failed to find queue"));
+                panic!();
+            }
+        };
+        let swapchain = match device_collection.swapchains.values().next() {
+            Some(swapchain) => swapchain.clone(),
+            None => {
+                write_log!(format!("failed to find swapchain"));
+                panic!();
+            }
+        };
+
+        let mut rendering = Rendering::new(queue.clone(), swapchain.clone())?;
 
         write_log!("-> create rendering: new created");
 
@@ -152,78 +283,80 @@ impl Overlay {
 
         // provide trait required by GuiHandler
         let ctx = Arc::new(ContextImpl::new(
-            self.device(),
-            self.queue(),
-            swapchain,
+            device.clone(),
+            queue.clone(),
+            swapchain.clone(),
             rendering.images().clone(),
         ));
 
+        write_log!("create rendering: context created");
+
         // create GuiHandler
         let gui_handler = GuiHandler::new(create_info, &(ctx as Arc<dyn ContextInterface>))?;
-        write_log!("GuiHandler successfully created");
+        write_log!("create rendering: GuiHandler successfully created");
 
         // create ui elements
 
         // create watermark
         if self.config.ui_config.enable_watermark {
-            let watermark = Rc::new(RefCell::new(Watermark::new(&gui_handler)?));
+            let watermark = Arc::new(Mutex::new(Watermark::new(&gui_handler)?));
 
             self.ui_elements.push(watermark);
 
-            write_log!("Watermark successfully created");
+            write_log!("create rendering: Watermark successfully created");
         }
 
         // create radar
         if self.config.ui_config.enable_radar {
-            let radar = Rc::new(RefCell::new(Radar::new(
+            let radar = Arc::new(Mutex::new(Radar::new(
                 self.config.radar_config,
-                self.device(),
-                self.queue(),
+                device.clone(),
+                queue.clone(),
                 &rendering,
             )?));
 
             rendering.add_render_callback({
                 let radar = radar.clone();
 
-                move |index| radar.borrow().render(index)
+                move |index| radar.lock().unwrap().render(index)
             });
 
             self.ui_elements.push(radar);
 
-            write_log!("Radar successfully created");
+            write_log!("create rendering: Radar successfully created");
         }
 
         // create pedals
         if self.config.ui_config.enable_pedals {
-            let pedals = Rc::new(RefCell::new(Pedals::new(
+            let pedals = Arc::new(Mutex::new(Pedals::new(
                 &gui_handler,
-                self.device(),
-                self.queue(),
+                device.clone(),
+                queue.clone(),
             )?));
 
             self.ui_elements.push(pedals.clone());
 
-            rendering.add_render_callback(move |_| pedals.borrow().render());
+            rendering.add_render_callback(move |_| pedals.lock().unwrap().render());
 
-            write_log!("Pedals successfully created");
+            write_log!("create rendering: Pedals successfully created");
         }
 
         // create leaderboard
         if self.config.ui_config.enable_leaderboard {
-            let leaderboard = Rc::new(RefCell::new(LeaderBoard::new(
+            let leaderboard = Arc::new(Mutex::new(LeaderBoard::new(
                 &gui_handler,
                 self.config.leader_board_config,
             )?));
             self.ui_elements.push(leaderboard);
 
-            write_log!("Leader Board successfully created");
+            write_log!("create rendering: Leader Board successfully created");
         }
 
         // add rendering callbacks
         rendering.add_render_callback({
             let gui_handler = gui_handler.clone();
-            let device = self.device();
-            let queue = self.queue();
+            let device = device.clone();
+            let queue = queue.clone();
 
             move |index| {
                 let command_buffer =
@@ -242,7 +375,7 @@ impl Overlay {
             }
         });
 
-        write_log!("render callbacks added");
+        write_log!("create rendering: render callbacks added");
 
         self.rendering = Some(rendering);
         self.gui_handler = Some(gui_handler);
diff --git a/src/overlay/rendering.rs b/src/overlay/rendering.rs
index 5f5c33c..1a99ac4 100644
--- a/src/overlay/rendering.rs
+++ b/src/overlay/rendering.rs
@@ -14,7 +14,7 @@ pub struct Rendering {
 
     queue: Arc<Mutex<Queue>>,
 
-    render_callbacks: Vec<Box<dyn Fn(u32) -> Result<Arc<CommandBuffer>>>>,
+    render_callbacks: Vec<Box<dyn Fn(u32) -> Result<Arc<CommandBuffer>> + Send + Sync>>,
 }
 
 impl Rendering {
@@ -60,7 +60,7 @@ impl Rendering {
 
     pub fn add_render_callback<F>(&mut self, f: F)
     where
-        F: Fn(u32) -> Result<Arc<CommandBuffer>> + 'static,
+        F: Fn(u32) -> Result<Arc<CommandBuffer>> + Send + Sync + 'static,
     {
         self.render_callbacks.push(Box::new(f));
     }
diff --git a/src/overlay/rfactor_data.rs b/src/overlay/rfactor_data.rs
index c542c3b..952af24 100644
--- a/src/overlay/rfactor_data.rs
+++ b/src/overlay/rfactor_data.rs
@@ -2,8 +2,7 @@ use anyhow::Result;
 use rfactor_sm_reader::*;
 
 use std::{
-    cell::RefCell,
-    rc::Rc,
+    sync::{Arc, Mutex},
     time::{Duration, Instant},
 };
 
@@ -11,7 +10,7 @@ use crate::write_log;
 
 use super::UiOverlay;
 
-pub trait DataReceiver {
+pub trait DataReceiver: Send + Sync {
     fn game_phase_change(&mut self, phase: GamePhase) -> Result<()>;
 
     fn update_for_phase(&self, phase: GamePhase) -> bool;
@@ -67,7 +66,7 @@ pub struct RFactorData {
     player_id: Option<i32>,
     previous_game_phase: GamePhase,
 
-    receivers: Vec<Rc<RefCell<dyn UiOverlay>>>,
+    receivers: Vec<Arc<Mutex<dyn UiOverlay>>>,
 }
 
 impl RFactorData {
@@ -89,7 +88,7 @@ impl RFactorData {
         })
     }
 
-    pub fn add_receiver(&mut self, receiver: Rc<RefCell<dyn UiOverlay>>) {
+    pub fn add_receiver(&mut self, receiver: Arc<Mutex<dyn UiOverlay>>) {
         self.receivers.push(receiver);
     }
 
@@ -131,7 +130,8 @@ impl RFactorData {
 
                         for receiver in self.receivers.iter() {
                             receiver
-                                .borrow_mut()
+                                .lock()
+                                .unwrap()
                                 .game_phase_change(self.previous_game_phase)?;
                         }
                     }
@@ -140,7 +140,7 @@ impl RFactorData {
                 }
 
                 for receiver in self.receivers.iter() {
-                    let mut rec_mut = receiver.borrow_mut();
+                    let mut rec_mut = receiver.lock().unwrap();
 
                     if rec_mut.update_for_phase(self.previous_game_phase) {
                         rec_mut.scoring_update(self.previous_game_phase, &vehicle_scorings)?;
@@ -156,7 +156,8 @@ impl RFactorData {
 
                         for receiver in self.receivers.iter() {
                             receiver
-                                .borrow_mut()
+                                .lock()
+                                .unwrap()
                                 .game_phase_change(self.previous_game_phase)?;
                         }
                     }
@@ -170,7 +171,7 @@ impl RFactorData {
             write_log!("new telemetry update");
 
             for receiver in self.receivers.iter() {
-                let mut rec_mut = receiver.borrow_mut();
+                let mut rec_mut = receiver.lock().unwrap();
 
                 if rec_mut.update_for_phase(self.previous_game_phase) {
                     rec_mut.telemetry_update(self.player_id, &telemetries)?;
diff --git a/src/vk_layer/mod.rs b/src/vk_layer/mod.rs
index 7227bf8..405f7da 100644
--- a/src/vk_layer/mod.rs
+++ b/src/vk_layer/mod.rs
@@ -13,7 +13,7 @@ use std::{ffi::c_void, mem, os::raw::c_char, ptr};
 static mut ACQUIRE_NEXT_IMAGE: PFN_vkAcquireNextImageKHR =
     unsafe { mem::transmute(vkVoidFunction as *const c_void) };
 
-use crate::{get_config, logging, write_log, OVERLAY};
+use crate::{get_config, logging, overlay, overlay_mut, write_log};
 
 #[no_mangle]
 #[allow(non_snake_case)]
@@ -24,9 +24,7 @@ pub(crate) extern "C" fn vkNegotiateLoaderLayerInterfaceVersion(
 
     check_logging(&home);
 
-    unsafe {
-        OVERLAY.set_config(get_config(&home));
-    }
+    overlay_mut().set_config(get_config(&home));
 
     unsafe {
         *pVersionStruct = VkNegotiateLayerInterface {
@@ -202,7 +200,7 @@ pub(crate) extern "system" fn create_instance(
                 }
             };
 
-            OVERLAY.set_instance(ins);
+            overlay_mut().add_instance(ins);
         }
 
         write_log!("-> created local instance handle");
@@ -222,6 +220,7 @@ pub(crate) extern "system" fn destroy_instance(
     unsafe {
         if let Some(vk_fn) = vk_handles().handle("vkDestroyInstance") {
             let destroy_instance: PFN_vkDestroyInstance = mem::transmute(vk_fn);
+            overlay_mut().remove_instance(instance);
 
             destroy_instance(instance, allocator);
         }
@@ -278,7 +277,9 @@ pub(crate) extern "system" fn create_device(
         };
     };
 
-    let pdev = match PhysicalDevice::from_raw(unsafe { OVERLAY.instance() }, physical_device) {
+    let instance = overlay().instance_by_physical_device(physical_device);
+
+    let pdev = match PhysicalDevice::from_raw(instance, physical_device) {
         Ok(pdev) => pdev,
         Err(err) => {
             write_log!(format!("failed creating physical device: {:?}", err));
@@ -332,10 +333,8 @@ pub(crate) extern "system" fn create_device(
 
     write_log!("got queue from device");
 
-    unsafe {
-        OVERLAY.set_device(device);
-        OVERLAY.set_queue(queue);
-    }
+    overlay_mut().set_device(device.clone());
+    overlay_mut().set_queue(queue);
 
     VK_SUCCESS
 }
@@ -378,11 +377,42 @@ pub(crate) extern "system" fn create_swapchain(
         *p_swapchain
     }));
 
-    let swapchain = unsafe { Swapchain::from_raw(OVERLAY.device(), &*create_info, *p_swapchain) };
+    overlay_mut().insert_swapchain(unsafe {
+        Swapchain::from_raw(overlay().device(_device), &*create_info, *p_swapchain)
+    });
+
+    {
+        let instances = &overlay().instances;
+
+        write_log!(format!("number of instances: {}", instances.len()));
+
+        for instance_collection in instances.values() {
+            write_log!(format!(
+                "\tnumber of physical devices: {}",
+                instance_collection.physical_devices.len()
+            ));
+
+            write_log!(format!(
+                "\tnumber of devices: {}",
+                instance_collection.device_collection.len()
+            ));
+
+            for device_collection in instance_collection.device_collection.values() {
+                write_log!(format!(
+                    "\t\tnumber of queues: {}",
+                    device_collection.queues.len()
+                ));
+                write_log!(format!(
+                    "\t\tnumber of swapchains: {}",
+                    device_collection.swapchains.len()
+                ));
+            }
+        }
+    }
 
     write_log!("-> created Arc<Swapchain>");
 
-    if let Err(err) = unsafe { OVERLAY.create_rendering(swapchain) } {
+    if let Err(err) = overlay_mut().create_rendering(_device) {
         write_log!(format!("create overlay rendering struct failed: {:?}", err));
         return VK_ERROR_INITIALIZATION_FAILED;
     }
@@ -400,84 +430,96 @@ pub(crate) extern "system" fn acquire_next_image(
     fence: VkFence,
     image_index: *mut u32,
 ) -> VkResult {
-    unsafe {
-        match OVERLAY.swapchain(swapchain) {
-            Some(sc) => {
-                let device = OVERLAY.device();
+    // unsafe {
+    //     match OVERLAY.swapchain(swapchain) {
+    //         Some(sc) => {
+    //             let device = OVERLAY.device();
 
-                let res = device.acquire_next_image(
-                    sc.vk_handle(),
-                    timeout,
-                    Some(semaphore),
-                    Some(fence),
-                );
+    //             let res = device.acquire_next_image(
+    //                 sc.vk_handle(),
+    //                 timeout,
+    //                 Some(semaphore),
+    //                 Some(fence),
+    //             );
 
-                write_log!(format!(
-                    "acquire (swapchain: {:?}) res: {:?}",
-                    sc.vk_handle(),
-                    res
-                ));
+    //             write_log!(format!(
+    //                 "acquire (swapchain: {:?}) res: {:?}",
+    //                 sc.vk_handle(),
+    //                 res
+    //             ));
 
-                match res {
-                    Ok(res) => match res {
-                        OutOfDate::Ok(index) => {
-                            sc.set_image_index(index);
-                            VK_SUCCESS
-                        }
-                        OutOfDate::OutOfDate => VK_ERROR_OUT_OF_DATE_KHR,
-                        OutOfDate::TimeOut => VK_TIMEOUT,
-                    },
-                    Err(err) => {
-                        write_log!(format!("failed acquiring next image {:?}", err));
-                        VK_ERROR_DEVICE_LOST
-                    }
-                }
-            }
-            None => {
-                write_log!("acquired other swapchain image");
-                ACQUIRE_NEXT_IMAGE(device, swapchain, timeout, semaphore, fence, image_index)
-            }
-        }
+    //             match res {
+    //                 Ok(res) => match res {
+    //                     OutOfDate::Ok(index) => {
+    //                         sc.set_image_index(index);
+    //                         *image_index = index;
+    //                         VK_SUCCESS
+    //                     }
+    //                     OutOfDate::OutOfDate => VK_ERROR_OUT_OF_DATE_KHR,
+    //                     OutOfDate::TimeOut => VK_TIMEOUT,
+    //                 },
+    //                 Err(err) => {
+    //                     write_log!(format!("failed acquiring next image {:?}", err));
+    //                     VK_ERROR_DEVICE_LOST
+    //                 }
+    //             }
+    //         }
+    //         None => {
+    //             write_log!("acquired other swapchain image");
+    //             ACQUIRE_NEXT_IMAGE(device, swapchain, timeout, semaphore, fence, image_index)
+    //         }
+    //     }
+    // }
+
+    let res =
+        unsafe { ACQUIRE_NEXT_IMAGE(device, swapchain, timeout, semaphore, fence, image_index) };
+
+    if res != VK_SUCCESS {
+        write_log!(" ================== vulkan layer acquire next image ==================");
+        write_log!(format!("image index: {}", unsafe { *image_index }));
+        write_log!(format!("result: {:?}", VkResult::from(res)));
     }
+
+    res
 }
 
 pub(crate) extern "system" fn present_queue(
     queue: VkQueue,
     present_info: *const VkPresentInfoKHR,
 ) -> VkResult {
-    if logging() {
-        write_log!(" ================== vulkan layer queue present ==================");
-        write_log!(format!("iq: {:?}, cq: {:?}", queue, unsafe {
-            OVERLAY.queue().lock().unwrap().vk_handle()
-        }));
-        unsafe {
-            let swapchains = std::slice::from_raw_parts(
-                (*present_info).pSwapchains,
-                (*present_info).swapchainCount as usize,
-            );
+    // if logging() {
+    //     write_log!(" ================== vulkan layer queue present ==================");
+    //     write_log!(format!("iq: {:?}, cq: {:?}", queue, unsafe {
+    //         OVERLAY.queue().lock().unwrap().vk_handle()
+    //     }));
+    //     unsafe {
+    //         let swapchains = std::slice::from_raw_parts(
+    //             (*present_info).pSwapchains,
+    //             (*present_info).swapchainCount as usize,
+    //         );
 
-            write_log!(format!("present {} swapchain(s)", swapchains.len()));
+    //         write_log!(format!("present {} swapchain(s)", swapchains.len()));
 
-            for swapchain in swapchains {
-                write_log!(format!("present swapchain: {:?}", swapchain));
+    //         for swapchain in swapchains {
+    //             write_log!(format!("present swapchain: {:?}", swapchain));
 
-                if let Some(swch) = OVERLAY.swapchain(*swapchain) {
-                    write_log!(format!(
-                        " -> internal swapchain found! ({:?})",
-                        swch.vk_handle()
-                    ));
-                }
-            }
-        }
-    }
+    //             if let Some(swch) = OVERLAY.swapchain(*swapchain) {
+    //                 write_log!(format!(
+    //                     " -> internal swapchain found! ({:?})",
+    //                     swch.vk_handle()
+    //                 ));
+    //             }
+    //         }
+    //     }
+    // }
 
-    match unsafe { OVERLAY.render() } {
-        Ok(_) => (),
-        Err(err) => {
-            write_log!(format!("overlay rendering failed: {:?}", err));
-            return VK_ERROR_DEVICE_LOST;
-        }
-    };
+    // match unsafe { OVERLAY.render() } {
+    //     Ok(_) => (),
+    //     Err(err) => {
+    //         write_log!(format!("overlay rendering failed: {:?}", err));
+    //         return VK_ERROR_DEVICE_LOST;
+    //     }
+    // };
 
     let pfn: PFN_vkQueuePresentKHR = match vk_handles().handle("vkQueuePresentKHR") {
         Some(pfn) => unsafe { mem::transmute(pfn) },
@@ -487,5 +529,11 @@ pub(crate) extern "system" fn present_queue(
         }
     };
 
-    pfn(queue, present_info)
+    let res = pfn(queue, present_info);
+
+    if res != VK_SUCCESS {
+        write_log!(format!("queue present failed: {:?}", VkResult::from(res)));
+    }
+
+    res
 }