fix(graphics): implement thread-safe interior mutability, dirty rect clamping, and ANativeWindow handle table

crates/molotov-core/src/graphics/c_api.rs

@@ -2,27 +2,61 @@
 #![allow(non_snake_case)]
 use super::surface::GraphicsSurface;
 use super::types::{ANativeWindow_Buffer, ARect, WindowFormat};
+use std::collections::HashMap;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::{Arc, RwLock};
+
+static NEXT_WINDOW_ID: AtomicUsize = AtomicUsize::new(2001);
+
+lazy_static::lazy_static! {
+    static ref WINDOW_TABLE: RwLock<HashMap<usize, Arc<GraphicsSurface>>> = RwLock::new(HashMap::new());
+}
+
+pub fn register_window_surface(surface: Arc<GraphicsSurface>) -> *mut () {
+    let id = NEXT_WINDOW_ID.fetch_add(1, Ordering::Relaxed);
+    if let Ok(mut table) = WINDOW_TABLE.write() {
+        table.insert(id, surface);
+        id as *mut ()
+    } else {
+        std::ptr::null_mut()
+    }
+}
+
+pub fn get_window_surface(window: *mut ()) -> Option<Arc<GraphicsSurface>> {
+    let id = window as usize;
+    if let Ok(table) = WINDOW_TABLE.read() {
+        table.get(&id).cloned()
+    } else {
+        None
+    }
+}
 
 #[no_mangle]
 pub unsafe extern "C" fn ANativeWindow_acquire(window: *mut ()) {
-    if let Some(s) = (window as *mut GraphicsSurface).as_ref() {
+    if let Some(s) = get_window_surface(window) {
         s.acquire();
     }
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn ANativeWindow_release(window: *mut ()) {
-    if !window.is_null() {
-        let ptr = window as *mut GraphicsSurface;
-        if (*ptr).release() == 0 {
-            drop(Box::from_raw(ptr));
+    let id = window as usize;
+    let should_remove = if let Some(s) = get_window_surface(window) {
+        s.release() == 0
+    } else {
+        false
+    };
+
+    if should_remove {
+        if let Ok(mut table) = WINDOW_TABLE.write() {
+            table.remove(&id);
         }
     }
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn ANativeWindow_getWidth(window: *mut ()) -> i32 {
-    if let Some(s) = (window as *mut GraphicsSurface).as_ref() {
+    if let Some(s) = get_window_surface(window) {
         s.width()
     } else {
         0
@@ -31,7 +65,7 @@ pub unsafe extern "C" fn ANativeWindow_getWidth(window: *mut ()) -> i32 {
 
 #[no_mangle]
 pub unsafe extern "C" fn ANativeWindow_getHeight(window: *mut ()) -> i32 {
-    if let Some(s) = (window as *mut GraphicsSurface).as_ref() {
+    if let Some(s) = get_window_surface(window) {
         s.height()
     } else {
         0
@@ -40,7 +74,7 @@ pub unsafe extern "C" fn ANativeWindow_getHeight(window: *mut ()) -> i32 {
 
 #[no_mangle]
 pub unsafe extern "C" fn ANativeWindow_getFormat(window: *mut ()) -> i32 {
-    if let Some(s) = (window as *mut GraphicsSurface).as_ref() {
+    if let Some(s) = get_window_surface(window) {
         s.format() as i32
     } else {
         0
@@ -54,10 +88,14 @@ pub unsafe extern "C" fn ANativeWindow_setBuffersGeometry(
     height: i32,
     format: i32,
 ) -> i32 {
-    if let Some(s) = (window as *mut GraphicsSurface).as_mut() {
-        let fmt = WindowFormat::from_i32(format).unwrap_or(WindowFormat::Rgba8888);
-        s.set_geometry(width, height, fmt);
-        0
+    let fmt = match WindowFormat::from_i32(format) {
+        Some(f) => f,
+        None if format == 0 => WindowFormat::Rgba8888,
+        None => return -libc::EINVAL,
+    };
+
+    if let Some(s) = get_window_surface(window) {
+        s.set_geometry(width, height, fmt)
     } else {
         -libc::EINVAL
     }
@@ -69,7 +107,7 @@ pub unsafe extern "C" fn ANativeWindow_lock(
     outBuffer: *mut ANativeWindow_Buffer,
     inOutDirtyBounds: *mut ARect,
 ) -> i32 {
-    if let Some(s) = (window as *mut GraphicsSurface).as_mut() {
+    if let Some(s) = get_window_surface(window) {
         s.lock(outBuffer, inOutDirtyBounds)
     } else {
         -libc::EINVAL
@@ -78,7 +116,7 @@ pub unsafe extern "C" fn ANativeWindow_lock(
 
 #[no_mangle]
 pub unsafe extern "C" fn ANativeWindow_unlockAndPost(window: *mut ()) -> i32 {
-    if let Some(s) = (window as *mut GraphicsSurface).as_mut() {
+    if let Some(s) = get_window_surface(window) {
         s.unlock_and_post()
     } else {
         -libc::EINVAL

crates/molotov-core/src/graphics/surface.rs

@@ -1,42 +1,54 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 use super::types::{ANativeWindow_Buffer, ARect, WindowFormat};
 use std::ffi::c_void;
-use std::sync::atomic::{AtomicU32, Ordering};
+use std::sync::atomic::{fence, AtomicU32, Ordering};
+use std::sync::Mutex;
 
-pub struct GraphicsSurface {
+struct SurfaceInner {
     width: i32,
     height: i32,
     format: WindowFormat,
     back_buffer: Vec<u8>,
     front_buffer: Vec<u8>,
     is_locked: bool,
+}
+
+pub struct GraphicsSurface {
+    inner: Mutex<SurfaceInner>,
     ref_count: AtomicU32,
 }
 
 impl GraphicsSurface {
     pub fn new(width: i32, height: i32, format: WindowFormat) -> Self {
-        let size = (width as usize) * (height as usize) * format.bytes_per_pixel();
-        Self {
-            width,
-            height,
+        let w = width.max(1);
+        let h = height.max(1);
+        let size = (w as usize) * (h as usize) * format.bytes_per_pixel();
+
+        let inner = SurfaceInner {
+            width: w,
+            height: h,
             format,
             back_buffer: vec![0u8; size],
             front_buffer: vec![0u8; size],
             is_locked: false,
+        };
+
+        Self {
+            inner: Mutex::new(inner),
             ref_count: AtomicU32::new(1),
         }
     }
 
     pub fn width(&self) -> i32 {
-        self.width
+        self.inner.lock().map(|i| i.width).unwrap_or(0)
     }
 
     pub fn height(&self) -> i32 {
-        self.height
+        self.inner.lock().map(|i| i.height).unwrap_or(0)
     }
 
     pub fn format(&self) -> WindowFormat {
-        self.format
+        self.inner.lock().map(|i| i.format).unwrap_or(WindowFormat::Rgba8888)
     }
 
     pub fn acquire(&self) -> u32 {
@@ -44,52 +56,91 @@ impl GraphicsSurface {
     }
 
     pub fn release(&self) -> u32 {
-        self.ref_count.fetch_sub(1, Ordering::Release) - 1
+        let prev = self.ref_count.fetch_sub(1, Ordering::Release);
+        if prev == 1 {
+            fence(Ordering::Acquire);
+            0
+        } else if prev == 0 {
+            0
+        } else {
+            prev - 1
+        }
+    }
+
+    pub fn set_geometry(&self, width: i32, height: i32, format: WindowFormat) -> i32 {
+        let mut inner = match self.inner.lock() {
+            Ok(g) => g,
+            Err(_) => return -libc::EINVAL,
+        };
+
+        if inner.is_locked {
+            return -libc::EBUSY;
         }
 
-    pub fn set_geometry(&mut self, width: i32, height: i32, format: WindowFormat) {
         if width > 0 && height > 0 {
-            self.width = width;
-            self.height = height;
-            self.format = format;
+            inner.width = width;
+            inner.height = height;
+            inner.format = format;
             let size = (width as usize) * (height as usize) * format.bytes_per_pixel();
-            self.back_buffer.resize(size, 0);
-            self.front_buffer.resize(size, 0);
+            inner.back_buffer.resize(size, 0);
+            inner.front_buffer.resize(size, 0);
+            0
+        } else {
+            -libc::EINVAL
         }
     }
 
     pub unsafe fn lock(
-        &mut self,
+        &self,
         out_buffer: *mut ANativeWindow_Buffer,
-        _in_out_dirty: *mut ARect,
+        in_out_dirty: *mut ARect,
     ) -> i32 {
         if out_buffer.is_null() {
             return -libc::EINVAL;
         }
-        if self.is_locked {
+
+        let mut inner = match self.inner.lock() {
+            Ok(g) => g,
+            Err(_) => return -libc::EINVAL,
+        };
+
+        if inner.is_locked {
             return -libc::EBUSY;
         }
 
-        self.is_locked = true;
+        inner.is_locked = true;
 
-        (*out_buffer).width = self.width;
-        (*out_buffer).height = self.height;
-        (*out_buffer).stride = self.width;
-        (*out_buffer).format = self.format as i32;
-        (*out_buffer).bits = self.back_buffer.as_mut_ptr() as *mut c_void;
+        // Clamp dirty bounds safely
+        if let Some(dirty) = in_out_dirty.as_mut() {
+            dirty.left = dirty.left.clamp(0, inner.width);
+            dirty.top = dirty.top.clamp(0, inner.height);
+            dirty.right = dirty.right.clamp(dirty.left, inner.width);
+            dirty.bottom = dirty.bottom.clamp(dirty.top, inner.height);
+        }
+
+        (*out_buffer).width = inner.width;
+        (*out_buffer).height = inner.height;
+        (*out_buffer).stride = inner.width;
+        (*out_buffer).format = inner.format as i32;
+        (*out_buffer).bits = inner.back_buffer.as_mut_ptr() as *mut c_void;
         (*out_buffer).reserved = [0; 6];
 
         0
     }
 
-    pub fn unlock_and_post(&mut self) -> i32 {
-        if !self.is_locked {
+    pub fn unlock_and_post(&self) -> i32 {
+        let mut guard = match self.inner.lock() {
+            Ok(g) => g,
+            Err(_) => return -libc::EINVAL,
+        };
+
+        if !guard.is_locked {
             return -libc::EINVAL;
         }
 
-        // Swap front and back buffer for presentation
-        std::mem::swap(&mut self.front_buffer, &mut self.back_buffer);
-        self.is_locked = false;
+        let inner = &mut *guard;
+        std::mem::swap(&mut inner.front_buffer, &mut inner.back_buffer);
+        inner.is_locked = false;
         0
     }
 }

crates/molotov-core/src/graphics/window.rs

@@ -1,6 +1,9 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
+use super::c_api::register_window_surface;
 use super::surface::GraphicsSurface;
 use super::types::WindowFormat;
+use crate::jni::activity::ActivityRunner;
+use std::sync::{Arc, Mutex};
 
 #[derive(Debug, Clone)]
 pub struct WindowConfig {
@@ -25,13 +28,32 @@ impl Default for WindowConfig {
 
 pub struct WindowManager {
     config: WindowConfig,
-    pub surface: GraphicsSurface,
+    pub surface: Arc<GraphicsSurface>,
+    pub window_handle: *mut (),
+    activity_runner: Option<Arc<Mutex<ActivityRunner>>>,
 }
 
 impl WindowManager {
     pub fn new(config: WindowConfig) -> Self {
-        let surface = GraphicsSurface::new(config.width, config.height, WindowFormat::Rgba8888);
-        Self { config, surface }
+        Self::new_with_activity(config, None)
+    }
+
+    pub fn new_with_activity(
+        config: WindowConfig,
+        activity_runner: Option<Arc<Mutex<ActivityRunner>>>,
+    ) -> Self {
+        let surface = Arc::new(GraphicsSurface::new(
+            config.width,
+            config.height,
+            WindowFormat::Rgba8888,
+        ));
+        let window_handle = register_window_surface(surface.clone());
+        Self {
+            config,
+            surface,
+            window_handle,
+            activity_runner,
+        }
     }
 
     pub fn width(&self) -> i32 {
@@ -46,8 +68,15 @@ impl WindowManager {
         if width > 0 && height > 0 {
             self.config.width = width;
             self.config.height = height;
-            self.surface.set_geometry(width, height, self.surface.format());
+            let _ = self.surface.set_geometry(width, height, self.surface.format());
             tracing::info!("WindowManager: surface resized to {}x{}", width, height);
+
+            // Notify activity runner if attached
+            if let Some(runner_arc) = &self.activity_runner {
+                if let Ok(mut runner) = runner_arc.lock() {
+                    runner.trigger_window_resized(self.window_handle as *mut _);
+                }
+            }
         }
     }
 }

crates/molotov-core/tests/anativewindow_c_api_test.rs

@@ -2,18 +2,19 @@
 use molotov_core::graphics::c_api::*;
 use molotov_core::graphics::surface::GraphicsSurface;
 use molotov_core::graphics::types::{ANativeWindow_Buffer, WindowFormat};
+use std::sync::Arc;
 
 #[test]
 fn test_anativewindow_c_api_lifecycle() {
-    let surface = Box::new(GraphicsSurface::new(640, 480, WindowFormat::Rgba8888));
-    let handle = Box::into_raw(surface) as *mut ();
+    let surface = Arc::new(GraphicsSurface::new(640, 480, WindowFormat::Rgba8888));
+    let handle = register_window_surface(surface);
 
     unsafe {
         assert_eq!(ANativeWindow_getWidth(handle), 640);
         assert_eq!(ANativeWindow_getHeight(handle), 480);
         assert_eq!(ANativeWindow_getFormat(handle), 1);
 
-        ANativeWindow_setBuffersGeometry(handle, 800, 600, 1);
+        assert_eq!(ANativeWindow_setBuffersGeometry(handle, 800, 600, 1), 0);
         assert_eq!(ANativeWindow_getWidth(handle), 800);
         assert_eq!(ANativeWindow_getHeight(handle), 600);
 

crates/molotov-core/tests/graphics_fixes_test.rs

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use molotov_core::graphics::c_api::*;
+use molotov_core::graphics::surface::GraphicsSurface;
+use molotov_core::graphics::types::{ANativeWindow_Buffer, ARect, WindowFormat};
+use molotov_core::graphics::window::{WindowConfig, WindowManager};
+use molotov_core::jni::activity::ActivityRunner;
+use std::sync::{Arc, Mutex};
+
+#[test]
+fn test_dirty_rect_clamping_on_lock() {
+    let surface = Arc::new(GraphicsSurface::new(800, 600, WindowFormat::Rgba8888));
+    let handle = register_window_surface(surface);
+
+    let mut buf = std::mem::MaybeUninit::<ANativeWindow_Buffer>::uninit();
+    let mut dirty = ARect {
+        left: -50,
+        top: -20,
+        right: 1500,
+        bottom: 2000,
+    };
+
+    unsafe {
+        assert_eq!(ANativeWindow_lock(handle, buf.as_mut_ptr(), &mut dirty), 0);
+        // Clamping check
+        assert_eq!(dirty.left, 0);
+        assert_eq!(dirty.top, 0);
+        assert_eq!(dirty.right, 800);
+        assert_eq!(dirty.bottom, 600);
+
+        // While locked, setBuffersGeometry must return -EBUSY
+        assert_eq!(ANativeWindow_setBuffersGeometry(handle, 1024, 768, 1), -libc::EBUSY);
+
+        assert_eq!(ANativeWindow_unlockAndPost(handle), 0);
+        ANativeWindow_release(handle);
+    }
+}
+
+#[test]
+fn test_window_manager_syncs_with_activity_runner() {
+    let runner = Arc::new(Mutex::new(ActivityRunner::new()));
+    let config = WindowConfig {
+        title: "Test".to_string(),
+        width: 1280,
+        height: 720,
+        fullscreen: false,
+        vulkan: true,
+    };
+
+    let mut manager = WindowManager::new_with_activity(config, Some(runner.clone()));
+    manager.handle_resize(1920, 1080);
+
+    assert_eq!(manager.width(), 1920);
+    assert_eq!(manager.height(), 1080);
+}

crates/molotov-core/tests/graphics_surface_test.rs

@@ -3,12 +3,13 @@ use molotov_core::graphics::c_api::*;
 use molotov_core::graphics::surface::GraphicsSurface;
 use molotov_core::graphics::types::{ANativeWindow_Buffer, WindowFormat};
 use molotov_core::jni::activity::ActivityRunner;
+use std::sync::Arc;
 
 #[test]
 fn test_end_to_end_graphics_surface_and_activity_binding() {
     let mut runner = ActivityRunner::new();
-    let surface = Box::new(GraphicsSurface::new(1280, 720, WindowFormat::Rgba8888));
-    let window_handle = Box::into_raw(surface) as *mut ();
+    let surface = Arc::new(GraphicsSurface::new(1280, 720, WindowFormat::Rgba8888));
+    let window_handle = register_window_surface(surface);
 
     unsafe {
         // 1. Notify activity that native window was created

crates/molotov-core/tests/surface_buffer_test.rs

@@ -4,7 +4,7 @@ use molotov_core::graphics::types::WindowFormat;
 
 #[test]
 fn test_surface_lock_and_unlock_post() {
-    let mut surface = GraphicsSurface::new(800, 600, WindowFormat::Rgba8888);
+    let surface = GraphicsSurface::new(800, 600, WindowFormat::Rgba8888);
     assert_eq!(surface.width(), 800);
     assert_eq!(surface.height(), 600);