Fix memory leak. (#140)

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/MetalRedrawer.kt

@@ -16,7 +16,7 @@ import javax.swing.SwingUtilities.getRootPane
 
 internal class MetalRedrawer(
     private val layer: SkiaLayer,
-    private val properties: SkiaLayerProperties
+    properties: SkiaLayerProperties
 ) : Redrawer {
     private var isDisposed = false
     private var disposeLock = Any()
@@ -58,38 +58,41 @@ internal class MetalRedrawer(
     }
 
     private suspend fun draw() {
-        if (layer.prepareDrawContext()) {
-            // 2,3 GHz 8-Core Intel Core i9
-            //
-            // Test1. 8 windows, multiple clocks, 800x600
-            //
-            // Executors.newSingleThreadExecutor().asCoroutineDispatcher(): 20 FPS, 130% CPU
-            // Dispatchers.IO: 58 FPS, 460% CPU
-            //
-            // Test2. 60 windows, single clock, 800x600
-            //
-            // Executors.newSingleThreadExecutor().asCoroutineDispatcher(): 50 FPS, 150% CPU
-            // Dispatchers.IO: 50 FPS, 200% CPU
-            withContext(Dispatchers.IO) {
+        withContext(Dispatchers.IO) {
+            val handle = startRendering()
+            if (layer.prepareDrawContext()) {
+                // 2,3 GHz 8-Core Intel Core i9
+                //
+                // Test1. 8 windows, multiple clocks, 800x600
+                //
+                // Executors.newSingleThreadExecutor().asCoroutineDispatcher(): 20 FPS, 130% CPU
+                // Dispatchers.IO: 58 FPS, 460% CPU
+                //
+                // Test2. 60 windows, single clock, 800x600
+                //
+                // Executors.newSingleThreadExecutor().asCoroutineDispatcher(): 50 FPS, 150% CPU
+                // Dispatchers.IO: 50 FPS, 200% CPU
                 synchronized(disposeLock) {
                     if (!isDisposed) {
                         layer.draw()
                     }
                 }
             }
-            // When window is not visible - it doesn't make sense to redraw fast to avoid battery drain.
-            // In theory, we could be more precise, and just suspend rendering in
-            // `NSWindowDidChangeOcclusionStateNotification`, but current approach seems to work as well in practise.
-            if (isOccluded(windowHandle))
-                delay(300)
+            endRendering(handle)
         }
+        // When window is not visible - it doesn't make sense to redraw fast to avoid battery drain.
+        // In theory, we could be more precise, and just suspend rendering in
+        // `NSWindowDidChangeOcclusionStateNotification`, but current approach seems to work as well in practise.
+        if (isOccluded(windowHandle))
+            delay(300)
     }
 
     override fun syncSize() {
         val rootPane = getRootPane(layer)
         val globalPosition = convertPoint(layer, layer.x, layer.y, rootPane)
         setContentScale(device, layer.contentScale)
-        resizeLayers(device,
+        resizeLayers(
+            device,
             globalPosition.x,
             rootPane.height - globalPosition.y - layer.height,
             layer.width.coerceAtLeast(0),
@@ -104,7 +107,7 @@ internal class MetalRedrawer(
     fun makeRenderTarget(width: Int, height: Int) = BackendRenderTarget(
         makeMetalRenderTarget(device, width, height)
     )
-    
+
     fun finishFrame() = finishFrame(device)
 
     fun getAdapterPriority(): Int {
@@ -130,4 +133,6 @@ internal class MetalRedrawer(
     private external fun isOccluded(window: Long): Boolean
     private external fun getAdapterName(device: Long): String
     private external fun getAdapterMemorySize(device: Long): Long
+    private external fun startRendering(): Long
+    private external fun endRendering(handle: Long)
 }

skiko/src/jvmMain/objectiveC/macos/MetalRedrawer.mm

@@ -101,17 +101,30 @@ JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_makeMeta
     MetalDevice *device = (MetalDevice *) devicePtr;
     GrBackendRenderTarget* renderTarget = NULL;
 
-    @autoreleasepool {
-        id<CAMetalDrawable> currentDrawable = [device.layer nextDrawable];
-        if (!currentDrawable) return 0;
-        device.drawableHandle = currentDrawable;
-        GrMtlTextureInfo info;
-        info.fTexture.retain(currentDrawable.texture);
-        renderTarget = new GrBackendRenderTarget(width, height, 0, info);
-    }
+    id<CAMetalDrawable> currentDrawable = [device.layer nextDrawable];
+    if (!currentDrawable) return 0;
+    device.drawableHandle = currentDrawable;
+    GrMtlTextureInfo info;
+    info.fTexture.retain(currentDrawable.texture);
+    renderTarget = new GrBackendRenderTarget(width, height, 0, info);
     return (jlong) renderTarget;
 }
 
+extern "C" void* objc_autoreleasePoolPush(void);
+extern "C" void objc_autoreleasePoolPop(void*);
+
+JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_startRendering(
+    JNIEnv * env, jobject redrawer)
+{
+    return (jlong)objc_autoreleasePoolPush();
+}
+
+JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_endRendering(
+    JNIEnv * env, jobject redrawer, jlong handle)
+{
+    objc_autoreleasePoolPop((void*)handle);
+}
+
 BOOL isUsingIntegratedGPU() {
     kern_return_t kernResult = 0;
     io_iterator_t iterator = IO_OBJECT_NULL;
@@ -241,18 +254,13 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_finishFra
 
     id<CAMetalDrawable> currentDrawable = device.drawableHandle;
 
-    id<MTLCommandBuffer> commandBuffer = [device.queue commandBuffer];
-    commandBuffer.label = @"Present";
-
-    [currentDrawable addPresentedHandler:^(id<MTLDrawable> dr) {
-         CFRelease(currentDrawable);
-    }];
-    [commandBuffer presentDrawable:currentDrawable];
-    [commandBuffer commit];
-
-    device.drawableHandle = nil;
-
-    currentDrawable = nil;
+    if (currentDrawable) {
+        id<MTLCommandBuffer> commandBuffer = [device.queue commandBuffer];
+        commandBuffer.label = @"Present";
+        [commandBuffer presentDrawable:currentDrawable];
+        [commandBuffer commit];
+        device.drawableHandle = nil;
+    }
 }
 
 JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_disposeDevice(