[Metal] Decouple onRender from draw (#1057)

skiko/src/androidMain/kotlin/org/jetbrains/skiko/Actuals.android.kt

@@ -15,8 +15,9 @@ internal class AndroidOpenGLRedrawer(
     private val properties: SkiaLayerProperties
 ) : Redrawer {
     override fun dispose() = TODO()
-    override fun needRedraw() = TODO()
-    override fun redrawImmediately() = TODO()
+    override fun needRedraw(canUpdateImmediately: Boolean) = TODO()
+    override fun redrawImmediately(updateNeeded: Boolean) = TODO()
+    override fun update(nanoTime: Long) = TODO()
 
     override val renderInfo: String get() = "Android renderer"
 }

skiko/src/androidMain/kotlin/org/jetbrains/skiko/SkiaLayer.android.kt

@@ -57,7 +57,7 @@ actual open class SkiaLayer {
         }
     }
 
-    actual fun needRedraw() {
+    actual fun needRedraw(throttledToVsync: Boolean) {
         glView?.apply {
             scheduleFrame()
         }

skiko/src/awtMain/kotlin/org/jetbrains/skiko/SkiaLayer.awt.kt

 package org.jetbrains.skiko
 
+import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
@@ -8,10 +9,12 @@ import org.jetbrains.skiko.redrawer.Redrawer
 import org.jetbrains.skiko.redrawer.RedrawerManager
 import java.awt.Color
 import java.awt.Component
+import java.awt.Graphics
 import java.awt.Point
 import java.awt.event.*
 import java.awt.geom.AffineTransform
 import java.awt.im.InputMethodRequests
+import java.beans.PropertyChangeListener
 import java.util.concurrent.CancellationException
 import javax.accessibility.Accessible
 import javax.swing.JComponent
@@ -100,18 +103,29 @@ actual open class SkiaLayer internal constructor(
         isOpaque = false
         layout = null
         backedLayer = object : HardwareLayer(externalAccessibleFactory) {
-            override fun paint(g: java.awt.Graphics) {
-                Logger.debug { "Paint called on $this" }
-                checkContentScale()
-
-                // 1. JPanel.paint is not always called (in rare cases).
-                //    For example if we call 'jframe.isResizable = false` on Ubuntu
-                //
-                // 2. HardwareLayer.paint is also not always called.
-                //    For example, on macOs when we resize window or change DPI
-                //
-                // 3. to avoid double paint in one single frame, use needRedraw instead of redrawImmediately
-                redrawer?.needRedraw()
+
+            @Suppress("OVERRIDE_DEPRECATION")
+            override fun reshape(x: Int, y: Int, width: Int, height: Int) {
+                Logger.debug { "reshape(x=$x, y=$y, w=$width, h=$height) called on $this" }
+                super.reshape(x, y, width, height)
+
+                redrawer?.syncBounds()
+                // There's no reason for the render delegate to directly cause resizing SkiaLayer, but protect
+                // against it anyway.
+                if (!isRendering) {
+                    // When the layer isn't yet showing, paint will not be called,
+                    // but in order to avoid the background flashing when the layer
+                    // does show, we already draw to the native surface.
+                    redrawer?.redrawImmediately(updateNeeded = true)
+                } else {
+                    redrawer?.needRedraw(throttledToVsync = false)
+                }
+            }
+
+            override fun paint(g: Graphics) {
+                Logger.debug { "paint called on $this" }
+                val updateNeeded = checkContentScale()
+                redrawer?.redrawImmediately(updateNeeded = updateNeeded)
             }
 
             override fun getInputMethodRequests(): InputMethodRequests? {
@@ -175,7 +189,6 @@ actual open class SkiaLayer internal constructor(
             }
         }
 
-
         addPropertyChangeListener("graphicsContextScaleTransform") {
             Logger.debug { "graphicsContextScaleTransform changed for $this" }
             latestReceivedGraphicsContextScaleTransform = it.newValue as AffineTransform
@@ -185,6 +198,7 @@ actual open class SkiaLayer internal constructor(
             // Workaround for JBR-5259
             if (hostOs == OS.Windows) {
                 peerBufferSizeFixJob?.cancel()
+                @OptIn(DelicateCoroutinesApi::class)
                 peerBufferSizeFixJob = GlobalScope.launch(MainUIDispatcher) {
                     backedLayer.setLocation(1, 0)
                     backedLayer.setLocation(0, 0)
@@ -193,6 +207,16 @@ actual open class SkiaLayer internal constructor(
         }
     }
 
+    // Override to make final, because it's called it in the init block
+    final override fun addAncestorListener(listener: AncestorListener?) {
+        super.addAncestorListener(listener)
+    }
+
+    // Override to make final, because it's called it in the init block
+    final override fun addPropertyChangeListener(propertyName: String?, listener: PropertyChangeListener?) {
+        super.addPropertyChangeListener(propertyName, listener)
+    }
+
     private var fullscreenAdapter = FullscreenAdapter(backedLayer)
 
     override fun removeNotify() {
@@ -356,6 +380,29 @@ actual open class SkiaLayer internal constructor(
         }
     }
 
+    @Suppress("OVERRIDE_DEPRECATION")
+    override fun reshape(x: Int, y: Int, w: Int, h: Int) {
+        super.reshape(x, y, w, h)
+
+        // Calling redrawImmediately as early as possible improves the situation with
+        // the visual glitch when the drawn content is scaled during window resize.
+        // Note, however, that this actually causes the reverse glitch (content appears
+        // scaled in the other direction from the window size), but this seems to
+        // happen less often.
+        //
+        // Calling redraw during layout might break software renderers,
+        // so apply this fix only for the Direct3D case.
+        if (renderApi == GraphicsApi.DIRECT3D && isShowing) {
+            redrawer?.syncBounds()
+            redrawer?.redrawImmediately(updateNeeded = true)
+        }
+
+        // Setting the bounds of children should be done only in the layout pass,
+        // but unfortunately, Compose expects the drawing area to be resized
+        // immediately when `SkiaLayer` is resized.
+        validate()
+    }
+
     override fun doLayout() {
         Logger.debug { "doLayout on $this" }
         backedLayer.setBounds(
@@ -365,52 +412,19 @@ actual open class SkiaLayer internal constructor(
             adjustSizeToContentScale(contentScale, height)
         )
         backedLayer.validate()
-        redrawer?.syncBounds()
-    }
-
-    override fun paint(g: java.awt.Graphics) {
-        Logger.debug { "Paint called on: $this" }
-        checkContentScale()
-        tryRedrawImmediately()
-    }
-
-    override fun setBounds(x: Int, y: Int, width: Int, height: Int) {
-        super.setBounds(x, y, width, height)
-
-        // To avoid visual artifacts on Windows/Direct3D,
-        // redrawing should be performed immediately, without scheduling to "later".
-        // Subscribing to events instead of overriding this method won't help too.
-        //
-        // Please note that calling redraw during layout might break software renderers,
-        // so applying this fix only for Direct3D case.
-        if (renderApi == GraphicsApi.DIRECT3D && isShowing) {
-            redrawer?.syncBounds()
-            tryRedrawImmediately()
-        }
-    }
-
-    private fun tryRedrawImmediately() {
-        // It might be called inside `renderDelegate`,
-        // so to avoid recursive call (not supported) just schedule redrawing.
-        //
-        // For example if we call some AWT function inside renderer.onRender,
-        // such as `jframe.isEnabled = false` on Linux
-        if (isRendering) {
-            redrawer?.needRedraw()
-        } else {
-            redrawer?.redrawImmediately()
-        }
     }
 
     // Workaround for JBR-5274 and JBR-5305
-    fun checkContentScale() {
+    fun checkContentScale(): Boolean {
         val currentGraphicsContextScaleTransform = graphicsConfiguration.defaultTransform
-        if (currentGraphicsContextScaleTransform != latestReceivedGraphicsContextScaleTransform) {
-            firePropertyChange(
-                "graphicsContextScaleTransform",
-                latestReceivedGraphicsContextScaleTransform,
-                currentGraphicsContextScaleTransform
-            )
+        return (currentGraphicsContextScaleTransform != latestReceivedGraphicsContextScaleTransform).also {
+            if (it) {
+                firePropertyChange(
+                    "graphicsContextScaleTransform",
+                    latestReceivedGraphicsContextScaleTransform,
+                    currentGraphicsContextScaleTransform
+                )
+            }
         }
     }
 
@@ -526,30 +540,25 @@ actual open class SkiaLayer internal constructor(
     /**
      * Redraw on the next animation Frame (on vsync signal if vsync is enabled).
      */
-    actual fun needRedraw() {
+    actual fun needRedraw(throttledToVsync: Boolean) {
         check(isEventDispatchThread()) { "Method should be called from AWT event dispatch thread" }
         check(!isDisposed) { "SkiaLayer is disposed" }
-        redrawer?.needRedraw()
+        redrawer?.needRedraw(throttledToVsync)
     }
 
-    @Suppress("LeakingThis")
-    private val fpsCounter = defaultFPSCounter(this)
-
     internal fun update(nanoTime: Long) {
         check(isEventDispatchThread()) { "Method should be called from AWT event dispatch thread" }
         check(!isDisposed) { "SkiaLayer is disposed" }
 
         checkContentScale()
-
         FrameWatcher.nextFrame()
-        fpsCounter?.tick()
 
         // The current approach is to render into a picture in the main thread, and render this picture in the render thread
         // If this approach will be changed, create an issue in https://youtrack.jetbrains.com/issues/CMP for changing it in
         // https://github.com/JetBrains/compose-multiplatform/blob/e4e2d329709cded91a09cc612d4defbce37aad96/benchmarks/multiplatform/benchmarks/src/commonMain/kotlin/MeasureComposable.kt#L151 as well
 
-        val pictureWidth = (width * contentScale).toInt().coerceAtLeast(0)
-        val pictureHeight = (height * contentScale).toInt().coerceAtLeast(0)
+        val pictureWidth = (backedLayer.width * contentScale).toInt().coerceAtLeast(0)
+        val pictureHeight = (backedLayer.height * contentScale).toInt().coerceAtLeast(0)
 
         val bounds = Rect.makeWH(pictureWidth.toFloat(), pictureHeight.toFloat())
         val pictureRecorder = pictureRecorder!!
@@ -578,10 +587,14 @@ actual open class SkiaLayer internal constructor(
         }
     }
 
+    @Suppress("LeakingThis")
+    private val fpsCounter = defaultFPSCounter(this)
+
     internal inline fun inDrawScope(body: () -> Unit) {
         check(isEventDispatchThread()) { "Method should be called from AWT event dispatch thread" }
         check(!isDisposed) { "SkiaLayer is disposed" }
         try {
+            fpsCounter?.tick()
             body()
         } catch (e: CancellationException) {
             // ignore
@@ -589,7 +602,7 @@ actual open class SkiaLayer internal constructor(
             if (!isDisposed) {
                 Logger.warn(e) { "Exception in draw scope" }
                 redrawerManager.findNextWorkingRenderApi()
-                redrawer?.redrawImmediately()
+                redrawer?.redrawImmediately(updateNeeded = true)
             }
         }
     }
@@ -651,7 +664,7 @@ fun orderEmojiAndSymbolsPopup() {
 internal fun defaultFPSCounter(
     component: Component
 ): FPSCounter? = with(SkikoProperties) {
-    if (!SkikoProperties.fpsEnabled) return@with null
+    if (!fpsEnabled) return@with null
 
     // it is slow on Linux (100ms), so we cache it. Also refreshRate available only after window is visible
     val refreshRate by lazy { component.graphicsConfiguration.device.displayMode.refreshRate }

skiko/src/awtMain/kotlin/org/jetbrains/skiko/context/MetalContextHandler.kt

@@ -66,6 +66,7 @@ internal class MetalContextHandler(
         super.flush()
         surface?.flushAndSubmit()
         finishFrame()
+        Logger.debug { "MetalContextHandler finished drawing frame" }
     }
 
     override fun rendererInfo(): String {

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/AWTRedrawer.kt

@@ -33,7 +33,7 @@ internal abstract class AWTRedrawer(
      * Should be called when the device name is known as early, as possible.
      */
     protected fun onDeviceChosen(deviceName: String?) {
-        require(!isDisposed) { "$javaClass is disposed" }
+        checkDisposed()
         require(deviceAnalytics == null) { "deviceAnalytics is not null" }
         rendererAnalytics.deviceChosen()
         deviceAnalytics = analytics.device(Version.skiko, hostOs, graphicsApi, deviceName)
@@ -44,13 +44,13 @@ internal abstract class AWTRedrawer(
      * Should be called when initialization of graphic context is ended. Only call it after [onDeviceChosen]
      */
     protected fun onContextInit() {
-        require(!isDisposed) { "$javaClass is disposed" }
+        checkDisposed()
         requireNotNull(deviceAnalytics) { "deviceAnalytics is not null. Call onDeviceChosen after choosing the drawing device" }
         deviceAnalytics?.contextInit()
     }
 
-    protected fun update(nanoTime: Long) {
-        require(!isDisposed) { "$javaClass is disposed" }
+    override fun update(nanoTime: Long) {
+        checkDisposed()
         layer.update(nanoTime)
     }
 
@@ -69,4 +69,8 @@ internal abstract class AWTRedrawer(
             isFirstFrameRendered = true
         }
     }
+
+    protected fun checkDisposed() {
+        check(!isDisposed) { "${this.javaClass.simpleName} is disposed" }
+    }
 }
\ No newline at end of file

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/AbstractDirectSoftwareRedrawer.kt

@@ -22,22 +22,26 @@ internal abstract class AbstractDirectSoftwareRedrawer(
         }
 
         if (layer.isShowing) {
-            update(System.nanoTime())
+            update()
             draw()
         }
     }
 
     protected var device = 0L
 
-    override fun needRedraw() {
+    override fun needRedraw(throttledToVsync: Boolean) {
         frameDispatcher.scheduleFrame()
     }
 
     protected open fun draw() = inDrawScope(contextHandler::draw)
 
-    override fun redrawImmediately() {
-        update(System.nanoTime())
-        draw()
+    override fun redrawImmediately(updateNeeded: Boolean) {
+        if (updateNeeded) {
+            update()
+        }
+        if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
+            draw()
+        }
     }
 
     open fun resize(width: Int, height: Int) = resize(device, width, height)

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/AngleRedrawer.kt

 package org.jetbrains.skiko.redrawer
 
-import kotlinx.coroutines.withContext
 import org.jetbrains.skia.BackendRenderTarget
 import org.jetbrains.skia.DirectContext
 import org.jetbrains.skiko.*
@@ -60,16 +59,20 @@ internal class AngleRedrawer(
         super.dispose()
     }
 
-    override fun needRedraw() {
-        check(!isDisposed) { "ANGLE redrawer is disposed" }
+    override fun needRedraw(throttledToVsync: Boolean) {
+        checkDisposed()
         frameDispatcher.scheduleFrame()
     }
 
-    override fun redrawImmediately() {
-        check(!isDisposed) { "ANGLE redrawer is disposed" }
+    override fun redrawImmediately(updateNeeded: Boolean) {
+        checkDisposed()
+        if (updateNeeded) {
+            update()
+        }
         inDrawScope {
-            update(System.nanoTime())
-            drawAndSwap(withVsync = SkikoProperties.windowsWaitForVsyncOnRedrawImmediately)
+            if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
+                drawAndSwap(withVsync = SkikoProperties.windowsWaitForVsyncOnRedrawImmediately)
+            }
         }
     }
 

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/Direct3DRedrawer.kt

@@ -46,7 +46,7 @@ internal class Direct3DRedrawer(
 
     private val frameDispatcher = FrameDispatcher(MainUIDispatcher) {
         if (layer.isShowing) {
-            update(System.nanoTime())
+            update()
             draw()
         }
     }
@@ -63,16 +63,20 @@ internal class Direct3DRedrawer(
         super.dispose()
     }
 
-    override fun needRedraw() {
-        check(!isDisposed) { "Direct3DRedrawer is disposed" }
+    override fun needRedraw(throttledToVsync: Boolean) {
+        checkDisposed()
         frameDispatcher.scheduleFrame()
     }
 
-    override fun redrawImmediately() {
-        check(!isDisposed) { "Direct3DRedrawer is disposed" }
+    override fun redrawImmediately(updateNeeded: Boolean) {
+        checkDisposed()
+        if (updateNeeded) {
+            update()
+        }
         inDrawScope {
-            update(System.nanoTime())
-            drawAndSwap(withVsync = SkikoProperties.windowsWaitForVsyncOnRedrawImmediately)
+            if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
+                drawAndSwap(withVsync = SkikoProperties.windowsWaitForVsyncOnRedrawImmediately)
+            }
         }
     }
 

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/DispatcherToBlockOn.kt

@@ -14,5 +14,6 @@ private val defaultFactory = Executors.defaultThreadFactory()
 internal val dispatcherToBlockOn = Executors.newCachedThreadPool {
     defaultFactory.newThread(it).apply {
         isDaemon = true
+        name = "skiko-dispatcher-to-block-on"
     }
 }.asCoroutineDispatcher()
\ No newline at end of file

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/LinuxOpenGLRedrawer.kt

@@ -60,7 +60,7 @@ internal class LinuxOpenGLRedrawer(
     }
 
     override fun dispose() {
-        check(!isDisposed) { "LinuxOpenGLRedrawer is disposed" }
+        checkDisposed()
         frameJob.cancel()
         layer.backedLayer.lockLinuxDrawingSurface {
             // makeCurrent is mandatory to destroy context, otherwise, OpenGL will destroy wrong context (from another window).
@@ -72,15 +72,17 @@ internal class LinuxOpenGLRedrawer(
         super.dispose()
     }
 
-    override fun needRedraw() {
-        check(!isDisposed) { "LinuxOpenGLRedrawer is disposed" }
+    override fun needRedraw(throttledToVsync: Boolean) {
+        checkDisposed()
         toRedraw.add(this)
         frameDispatcher.scheduleFrame()
     }
 
-    override fun redrawImmediately() = layer.backedLayer.lockLinuxDrawingSurface {
-        check(!isDisposed) { "LinuxOpenGLRedrawer is disposed" }
-        update(System.nanoTime())
+    override fun redrawImmediately(updateNeeded: Boolean) = layer.backedLayer.lockLinuxDrawingSurface {
+        checkDisposed()
+        if (updateNeeded) {
+            update()
+        }
         inDrawScope {
             it.makeCurrent(context)
             contextHandler.draw()
@@ -116,7 +118,6 @@ internal class LinuxOpenGLRedrawer(
             toRedrawVisible.maxByOrNull { it.frameLimit }?.limitFramesIfNeeded()
 
             val nanoTime = System.nanoTime()
-
             for (redrawer in toRedrawVisible) {
                 try {
                     redrawer.update(nanoTime)

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/LinuxSoftwareRedrawer.kt

@@ -31,8 +31,8 @@ internal class LinuxSoftwareRedrawer(
         super.draw()
     }
 
-    override fun redrawImmediately() = layer.backedLayer.lockLinuxDrawingSurface {
-        super.redrawImmediately()
+    override fun redrawImmediately(updateNeeded: Boolean) = layer.backedLayer.lockLinuxDrawingSurface {
+        super.redrawImmediately(updateNeeded)
     }
 
     override fun resize(width: Int, height: Int) = layer.backedLayer.lockLinuxDrawingSurface {

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

@@ -4,6 +4,7 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.channels.Channel
 import org.jetbrains.skiko.*
 import org.jetbrains.skiko.context.MetalContextHandler
+import java.util.concurrent.atomic.AtomicBoolean
 import javax.swing.SwingUtilities.*
 
 /**
@@ -24,7 +25,6 @@ internal value class MetalDevice(val ptr: Long)
  *
  * This [MetalRedrawer] draws content on-screen for maximum efficiency,
  * but it may prevent for using it in embedded components (such as interop with Swing).
- * For off-screen implementation see [MetalOffScreenRedrawer]
  *
  * Content to draw is provided by [SkiaLayer.draw].
  *
@@ -34,7 +34,7 @@ internal value class MetalDevice(val ptr: Long)
 internal class MetalRedrawer(
     private val layer: SkiaLayer,
     analytics: SkiaLayerAnalytics,
-    private val properties: SkiaLayerProperties
+    properties: SkiaLayerProperties
 ) : AWTRedrawer(layer, analytics, GraphicsApi.METAL) {
     private val contextHandler: MetalContextHandler
 
@@ -60,7 +60,7 @@ internal class MetalRedrawer(
         }
 
     private val adapter = chooseMetalAdapter(properties.adapterPriority)
-    private val displayLinkThrottler = DisplayLinkThrottler(layer.windowHandle)
+    private val vSyncer = if (properties.isVsyncEnabled) MetalVSyncer(layer.windowHandle) else null
 
     private val windowOcclusionStateChannel = Channel<Boolean>(Channel.CONFLATED)
     @Volatile private var isWindowOccluded = false
@@ -78,12 +78,7 @@ internal class MetalRedrawer(
 
     override val renderInfo: String get() = contextHandler.rendererInfo()
 
-    private val frameDispatcher = FrameDispatcher(MainUIDispatcher) {
-        if (layer.isShowing) {
-            update(System.nanoTime())
-            draw()
-        }
-    }
+    private val frameDispatcher = FrameScheduler()
 
     init {
         onContextInit()
@@ -94,39 +89,41 @@ internal class MetalRedrawer(
         contextHandler.dispose()
         disposeDevice(device.ptr)
         adapter.dispose()
-        displayLinkThrottler.dispose()
+        vSyncer?.dispose()
         _device = null
         super.dispose()
     }
 
-    override fun needRedraw() {
-        check(!isDisposed) { "MetalRedrawer is disposed" }
-        frameDispatcher.scheduleFrame()
+    override fun needRedraw(throttledToVsync: Boolean) {
+        checkDisposed()
+        frameDispatcher.scheduleFrame(needUpdate = true, throttledToVsync = throttledToVsync)
     }
 
-    override fun redrawImmediately() {
-        check(!isDisposed) { "MetalRedrawer is disposed" }
-        inDrawScope {
-            update(System.nanoTime())
-            if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
-                performDraw(waitVsync = SkikoProperties.macOSWaitForPreviousFrameVsyncOnRedrawImmediately)
+    override fun redrawImmediately(updateNeeded: Boolean) {
+        checkDisposed()
+        if (updateNeeded) {
+            update()
+        }
+        // Trying to draw immediately in Metal will result in lost (undrawn)
+        // frames if there are more than two between consecutive vsync events.
+        if (layer.isShowing) {
+            frameDispatcher.scheduleFrame(needUpdate = false, throttledToVsync = false)
+        } else {
+            // But if the layer isn't showing yet, we want to draw immediately,
+            // so that if it shows before the next vsync, there is no background flash
+            inDrawScope {
+                if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
+                    performDraw()
+                }
             }
         }
     }
 
     private suspend fun draw() {
-        // 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
         inDrawScope {
+            // Move drawing to another thread to free the main thread
+            // It can be expensive to run it in the main thread and FPS can become unstable.
+            // This is visible by running [SkiaLayerPerformanceTest], standard deviation is increased significantly.
             withContext(dispatcherToBlockOn) {
                 performDraw()
             }
@@ -150,14 +147,8 @@ internal class MetalRedrawer(
         windowOcclusionStateChannel.trySend(isOccluded)
     }
 
-    private fun performDraw(waitVsync: Boolean = true) = synchronized(drawLock) {
+    private fun performDraw() = synchronized(drawLock) {
         if (!isDisposed) {
-            if (waitVsync) {
-                // Wait for vsync because:
-                // - macOS drops the second/next drawables if they are sent in the same vsync
-                // - it makes frames consistent and limits FPS
-                displayLinkThrottler.waitVSync()
-            }
             autoreleasepool {
                 contextHandler.draw()
             }
@@ -178,7 +169,7 @@ internal class MetalRedrawer(
     }
 
     override fun setVisible(isVisible: Boolean) {
-        Logger.debug { "MetalRedrawer#setVisible $this $isVisible" }
+        Logger.debug { "MetalRedrawer#setVisible($isVisible)" }
         setLayerVisible(device.ptr, isVisible)
     }
 
@@ -196,4 +187,44 @@ internal class MetalRedrawer(
      * @note see https://developer.apple.com/documentation/quartzcore/cametallayer/2887087-displaysyncenabled
      */
     private external fun setDisplaySyncEnabled(device: Long, enabled: Boolean)
+
+    private inner class FrameScheduler {
+        private var updateRequested = AtomicBoolean(false)
+
+        private fun updateIfRequested() {
+            if (updateRequested.getAndSet(false)) {
+                update()
+            }
+        }
+
+        private val updateDispatcher = FrameDispatcher(MainUIDispatcher) {
+            if (layer.isShowing) {
+                updateIfRequested()
+            }
+        }
+
+        private val frameDispatcher = FrameDispatcher(MainUIDispatcher) {
+            if (layer.isShowing) {
+                updateIfRequested()
+                draw()
+            }
+            vSyncer?.waitForVSync()
+        }
+
+        fun scheduleFrame(needUpdate: Boolean, throttledToVsync: Boolean) {
+            if (needUpdate) {
+                updateRequested.set(true)
+
+                if (!throttledToVsync) {
+                    updateDispatcher.scheduleFrame()
+                }
+            }
+            frameDispatcher.scheduleFrame()
+        }
+
+        fun cancel() {
+            updateDispatcher.cancel()
+            frameDispatcher.cancel()
+        }
+    }
 }

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/DisplayLinkThrottler.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/MetalVSyncer.kt

 package org.jetbrains.skiko.redrawer
 
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
 import org.jetbrains.skiko.Library
+import org.jetbrains.skiko.RendezvousBroadcastChannel
 
-internal class DisplayLinkThrottler(windowPtr: Long) {
+
+/**
+ * A utility allowing several coroutines to wait for the next vsync.
+ */
+internal class MetalVSyncer(windowPtr: Long) {
+
+    // The underlying throttler that blocks a thread
+    private val displayLinkThrottler = DisplayLinkThrottler(windowPtr)
+
+    private val channel = RendezvousBroadcastChannel<Unit>()
+
+    // A channel to trigger the thread that waits on vsync to doing so
+    private val triggerResumeOnVSync = Channel<Unit>(Channel.CONFLATED)
+
+    private val job = CoroutineScope(dispatcherToBlockOn).launch {
+        while (isActive) {
+            triggerResumeOnVSync.receive()  // Suspend until needed
+            displayLinkThrottler.waitVSync()  // This blocks (not suspends!) the thread
+            if (isActive) {
+                channel.sendAll(Unit)
+            }
+        }
+    }.also {
+        it.invokeOnCompletion {
+            displayLinkThrottler.dispose()
+        }
+    }
+
+    /**
+     * Suspends until the next vsync.
+     */
+    suspend fun waitForVSync() {
+        triggerResumeOnVSync.trySend(Unit)
+        channel.receive()
+    }
+
+    fun dispose() {
+        job.cancel()
+    }
+}
+
+private class DisplayLinkThrottler(windowPtr: Long) {
     private val implPtr = create(windowPtr)
 
-    internal fun dispose() = dispose(implPtr)
+    fun dispose() = dispose(implPtr)
 
     /*
      * Creates a DisplayLink if needed with refresh rate matching NSScreen of NSWindow passed in [windowPtr].
@@ -24,4 +70,4 @@ internal class DisplayLinkThrottler(windowPtr: Long) {
             Library.load()
         }
     }
-}
+}
\ No newline at end of file

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/SoftwareRedrawer.kt

@@ -8,7 +8,7 @@ import org.jetbrains.skiko.context.SoftwareContextHandler
 internal class SoftwareRedrawer(
     private val layer: SkiaLayer,
     analytics: SkiaLayerAnalytics,
-    private val properties: SkiaLayerProperties
+    properties: SkiaLayerProperties
 ) : AWTRedrawer(layer, analytics, GraphicsApi.SOFTWARE_FAST) {
     init {
         onDeviceChosen("Software")
@@ -17,16 +17,16 @@ internal class SoftwareRedrawer(
     private val contextHandler = SoftwareContextHandler(layer)
     override val renderInfo: String get() = contextHandler.rendererInfo()
 
-    private val frameJob = Job()
-    private val frameLimiter = layerFrameLimiter(CoroutineScope(frameJob), layer.backedLayer)
+    private val frameJob = if (properties.isVsyncEnabled && properties.isVsyncFramelimitFallbackEnabled) Job() else null
+    private val frameLimiter = frameJob?.let {
+        layerFrameLimiter(CoroutineScope(it), layer.backedLayer)
+    }
 
     private val frameDispatcher = FrameDispatcher(MainUIDispatcher) {
-        if (properties.isVsyncEnabled && properties.isVsyncFramelimitFallbackEnabled) {
-            frameLimiter.awaitNextFrame()
-        }
+        frameLimiter?.awaitNextFrame()
 
         if (layer.isShowing) {
-            update(System.nanoTime())
+            update()
             inDrawScope(contextHandler::draw)
         }
     }
@@ -36,18 +36,25 @@ internal class SoftwareRedrawer(
     }
 
     override fun dispose() {
-        frameJob.cancel()
+        frameJob?.cancel()
         frameDispatcher.cancel()
         contextHandler.dispose()
         super.dispose()
     }
 
-    override fun needRedraw() {
+    override fun needRedraw(throttledToVsync: Boolean) {
         frameDispatcher.scheduleFrame()
     }
 
-    override fun redrawImmediately() {
-        update(System.nanoTime())
-        inDrawScope(contextHandler::draw)
+    override fun redrawImmediately(updateNeeded: Boolean) {
+        checkDisposed()
+        if (updateNeeded) {
+            update()
+        }
+        inDrawScope {
+            if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
+                contextHandler.draw()
+            }
+        }
     }
 }
\ No newline at end of file

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/WindowsOpenGLRedrawer.kt

@@ -55,22 +55,26 @@ internal class WindowsOpenGLRedrawer(
         super.dispose()
     }
 
-    override fun needRedraw() {
+    override fun needRedraw(throttledToVsync: Boolean) {
         check(!isDisposed) { "WindowsOpenGLRedrawer is disposed" }
         toRedraw.add(this)
         frameDispatcher.scheduleFrame()
     }
 
-    override fun redrawImmediately() {
+    override fun redrawImmediately(updateNeeded: Boolean) {
         check(!isDisposed) { "WindowsOpenGLRedrawer is disposed" }
+        if (updateNeeded) {
+            update()
+        }
         inDrawScope {
-            update(System.nanoTime())
-            makeCurrent()
-            contextHandler.draw()
-            swapBuffers()
-            OpenGLApi.instance.glFinish()
-            if (SkikoProperties.windowsWaitForVsyncOnRedrawImmediately) {
-                dwmFlush()
+            if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
+                makeCurrent()
+                contextHandler.draw()
+                swapBuffers()
+                OpenGLApi.instance.glFinish()
+                if (SkikoProperties.windowsWaitForVsyncOnRedrawImmediately) {
+                    dwmFlush()
+                }
             }
         }
     }
@@ -95,7 +99,6 @@ internal class WindowsOpenGLRedrawer(
             toRedraw.clear()
 
             val nanoTime = System.nanoTime()
-
             for (redrawer in toRedrawVisible) {
                 try {
                     redrawer.update(nanoTime)

skiko/src/awtTest/kotlin/org/jetbrains/skiko/SkiaLayerTest.kt

@@ -3,6 +3,7 @@
 package org.jetbrains.skiko
 
 import kotlinx.coroutines.*
+import kotlinx.coroutines.channels.Channel
 import org.jetbrains.skia.*
 import org.jetbrains.skia.Canvas
 import org.jetbrains.skia.Paint
@@ -12,6 +13,7 @@ import org.jetbrains.skia.paragraph.ParagraphStyle
 import org.jetbrains.skia.paragraph.TextStyle
 import org.jetbrains.skiko.context.JvmContextHandler
 import org.jetbrains.skiko.redrawer.MetalRedrawer
+import org.jetbrains.skiko.redrawer.MetalVSyncer
 import org.jetbrains.skiko.redrawer.Redrawer
 import org.jetbrains.skiko.swing.SkiaSwingLayer
 import org.jetbrains.skiko.util.ScreenshotTestRule
@@ -36,9 +38,10 @@ import javax.swing.JPanel
 import javax.swing.SwingUtilities
 import javax.swing.WindowConstants
 import kotlin.concurrent.thread
+import kotlin.math.absoluteValue
 import kotlin.random.Random
-import kotlin.test.assertFalse
 import kotlin.test.assertNotNull
+import kotlin.test.assertNull
 import kotlin.test.assertTrue
 import kotlin.time.Duration
 
@@ -103,11 +106,11 @@ class SkiaLayerTest {
                 override fun keyTyped(e: KeyEvent?) {
                     launch {
                         val redrawer = window.layer.redrawer as MetalRedrawer
-                        redrawer.redrawImmediately()
+                        redrawer.redrawImmediately(updateNeeded = true)
                         counter1 += 1
-                        redrawer.redrawImmediately()
+                        redrawer.redrawImmediately(updateNeeded = true)
                         counter2 += 1
-                        redrawer.redrawImmediately()
+                        redrawer.redrawImmediately(updateNeeded = true)
                     }
                 }
             })
@@ -273,19 +276,16 @@ class SkiaLayerTest {
 
             renderedWidth = -1
             layer.size = Dimension(30, 40)
-            layer.needRedraw()
             delay(1000)
             assertEquals((30 * density).toInt(), renderedWidth)
 
             renderedWidth = -1
             layer.size = Dimension(0, 0)
-            layer.needRedraw()
             delay(1000)
             assertEquals(0, renderedWidth)
 
             renderedWidth = -1
             layer.size = Dimension(40, 40)
-            layer.needRedraw()
             delay(1000)
             assertEquals((40 * density).toInt(), renderedWidth)
         } finally {
@@ -546,10 +546,12 @@ class SkiaLayerTest {
         }
     }
 
-    private abstract class BaseTestRedrawer: Redrawer {
+    private abstract class BaseTestRedrawer(val layer: SkiaLayer): Redrawer {
         override fun dispose() = Unit
-        override fun needRedraw() = Unit
-        override fun redrawImmediately() = Unit
+        override fun needRedraw(throttledToVsync: Boolean) = Unit
+        override fun redrawImmediately(updateNeeded: Boolean) = Unit
+        override fun update(nanoTime: Long) = layer.update(nanoTime)
+
         override val renderInfo: String
             get() = ""
     }
@@ -557,12 +559,12 @@ class SkiaLayerTest {
     @Test(timeout = 60000)
     fun `fallback to software renderer, fail on init context`() = uiTest {
         testFallbackToSoftware { layer, _, _, _ ->
-            object : BaseTestRedrawer() {
+            object : BaseTestRedrawer(layer) {
                 private val contextHandler = object : JvmContextHandler(layer) {
                     override fun initContext() = false
                     override fun initCanvas() = Unit
                 }
-                override fun redrawImmediately() = layer.inDrawScope(contextHandler::draw)
+                override fun redrawImmediately(updateNeeded: Boolean) = layer.inDrawScope(contextHandler::draw)
             }
         }
     }
@@ -575,8 +577,8 @@ class SkiaLayerTest {
     @Test(timeout = 60000)
     fun `fallback to software renderer, fail on draw`() = uiTest {
         testFallbackToSoftware { layer, _, _, _ ->
-            object : BaseTestRedrawer() {
-                override fun redrawImmediately() = layer.inDrawScope {
+            object : BaseTestRedrawer(layer) {
+                override fun redrawImmediately(updateNeeded: Boolean) = layer.inDrawScope {
                     throw RenderException()
                 }
             }
@@ -631,8 +633,8 @@ class SkiaLayerTest {
     fun `renderApi change callback is invoked on fallback`() = uiTest {
         val window = UiTestWindow(
             renderFactory = OverrideNonSoftwareRenderFactory { layer, _, _, _ ->
-                object : BaseTestRedrawer() {
-                    override fun redrawImmediately() = layer.inDrawScope {
+                object : BaseTestRedrawer(layer) {
+                    override fun redrawImmediately(updateNeeded: Boolean) = layer.inDrawScope {
                         throw RenderException()
                     }
                 }
@@ -1017,14 +1019,27 @@ class SkiaLayerTest {
 
     @Test
     fun `no window flash on hide or dispose while animation is running`() = uiTest {
-        assumeTrue(hostOs == OS.MacOS)  // Until the issue is fixed on Windows and Linux
+        assumeTrue(hostOs.isMacOS)
+        // Until the issue is fixed in other redrawers
+        // Don't use assumeTrue, as uiTest iterates over multiple renderers,
+        // and if one of them skipped, the whole test is skipped
+        if (renderApi != GraphicsApi.METAL) return@uiTest
 
         // Put up a large green window, and then repeatedly show and hide/dispose
         // a smaller black window on top of it while screenshotting the pixel at the center,
         // and making sure that pixel is always either black or green.
 
-        val bgColor = Color.GREEN  // Green
-        val fgColor = Color.BLACK  // Black
+        // We can't compare colors exactly because java.awt.Robot can return a slightly different color due to
+        // system color profile
+        fun Color.closeTo(other: Color): Boolean {
+            val diffLimit = 10
+            return (red - other.red).absoluteValue < diffLimit
+                    && (green - other.green).absoluteValue < diffLimit
+                    && (blue - other.blue).absoluteValue < diffLimit
+        }
+
+        val bgColor = Color.GREEN
+        val fgColor = Color.BLACK
         val backgroundWindow = JFrame().also {
             it.size = Dimension(1000, 1000)
             it.location = Point(200, 200)
@@ -1051,10 +1066,10 @@ class SkiaLayerTest {
             Point(it.x + it.width/2, it.y + it.height/2)
         }
 
-        var nonBlackPixelDetected = false
+        var nonBlackPixelDetected: Color? = null
         val stopThread = AtomicBoolean(false)
         // This semaphore ensures that screenshots are only taken when the window is becoming hidden/disposed.
-        // It's needed because the window can (and does, with SOFTWARE_COMPAT) also flash when becoming visible.
+        // It's necessary because the window can (and does, with SOFTWARE_COMPAT) also flash when becoming visible.
         val semaphore = Semaphore(1, true)
         val t = thread {
             val robot = Robot()
@@ -1062,36 +1077,37 @@ class SkiaLayerTest {
                 semaphore.acquire()
                 val pixel = robot.getPixelColor(pixelLocation.x, pixelLocation.y)
                 semaphore.release()
-                if ((pixel != fgColor) && (pixel != bgColor)) {
-                    println("window is visible: ${window.isVisible}")
-                    nonBlackPixelDetected = true
+                if (!pixel.closeTo(fgColor) && !pixel.closeTo(bgColor)) {
+                    nonBlackPixelDetected = pixel
                     return@thread
                 }
             }
         }
 
         try {
+            // Check with `window.isVisible = false`
             repeat(20) {
                 delay(200)
                 window.isVisible = false
                 delay(300)
-                assertFalse(nonBlackPixelDetected, "Detected a non-black pixel when hiding window")
+                assertNull(nonBlackPixelDetected, "Detected a non-black pixel when hiding window")
                 // Acquire the semaphore while making the window visible, to disable screenshotting
                 semaphore.acquire()
                 window.isVisible = true
-                delay(1000)
+                delay(500)
                 semaphore.release()
             }
 
+            // Check with `window.dispose()`
             repeat(20) {
                 delay(200)
                 window.dispose()
                 delay(300)
-                assertFalse(nonBlackPixelDetected, "Detected a non-black pixel when disposing window")
+                assertNull(nonBlackPixelDetected, "Detected a non-black pixel when disposing window")
                 // Acquire the semaphore while making the window visible, to disable screenshotting
                 semaphore.acquire()
                 window.isVisible = true
-                delay(1000)
+                delay(500)
                 semaphore.release()
             }
         } finally {
@@ -1103,6 +1119,142 @@ class SkiaLayerTest {
         }
     }
 
+    @Test
+    fun `temporary change is not visible`() = uiTest {
+        assumeTrue(hostOs.isMacOS)
+        // The separation between update and draw is only implemented in MetalRedrawer at the moment
+        // Don't use assumeTrue, as uiTest iterates over multiple renderers,
+        // and if one of them skipped, the whole test is skipped
+        if (renderApi != GraphicsApi.METAL) return@uiTest
+
+        val color = Color.BLACK
+        val tempColor = Color.WHITE
+        lateinit var renderDelegate: SolidColorRenderer
+        val renderChannel = Channel<Unit>(Channel.CONFLATED)
+        val window = UiTestWindow {
+            size = Dimension(600, 600)
+            location = Point(400, 400)
+            renderDelegate = object: SolidColorRenderer(
+                layer = layer,
+                color = color,
+                continuousRedraw = true
+            ) {
+                override fun onRender(canvas: Canvas, width: Int, height: Int, nanoTime: Long) {
+                    super.onRender(canvas, width, height, nanoTime)
+                    assertTrue(renderChannel.trySend(Unit).isSuccess)
+                }
+            }
+            layer.renderDelegate = renderDelegate
+            contentPane.add(layer, BorderLayout.CENTER)
+        }
+
+        window.isVisible = true
+        delay(1500)
+        val pixelLocation = window.bounds.let {
+            Point(it.x + it.width/2, it.y + it.height/2)
+        }
+        val robot = Robot()
+
+        var tempColorVisibleCount = 0
+        try {
+            repeat(50) {
+                // Wait for just after the next vsync, so we have plenty of time until the one after it
+                val vSyncer = MetalVSyncer(window.layer.windowHandle)
+                vSyncer.waitForVSync()
+
+                // Set the color to temp, then immediately back to normal
+                renderDelegate.color = tempColor
+                renderDelegate.layer.needRedraw(throttledToVsync = false)
+                renderChannel.receive()  // Wait until render is actually called
+                renderDelegate.color = color
+                renderDelegate.layer.needRedraw(throttledToVsync = false)
+
+                // Check whether the temp color was visible
+                val startTime = System.currentTimeMillis()
+                while (System.currentTimeMillis() - startTime < 400) {
+                    val pixel = robot.getPixelColor(pixelLocation.x, pixelLocation.y)
+                    if (pixel != color) {
+                        tempColorVisibleCount++
+                    }
+                }
+            }
+
+            // Because the temp color can theoretically be visible if the JVM hiccups and a vsync happens before the
+            // color is reverted, we allow a small percentage of the tries to fail. This way the flakiness of the test
+            // is reduced.
+            // Note that in practice, however, this test had never failed on an M1 Ultra machine with a 60Hz monitor.
+            assertTrue(tempColorVisibleCount < 5)
+        } finally {
+            window.dispose()
+        }
+    }
+
+    @Test
+    fun `needRedraw throttled and regular calls render and draw once`() = uiTest {
+        // Check that calling both needRedraw(true) and needRedraw(false) causes only one render and one draw call
+        var renderCalls = 0
+        val renderChannel = Channel<Unit>(Channel.CONFLATED)
+
+        var drawCalls = 0
+        val deviceAnalytics = object : SkiaLayerAnalytics.DeviceAnalytics {
+            override fun beforeFrameRender() {
+                drawCalls++
+            }
+        }
+        val analytics = object : SkiaLayerAnalytics {
+            @ExperimentalSkikoApi
+            override fun device(
+                skikoVersion: String,
+                os: OS,
+                api: GraphicsApi,
+                deviceName: String?
+            ): SkiaLayerAnalytics.DeviceAnalytics {
+                return deviceAnalytics
+            }
+        }
+        val window = UiTestWindow(analytics = analytics) {
+            size = Dimension(600, 600)
+            location = Point(400, 400)
+            layer.renderDelegate = object: SkikoRenderDelegate {
+                override fun onRender(canvas: Canvas, width: Int, height: Int, nanoTime: Long) {
+                    renderCalls++
+                    renderChannel.trySend(Unit)
+                }
+            }
+            contentPane.add(layer, BorderLayout.CENTER)
+        }
+        window.isVisible = true
+
+        // Wait for things to settle down, specifically the workaround for JBR-5259, which moves
+        // the backed layer when graphicsContextScaleTransform changes
+        delay(100)
+
+        try {
+            renderChannel.receive()
+            renderCalls = 0
+            drawCalls = 0
+            withContext(MainUIDispatcher) {
+                window.layer.needRedraw(true)
+                window.layer.needRedraw(false)
+            }
+            delay(100)
+            assertEquals("Render was called more than once on needRedraw(true), needRedraw(false)", 1, renderCalls)
+            assertEquals("Draw was called more than once on needRedraw(true), needRedraw(false)", 1, drawCalls)
+
+            renderCalls = 0
+            drawCalls = 0
+            withContext(MainUIDispatcher) {
+                window.layer.needRedraw(false)
+                window.layer.needRedraw(true)
+            }
+            delay(100)
+            assertEquals("Render was called more than once on needRedraw(false), needRedraw(true)", 1, renderCalls)
+            assertEquals("Draw was called more than once on needRedraw(true), needRedraw(true)", 1, drawCalls)
+        } finally {
+            window.dispose()
+        }
+    }
+
     private class RectRenderer(
         private val getContentScale: () -> Float,
         var rectWidth: Int,
@@ -1139,6 +1291,8 @@ class SkiaLayerTest {
         }
     }
 
+
+
     private class AnimatedBoxRenderer(
         private val layer: SkiaLayer,
         private val pixelsPerSecond: Double,
@@ -1166,7 +1320,7 @@ class SkiaLayerTest {
         }
     }
 
-    private class SolidColorRenderer(
+    private open class SolidColorRenderer(
         val layer: SkiaLayer,
         color: Color,
         continuousRedraw: Boolean = false
@@ -1175,11 +1329,18 @@ class SkiaLayerTest {
         var continuousRedraw = continuousRedraw
             set(value) {
                 if (value)
-                    layer.needRedraw()
+                    layer.needRedraw(throttledToVsync = true)
+                field = value
+            }
+
+        var color = color
+            set(value) {
+                Logger.debug { "Color set to $value" }
                 field = value
+                paint.color = color.rgb
             }
 
-        val paint = Paint().also { it.color = color.rgb }
+        private var paint = Paint().also { it.color = color.rgb }
 
         override fun onRender(canvas: Canvas, width: Int, height: Int, nanoTime: Long) {
             canvas.drawRect(Rect(0f, 0f, width.toFloat(), height.toFloat()), paint)

skiko/src/commonMain/kotlin/org/jetbrains/skiko/FrameDispatcher.kt

@@ -13,11 +13,11 @@ import kotlin.coroutines.CoroutineContext
  */
 class FrameDispatcher(
     scope: CoroutineScope,
-    private val onFrame: suspend () -> Unit
+    private val onFrame: suspend CoroutineScope.() -> Unit
 ) {
     constructor(
         context: CoroutineContext,
-        onFrame: suspend () -> Unit
+        onFrame: suspend CoroutineScope.() -> Unit
     ) : this(
         CoroutineScope(context),
         onFrame
@@ -56,7 +56,7 @@ class FrameDispatcher(
     fun scheduleFrame() {
         if (!frameScheduled) {
             frameScheduled = true
-            frameChannel.trySend(Unit).isSuccess
+            frameChannel.trySend(Unit)
         }
     }
 }
\ No newline at end of file

skiko/src/commonMain/kotlin/org/jetbrains/skiko/Logging.kt

 package org.jetbrains.skiko
 
+import kotlin.time.Duration.Companion.nanoseconds
+
 interface SkikoLoggerInterface {
     val isTraceEnabled: Boolean
     val isDebugEnabled: Boolean
@@ -36,11 +38,14 @@ internal enum class LogLevel {
     }
 }
 
-class DefaultConsoleLogger(override val isTraceEnabled: Boolean = false,
-                           override val isDebugEnabled: Boolean = false,
-                           override val isInfoEnabled: Boolean = true,
-                           override val isWarnEnabled: Boolean = true,
-                           override val isErrorEnabled: Boolean = true): SkikoLoggerInterface {
+class DefaultConsoleLogger(
+    override val isTraceEnabled: Boolean = false,
+    override val isDebugEnabled: Boolean = false,
+    override val isInfoEnabled: Boolean = true,
+    override val isWarnEnabled: Boolean = true,
+    override val isErrorEnabled: Boolean = true,
+    private val logTimestamp: Boolean = false
+): SkikoLoggerInterface {
 
     companion object {
         fun fromLevel(level: String): DefaultConsoleLogger {
@@ -55,48 +60,52 @@ class DefaultConsoleLogger(override val isTraceEnabled: Boolean = false,
         }
     }
 
+    private fun logMessagePrefix() = if (logTimestamp) {
+        "[${currentNanoTime().nanoseconds.inWholeMilliseconds.mod(1_000)}]"
+    } else "[SKIKO]"
+
     override fun trace(message: String) {
-        println("[SKIKO] trace: $message")
+        println("${logMessagePrefix()} trace: $message")
     }
 
     override fun trace(t: Throwable, message: String) {
-        println("[SKIKO] trace: $message")
+        println("${logMessagePrefix()} trace: $message")
         println(t)
     }
 
     override fun debug(message: String) {
-        println("[SKIKO] debug: $message")
+        println("${logMessagePrefix()} debug: $message")
     }
 
     override fun debug(t: Throwable, message: String) {
-        println("[SKIKO] debug: $message")
+        println("${logMessagePrefix()} debug: $message")
         println(t)
     }
 
     override fun info(message: String) {
-        println("[SKIKO] info: $message")
+        println("${logMessagePrefix()} info: $message")
     }
 
     override fun info(t: Throwable, message: String) {
-        println("[SKIKO] info: $message")
+        println("${logMessagePrefix()} info: $message")
         println(t)
     }
 
     override fun warn(message: String) {
-        println("[SKIKO] warn: $message")
+        println("${logMessagePrefix()} warn: $message")
     }
 
     override fun warn(t: Throwable, message: String) {
-        println("[SKIKO] warn: $message")
+        println("${logMessagePrefix()} warn: $message")
         println(t)
     }
 
     override fun error(message: String) {
-        println("[SKIKO] error: $message")
+        println("${logMessagePrefix()} error: $message")
     }
 
     override fun error(t: Throwable, message: String) {
-        println("[SKIKO] error: $message")
+        println("${logMessagePrefix()} error: $message")
         println(t)
     }
 }

skiko/src/commonMain/kotlin/org/jetbrains/skiko/RendezvousBroadcastChannel.kt

@@ -2,33 +2,37 @@ package org.jetbrains.skiko
 
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.suspendCancellableCoroutine
-import kotlin.coroutines.Continuation
-import kotlin.coroutines.resume
+import kotlin.coroutines.*
 
 /**
- * Behaves as `Channel<Unit>(Channel.RENDEZVOUS)`, but with ability to send a value to all current consumers
- * (which will await on `receive` method).
+ * Behaves like `Channel<Unit>(Channel.RENDEZVOUS)`, but with the ability to send a value to all current consumers
+ * suspended in [receive].
  */
 internal class RendezvousBroadcastChannel<T> {
     private val onRequest = Channel<Unit>(Channel.CONFLATED)
-    private val receivers = mutableListOf<Continuation<T>>()
+    private var suspended = mutableListOf<Continuation<T>>()
+    private var suspendedCopy = mutableListOf<Continuation<T>>()
 
     /**
-     * Send value to all current consumers which await value on `receive` method, or await for the first one.
+     * Send value to all current consumers that await value on `receive` method, or await for the first one.
      *
      * Can't be called concurrently from multiple threads.
      */
     suspend fun sendAll(value: T) {
         onRequest.receive()
-        val receiversCopy = maybeSynchronized(receivers) {
-            mutableListOf<Continuation<T>>().apply {
-                addAll(receivers)
-                receivers.clear()
-            }
+
+        // Swap the lists
+        maybeSynchronized(this) {
+            val tmp = suspended
+            suspended = suspendedCopy
+            suspendedCopy = tmp
         }
-        for (receiver in receiversCopy) {
-            receiver.resume(value)
+
+        // Safe to touch `suspendedCopy` without lock because receive will now add to `suspended`.
+        for (cont in suspendedCopy) {
+            cont.resume(value)
         }
+        suspendedCopy.clear()
     }
 
     /**
@@ -37,8 +41,8 @@ internal class RendezvousBroadcastChannel<T> {
      * Can be called concurrently from multiple threads.
      */
     suspend fun receive(): T = suspendCancellableCoroutine { continuation ->
-        maybeSynchronized(receivers) {
-            receivers.add(continuation)
+        maybeSynchronized(this) {
+            suspended.add(continuation)
         }
         onRequest.trySend(Unit)
     }

skiko/src/commonMain/kotlin/org/jetbrains/skiko/SkiaLayer.kt

@@ -55,9 +55,13 @@ expect open class SkiaLayer {
     fun detach()
 
     /**
-     * Force redraw.
+     * Request redrawing of the content; The [renderDelegate] will be asked to re-render, and the result will be drawn
+     * on the screen.
+     *
+     * @param throttledToVsync Whether to throttle calling [renderDelegate]'s [SkikoRenderDelegate.onRender] to at most
+     * once between vsync signals (if vsync is enabled).
      */
-    fun needRedraw()
+    fun needRedraw(throttledToVsync: Boolean = true)
 
     /**
      * Drawing function.

skiko/src/commonMain/kotlin/org/jetbrains/skiko/redrawer/Redrawer.kt

 package org.jetbrains.skiko.redrawer
 
+import kotlin.time.TimeSource
+
+private val initialTime = TimeSource.Monotonic.markNow()
+
 internal interface Redrawer {
     fun dispose()
-    fun needRedraw()
-    fun redrawImmediately()
+    fun needRedraw(throttledToVsync: Boolean)
+    fun redrawImmediately(updateNeeded: Boolean)
     fun syncBounds() = Unit
+    fun update(nanoTime: Long = initialTime.elapsedNow().inWholeNanoseconds)
     fun setVisible(isVisible: Boolean) = Unit
     val renderInfo: String
 }
\ No newline at end of file

skiko/src/jsWasmMain/kotlin/org/jetbrains/skiko/SkiaLayer.js.kt

@@ -48,7 +48,7 @@ actual open class SkiaLayer {
     /**
      * Schedules a drawFrame to the appropriate moment.
      */
-    actual fun needRedraw() {
+    actual fun needRedraw(throttledToVsync: Boolean) {
         state?.needRedraw()
     }
 

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/FrameLimiter.kt

 package org.jetbrains.skiko
 
 import kotlinx.coroutines.*
-import java.util.concurrent.Executors
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.Duration.Companion.nanoseconds
-import kotlin.time.TimeSource
 
 /**
  * Limit the duration of the frames (to avoid high CPU usage) to [frameMillis].
@@ -32,7 +30,7 @@ class FrameLimiter(
 
     private suspend fun preciseDelay(millis: Long) {
         val start = currentTime()
-        // delay aren't precise, so we should measure what is the actual precision of delay is,
+        // delay isn't precise, so we should measure what the actual precision of delay is,
         // so we don't wait longer than we need
         var actual1msDelay = 1.milliseconds
 

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SkikoProperties.kt

@@ -42,10 +42,6 @@ object SkikoProperties {
         }
     }
 
-    val macOSWaitForPreviousFrameVsyncOnRedrawImmediately: Boolean get() {
-        return getProperty("skiko.rendering.macos.waitForPreviousFrameVsyncOnRedrawImmediately")?.toBoolean() ?: true
-    }
-
     val windowsWaitForVsyncOnRedrawImmediately: Boolean get() {
         return getProperty("skiko.rendering.windows.waitForFrameVsyncOnRedrawImmediately")?.toBoolean() ?: false
     }

skiko/src/jvmTest/kotlin/org/jetbrains/skiko/RendezvousBroadcastChannelTest.kt

 package org.jetbrains.skiko
 
 import kotlinx.coroutines.*
-import kotlinx.coroutines.test.advanceUntilIdle
-import kotlinx.coroutines.test.pauseDispatcher
-import kotlinx.coroutines.test.runBlockingTest
 import kotlinx.coroutines.test.runTest
 import org.junit.Assert.assertEquals
 import org.junit.Test

skiko/src/linuxMain/kotlin/org/jetbrains/skiko/SkiaLayer.linux.kt

@@ -17,7 +17,7 @@ actual open class SkiaLayer  {
         set(value) {}
     actual val component: Any?
         get() = TODO("Not yet implemented")
-    actual fun needRedraw() {
+    actual fun needRedraw(throttledToVsync: Boolean) {
         TODO("unimplemented")
     }
     actual fun attachTo(container: Any) {

skiko/src/macosMain/kotlin/org/jetbrains/skiko/SkiaLayer.macos.kt

@@ -85,13 +85,13 @@ actual open class SkiaLayer {
         @ObjCAction
         fun frameDidChange(notification: NSNotification) {
             redrawer?.syncBounds()
-            redrawer?.redrawImmediately()
+            redrawer?.redrawImmediately(updateNeeded = true)
         }
 
         @ObjCAction
         fun windowDidChangeBackingProperties(notification: NSNotification) {
             redrawer?.syncBounds()
-            redrawer?.redrawImmediately()
+            redrawer?.redrawImmediately(updateNeeded = true)
         }
 
         fun addObserver() {
@@ -140,8 +140,8 @@ actual open class SkiaLayer {
     /**
      * Schedules a frame to an appropriate moment.
      */
-    actual fun needRedraw() {
-        redrawer?.needRedraw()
+    actual fun needRedraw(throttledToVsync: Boolean) {
+        redrawer?.needRedraw(throttledToVsync)
     }
 
     /**

skiko/src/macosMain/kotlin/org/jetbrains/skiko/redrawer/MetalRedrawer.macos.kt

@@ -14,6 +14,7 @@ import org.jetbrains.skiko.SkikoDispatchers
 import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.context.ContextHandler
 import org.jetbrains.skiko.context.MacOsMetalContextHandler
+import org.jetbrains.skiko.currentNanoTime
 import platform.AppKit.NSWindowDidChangeOcclusionStateNotification
 import platform.AppKit.NSWindowOcclusionStateVisible
 import platform.CoreGraphics.CGColorCreate
@@ -28,7 +29,6 @@ import platform.QuartzCore.CATransaction
 import platform.QuartzCore.kCAGravityTopLeft
 import platform.QuartzCore.kCALayerHeightSizable
 import platform.QuartzCore.kCALayerWidthSizable
-import kotlin.system.getTimeNanos
 import platform.CoreGraphics.CGSizeMake
 import platform.Foundation.NSNotification
 import platform.Foundation.NSNotificationCenter
@@ -127,22 +127,33 @@ internal class MacOsMetalRedrawer(
         CATransaction.flush()
     }
 
+    private fun checkDisposed() {
+        check(!isDisposed) { "MetalRedrawer is disposed" }
+    }
+
     /**
      * Schedules a frame [draw] to an appropriate moment.
      */
-    override fun needRedraw() {
-        check(!isDisposed) { "MetalRedrawer is disposed" }
+    override fun needRedraw(throttledToVsync: Boolean) {
+        checkDisposed()
         frameDispatcher.scheduleFrame()
     }
 
+    override fun update(nanoTime: Long) {
+        checkDisposed()
+        skiaLayer.update(nanoTime)
+    }
+
     /**
      * Invokes [draw] right away.
      */
-    override fun redrawImmediately() {
-        check(!isDisposed) { "MetalRedrawer is disposed" }
+    override fun redrawImmediately(updateNeeded: Boolean) {
+        checkDisposed()
         autoreleasepool {
-            if (!isDisposed) {
-                skiaLayer.update(getTimeNanos())
+            if (!isDisposed && updateNeeded) {
+                update()
+            }
+            if (!isDisposed) { // Redrawer may be disposed in user code, during `update`
                 contextHandler.draw()
             }
         }
@@ -151,7 +162,7 @@ internal class MacOsMetalRedrawer(
     private suspend fun draw() {
         autoreleasepool {
             if (!isDisposed) {
-                skiaLayer.update(getTimeNanos())
+                update()
                 contextHandler.draw()
             }
         }
@@ -208,7 +219,7 @@ internal class MetalLayer : CAMetalLayer {
         this.framebufferOnly = false
         skiaLayer.nsView.layer = this
         skiaLayer.nsView.wantsLayer = true
-        this.contentsGravity = kCAGravityTopLeft;
+        this.contentsGravity = kCAGravityTopLeft
     }
 
     fun dispose() {
@@ -216,7 +227,7 @@ internal class MetalLayer : CAMetalLayer {
     }
 
     override fun drawInContext(ctx: CGContextRef?) {
-        skiaLayer.update(getTimeNanos())
+        skiaLayer.update(currentNanoTime())
         contextHandler.draw()
     }
 }

skiko/src/macosMain/kotlin/org/jetbrains/skiko/redrawer/OpenGLRedrawer.macos.kt

@@ -7,6 +7,7 @@ import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.SkikoDispatchers
 import org.jetbrains.skiko.context.ContextHandler
 import org.jetbrains.skiko.context.MacOSOpenGLContextHandler
+import org.jetbrains.skiko.currentNanoTime
 import platform.CoreFoundation.CFTimeInterval
 import platform.CoreGraphics.CGRectMake
 import platform.CoreVideo.CVTimeStamp
@@ -15,7 +16,6 @@ import platform.OpenGLCommon.CGLPixelFormatObj
 import platform.OpenGLCommon.CGLSetCurrentContext
 import platform.QuartzCore.CAOpenGLLayer
 import platform.QuartzCore.*
-import kotlin.system.getTimeNanos
 
 /**
  * OpenGL [Redrawer] implementation for MacOs.
@@ -35,7 +35,7 @@ internal class MacOsOpenGLRedrawer(
     }
 
     private val frameDispatcher = FrameDispatcher(SkikoDispatchers.Main) {
-        redrawImmediately()
+        redrawImmediately(updateNeeded = true)
     }
 
     override fun dispose() {
@@ -63,11 +63,15 @@ internal class MacOsOpenGLRedrawer(
         CATransaction.flush()
     }
 
-    override fun needRedraw() {
+    override fun update(nanoTime: Long) {
+        skiaLayer.update(nanoTime)
+    }
+
+    override fun needRedraw(throttledToVsync: Boolean) {
         frameDispatcher.scheduleFrame()
     }
 
-    override fun redrawImmediately() {
+    override fun redrawImmediately(updateNeeded: Boolean) {
         glLayer.setNeedsDisplay()
         skiaLayer.nsView.setNeedsDisplay(true)
     }
@@ -90,7 +94,7 @@ internal class MacosGLLayer : CAOpenGLLayer {
         this.setAutoresizingMask(kCALayerWidthSizable or kCALayerHeightSizable )
         skiaLayer.nsView.layer = this
         skiaLayer.nsView.wantsLayer = true
-        this.contentsGravity = kCAGravityTopLeft;
+        this.contentsGravity = kCAGravityTopLeft
     }
 
     fun setFrame(x: Int, y: Int, width: Int, height: Int) {
@@ -121,9 +125,9 @@ internal class MacosGLLayer : CAOpenGLLayer {
         forLayerTime: CFTimeInterval,
         displayTime: CPointer<CVTimeStamp>?
     ) {
-        CGLSetCurrentContext(ctx);
+        CGLSetCurrentContext(ctx)
         try {
-            skiaLayer.update(getTimeNanos())
+            skiaLayer.update(currentNanoTime())
             contextHandler.draw()
         } catch (e: Throwable) {
             e.printStackTrace()

skiko/src/uikitMain/kotlin/org/jetbrains/skiko/SkiaLayer.uikit.kt

@@ -4,8 +4,6 @@ import kotlinx.cinterop.useContents
 import org.jetbrains.skia.Canvas
 import org.jetbrains.skia.PixelGeometry
 import org.jetbrains.skia.Surface
-import platform.UIKit.*
-import kotlin.system.getTimeNanos
 
 actual open class SkiaLayer {
     internal var needRedrawCallback: () -> Unit = {}
@@ -25,7 +23,7 @@ actual open class SkiaLayer {
         get() = false
         set(_) { throw UnsupportedOperationException() }
 
-    actual fun needRedraw() {
+    actual fun needRedraw(throttledToVsync: Boolean) {
         needRedrawCallback.invoke()
     }
 
@@ -63,7 +61,7 @@ actual open class SkiaLayer {
     }
 
     internal fun draw(surface: Surface) {
-        renderDelegate?.onRender(surface.canvas, surface.width, surface.height, getTimeNanos())
+        renderDelegate?.onRender(surface.canvas, surface.width, surface.height, currentNanoTime())
     }
 
     actual val pixelGeometry: PixelGeometry