Emulate vsync tick on Software renderer and Linux with unsupported vsync (#148)

* Emulate vsync tick on Software renderer and Linux with unsupported vsync

Otherwise there is no delay between frames and we will have high CPU usage

* Discussions

* Fix frame limit on Linux

* Fix tests

* Refactor. Move lockLinuxDrawingSurface

* FrameLimiter. Proper cancel

* Make FrameLimiter local for each window

* Dynamically load Xrandr.

* Search paths

* Fix loadXrandr

* libxrandr-dev for docker
Co-authored-by: Nikolay Igotti <igotti@gmail.com>

.github/workflows/blank.yml

@@ -58,7 +58,7 @@ jobs:
           sudo apt-get install gcc-9 g++-9 -y
           sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 60 --slave /usr/bin/g++ g++ /usr/bin/g++-9
           sudo update-alternatives --config gcc 
-          sudo apt-get install ninja-build fontconfig libfontconfig1-dev libglu1-mesa-dev zip -y          
+          sudo apt-get install ninja-build fontconfig libfontconfig1-dev libglu1-mesa-dev libxrandr-dev zip -y
           ./gradlew jvmTest
           ./gradlew publishToMavenLocal
    windows:

samples/SkiaJvmSample/build.gradle.kts

@@ -36,8 +36,8 @@ if (project.hasProperty("skiko.version")) {
 dependencies {
     implementation(platform("org.jetbrains.kotlin:kotlin-bom"))
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-swing:1.4.1")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.4.1")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-swing:1.5.0")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.5.0")
     implementation("org.jetbrains.skiko:skiko-jvm-runtime-$target:$version")
     testImplementation("org.jetbrains.kotlin:kotlin-test")
     testImplementation("org.jetbrains.kotlin:kotlin-test-junit")

skiko/docker/linux-amd64/Dockerfile

@@ -17,7 +17,7 @@ ENV PATH=/usr/lib/binutils-2.26/bin:$PATH
 ENV DEPOT_TOOLS=/usr/depot_tools
 ENV PATH=$DEPOT_TOOLS:$PATH
 RUN apt-get install git python wget -y && \
-    apt-get install fontconfig libfontconfig1-dev libglu1-mesa-dev curl zip -y && \
+    apt-get install fontconfig libfontconfig1-dev libglu1-mesa-dev libxrandr-dev curl zip -y && \
     git clone 'https://chromium.googlesource.com/chromium/tools/depot_tools.git' $DEPOT_TOOLS
 
 # Install Java

skiko/docker/linux-arm64/Dockerfile

@@ -3,7 +3,7 @@ ARG DEBIAN_FRONTEND=noninteractive
 RUN apt-get update -y
 RUN apt-get install binutils build-essential -y
 RUN apt-get install software-properties-common -y
-RUN apt-get install python git fontconfig libfontconfig1-dev libglu1-mesa-dev curl wget -y
+RUN apt-get install python git fontconfig libfontconfig1-dev libglu1-mesa-dev libxrandr-dev curl wget -y
 RUN apt-get install openjdk-11-jdk -y
 RUN apt-get install clang-11 -y && \
     apt-get remove g++ -y && \

skiko/src/jvmMain/cpp/linux/awt.cc

+#include <jawt_md.h>
+#include <GL/gl.h>
+#include <GL/glx.h>
+#include <X11/X.h>
+#include <X11/Xlib.h>
+#include <X11/Xresource.h>
+#include <cstdlib>
+#include <unistd.h>
+#include <stdio.h>
+#include "jni_helpers.h"
+
+extern "C"
+{
+    JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_AWTLinuxDrawingSurfaceKt_getDisplay(JNIEnv *env, jobject redrawer, jlong platformInfoPtr)
+    {
+        JAWT_X11DrawingSurfaceInfo *dsi_x11 = fromJavaPointer<JAWT_X11DrawingSurfaceInfo *>(platformInfoPtr);
+        Display *display = dsi_x11->display;
+        return toJavaPointer(display);
+    }
+
+    JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_AWTLinuxDrawingSurfaceKt_getWindow(JNIEnv *env, jobject redrawer, jlong platformInfoPtr)
+    {
+        JAWT_X11DrawingSurfaceInfo *dsi_x11 = fromJavaPointer<JAWT_X11DrawingSurfaceInfo *>(platformInfoPtr);
+        Window window = dsi_x11->drawable;
+        return toJavaPointer(window);
+    }
+}

skiko/src/jvmMain/cpp/linux/display.cc

+#include <jawt_md.h>
+#include <GL/gl.h>
+#include <GL/glx.h>
+#include <X11/X.h>
+#include <X11/Xlib.h>
+#include <X11/Xresource.h>
+#include <X11/extensions/Xrandr.h>
+#include <cstdlib>
+#include <dlfcn.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include "jni_helpers.h"
+
+static void* loadXrandr() {
+    static void* result = nullptr;
+    if (result != nullptr) return result;
+    result = dlopen("libXrandr.so", RTLD_LAZY | RTLD_LOCAL);
+    return result;
+}
+
+static XRRScreenResources* XRRGetScreenResourcesCurrentDynamic(Display* display, Window window) {
+    typedef XRRScreenResources* (*XRRGetScreenResourcesCurrent_t)(Display*, Window);
+    static XRRGetScreenResourcesCurrent_t func = nullptr;
+    if (!func) {
+        void* lib = loadXrandr();
+        if (!lib) return nullptr;
+        func = (XRRGetScreenResourcesCurrent_t)dlsym(lib, "XRRGetScreenResourcesCurrent");
+    }
+    if (!func) return nullptr;
+    return func(display, window);
+}
+
+static XRRCrtcInfo* XRRGetCrtcInfoDynamic(
+    Display *display, XRRScreenResources *resources, RRCrtc crtc) {
+    typedef XRRCrtcInfo* (*XRRGetCrtcInfo_t)(Display*, XRRScreenResources*, RRCrtc);
+    static XRRGetCrtcInfo_t func = nullptr;
+    if (!func) {
+        void* lib = loadXrandr();
+        if (!lib) return nullptr;
+        func = (XRRGetCrtcInfo_t)dlsym(lib, "XRRGetCrtcInfo");
+    }
+    if (!func) return nullptr;
+    return func(display, resources, crtc);
+}
+
+void XRRFreeCrtcInfoDynamic(XRRCrtcInfo* crtcInfo) {
+    typedef void (*XRRFreeCrtcInfo_t)(XRRCrtcInfo*);
+    static XRRFreeCrtcInfo_t func = nullptr;
+    if (!func) {
+        void* lib = loadXrandr();
+        if (!lib) return;
+        func = (XRRFreeCrtcInfo_t)dlsym(lib, "XRRFreeCrtcInfo");
+    }
+    if (!func) return;
+    func(crtcInfo);
+}
+
+void XRRFreeScreenResourcesDynamic(XRRScreenResources *resources) {
+    typedef void (*XRRFreeScreenResources_t)(XRRScreenResources*);
+    static XRRFreeScreenResources_t func = nullptr;
+    if (!func) {
+        void* lib = loadXrandr();
+        if (!lib) return;
+        func = (XRRFreeScreenResources_t)dlsym(lib, "XRRFreeScreenResources");
+    }
+    if (!func) return;
+    func(resources);
+}
+
+extern "C"
+{
+    JNIEXPORT jdouble JNICALL Java_org_jetbrains_skiko_DisplayKt_getLinuxDisplayRefreshRate(JNIEnv *env, jobject obj, jlong displayPtr, jlong windowPtr)
+    {
+        Display *display = fromJavaPointer<Display *>(displayPtr);
+        Window window = fromJavaPointer<Window>(windowPtr);
+        XRRScreenResources *screenResources = XRRGetScreenResourcesCurrentDynamic(display, window);
+
+        RRMode activeModeId = 0;
+
+        if (!screenResources) return 60.0;
+
+        for (int i = 0; i < screenResources->ncrtc; ++i) {
+            XRRCrtcInfo *info = XRRGetCrtcInfoDynamic(display, screenResources, screenResources->crtcs[i]);
+            if (info->mode != None) {
+                activeModeId = info->mode;
+            }
+            XRRFreeCrtcInfoDynamic(info);
+        }
+
+        double rate = 0;
+        for (int i = 0; i < screenResources->nmode; ++i) {
+            XRRModeInfo info = screenResources->modes[i];
+            if (info.id == activeModeId) {
+                rate = (double) info.dotClock / ((double) info.hTotal * (double) info.vTotal);
+            }
+        }
+
+        XRRFreeScreenResourcesDynamic(screenResources);
+
+        return rate;
+    }
+}

skiko/src/jvmMain/cpp/linux/redrawer.cc

@@ -13,20 +13,6 @@ typedef GLXContext (*glXCreateContextAttribsARBProc)(Display *, GLXFBConfig, GLX
 
 extern "C"
 {
-    JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_redrawer_LinuxOpenGLRedrawerKt_getDisplay(JNIEnv *env, jobject redrawer, jlong platformInfoPtr)
-    {
-        JAWT_X11DrawingSurfaceInfo *dsi_x11 = fromJavaPointer<JAWT_X11DrawingSurfaceInfo *>(platformInfoPtr);
-        Display *display = dsi_x11->display;
-        return toJavaPointer(display);
-    }
-
-    JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_redrawer_LinuxOpenGLRedrawerKt_getWindow(JNIEnv *env, jobject redrawer, jlong platformInfoPtr)
-    {
-        JAWT_X11DrawingSurfaceInfo *dsi_x11 = fromJavaPointer<JAWT_X11DrawingSurfaceInfo *>(platformInfoPtr);
-        Window window = dsi_x11->drawable;
-        return toJavaPointer(window);
-    }
-
     JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_LinuxOpenGLRedrawerKt_setSwapInterval(JNIEnv *env, jobject redrawer, jlong displayPtr, jlong windowPtr, jint interval)
     {
         Display *display = fromJavaPointer<Display *>(displayPtr);

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

+package org.jetbrains.skiko
+
+internal inline fun <T> HardwareLayer.lockLinuxDrawingSurface(action: (LinuxDrawingSurface) -> T): T {
+    val drawingSurface = lockLinuxDrawingSurface(this)
+    try {
+        return action(drawingSurface)
+    } finally {
+        unlockLinuxDrawingSurface(drawingSurface)
+    }
+}
+
+internal fun lockLinuxDrawingSurface(layer: HardwareLayer): LinuxDrawingSurface {
+    val drawingSurface = layer.getDrawingSurface()
+    drawingSurface.lock()
+    return drawingSurface.getInfo().use {
+        LinuxDrawingSurface(
+            drawingSurface,
+            getDisplay(it.platformInfo),
+            getWindow(it.platformInfo)
+        )
+    }
+}
+
+internal fun unlockLinuxDrawingSurface(drawingSurface: LinuxDrawingSurface) {
+    drawingSurface.common.unlock()
+    drawingSurface.common.close()
+}
+
+internal class LinuxDrawingSurface(
+    val common: DrawingSurface,
+    val display: Long,
+    val window: Long
+) {
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as LinuxDrawingSurface
+
+        if (display != other.display) return false
+        if (window != other.window) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = display.hashCode()
+        result = 31 * result + window.hashCode()
+        return result
+    }
+}
+
+private external fun getDisplay(platformInfo: Long): Long
+private external fun getWindow(platformInfo: Long): Long

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

+package org.jetbrains.skiko
+
+import kotlin.time.ExperimentalTime
+
+internal const val MinMainstreamMonitorRefreshRate = 60.0
+
+@OptIn(ExperimentalTime::class)
+internal fun HardwareLayer.getDisplayRefreshRate(): Double {
+    // We use different method for Linux, because it.displayMode.refreshRate returns always a wrong value: 50 (probably because of the using the old xrandr API)
+    return if (hostOs == OS.Linux) {
+        lockLinuxDrawingSurface {
+            getLinuxDisplayRefreshRate(it.display, it.window)
+        }
+    } else {
+        graphicsConfiguration
+            .device
+            .displayMode
+            .refreshRate
+            .toDouble()
+            .coerceAtLeast(MinMainstreamMonitorRefreshRate)
+    }
+}
+
+private external fun getLinuxDisplayRefreshRate(display: Long, window: Long): Double
\ No newline at end of file

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

+package org.jetbrains.skiko
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import kotlin.time.ExperimentalTime
+
+private const val NanosecondsPerMillisecond = 1_000_000L
+
+/**
+ * HardwareLayer should not dispose native resources while [scope] is active.
+ *
+ * So wait for scope cancellation in dispose method:
+ * ```
+ *  runBlocking {
+ *      frameJob.cancelAndJoin()
+ *  }
+ * ```
+ */
+@OptIn(ExperimentalTime::class)
+@Suppress("UNUSED_PARAMETER")
+internal fun FrameLimiter(
+    scope: CoroutineScope,
+    component: HardwareLayer,
+    onNewFrameLimit: (frameLimit: Double) -> Unit = {}
+): FrameLimiter {
+    val state = object {
+        @Volatile
+        var frameLimit = MinMainstreamMonitorRefreshRate
+    }
+
+    val frames = Channel<Unit>(Channel.CONFLATED)
+    frames.trySend(Unit)
+
+    scope.launch {
+        while (true) {
+            frames.receive()
+            // TODO will lockLinuxDrawingSurface inside getDisplayRefreshRate can cause draw lock too?
+            // it takes 2ms on my machine on Linux (0.01ms on macOs, 0.1ms on Windows)
+            state.frameLimit = component.getDisplayRefreshRate()
+            onNewFrameLimit(state.frameLimit)
+            delay(1000)
+        }
+    }
+
+    return FrameLimiter(
+        scope,
+        frameMillis = {
+            frames.trySend(Unit)
+            (1000 / state.frameLimit).toLong()
+        }
+    )
+}
+
+/**
+ * Limit the duration of the frames (to avoid high CPU usage) to [frameMillis].
+ * The actual delay depends on the precision of the system timer
+ * (Windows has ~15ms precision by default, Linux/macOs ~2ms).
+ * FrameLimiter will try to delay frames as close as possible to [frameMillis], but not greater
+ */
+@OptIn(ExperimentalTime::class)
+class FrameLimiter(
+    private val coroutineScope: CoroutineScope,
+    private val frameMillis: () -> Long,
+    private val nanoTime: () -> Long = System::nanoTime
+) {
+    private val channel = RendezvousBroadcastChannel<Unit>()
+
+    init {
+        coroutineScope.launch {
+            while (true) {
+                channel.sendAll(Unit)
+                preciseDelay(frameMillis())
+            }
+        }
+    }
+
+    private suspend fun preciseDelay(millis: Long) {
+        val start = nanoTime()
+        // delay aren't precise, so we should measure what is the actual precision of delay is,
+        // so we don't wait longer than we need
+        var actual1msDelay = 1L
+
+        while (nanoTime() - start <= millis * NanosecondsPerMillisecond - actual1msDelay) {
+            val beforeDelay = nanoTime()
+            delay(1) // TODO do multiple delays instead of the single one consume more energy? Test it
+            actual1msDelay = maxOf(actual1msDelay, nanoTime() - beforeDelay)
+        }
+    }
+
+    /**
+     * Await the next frame, if it is not ready yet (the previous [awaitNextFrame]
+     * was called less than [frameMillis] ago)
+     */
+    suspend fun awaitNextFrame() {
+        withContext(coroutineScope.coroutineContext) {
+            channel.receive()
+        }
+    }
+}
\ No newline at end of file

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

 package org.jetbrains.skiko
 
+import org.jetbrains.skiko.redrawer.Direct3DRedrawer
 import org.jetbrains.skiko.redrawer.LinuxOpenGLRedrawer
 import org.jetbrains.skiko.redrawer.MacOsOpenGLRedrawer
-import org.jetbrains.skiko.redrawer.SoftwareRedrawer
+import org.jetbrains.skiko.redrawer.MetalRedrawer
 import org.jetbrains.skiko.redrawer.Redrawer
+import org.jetbrains.skiko.redrawer.SoftwareRedrawer
 import org.jetbrains.skiko.redrawer.WindowsOpenGLRedrawer
-import org.jetbrains.skiko.redrawer.Direct3DRedrawer
-import org.jetbrains.skiko.redrawer.MetalRedrawer
 import java.awt.Component
 import java.awt.Window
 import javax.swing.SwingUtilities
@@ -48,7 +48,7 @@ internal val platformOperations: PlatformOperations by lazy {
                     renderApi: GraphicsApi,
                     properties: SkiaLayerProperties
                 ) = when(renderApi) {
-                    GraphicsApi.SOFTWARE -> SoftwareRedrawer(layer)
+                    GraphicsApi.SOFTWARE -> SoftwareRedrawer(layer, properties)
                     GraphicsApi.METAL -> MetalRedrawer(layer, properties)
                     else -> MacOsOpenGLRedrawer(layer, properties)
                 }
@@ -82,7 +82,7 @@ internal val platformOperations: PlatformOperations by lazy {
                     renderApi: GraphicsApi,
                     properties: SkiaLayerProperties
                 ) = when(renderApi) {
-                    GraphicsApi.SOFTWARE -> SoftwareRedrawer(layer)
+                    GraphicsApi.SOFTWARE -> SoftwareRedrawer(layer, properties)
                     GraphicsApi.DIRECT3D -> Direct3DRedrawer(layer, properties)
                     else -> WindowsOpenGLRedrawer(layer, properties)
                 }
@@ -117,7 +117,7 @@ internal val platformOperations: PlatformOperations by lazy {
                     renderApi: GraphicsApi,
                     properties: SkiaLayerProperties
                 ) = when(renderApi) {
-                    GraphicsApi.SOFTWARE -> SoftwareRedrawer(layer)
+                    GraphicsApi.SOFTWARE -> SoftwareRedrawer(layer, properties)
                     else -> LinuxOpenGLRedrawer(layer, properties)
                 }
             }

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

+package org.jetbrains.skiko
+
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.channels.Channel
+import java.util.concurrent.atomic.AtomicReference
+
+/**
+ * Behaves as Channel<Unit>(Channel.RENDEZVOUS), but with ability to send value to all current consumers
+ * (which await on `receive` method)
+ */
+internal class RendezvousBroadcastChannel<T> {
+    private val onRequest = Channel<Unit>(Channel.CONFLATED)
+    private val onResult = AtomicReference(CompletableDeferred<T>())
+
+    /**
+     * Send value to all current consumers which await value on `receive` method, or await for the first one
+     */
+    suspend fun sendAll(value: T) {
+        onRequest.receive()
+        onResult.getAndSet(CompletableDeferred()).complete(value)
+    }
+
+    /**
+     * Wait when the producer will send a value and return it.
+     */
+    suspend fun receive(): T {
+        onRequest.trySend(Unit)
+        return onResult.get().await()
+    }
+}
\ No newline at end of file

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

 package org.jetbrains.skiko
 
 class SkiaLayerProperties(
-    val isVsyncEnabled: Boolean = SkikoProperties.vsyncEnabled
+    val isVsyncEnabled: Boolean = SkikoProperties.vsyncEnabled,
+    val isVsyncFramelimitFallbackEnabled: Boolean = SkikoProperties.vsyncFramelimitFallbackEnabled
 )
\ No newline at end of file

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

 package org.jetbrains.skiko
 
+// TODO maybe we can get rid of global properties, and pass SkiaLayerProperties to Window -> ComposeWindow -> SkiaLayer
 @Suppress("SameParameterValue")
 internal object SkikoProperties {
     val vsyncEnabled: Boolean by property("skiko.vsync.enabled", default = true)
 
+    /**
+     * If vsync is enabled, but platform can't support it (Software renderer, Linux with uninstalled drivers),
+     * we enable frame limit by the display refresh rate.
+     */
+    val vsyncFramelimitFallbackEnabled: Boolean by property(
+        "skiko.vsync.framelimit.fallback.enabled", default = true
+    )
+
     val fpsEnabled: Boolean by property("skiko.fps.enabled", default = false)
     val fpsPeriodSeconds: Double by property("skiko.fps.periodSeconds", default = 2.0)
 

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

 package org.jetbrains.skiko.redrawer
 
-import kotlinx.coroutines.CancellationException
-import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.*
 import kotlinx.coroutines.swing.Swing
-import org.jetbrains.skiko.DrawingSurface
-import org.jetbrains.skiko.FrameDispatcher
-import org.jetbrains.skiko.HardwareLayer
-import org.jetbrains.skiko.OpenGLApi
-import org.jetbrains.skiko.SkiaLayer
-import org.jetbrains.skiko.SkiaLayerProperties
-import org.jetbrains.skiko.getDrawingSurface
-import org.jetbrains.skiko.isVideoCardSupported
+import org.jetbrains.skiko.*
 
 internal class LinuxOpenGLRedrawer(
     private val layer: SkiaLayer,
     private val properties: SkiaLayerProperties
 ) : Redrawer {
-    private val context = layer.backedLayer.lockDrawingSurface {
-        val result = it.createContext()
-        it.makeCurrent(result)
-        if (result == 0L || !isVideoCardSupported(layer.renderApi)) {
-            throw IllegalArgumentException("Cannot create Linux GL context")
+    private var isDisposed = false
+    private var context = 0L
+    private val swapInterval = if (properties.isVsyncEnabled) 1 else 0
+
+    init {
+    	layer.backedLayer.lockLinuxDrawingSurface {
+            context = it.createContext()
+            it.makeCurrent(context)
+            if (context == 0L || !isVideoCardSupported(layer.renderApi)) {
+                throw IllegalArgumentException("Cannot create Linux GL context")
+            }
+            it.setSwapInterval(swapInterval)
+        }
+    }
+    private val frameJob = Job()
+    @Volatile
+    private var frameLimit = 0.0
+    private val frameLimiter = FrameLimiter(
+        CoroutineScope(Dispatchers.IO + frameJob),
+        layer.backedLayer,
+        onNewFrameLimit = { frameLimit = it }
+    )
+
+    private suspend fun limitFramesIfNeeded() {
+        // Some Linuxes don't turn vsync on, so we apply additional frame limit (which should be no longer than enabled vsync)
+        if (properties.isVsyncEnabled) {
+            try {
+                frameLimiter.awaitNextFrame()
+            } catch (e: CancellationException) {
+                // ignore
+            }
         }
-        result
     }
-    private var isDisposed = false
 
     override fun dispose() {
         check(!isDisposed) { "LinuxOpenGLRedrawer is disposed" }
-        layer.backedLayer.lockDrawingSurface {
+        layer.backedLayer.lockLinuxDrawingSurface {
             it.destroyContext(context)
         }
+        runBlocking {
+            frameJob.cancelAndJoin()
+        }
         isDisposed = true
     }
 
@@ -44,7 +63,7 @@ internal class LinuxOpenGLRedrawer(
         return frameDispatcher.awaitFrame()
     }
 
-    override fun redrawImmediately() = layer.backedLayer.lockDrawingSurface {
+    override fun redrawImmediately() = layer.backedLayer.lockLinuxDrawingSurface {
         check(!isDisposed) { "LinuxOpenGLRedrawer is disposed" }
         update(System.nanoTime())
         it.makeCurrent(context)
@@ -52,6 +71,7 @@ internal class LinuxOpenGLRedrawer(
         it.setSwapInterval(0)
         it.swapBuffers()
         OpenGLApi.instance.glFinish()
+        it.setSwapInterval(swapInterval)
     }
 
     private fun update(nanoTime: Long) {
@@ -70,6 +90,9 @@ internal class LinuxOpenGLRedrawer(
         private val toRedrawAlive = toRedrawCopy.asSequence().filterNot(LinuxOpenGLRedrawer::isDisposed)
 
         private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
+            // we should wait for the window with the maximum frame limit to avoid bottleneck when there is a window on a slower monitor
+            toRedrawAlive.maxByOrNull { it.frameLimit }?.limitFramesIfNeeded()
+
             toRedrawCopy.clear()
             toRedrawCopy.addAll(toRedraw)
             toRedraw.clear()
@@ -84,68 +107,36 @@ internal class LinuxOpenGLRedrawer(
                 }
             }
 
-            val isVsyncEnabled = toRedrawAlive.all { it.properties.isVsyncEnabled }
-
-            val drawingSurfaces = toRedrawAlive.map { lockDrawingSurface(it.layer.backedLayer) }.toList()
+            val drawingSurfaces = toRedrawAlive.associateWith { lockLinuxDrawingSurface(it.layer.backedLayer) }
             try {
-                toRedrawAlive.forEachIndexed { index, redrawer ->
-                    drawingSurfaces[index].makeCurrent(redrawer.context)
+                toRedrawAlive.forEach { redrawer ->
+                    drawingSurfaces[redrawer]!!.makeCurrent(redrawer.context)
                     redrawer.draw()
                 }
 
-                toRedrawAlive.forEachIndexed { index, _ ->
-                    // it is ok to set swap interval every frame, there is no performance overhead
-                    drawingSurfaces[index].setSwapInterval(if (isVsyncEnabled) 1 else 0)
-                    drawingSurfaces[index].swapBuffers()
+                // TODO(demin) it seems now vsync doesn't work as expected with two windows (we have fps = refreshRate / windowCount)
+                //  perhaps we should create frameDispatcher for each display.
+                //  Don't know what happened, but on 620547a commit everything was okay. maybe something changed in the code, maybe my system changed
+                toRedrawAlive.forEach { redrawer ->
+                    drawingSurfaces[redrawer]!!.swapBuffers()
                 }
 
-                toRedrawAlive.forEachIndexed { index, redrawer ->
-                    drawingSurfaces[index].makeCurrent(redrawer.context)
+                toRedrawAlive.forEach { redrawer ->
+                    drawingSurfaces[redrawer]!!.makeCurrent(redrawer.context)
                     OpenGLApi.instance.glFinish()
                 }
             } finally {
-                drawingSurfaces.forEach(::unlockDrawingSurface)
+                drawingSurfaces.values.forEach(::unlockLinuxDrawingSurface)
             }
         }
     }
 }
 
-private inline fun <T> HardwareLayer.lockDrawingSurface(action: (LinuxDrawingSurface) -> T): T {
-    val drawingSurface = lockDrawingSurface(this)
-    try {
-        return action(drawingSurface)
-    } finally {
-        unlockDrawingSurface(drawingSurface)
-    }
-}
-
-private fun lockDrawingSurface(layer: HardwareLayer): LinuxDrawingSurface {
-    val drawingSurface = layer.getDrawingSurface()
-    drawingSurface.lock()
-    return drawingSurface.getInfo().use {
-        LinuxDrawingSurface(drawingSurface, getDisplay(it.platformInfo), getWindow(it.platformInfo))
-    }
-}
-
-private fun unlockDrawingSurface(drawingSurface: LinuxDrawingSurface) {
-    drawingSurface.common.unlock()
-    drawingSurface.common.close()
-}
-
-private class LinuxDrawingSurface(
-    val common: DrawingSurface,
-    val display: Long,
-    val window: Long
-) {
-    fun createContext() = createContext(display)
-    fun destroyContext(context: Long) = destroyContext(display, context)
-    fun makeCurrent(context: Long) = makeCurrent(display, window, context)
-    fun swapBuffers() = swapBuffers(display, window)
-    fun setSwapInterval(interval: Int) = setSwapInterval(display, window, interval)
-}
-
-private external fun getDisplay(platformInfo: Long): Long
-private external fun getWindow(platformInfo: Long): Long
+private fun LinuxDrawingSurface.createContext() = createContext(display)
+private fun LinuxDrawingSurface.destroyContext(context: Long) = destroyContext(display, context)
+private fun LinuxDrawingSurface.makeCurrent(context: Long) = makeCurrent(display, window, context)
+private fun LinuxDrawingSurface.swapBuffers() = swapBuffers(display, window)
+private fun LinuxDrawingSurface.setSwapInterval(interval: Int) = setSwapInterval(display, window, interval)
 
 private external fun makeCurrent(display: Long, window: Long, context: Long)
 private external fun createContext(display: Long): Long

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

 package org.jetbrains.skiko.redrawer
 
-import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.*
 import kotlinx.coroutines.swing.Swing
 import org.jetbrains.skiko.FrameDispatcher
+import org.jetbrains.skiko.FrameLimiter
 import org.jetbrains.skiko.SkiaLayer
+import org.jetbrains.skiko.SkiaLayerProperties
 
 internal class SoftwareRedrawer(
-    private val layer: SkiaLayer
+    private val layer: SkiaLayer,
+    private val properties: SkiaLayerProperties
 ) : Redrawer {
+    private val frameJob = Job()
+    private val frameLimiter = FrameLimiter(CoroutineScope(Dispatchers.IO + frameJob), layer.backedLayer)
 
     private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
+        if (properties.isVsyncEnabled && properties.isVsyncFramelimitFallbackEnabled) {
+            frameLimiter.awaitNextFrame()
+        }
+
         layer.update(System.nanoTime())
         if (layer.prepareDrawContext()) {
             layer.draw()
@@ -18,6 +27,9 @@ internal class SoftwareRedrawer(
 
     override fun dispose() {
         frameDispatcher.cancel()
+        runBlocking {
+            frameJob.cancelAndJoin()
+        }
     }
 
     override fun needRedraw() {

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

+package org.jetbrains.skiko
+
+import kotlinx.coroutines.*
+import kotlinx.coroutines.test.DelayController
+import kotlinx.coroutines.test.TestCoroutineDispatcher
+import kotlinx.coroutines.test.TestCoroutineScope
+import kotlinx.coroutines.test.runBlockingTest
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import kotlin.coroutines.CoroutineContext
+import kotlin.math.ceil
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class FrameLimiterTest {
+    private val frameCount = 8
+    private val frames = 0 until frameCount
+    
+    @Test
+    fun `limit 10ms, render 0ms`() {
+        fun frameTicksOf(delayPrecisionMillis: Long) =
+            frameTicksOf(frameLimitMillis = 10, delayPrecisionMillis, frameRenderMillis = 0)
+
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 1))
+        assertEquals(frames.map { it * 9 }, frameTicksOf(delayPrecisionMillis = 3))
+        assertEquals(frames.map { it * 7 }, frameTicksOf(delayPrecisionMillis = 7))
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 10))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 11))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 21))
+    }
+
+    @Test
+    fun `limit 10ms, render 1ms`() {
+        fun frameTicksOf(delayPrecisionMillis: Long) =
+            frameTicksOf(frameLimitMillis = 10, delayPrecisionMillis, frameRenderMillis = 1)
+
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 1))
+        assertEquals(frames.map { it * 9 }, frameTicksOf(delayPrecisionMillis = 3))
+        assertEquals(frames.map { it * 7 }, frameTicksOf(delayPrecisionMillis = 7))
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 10))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 11))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 21))
+    }
+
+    @Test
+    fun `limit 10ms, render 9ms`() {
+        fun frameTicksOf(delayPrecisionMillis: Long) =
+            frameTicksOf(frameLimitMillis = 10, delayPrecisionMillis, frameRenderMillis = 9)
+
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 1))
+        assertEquals(frames.map { it * 9 }, frameTicksOf(delayPrecisionMillis = 3))
+        assertEquals(frames.map { it * 9 }, frameTicksOf(delayPrecisionMillis = 7))
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 10))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 11))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 21))
+    }
+
+    @Test
+    fun `limit 10ms, render 10ms`() {
+        fun frameTicksOf(delayPrecisionMillis: Long) =
+            frameTicksOf(frameLimitMillis = 10, delayPrecisionMillis, frameRenderMillis = 10)
+
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 1))
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 3))
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 7))
+        assertEquals(frames.map { it * 10 }, frameTicksOf(delayPrecisionMillis = 10))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 11))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 21))
+    }
+
+    @Test
+    fun `limit 10ms, render 11ms`() {
+        fun frameTicksOf(delayPrecisionMillis: Long) =
+            frameTicksOf(frameLimitMillis = 10, delayPrecisionMillis, frameRenderMillis = 11)
+
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 1))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 3))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 7))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 10))
+        assertEquals(frames.map { it * 11 }, frameTicksOf(delayPrecisionMillis = 11))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 21))
+    }
+
+    @Test
+    fun `limit 10ms, render 21ms`() {
+        fun frameTicksOf(delayPrecisionMillis: Long) =
+            frameTicksOf(frameLimitMillis = 10, delayPrecisionMillis, frameRenderMillis = 21)
+
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 1))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 3))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 7))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 10))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 11))
+        assertEquals(frames.map { it * 21 }, frameTicksOf(delayPrecisionMillis = 21))
+    }
+
+    @Suppress("SameParameterValue")
+    private fun frameTicksOf(
+        frameLimitMillis: Long,
+        delayPrecisionMillis: Long,
+        frameRenderMillis: Long,
+    ): List<Int> {
+        val ticks = mutableListOf<Int>()
+        frameLimiterTest(
+            frameLimitMillis,
+            delayPrecisionMillis
+        ) { limiter ->
+            repeat(frameCount) {
+                limiter.awaitNextFrame()
+                ticks.add(currentTime.toInt())
+                advanceTimeBy(frameRenderMillis)
+            }
+        }
+        return ticks
+    }
+
+    @Test
+    fun `multiple awaiters`() {
+        val ticks1 = mutableListOf<Int>()
+        val ticks2 = mutableListOf<Int>()
+        val ticks3 = mutableListOf<Int>()
+        frameLimiterTest(
+            frameLimitMillis = 10,
+            delayPrecisionMillis = 1
+        ) { limiter ->
+            launch {
+                repeat(frameCount) {
+                    limiter.awaitNextFrame()
+                    ticks1.add(currentTime.toInt())
+                    advanceTimeBy(3)
+                }
+            }
+            launch {
+                repeat(frameCount) {
+                    limiter.awaitNextFrame()
+                    ticks2.add(currentTime.toInt())
+                    advanceTimeBy(1)
+                }
+            }
+            launch {
+                repeat(frameCount) {
+                    limiter.awaitNextFrame()
+                    ticks3.add(currentTime.toInt())
+                    advanceTimeBy(1)
+                }
+            }
+        }
+
+        assertEquals(frames.map { it * 10 }, ticks1)
+        assertEquals(frames.map { it * 10 }, ticks2)
+        assertEquals(frames.map { it * 10 }, ticks3)
+    }
+
+    @Test
+    fun `cancel scope before awaitNextFrame`() = runBlockingTest {
+        pauseDispatcher()
+        val scope = CoroutineScope(coroutineContext + Job())
+        val frameLimiter = FrameLimiter(scope, { 10 }, nanoTime = { currentTime * 1_000_000 })
+
+        scope.cancel()
+
+        assertThrow<kotlin.coroutines.cancellation.CancellationException> {
+            frameLimiter.awaitNextFrame()
+        }
+    }
+
+    @Test
+    fun `cancel scope after awaitNextFrame`() = runBlockingTest {
+        pauseDispatcher()
+        val scope = CoroutineScope(coroutineContext + Job())
+
+        val frameLimiter = FrameLimiter(scope, { 10 }, nanoTime = { currentTime * 1_000_000 })
+
+        launch {
+            scope.cancel()
+        }
+
+        assertThrow<kotlin.coroutines.cancellation.CancellationException> {
+            frameLimiter.awaitNextFrame()
+        }
+    }
+
+    private inline fun <reified T : Throwable> assertThrow(body: () -> Unit) {
+        var actualE: Throwable? = null
+        try {
+            body()
+        } catch (e: Throwable) {
+            actualE = e
+        }
+        assertTrue("Actual ${actualE?.javaClass}, expected ${T::class.java}", actualE is T)
+    }
+
+    private fun frameLimiterTest(
+        frameLimitMillis: Long,
+        delayPrecisionMillis: Long,
+        block: suspend TestCoroutineScope.(FrameLimiter) -> Unit
+    ) {
+        runFrameTest(
+            delayPrecisionMillis = delayPrecisionMillis
+        ) {
+            val scope = CoroutineScope(coroutineContext + Job())
+            val limiter = FrameLimiter(
+                this,
+                frameMillis = { frameLimitMillis },
+                nanoTime = { currentTime * 1_000_000 }
+            )
+            block(limiter)
+            scope.cancel()
+        }
+    }
+
+    private fun runFrameTest(
+        delayPrecisionMillis: Long,
+        block: suspend TestCoroutineScope.() -> Unit
+    ) = runBlockingTest{
+        val dispatcher = NonpreciseTestCoroutineDispatcher(delayPrecisionMillis)
+        dispatcher.pauseDispatcher()
+        val scope = TestCoroutineScope(dispatcher)
+        scope.launch {
+            scope.block()
+        }
+        dispatcher.advanceUntilIdle()
+    }
+
+    @OptIn(InternalCoroutinesApi::class)
+    private class NonpreciseTestCoroutineDispatcher(
+        private val delayPrecisionMillis: Long,
+        private val original: TestCoroutineDispatcher = TestCoroutineDispatcher()
+    ) : CoroutineDispatcher(), Delay, DelayController by original {
+        override fun dispatch(context: CoroutineContext, block: Runnable) {
+            original.dispatch(context, block)
+        }
+
+        override fun scheduleResumeAfterDelay(timeMillis: Long, continuation: CancellableContinuation<Unit>) {
+            val delay = ceil(timeMillis.toDouble() / delayPrecisionMillis).toInt() * delayPrecisionMillis
+            original.scheduleResumeAfterDelay(delay, continuation)
+        }
+    }
+}
\ No newline at end of file

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

+package org.jetbrains.skiko
+
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.test.runBlockingTest
+import kotlinx.coroutines.withTimeout
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import kotlin.random.Random
+
+class RendezvousBroadcastChannelTest {
+    @Test(timeout = 5000)
+    fun `receive, send`() {
+        var actualValue = -1
+
+        val channel = RendezvousBroadcastChannel<Int>()
+
+        runBlocking {
+            launch {
+                actualValue = channel.receive()
+            }
+
+            launch {
+                channel.sendAll(1)
+            }
+        }
+
+        assertEquals(1, actualValue)
+    }
+
+    @Test(timeout = 5000)
+    fun `send, receive`() {
+        var actualValue = -1
+
+        val channel = RendezvousBroadcastChannel<Int>()
+
+        runBlocking {
+            launch {
+                channel.sendAll(1)
+            }
+
+            launch {
+                actualValue = channel.receive()
+            }
+        }
+
+        assertEquals(1, actualValue)
+    }
+
+    @Test(timeout = 5000)
+    fun `send when there is multiple receivers`() {
+        val actualValues = mutableListOf<Int>()
+
+        val channel = RendezvousBroadcastChannel<Int>()
+
+        runBlocking {
+            repeat(5) {
+                launch {
+                    actualValues.add(channel.receive())
+                }
+            }
+
+            launch {
+                channel.sendAll(1)
+            }
+        }
+
+        assertEquals(listOf(1, 1, 1, 1, 1), actualValues)
+    }
+
+    @Test
+    fun `first send should not end if there is no received value`() {
+        var isExceptionThrown = false
+        val channel = RendezvousBroadcastChannel<Int>()
+        runBlocking {
+            try {
+                withTimeout(1000) {
+                    channel.sendAll(1)
+                }
+            } catch (e: TimeoutCancellationException) {
+                isExceptionThrown = true
+            }
+        }
+
+        assertEquals(true, isExceptionThrown)
+    }
+
+    @Test
+    fun `second send should not end if there is no second received value`() {
+        var isExceptionThrown = false
+        val channel = RendezvousBroadcastChannel<Int>()
+        runBlocking {
+            launch {
+                channel.sendAll(1)
+                try {
+                    withTimeout(1000) {
+                        channel.sendAll(1)
+                    }
+                } catch (e: TimeoutCancellationException) {
+                    isExceptionThrown = true
+                }
+            }
+
+            launch {
+                channel.receive()
+            }
+        }
+
+        assertEquals(true, isExceptionThrown)
+    }
+
+    @Test
+    fun `first receive should not end if there is no received value`() {
+        var isExceptionThrown = false
+        val channel = RendezvousBroadcastChannel<Int>()
+        runBlocking {
+            try {
+                withTimeout(1000) {
+                    channel.receive()
+                }
+            } catch (e: TimeoutCancellationException) {
+                isExceptionThrown = true
+            }
+        }
+
+        assertEquals(true, isExceptionThrown)
+    }
+
+    @Test
+    fun `second receive should not end if there is no second received value`() {
+        var isExceptionThrown = false
+        val channel = RendezvousBroadcastChannel<Int>()
+        runBlocking {
+            launch {
+                channel.receive()
+                try {
+                    withTimeout(1000) {
+                        channel.receive()
+                    }
+                } catch (e: TimeoutCancellationException) {
+                    isExceptionThrown = true
+                }
+            }
+
+            launch {
+                channel.sendAll(1)
+            }
+        }
+
+        assertEquals(true, isExceptionThrown)
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun `produce values, consume from multiple coroutines`() = runBlockingTest {
+        pauseDispatcher()
+
+        val frames1 = mutableListOf<Int>()
+        val frames2 = mutableListOf<Int>()
+        val frames3 = mutableListOf<Int>()
+
+        val channel = RendezvousBroadcastChannel<Int>()
+
+        val produceJob = launch {
+            for (i in 0 until 1000) {
+                channel.sendAll(i)
+                delay(10)
+            }
+        }
+
+        val random = Random(5435)
+
+        launch {
+            repeat(1000) {
+                frames1.add(channel.receive())
+                delay(random.nextLong(10L))
+            }
+        }
+        launch {
+            repeat(1000) {
+                frames2.add(channel.receive())
+                delay(random.nextLong(10L))
+            }
+        }
+        launch {
+            repeat(1000) {
+                frames3.add(channel.receive())
+                delay(random.nextLong(10L))
+            }
+        }
+
+        advanceUntilIdle()
+        produceJob.cancel()
+
+        assertEquals((0 until 1000).toList(), frames1)
+        assertEquals((0 until 1000).toList(), frames2)
+        assertEquals((0 until 1000).toList(), frames3)
+    }
+}
\ No newline at end of file