diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TRuntime.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TRuntime.java
index e5df6a87f..343e0dac3 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/lang/TRuntime.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TRuntime.java
@@ -16,6 +16,9 @@
 package org.teavm.classlib.java.lang;
 
 import org.teavm.interop.DelegateTo;
+import org.teavm.interop.Platforms;
+import org.teavm.interop.SupportedOn;
+import org.teavm.jso.browser.Navigator;
 import org.teavm.runtime.GC;
 
 /**
@@ -85,4 +88,9 @@ public class TRuntime {
     private long totalMemoryLowLevel() {
         return GC.availableBytes();
     }
+
+    @SupportedOn(Platforms.JAVASCRIPT)
+    public int availableProcessors() {
+        return Navigator.hardwareConcurrency();
+    }
 }
\ No newline at end of file
diff --git a/jso/apis/src/main/java/org/teavm/jso/browser/Navigator.java b/jso/apis/src/main/java/org/teavm/jso/browser/Navigator.java
index 254953411..4dfb4d99e 100644
--- a/jso/apis/src/main/java/org/teavm/jso/browser/Navigator.java
+++ b/jso/apis/src/main/java/org/teavm/jso/browser/Navigator.java
@@ -40,4 +40,7 @@ public final class Navigator {
     
     @JSBody(script = "return navigator.getGamepads();")
     public static native Gamepad[] getGamepads();
+
+    @JSBody(script = "return navigator.hardwareConcurrency")
+    public static native int hardwareConcurrency();
 }
diff --git a/jso/apis/src/main/java/org/teavm/jso/browser/Window.java b/jso/apis/src/main/java/org/teavm/jso/browser/Window.java
index 1b7e57faa..4f0dc7372 100644
--- a/jso/apis/src/main/java/org/teavm/jso/browser/Window.java
+++ b/jso/apis/src/main/java/org/teavm/jso/browser/Window.java
@@ -155,6 +155,8 @@ public abstract class Window implements JSObject, WindowEventTarget, StorageProv
 
     public abstract void postMessage(JSObject message);
 
+    public abstract void postMessage(JSObject message, JSArrayReader<JSObject> transfer);
+
     public abstract void postMessage(JSObject message, String targetOrigin);
 
     public abstract void postMessage(JSObject message, String targetOrigin, JSArrayReader<JSObject> transfer);
@@ -163,6 +165,10 @@ public abstract class Window implements JSObject, WindowEventTarget, StorageProv
         postMessage(message, targetOrigin, JSArray.of(transfer));
     }
 
+    public final void postMessage(JSObject message, JSObject... transfer) {
+        postMessage(message, JSArray.of(transfer));
+    }
+
     @JSBody(script = "return window;")
     public static native Window current();
 
diff --git a/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/Worker.kt b/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/Worker.kt
index d64b45b8b..47baf9a30 100644
--- a/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/Worker.kt
+++ b/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/Worker.kt
@@ -65,7 +65,7 @@ class RenderWorker {
         renderer.render()
         val perfEnd = System.nanoTime()
         val buffer = extractBuffer(raster.flip())
-        postMessageFromWorker(JSObjects.createWithoutProto<JSMapLike<JSObject>>().apply {
+        Window.worker().postMessage(JSObjects.createWithoutProto<JSMapLike<JSObject>>().apply {
             set("data", buffer)
             set("time", JSNumber.valueOf((perfEnd - perfStart).toInt()))
         }, JSArray.of(buffer))
diff --git a/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/main.kt b/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/main.kt
index fb9100c1b..a4d5a2860 100644
--- a/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/main.kt
+++ b/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/main.kt
@@ -35,7 +35,7 @@ fun main(args: Array<out String>) {
 fun runController() {
     val performanceIndicator = HTMLDocument.current().getElementById("performance-indicator")
     var performanceIndicatorByWorkers: List<HTMLElement> = emptyList()
-    val maxWorkers = cpuCount()
+    val maxWorkers = Runtime.getRuntime().availableProcessors()
     var workerType = WorkerType.JS
     val controller = Controller(SCENE_WIDTH, SCENE_HEIGHT) { index, value ->
         if (index == -1) {
diff --git a/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/nativeJs.kt b/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/nativeJs.kt
index 1d64ca742..62f205423 100644
--- a/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/nativeJs.kt
+++ b/samples/software3d/src/jvmMain/kotlin/org/teavm/samples/software3d/teavm/nativeJs.kt
@@ -18,15 +18,7 @@ package org.teavm.samples.software3d.teavm
 
 import org.teavm.jso.JSBody
 import org.teavm.jso.JSByRef
-import org.teavm.jso.JSObject
-import org.teavm.jso.core.JSArray
 import org.teavm.jso.typedarrays.ArrayBuffer
 
 @JSBody(params = ["data"], script = "return data.buffer;")
-external fun extractBuffer(@JSByRef data: IntArray): ArrayBuffer
-
-@JSBody(params = ["message", "transferable"], script = "self.postMessage(message, transferable);")
-external fun postMessageFromWorker(message: JSObject, transferable: JSArray<out JSObject>)
-
-@JSBody(script = "return navigator.hardwareConcurrency;")
-external fun cpuCount(): Int
\ No newline at end of file
+external fun extractBuffer(@JSByRef data: IntArray): ArrayBuffer
\ No newline at end of file