more ios/macos targets implementation

src/macosX64Main/kotlin/net/sergeych/synctools/WaitHandle.macosX64.kt

@@ -0,0 +1,34 @@
+package net.sergeych.synctools
+
+import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withTimeout
+
+@Suppress("EXPECT_ACTUAL_CLASSIFIERS_ARE_IN_BETA_WARNING")
+actual class WaitHandle {
+    private val channel = Channel<Unit>()
+    actual fun await(milliseconds: Long): Boolean {
+        return runBlocking {
+            try {
+                if( milliseconds > 0) {
+                    withTimeout(milliseconds) {
+                        channel.receive()
+                        true
+                    }
+                }
+                else {
+                    channel.receive()
+                    true
+                }
+            }
+            catch(_: TimeoutCancellationException) {
+                false
+            }
+        }
+    }
+
+    actual fun wakeUp() {
+        runBlocking { channel.send(Unit) }
+    }
+}