Update

Kha/Tools/windows_x64/std/java/_std/sys/FileSystem.hx

@@ -41,19 +41,41 @@ class FileSystem {
 		var f = new File(path);
 		if (!f.exists())
 			throw "Path " + path + " doesn't exist";
-		return {
-			gid: 0, // java doesn't let you get this info
-			uid: 0, // same
-			atime: Date.now(), // same
-			mtime: Date.fromTime(cast(f.lastModified(), Float)),
-			ctime: Date.fromTime(cast(f.lastModified(), Float)), // same
-			size: cast(f.length(), Int), // TODO: maybe change to Int64 for Haxe 3?
-			dev: 0, // FIXME: not sure what that is
-			ino: 0, // FIXME: not sure what that is
-			nlink: 0, // FIXME: not sure what that is
-			rdev: 0, // FIXME: not sure what that is
-			mode: 0 // FIXME: not sure what that is
-		};
+
+		try {
+			final pathObject = java.nio.file.Paths.get(path);
+			final attributes = java.nio.file.Files.readAttributes(pathObject, "unix:*");
+
+			return {
+				atime: Date.fromTime(cast(attributes.get("lastAccessTime").toMillis(), Float)),
+				ctime: Date.fromTime(cast(attributes.get("creationTime").toMillis(), Float)),
+				dev: cast(attributes.get("dev"), Int),
+				gid: attributes.get("gid"),
+				ino: cast(attributes.get("ino"), Int),
+				mode: attributes.get("mode"),
+				mtime: Date.fromTime(cast(attributes.get("lastModifiedTime").toMillis(), Float)),
+				nlink: attributes.get("nlink"),
+				rdev: cast(attributes.get("rdev"), Int),
+				size: cast(attributes.get("size"), Int),
+				uid: attributes.get("uid"),
+			};
+		}
+
+		catch (e) {
+			return {
+				gid: 0, // java doesn't let you get this info
+				uid: 0, // same
+				atime: Date.now(), // same
+				mtime: Date.fromTime(cast(f.lastModified(), Float)),
+				ctime: Date.fromTime(cast(f.lastModified(), Float)), // same
+				size: cast(f.length(), Int), // TODO: maybe change to Int64 for Haxe 3?
+				dev: 0, // FIXME: not sure what that is
+				ino: 0, // FIXME: not sure what that is
+				nlink: 0, // FIXME: not sure what that is
+				rdev: 0, // FIXME: not sure what that is
+				mode: 0 // FIXME: not sure what that is
+			};
+		}
 	}
 
 	public static function fullPath(relPath:String):String {

Kha/Tools/windows_x64/std/java/_std/sys/io/Process.hx

@@ -75,7 +75,7 @@ class Process {
 			}
 		}
 
-		return new java.lang.ProcessBuilder(pargs);
+		return new java.lang.ProcessBuilder(...pargs);
 	}
 
 	public function new(cmd:String, ?args:Array<String>, ?detached:Bool):Void {

Kha/Tools/windows_x64/std/java/_std/sys/thread/Condition.hx

@@ -0,0 +1,45 @@
+package sys.thread;
+
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.locks.Condition as NativeCondition;
+
+@:access(sys.thread.Mutex)
+@:coreApi
+@:native('haxe.java.vm.Condition')
+class Condition {
+	final lock:ReentrantLock;
+	final native:NativeCondition;
+
+	public function new():Void {
+		this.lock = new ReentrantLock();
+		this.native = lock.newCondition();
+	}
+
+	public function acquire():Void {
+		lock.lock();
+	}
+
+	public function tryAcquire():Bool {
+		return this.lock.tryLock();
+	}
+
+	public function release():Void {
+		lock.unlock();
+	}
+
+	// without the @:native, you get "java.lang.VerifyError: class sys.thread.Condition overrides final method java.lang.Object.wait()V" on jvm
+	// and "wait() in Condition cannot override wait() in Object" from javac
+
+	@:native("waitOn")
+	public function wait():Void {
+		native.await();
+	}
+
+	public function signal():Void {
+		native.signal();
+	}
+
+	public function broadcast():Void {
+		native.signalAll();
+	}
+}

Kha/Tools/windows_x64/std/java/_std/sys/thread/Semaphore.hx

@@ -0,0 +1,25 @@
+package sys.thread;
+
+import java.util.concurrent.TimeUnit;
+
+@:coreApi
+@:native('haxe.java.vm.Semaphore')
+class Semaphore {
+	final native:java.util.concurrent.Semaphore;
+
+	public function new(value:Int):Void {
+		this.native = new java.util.concurrent.Semaphore(value);
+	}
+
+	public function acquire():Void {
+		native.acquire();
+	}
+
+	public function tryAcquire(?timeout:Float):Bool {
+		return timeout == null ? native.tryAcquire() : native.tryAcquire(haxe.Int64.fromFloat(timeout * 1000000000),TimeUnit.NANOSECONDS);
+	}
+
+	public function release():Void {
+		native.release();
+	}
+}