import 'dart:ffi';
import 'dart:io';
import 'package:ffi/ffi.dart';
int rss() => int.parse(File('/proc/self/status').readAsLinesSync()
    .firstWhere((l)=>l.startsWith('VmRSS')).split(RegExp(r'\s+'))[1]);

void main(){
  final lib = DynamicLibrary.open('libvflutter.so');
  final greet = lib.lookupFunction<Pointer<Utf8> Function(Pointer<Utf8>),
      Pointer<Utf8> Function(Pointer<Utf8>)>('vf_greet');
  final vfree = lib.lookupFunction<Void Function(Pointer<Void>),
      void Function(Pointer<Void>)>('vf_free');

  // Regression guard for the -gc none ownership rule: RSS must stay flat.
  final arg = 'fixed'.toNativeUtf8();
  for (var i=0;i<5000;i++){ vfree(greet(arg).cast()); }
  final before = rss();
  for (var i=0;i<900000;i++){ vfree(greet(arg).cast()); }
  print('native-only  before: $before kB  after: ${rss()} kB');
  calloc.free(arg);
}