A pseudocode explanation of why class instance counting is slow on Android Lollipop

gistfile1.txt

// StrictMode.conditionallyCheckInstanceCounts
force_garbage_collection // because I don’t trust VMDebug to get this right

foreach(c in classes) {

  // VMDebug.countInstancesofClass()
  force_garbage_collection // because I don’t trust my caller to get this right
  classes2.add(c)
 
  // Heap::CountInstances
  visit objects (obj =>
    foreach(c2 in classes2) {
      if (c2 is assignable from obj.class) {
        increment c2 instance count
      }
    }) 
}