[SOLVED] Is SharedPreferences a safe way of sharing settings between a service and the UI?

Is SharedPreferences a safe way of sharing settings between a service and the UI?

I am calling commit() in a service and when I read the prefs in the UI 300ms later, the data is not there. This is on API 27.

I already use the Messenger for communicating between the service and the UI.

This is how I'm storing data on the services side:

  local e = context:getSharedPreferences("characters", context.MODE_PRIVATE):edit()
  e:putString("list", table.concat(names, "|"))
  log("saved these names in characters: %s", tstring(names))
  e:commit()
  local stuff = context:getSharedPreferences("characters", context.MODE_PRIVATE)

Retrieving it in the UI:

  charlist_settings = activity:getSharedPreferences("characters", activity.MODE_PRIVATE)
  log("refreshlist hit")
  if charlist_settings:contains("list") and charlist_settings:getString("list", "") ~= "" then
    [...]
  else
    log("no list in char_settings :(")
    log("all: %s", charlist_settings:getAll():toString())
  end

Service log, notice timestamp:

12-22 18:56:30.246 4142-4142/org.vadisystems.irehelper:Service I/IRE Helper: modified is: added
12-22 18:56:30.253 4142-4142/org.vadisystems.irehelper:Service I/IRE Helper: saved these names in characters: {"Vadimuses_Achaea"}

UI log, this is after a message is received from the service:

12-22 18:56:30.700 4120-4120/org.vadisystems.irehelper I/IRE Helper: refreshlist hit
12-22 18:56:30.701 4120-4120/org.vadisystems.irehelper I/IRE Helper: no list in char_settings :(
12-22 18:56:30.702 4120-4120/org.vadisystems.irehelper I/IRE Helper: all: {}

Solution

Not even restarting the activity worked to get the data after it has been commited. The only thing that did was restarting the application entirely. This was on API 27.