if (!.Call(`_rxode2_isIntel`)) {
  # locking tests

  ode <- rxode2({
    a <- -8 / 3
    b <- -10
    c <- -1
    d / dt(X) <- a * X + Y * Z
    d / dt(Y) <- b * (Y - Z)
    d / dt(Z) <- -X * Y + c * Y - Z
  })

  test_that("Unlocked when simply loading", {
    expect_true(rxModels_()[[rxDll(ode)]] == 0L)
  })

  et <- eventTable(time.units = "hr") # default time units
  et$add.sampling(seq(from = 0, to = 100, by = 0.01))

  out <- rxSolve(ode,
                 events = et,
                 inits = c(X = 1, Y = 1, Z = 1),
                 .setupOnly = TRUE
                 )

  test_that("Locked after .setupOnly", {
    expect_true(rxModels_()[[rxDll(ode)]] == 1L)
  })

  out <- rxSolve(ode,
                 events = et,
                 inits = c(X = 1, Y = 1, Z = 1)
                 )

  test_that("Unlocked after other solve", {
    expect_true(rxModels_()[[rxDll(ode)]] == 0L)
  })
}