1. 31 Oct, 2018 5 commits
    • Robbert Krebbers's avatar
      98ddbead
    • Robbert Krebbers's avatar
      f7af5b3f
    • Robbert Krebbers's avatar
      Fine-grained post-conditions for forked-off threads. · ebf06f91
      Robbert Krebbers authored
      This commit extends the state interpretation with an additional parameter to
      talk about the number of forked-off threads, and a fixed postcondition for each
      forked-off thread:
      
          state_interp : Λstate → list Λobservation → nat → iProp Σ;
          fork_post : iProp Σ;
      
      This way, instead of having `True` as the post-condition of `Fork`, one can
      have any post-condition, which is then recorded in the state interpretation.
      The point of keeping track of the postconditions of forked-off threads, is that
      we get an (additional) stronger adequacy theorem:
      
          Theorem wp_strong_all_adequacy Σ Λ `{invPreG Σ} s e σ1 v vs σ2 φ :
             (∀ `{Hinv : invG Σ} κs,
               (|={⊤}=> ∃
                   (stateI : state Λ → list (observation Λ) → nat → iProp Σ)
                   (fork_post : iProp Σ),
                 let _ : irisG Λ Σ := IrisG _ _ _ Hinv stateI fork_post in
                 stateI σ1 κs 0 ∗ WP e @ s; ⊤ {{ v,
                   let m := length vs in
                   stateI σ2 [] m -∗ [∗] replicate m fork_post ={⊤,∅}=∗ ⌜ φ v ⌝ }})%I) →
            rtc erased_step ([e], σ1) (of_val <$> v :: vs, σ2) →
            φ v.
      
      The difference with the ordinary adequacy theorem is that this one only applies
      once all threads terminated. In this case, one gets back the post-conditions
      `[∗] replicate m fork_post` of all forked-off threads.
      
      In Iron we showed that we can use this mechanism to make sure that all
      resources are disposed of properly in the presence of fork-based concurrency.
      ebf06f91
    • Robbert Krebbers's avatar
    • Robbert Krebbers's avatar
      f716d0dc
  2. 24 Oct, 2018 3 commits
  3. 22 Oct, 2018 2 commits
  4. 18 Oct, 2018 3 commits
  5. 05 Oct, 2018 8 commits
  6. 03 Oct, 2018 1 commit
  7. 13 Jul, 2018 6 commits
  8. 02 Jul, 2018 1 commit
  9. 25 Jun, 2018 1 commit
  10. 21 Jun, 2018 1 commit
  11. 20 Jun, 2018 1 commit
  12. 18 Jun, 2018 2 commits
  13. 15 Jun, 2018 2 commits
  14. 14 Jun, 2018 4 commits