From 9ae1671e4f53e2767ba6216a9212f2ffd0997ced Mon Sep 17 00:00:00 2001
From: Tyler Neely <t@jujit.su>
Date: Wed, 20 Jul 2022 18:17:06 +0000
Subject: [PATCH] Fix bug with MgFuture where its safety check was not
 correctly initialized

---
 src/io/v3/future.hpp           | 48 ++++++++++++++++------------------
 src/io/v3/simulator_handle.hpp |  1 +
 tests/simulation/raft.cpp      |  2 +-
 3 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/src/io/v3/future.hpp b/src/io/v3/future.hpp
index 55b984ba2..dd909cbc4 100644
--- a/src/io/v3/future.hpp
+++ b/src/io/v3/future.hpp
@@ -36,21 +36,18 @@ std::pair<MgFuture<T>, MgPromise<T>> FuturePromisePairWithNotifier(std::function
 
 template <typename T>
 class Shared {
+  std::condition_variable cv_;
+  std::mutex mu_;
+  std::optional<T> item_;
+  bool consumed_ = false;
+  bool waiting_ = false;
+  std::optional<std::function<bool()>> simulator_notifier_;
+
   friend std::pair<MgFuture<T>, MgPromise<T>> FuturePromisePair<T>();
   friend std::pair<MgFuture<T>, MgPromise<T>> FuturePromisePairWithNotifier<T>(std::function<bool()>);
   friend MgPromise<T>;
   friend MgFuture<T>;
 
- public:
-  Shared(std::function<bool()> simulator_notifier) : simulator_notifier_(simulator_notifier) {}
-  Shared() = default;
-  Shared(Shared &&) = delete;
-  Shared &operator=(Shared &&) = delete;
-  Shared(const Shared &) = delete;
-  Shared &operator=(const Shared &) = delete;
-  ~Shared() = default;
-
- private:
   T Wait() {
     std::unique_lock<std::mutex> lock(mu_);
     waiting_ = true;
@@ -132,16 +129,22 @@ class Shared {
     return waiting_;
   }
 
-  std::condition_variable cv_;
-  std::mutex mu_;
-  std::optional<T> item_;
-  bool consumed_;
-  bool waiting_;
-  std::optional<std::function<bool()>> simulator_notifier_;
+ public:
+  Shared(std::function<bool()> simulator_notifier) : simulator_notifier_(simulator_notifier) {}
+  Shared() = default;
+  Shared(Shared &&) = delete;
+  Shared &operator=(Shared &&) = delete;
+  Shared(const Shared &) = delete;
+  Shared &operator=(const Shared &) = delete;
+  ~Shared() = default;
 };
 
 template <typename T>
 class MgFuture {
+  MgFuture(std::shared_ptr<Shared<T>> shared) : shared_(shared) {}
+
+  bool consumed_or_moved_ = false;
+  std::shared_ptr<Shared<T>> shared_;
   friend std::pair<MgFuture<T>, MgPromise<T>> FuturePromisePair<T>();
   friend std::pair<MgFuture<T>, MgPromise<T>> FuturePromisePairWithNotifier<T>(std::function<bool()>);
 
@@ -196,16 +199,13 @@ class MgFuture {
     MG_ASSERT(!consumed_or_moved_, "MgFuture::Cancel called on a future that was already moved or consumed!");
     consumed_or_moved_ = true;
   }
-
- private:
-  MgFuture(std::shared_ptr<Shared<T>> shared) : shared_(shared) {}
-
-  bool consumed_or_moved_ = false;
-  std::shared_ptr<Shared<T>> shared_;
 };
 
 template <typename T>
 class MgPromise {
+  std::shared_ptr<Shared<T>> shared_;
+  bool filled_or_moved_ = false;
+
   friend std::pair<MgFuture<T>, MgPromise<T>> FuturePromisePair<T>();
   friend std::pair<MgFuture<T>, MgPromise<T>> FuturePromisePairWithNotifier<T>(std::function<bool()>);
 
@@ -244,10 +244,6 @@ class MgPromise {
 
     return up;
   }
-
- private:
-  std::shared_ptr<Shared<T>> shared_;
-  bool filled_or_moved_ = false;
 };
 
 template <typename T>
diff --git a/src/io/v3/simulator_handle.hpp b/src/io/v3/simulator_handle.hpp
index 109b636f0..7a45c9980 100644
--- a/src/io/v3/simulator_handle.hpp
+++ b/src/io/v3/simulator_handle.hpp
@@ -256,6 +256,7 @@ class SimulatorHandle {
     for (auto &[promise_key, dop] : promises_) {
       // TODO queue this up and drop it after its deadline
       if (dop.deadline < now) {
+        std::cout << "timing out request" << std::endl;
         DeadlineAndOpaquePromise dop = std::move(promises_.at(promise_key));
         promises_.erase(promise_key);
         dop.promise.TimeOut();
diff --git a/tests/simulation/raft.cpp b/tests/simulation/raft.cpp
index df0c2869b..aa6e8bd5a 100644
--- a/tests/simulation/raft.cpp
+++ b/tests/simulation/raft.cpp
@@ -627,7 +627,7 @@ void RunSimulation() {
       .perform_timeouts = true,
       .scramble_messages = true,
       .rng_seed = 0,
-      .start_time = 200000,
+      .start_time = 256 * 1024,
       .abort_time = 8 * 1024 * 1024,
   };