sim: Ensure draining is deterministic

The traversal of drainable objects could potentially be
non-deterministic when using an unordered set containing object
pointers. To ensure that the iteration is deterministic, we switch to
a vector. Note that the lookup and traversal of the drainable objects
is not performance critical, so the change has no negative consequences.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/sim/drain.hh b/src/sim/drain.hh
index b3145e7ed..663946616 100644
--- a/src/sim/drain.hh
+++ b/src/sim/drain.hh
@@ -42,7 +42,7 @@
 
 #include <atomic>
 #include <mutex>
-#include <unordered_set>
+#include <vector>
 
 class Drainable;
 
@@ -162,7 +162,7 @@ class DrainManager
     mutable std::mutex globalLock;
 
     /** Set of all drainable objects */
-    std::unordered_set<Drainable *> _allDrainable;
+    std::vector<Drainable *> _allDrainable;
 
     /**
      * Number of objects still draining. This is flagged atomic since