From c78cec6e732618613af304f8e4a58c97bd0e05a0 Mon Sep 17 00:00:00 2001
From: Gregorius Soedharmo <arkatufus@yahoo.com>
Date: Tue, 18 Oct 2022 03:19:36 +0700
Subject: [PATCH] removed boxing allocations inside `FSM` (#6183) (#6196)

The `object.Equals` call here generated hundreds of mb in boxing allocations inside RemotePingPong - using the `EqualityComparer<TState>.Default.Equals` eliminates them.

(cherry picked from commit 183ec5ae1229b2948e1b18c2e90aa75eb52f8955)

Co-authored-by: Aaron Stannard <aaron@petabridge.com>
---
 src/core/Akka/Actor/FSM.cs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/core/Akka/Actor/FSM.cs b/src/core/Akka/Actor/FSM.cs
index 8fd4c9ddd20..b817b2c6935 100644
--- a/src/core/Akka/Actor/FSM.cs
+++ b/src/core/Akka/Actor/FSM.cs
@@ -1262,12 +1262,14 @@ private void MakeTransition(State<TState, TData> nextState)
                 {
                     Sender.Tell(nextState.Replies[i]);
                 }
-                if (!_currentState.StateName.Equals(nextState.StateName) || nextState.Notifies)
+                
+                // avoid boxing
+                if (!EqualityComparer<TState>.Default.Equals(_currentState.StateName, nextState.StateName) || nextState.Notifies)
                 {
                     _nextState = nextState;
                     HandleTransition(_currentState.StateName, nextState.StateName);
                     Listeners.Gossip(new Transition<TState>(Self, _currentState.StateName, nextState.StateName));
-                    _nextState = default(State<TState, TData>);
+                    _nextState = default;
                 }
                 _currentState = nextState;