From 9e8930f02e7a53a41b713c642bcb53b3b61f7cb5 Mon Sep 17 00:00:00 2001
From: Benoit Germain <benoit.germain@ubisoft.com>
Date: Wed, 13 Nov 2024 10:41:01 +0100
Subject: Cleaning up guano

Lane::selfdestruct_next and Universe::selfdestructFirst do not need to be volatile or anything else, all accesses are mutex-protected
---
 src/lane.cpp     | 7 ++++---
 src/lane.hpp     | 3 ++-
 src/universe.hpp | 3 ++-
 3 files changed, 8 insertions(+), 5 deletions(-)

(limited to 'src')

diff --git a/src/lane.cpp b/src/lane.cpp
index 4caebcb..2bc3431 100644
--- a/src/lane.cpp
+++ b/src/lane.cpp
@@ -633,6 +633,8 @@ void Lane::selfdestructAdd()
     assert(selfdestruct_next == nullptr);
 
     selfdestruct_next = U->selfdestructFirst;
+    assert(selfdestruct_next);
+
     U->selfdestructFirst = this;
 }
 
@@ -648,7 +650,7 @@ void Lane::selfdestructAdd()
     // cancel/kill).
     //
     if (selfdestruct_next != nullptr) {
-        Lane* volatile* _ref = static_cast<Lane* volatile*>(&U->selfdestructFirst);
+        Lane** _ref{ &U->selfdestructFirst };
 
         while (*_ref != SELFDESTRUCT_END) {
             if (*_ref == this) {
@@ -659,7 +661,7 @@ void Lane::selfdestructAdd()
                 _found = true;
                 break;
             }
-            _ref = static_cast<Lane* volatile*>(&((*_ref)->selfdestruct_next));
+            _ref = &((*_ref)->selfdestruct_next);
         }
         assert(_found);
     }
@@ -846,7 +848,6 @@ static LUAG_FUNC(lane_gc)
     if (_lane->status.load(std::memory_order_acquire) < Lane::Done) {
         // still running: will have to be cleaned up later
         _lane->selfdestructAdd();
-        assert(_lane->selfdestruct_next);
         if (_have_gc_cb) {
             luaG_pushstring(L_, "selfdestruct");                                                   // L_: ud gc_cb name status
             lua_call(L_, 2, 0);                                                                    // L_: ud
diff --git a/src/lane.hpp b/src/lane.hpp
index 1926824..4f87e2a 100644
--- a/src/lane.hpp
+++ b/src/lane.hpp
@@ -128,7 +128,8 @@ class Lane
     // M: sets to false, flags true for cancel request
     // S: reads to see if cancel is requested
 
-    Lane* volatile selfdestruct_next{ nullptr };
+    // access is protected by Universe::selfDestructMutex
+    Lane* selfdestruct_next{ nullptr };
     //
     // M: sets to non-nullptr if facing lane handle '__gc' cycle but the lane
     //    is still running
diff --git a/src/universe.hpp b/src/universe.hpp
index 18e125f..a45ce86 100644
--- a/src/universe.hpp
+++ b/src/universe.hpp
@@ -113,7 +113,8 @@ class Universe
     std::atomic<int> debugspewIndentDepth{ 0 };
 #endif // USE_DEBUG_SPEW()
 
-    Lane* volatile selfdestructFirst{ nullptr };
+    // access is protected by selfDestructMutex
+    Lane* selfdestructFirst{ nullptr };
     // After a lane has removed itself from the chain, it still performs some processing.
     // The terminal desinit sequence should wait for all such processing to terminate before force-killing threads
     std::atomic<int> selfdestructingCount{ 0 };
-- 
cgit v1.2.3-55-g6feb