From 4182d904c56e4ca14ddcb43fdcc7c227df8bfa63 Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Thu, 11 Jul 2024 16:40:18 -0700
Subject: [PATCH] Fix an issue where gc wasn't outpacing writes

---
 ConflictSet.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index abfe6d2..600fe4a 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -3070,8 +3070,12 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       rootMaxVersion = std::max(rootMaxVersion, oldestVersion);
       n = nextPhysical(n);
     }
-    for (; fuel > 0 && n != nullptr; --fuel) {
+    for (; fuel > 0 && n != nullptr;) {
       rezero(n, oldestVersion);
+      // The "make sure gc keeps up with writes" calculations assume that we're
+      // scanning key by key, not node by node. Make sure we only spend fuel
+      // when there's a logical entry.
+      fuel -= n->entryPresent;
       if (n->entryPresent && std::max(n->entry.pointVersion,
                                       n->entry.rangeVersion) <= oldestVersion) {
         // Any transaction n would have prevented from committing is