From de52b3b5ddf22cfdf7bd0e25163f73eaf0302239 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Tue, 24 Mar 2026 22:15:53 -0400
Subject: [PATCH] xo-alloc2: + DArena.scrub() for diagnostics

---
 include/xo/arena/DArena.hpp | 3 +++
 src/arena/DArena.cpp        | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/include/xo/arena/DArena.hpp b/include/xo/arena/DArena.hpp
index 73ca67d..74f4832 100644
--- a/include/xo/arena/DArena.hpp
+++ b/include/xo/arena/DArena.hpp
@@ -229,6 +229,9 @@ namespace xo {
             void restore(Checkpoint ckp) noexcept { free_ = ckp.free_; }
 
 
+            /** zero out all allocated memory. Likely use case is diagnostics **/
+            void scrub() noexcept;
+
             /** discard all allocated memory, return to empty state
              *  Promise:
              *  - committed memory unchanged
diff --git a/src/arena/DArena.cpp b/src/arena/DArena.cpp
index e5bbb11..ebee471 100644
--- a/src/arena/DArena.cpp
+++ b/src/arena/DArena.cpp
@@ -583,6 +583,12 @@ namespace xo {
             return true;
         } /*expand*/
 
+        void
+        DArena::scrub() noexcept
+        {
+            ::memset(this->lo_, 0, this->free_ - this->lo_);
+        }
+
         void
         DArena::clear() noexcept
         {