Seeking TSAN's approval

Author: mjp41

src/snmalloc/ds_core/stats.h

@@ -70,22 +70,22 @@ namespace snmalloc
    */
   class MonotoneLocalStat
   {
-    size_t value{0};
+    std::atomic<size_t> value{0};
 
   public:
     void operator++(int)
     {
-      value++;
+      value.fetch_add(1, std::memory_order_relaxed);
     }
 
     void operator+=(const MonotoneLocalStat& other)
     {
-      value += other.value;
+      value.fetch_add(other.value.load(std::memory_order_relaxed), std::memory_order_relaxed);
     }
 
     size_t operator*()
     {
-      return value;
+      return value.load(std::memory_order_relaxed);
     }
   };
 } // namespace snmalloc

src/snmalloc/mem/globalalloc.h

@@ -139,16 +139,14 @@ namespace snmalloc
   }
 
   template<SNMALLOC_CONCEPT(IsConfig) Config>
-  inline static AllocStats get_stats()
+  inline static void get_stats(AllocStats& stats)
   {
     auto alloc = AllocPool<Config>::iterate();
-    AllocStats stats;
     while (alloc != nullptr)
     {
       stats += alloc->get_stats();
       alloc = AllocPool<Config>::iterate(alloc);
     }
-    return stats;
   }
 
   template<SNMALLOC_CONCEPT(IsConfig) Config>
@@ -168,7 +166,8 @@ namespace snmalloc
         "count");
     }
 
-    auto stats = snmalloc::get_stats<Config>();
+    AllocStats stats;
+    snmalloc::get_stats<Config>(stats);
     size_t total_live{0};
     size_t total_live_slabs{0};
     for (size_t i = 0; i < snmalloc::SIZECLASS_REP_SIZE; i++)