destroyTree -> eraseTree. Use freelist

ConflictSet.cpp

@@ -1715,50 +1715,50 @@ void maybeDownsize(Node *self, WriteContext *tls, ConflictSet::Impl *impl,
   }
 }
 
-void destroyTree(Node *root, WriteContext::Accum *accum) {
+void eraseTree(Node *root, WriteContext *tls) {
   Arena arena;
   auto toFree = vector<Node *>(arena);
   toFree.push_back(root);
 
-#if SHOW_MEMORY
-  for (auto *iter = root; iter != nullptr; iter = nextPhysical(iter)) {
-    removeNode(iter);
-    removeKey(iter);
-  }
-#endif
-
   while (toFree.size() > 0) {
     auto *n = toFree.back();
     toFree.pop_back();
-    accum->entries_erased += n->entryPresent;
-    ++accum->nodes_released;
+    tls->accum.entries_erased += n->entryPresent;
+    ++tls->accum.nodes_released;
+
+    removeNode(n);
+    removeKey(n);
 
     switch (n->getType()) {
     case Type_Node0: {
+      auto *n0 = static_cast<Node0 *>(n);
+      tls->release(n0);
     } break;
     case Type_Node3: {
       auto *n3 = static_cast<Node3 *>(n);
       toFree.append(std::span<Node *>(n3->children, n3->numChildren));
+      tls->release(n3);
     } break;
     case Type_Node16: {
       auto *n16 = static_cast<Node16 *>(n);
       toFree.append(std::span<Node *>(n16->children, n16->numChildren));
+      tls->release(n16);
     } break;
     case Type_Node48: {
       auto *n48 = static_cast<Node48 *>(n);
       toFree.append(std::span<Node *>(n48->children, n48->numChildren));
+      tls->release(n48);
     } break;
     case Type_Node256: {
       auto *n256 = static_cast<Node256 *>(n);
       auto *out = toFree.unsafePrepareAppend(n256->numChildren).data();
       n256->bitSet.forEachSet([&](int i) { *out++ = n256->children[i]; });
       assert(out == toFree.end());
+      tls->release(n256);
     } break;
     default:                   // GCOVR_EXCL_LINE
       __builtin_unreachable(); // GCOVR_EXCL_LINE
     }
-    removeNode(n);
-    safe_free(n, n->size());
   }
 }
 
@@ -1772,7 +1772,7 @@ void eraseBetween(Node3 *&n, int begin, int end, WriteContext *tls,
   InternalVersionT *maxVOut = n->childMaxVersion;
   for (int i = 0; i < n->numChildren; ++i) {
     if (inBounds(n->index[i])) {
-      destroyTree(n->children[i], &tls->accum);
+      eraseTree(n->children[i], tls);
     } else {
       *nodeOut++ = n->children[i];
       *indexOut++ = n->index[i];
@@ -1800,7 +1800,7 @@ void eraseBetween(Node16 *&n, int begin, int end, WriteContext *tls,
   InternalVersionT *maxVOut = n->childMaxVersion;
   for (int i = 0; i < n->numChildren; ++i) {
     if (inBounds(n->index[i])) {
-      destroyTree(n->children[i], &tls->accum);
+      eraseTree(n->children[i], tls);
     } else {
       *nodeOut++ = n->children[i];
       *indexOut++ = n->index[i];
@@ -1840,7 +1840,7 @@ void eraseBetween(Node48 *&n, int begin, int end, WriteContext *tls,
   n->nextFree = 0;
   for (int i = 0; i < n->numChildren; ++i) {
     if (inBounds(n->reverseIndex[i])) {
-      destroyTree(n->children[i], &tls->accum);
+      eraseTree(n->children[i], tls);
     } else {
       *nodeOut++ = n->children[i];
       *indexOut++ = n->reverseIndex[i];
@@ -1883,7 +1883,7 @@ void eraseBetween(Node256 *&n, int begin, int end, WriteContext *tls,
   BitSet newBitSet;
   n->bitSet.forEachSet([&](int i) {
     if (inBounds(i)) {
-      destroyTree(std::exchange(n->children[i], nullptr), &tls->accum);
+      eraseTree(std::exchange(n->children[i], nullptr), tls);
     } else {
       ++n->numChildren;
       newBitSet.set(i);
@@ -3412,7 +3412,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     if (oldestExtantVersion < writeVersion - kMaxCorrectVersionWindow)
         [[unlikely]] {
       if (writeVersion > newestVersionFullPrecision + kNominalVersionWindow) {
-        destroyTree(root, &tls.accum);
+        eraseTree(root, &tls);
         init(writeVersion - kNominalVersionWindow);
       }
 
@@ -3581,7 +3581,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     initMetrics();
   }
   ~Impl() {
-    destroyTree(root, &tls.accum);
+    eraseTree(root, &tls);
     safe_free(metrics, metricsCount * sizeof(metrics[0]));
   }