Better support a lack of musttail and preserve_none

Prepare to add write namespace

ConflictSet.cpp

@@ -264,7 +264,7 @@ struct Node {
   /* begin section that's copied to the next node */
   union {
     Entry entry;
-    /* Set to the forwarding point for this node if deferredReleased is set */
+    /* Set to the forwarding point for this node if releaseDeferred is set */
     Node *forwardTo;
   };
   Node *parent;
@@ -278,15 +278,12 @@ struct Node {
 
   /* If set, this node has been replaced and the next node in the forwarding
    * chain is `forwardTo`*/
-  bool deferredReleased;
+  bool releaseDeferred;
 
   uint8_t *partialKey();
-  Type getType() const {
-    assert(!deferredReleased);
-    return type;
-  }
+  Type getType() const { return type; }
   int32_t getCapacity() const {
-    assert(!deferredReleased);
+    assert(!releaseDeferred);
     return partialKeyCapacity;
   }
 
@@ -320,7 +317,7 @@ struct Node0 : Node {
   constexpr static auto kType = Type_Node0;
 
   uint8_t *partialKey() {
-    assert(!deferredReleased);
+    assert(!releaseDeferred);
     return (uint8_t *)(this + 1);
   }
   void copyChildrenAndKeyFrom(const Node0 &other);
@@ -338,7 +335,7 @@ struct Node3 : Node {
   uint8_t index[kMaxNodes];
 
   uint8_t *partialKey() {
-    assert(!deferredReleased);
+    assert(!releaseDeferred);
     return (uint8_t *)(this + 1);
   }
   void copyChildrenAndKeyFrom(const Node0 &other);
@@ -357,7 +354,7 @@ struct Node16 : Node {
   uint8_t index[kMaxNodes];
 
   uint8_t *partialKey() {
-    assert(!deferredReleased);
+    assert(!releaseDeferred);
     return (uint8_t *)(this + 1);
   }
   void copyChildrenAndKeyFrom(const Node3 &other);
@@ -382,7 +379,7 @@ struct Node48 : Node {
   int8_t index[256];
 
   uint8_t *partialKey() {
-    assert(!deferredReleased);
+    assert(!releaseDeferred);
     return (uint8_t *)(this + 1);
   }
   void copyChildrenAndKeyFrom(const Node16 &other);
@@ -405,7 +402,7 @@ struct Node256 : Node {
   InternalVersionT maxOfMax[kMaxOfMaxTotalPages];
 
   uint8_t *partialKey() {
-    assert(!deferredReleased);
+    assert(!releaseDeferred);
     return (uint8_t *)(this + 1);
   }
   void copyChildrenAndKeyFrom(const Node48 &other);
@@ -708,7 +705,7 @@ template <class T> struct BoundedFreeListAllocator {
   T *allocate(int partialKeyCapacity) {
     T *result = allocate_helper(partialKeyCapacity);
     result->endOfRange = false;
-    result->deferredReleased = false;
+    result->releaseDeferred = false;
     if constexpr (!std::is_same_v<T, Node0>) {
       memset(result->children, 0, sizeof(result->children));
       const auto z = InternalVersionT::zero;
@@ -852,10 +849,13 @@ struct WriteContext {
   }
 
   // Place in a list to be released in the next call to releaseDeferred.
-  void deferRelease(Node *n) {
+  void deferRelease(Node *n, Node *forwardTo) {
+    n->releaseDeferred = true;
+    n->forwardTo = forwardTo;
     n->parent = deferredList;
     deferredList = n;
   }
+
   // Release all nodes passed to deferRelease since the last call to
   // releaseDeferred.
   void releaseDeferred() {
@@ -1204,6 +1204,136 @@ TaggedNodePointer getChild(Node *self, uint8_t index) {
   }
 }
 
+TaggedNodePointer *getChildUpdatingMaxVersion(Node0 *,
+                                              std::span<const uint8_t> &,
+                                              InternalVersionT) {
+  return nullptr;
+}
+TaggedNodePointer *
+getChildUpdatingMaxVersion(Node3 *self, std::span<const uint8_t> &remaining,
+                           InternalVersionT maxVersion) {
+  assert(remaining.size() > 0);
+  int index = remaining.front();
+  auto key = remaining.subspan(1, remaining.size() - 1);
+  int i = getNodeIndex(self, index);
+  if (i < 0) {
+    return nullptr;
+  }
+  Node *c = self->children[i];
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
+  }
+  remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
+  self->childMaxVersion[i] = maxVersion;
+  return &self->children[i];
+}
+TaggedNodePointer *
+getChildUpdatingMaxVersion(Node16 *self, std::span<const uint8_t> &remaining,
+                           InternalVersionT maxVersion) {
+  assert(remaining.size() > 0);
+  int index = remaining.front();
+  auto key = remaining.subspan(1, remaining.size() - 1);
+  int i = getNodeIndex(self, index);
+  if (i < 0) {
+    return nullptr;
+  }
+  Node *c = self->children[i];
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
+  }
+  remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
+  self->childMaxVersion[i] = maxVersion;
+  return &self->children[i];
+}
+TaggedNodePointer *
+getChildUpdatingMaxVersion(Node48 *self, std::span<const uint8_t> &remaining,
+                           InternalVersionT maxVersion) {
+  assert(remaining.size() > 0);
+  int index = remaining.front();
+  auto key = remaining.subspan(1, remaining.size() - 1);
+  int i = self->index[index];
+  if (i < 0) {
+    return nullptr;
+  }
+  Node *c = self->children[i];
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
+  }
+  remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
+  self->childMaxVersion[i] = maxVersion;
+  self->maxOfMax[i >> Node48::kMaxOfMaxShift] =
+      std::max(self->maxOfMax[i >> Node48::kMaxOfMaxShift], maxVersion);
+  return &self->children[i];
+}
+TaggedNodePointer *
+getChildUpdatingMaxVersion(Node256 *self, std::span<const uint8_t> &remaining,
+                           InternalVersionT maxVersion) {
+  assert(remaining.size() > 0);
+  int index = remaining.front();
+  auto key = remaining.subspan(1, remaining.size() - 1);
+  auto &n = self->children[index];
+  if (n == nullptr) {
+    return nullptr;
+  }
+  Node *c = n;
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
+  }
+  remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
+  self->childMaxVersion[index] = maxVersion;
+  self->maxOfMax[index >> Node256::kMaxOfMaxShift] =
+      std::max(self->maxOfMax[index >> Node256::kMaxOfMaxShift], maxVersion);
+  return &n;
+}
+
+// Precondition: remaining.size() > 0
+// If a child of self lies along the search path of remaining, return a pointer
+// to that child, update max version, and consume the matching prefix bytes from
+// remaining. Otherwise return nullptr without changing the tree at all.
+TaggedNodePointer *
+getChildUpdatingMaxVersion(Node *self, std::span<const uint8_t> &remaining,
+                           InternalVersionT maxVersion) {
+  switch (self->getType()) {
+  case Type_Node0:
+    return getChildUpdatingMaxVersion(static_cast<Node0 *>(self), remaining,
+                                      maxVersion);
+  case Type_Node3:
+    return getChildUpdatingMaxVersion(static_cast<Node3 *>(self), remaining,
+                                      maxVersion);
+  case Type_Node16:
+    return getChildUpdatingMaxVersion(static_cast<Node16 *>(self), remaining,
+                                      maxVersion);
+  case Type_Node48:
+    return getChildUpdatingMaxVersion(static_cast<Node48 *>(self), remaining,
+                                      maxVersion);
+  case Type_Node256:
+    return getChildUpdatingMaxVersion(static_cast<Node256 *>(self), remaining,
+                                      maxVersion);
+  default:                   // GCOVR_EXCL_LINE
+    __builtin_unreachable(); // GCOVR_EXCL_LINE
+  }
+}
+
 struct ChildAndMaxVersion {
   TaggedNodePointer child;
   InternalVersionT maxVersion;
@@ -1550,7 +1680,7 @@ TaggedNodePointer &getOrCreateChild(TaggedNodePointer &self,
 
     auto *newSelf = writeContext->allocate<Node3>(self->partialKeyLen);
     newSelf->copyChildrenAndKeyFrom(*self0);
-    writeContext->release(self0);
+    writeContext->deferRelease(self0, newSelf);
     self = newSelf;
 
     goto insert3;
@@ -1560,7 +1690,7 @@ TaggedNodePointer &getOrCreateChild(TaggedNodePointer &self,
       auto *self3 = static_cast<Node3 *>(self);
       auto *newSelf = writeContext->allocate<Node16>(self->partialKeyLen);
       newSelf->copyChildrenAndKeyFrom(*self3);
-      writeContext->release(self3);
+      writeContext->deferRelease(self3, newSelf);
       self = newSelf;
       goto insert16;
     }
@@ -1589,7 +1719,7 @@ TaggedNodePointer &getOrCreateChild(TaggedNodePointer &self,
       auto *self16 = static_cast<Node16 *>(self);
       auto *newSelf = writeContext->allocate<Node48>(self->partialKeyLen);
       newSelf->copyChildrenAndKeyFrom(*self16);
-      writeContext->release(self16);
+      writeContext->deferRelease(self16, newSelf);
       self = newSelf;
       goto insert48;
     }
@@ -1620,7 +1750,7 @@ TaggedNodePointer &getOrCreateChild(TaggedNodePointer &self,
       auto *self48 = static_cast<Node48 *>(self);
       auto *newSelf = writeContext->allocate<Node256>(self->partialKeyLen);
       newSelf->copyChildrenAndKeyFrom(*self48);
-      writeContext->release(self48);
+      writeContext->deferRelease(self48, newSelf);
       self = newSelf;
       goto insert256;
     }
@@ -3103,11 +3233,12 @@ Node *firstGeqPhysical(Node *n, const std::span<const uint8_t> key) {
 #define PRESERVE_NONE
 #endif
 
-typedef PRESERVE_NONE void (*Continuation)(struct CheckJob *,
-                                           struct CheckContext *);
+namespace check {
+
+typedef PRESERVE_NONE void (*Continuation)(struct Job *, struct Context *);
 
 // State relevant to an individual query
-struct CheckJob {
+struct Job {
   void setResult(bool ok) {
     *result = ok ? ConflictSet::Commit : ConflictSet::Conflict;
   }
@@ -3126,12 +3257,12 @@ struct CheckJob {
   InternalVersionT readVersion;
   ConflictSet::Result *result;
   Continuation continuation;
-  CheckJob *prev;
-  CheckJob *next;
+  Job *prev;
+  Job *next;
 };
 
 // State relevant to every query
-struct CheckContext {
+struct Context {
   int count;
   int64_t oldestVersionFullPrecision;
   Node *root;
@@ -3141,36 +3272,37 @@ struct CheckContext {
   ReadContext readContext;
 };
 
-PRESERVE_NONE void keepGoing(CheckJob *job, CheckContext *context) {
+PRESERVE_NONE void keepGoing(Job *job, Context *context) {
   job = job->next;
   MUSTTAIL return job->continuation(job, context);
 }
 
-PRESERVE_NONE void complete(CheckJob *job, CheckContext *context) {
+PRESERVE_NONE void complete(Job *job, Context *context) {
   if (context->started == context->count) {
     if (job->prev == job) {
       return;
     }
     job->prev->next = job->next;
     job->next->prev = job->prev;
-    job = job->prev;
+    job = job->next;
+    MUSTTAIL return job->continuation(job, context);
   } else {
     int temp = context->started++;
     job->init(context->queries + temp, context->results + temp, context->root,
               context->oldestVersionFullPrecision);
+    MUSTTAIL return job->continuation(job, context);
   }
-  MUSTTAIL return keepGoing(job, context);
 }
 
 template <class NodeT>
-PRESERVE_NONE void down_left_spine(CheckJob *job, CheckContext *context);
+PRESERVE_NONE void down_left_spine(Job *job, Context *context);
 
 static Continuation downLeftSpineTable[] = {
     down_left_spine<Node0>, down_left_spine<Node3>, down_left_spine<Node16>,
     down_left_spine<Node48>, down_left_spine<Node256>};
 
 template <class NodeT>
-PRESERVE_NONE void down_left_spine(CheckJob *job, CheckContext *context) {
+PRESERVE_NONE void down_left_spine(Job *job, Context *context) {
   assert(job->n->getType() == NodeT::kType);
   NodeT *n = static_cast<NodeT *>(job->n);
   if (n->entryPresent) {
@@ -3184,16 +3316,16 @@ PRESERVE_NONE void down_left_spine(CheckJob *job, CheckContext *context) {
   MUSTTAIL return keepGoing(job, context);
 }
 
-namespace check_point_read_state_machine {
+namespace point_read_state_machine {
 
-PRESERVE_NONE void begin(CheckJob *, CheckContext *);
+PRESERVE_NONE void begin(Job *, Context *);
 
-template <class NodeT> PRESERVE_NONE void iter(CheckJob *, CheckContext *);
+template <class NodeT> PRESERVE_NONE void iter(Job *, Context *);
 
 static Continuation iterTable[] = {iter<Node0>, iter<Node3>, iter<Node16>,
                                    iter<Node48>, iter<Node256>};
 
-void begin(CheckJob *job, CheckContext *context) {
+void begin(Job *job, Context *context) {
   ++context->readContext.point_read_accum;
 #if DEBUG_VERBOSE && !defined(NDEBUG)
   fprintf(stderr, "Check point read: %s\n", printable(key).c_str());
@@ -3228,7 +3360,7 @@ void begin(CheckJob *job, CheckContext *context) {
   MUSTTAIL return keepGoing(job, context);
 }
 
-template <class NodeT> void iter(CheckJob *job, CheckContext *context) {
+template <class NodeT> void iter(Job *job, Context *context) {
 
   assert(NodeT::kType == job->n->getType());
   NodeT *n = static_cast<NodeT *>(job->n);
@@ -3311,18 +3443,18 @@ template <class NodeT> void iter(CheckJob *job, CheckContext *context) {
   MUSTTAIL return keepGoing(job, context);
 }
 
-} // namespace check_point_read_state_machine
+} // namespace point_read_state_machine
 
-namespace check_prefix_read_state_machine {
+namespace prefix_read_state_machine {
 
-PRESERVE_NONE void begin(CheckJob *, CheckContext *);
+PRESERVE_NONE void begin(Job *, Context *);
 
-template <class NodeT> PRESERVE_NONE void iter(CheckJob *, CheckContext *);
+template <class NodeT> PRESERVE_NONE void iter(Job *, Context *);
 
 static Continuation iterTable[] = {iter<Node0>, iter<Node3>, iter<Node16>,
                                    iter<Node48>, iter<Node256>};
 
-void begin(CheckJob *job, CheckContext *context) {
+void begin(Job *job, Context *context) {
   ++context->readContext.prefix_read_accum;
 #if DEBUG_VERBOSE && !defined(NDEBUG)
   fprintf(stderr, "Check prefix read: %s\n", printable(key).c_str());
@@ -3353,7 +3485,7 @@ void begin(CheckJob *job, CheckContext *context) {
   MUSTTAIL return keepGoing(job, context);
 }
 
-template <class NodeT> void iter(CheckJob *job, CheckContext *context) {
+template <class NodeT> void iter(Job *job, Context *context) {
 
   assert(NodeT::kType == job->n->getType());
   NodeT *n = static_cast<NodeT *>(job->n);
@@ -3434,16 +3566,15 @@ template <class NodeT> void iter(CheckJob *job, CheckContext *context) {
   MUSTTAIL return keepGoing(job, context);
 }
 
-} // namespace check_prefix_read_state_machine
+} // namespace prefix_read_state_machine
 
-namespace check_range_read_state_machine {
-PRESERVE_NONE void begin(CheckJob *, CheckContext *);
+namespace range_read_state_machine {
+PRESERVE_NONE void begin(Job *, Context *);
+
+template <class NodeT> PRESERVE_NONE void common_prefix_iter(Job *, Context *);
 
 template <class NodeT>
-PRESERVE_NONE void common_prefix_iter(CheckJob *, CheckContext *);
-
-template <class NodeT>
-PRESERVE_NONE void done_common_prefix_iter(CheckJob *, CheckContext *);
+PRESERVE_NONE void done_common_prefix_iter(Job *, Context *);
 
 static Continuation commonPrefixIterTable[] = {
     common_prefix_iter<Node0>, common_prefix_iter<Node3>,
@@ -3455,43 +3586,41 @@ static Continuation doneCommonPrefixIterTable[] = {
     done_common_prefix_iter<Node16>, done_common_prefix_iter<Node48>,
     done_common_prefix_iter<Node256>};
 
-template <class NodeT>
-PRESERVE_NONE void left_side_iter(CheckJob *, CheckContext *);
+template <class NodeT> PRESERVE_NONE void left_side_iter(Job *, Context *);
 
 template <class NodeT>
-PRESERVE_NONE void left_side_down_left_spine(CheckJob *, CheckContext *);
+PRESERVE_NONE void left_side_down_left_spine(Job *, Context *);
 
 static Continuation leftSideDownLeftSpineTable[] = {
     left_side_down_left_spine<Node0>, left_side_down_left_spine<Node3>,
     left_side_down_left_spine<Node16>, left_side_down_left_spine<Node48>,
     left_side_down_left_spine<Node256>};
 
-PRESERVE_NONE void done_left_side_iter(CheckJob *, CheckContext *);
+PRESERVE_NONE void done_left_side_iter(Job *, Context *);
 
 static Continuation leftSideIterTable[] = {
     left_side_iter<Node0>, left_side_iter<Node3>, left_side_iter<Node16>,
     left_side_iter<Node48>, left_side_iter<Node256>};
 
-template <class NodeT>
-PRESERVE_NONE void right_side_iter(CheckJob *, CheckContext *);
+template <class NodeT> PRESERVE_NONE void right_side_iter(Job *, Context *);
 
 static Continuation rightSideIterTable[] = {
     right_side_iter<Node0>, right_side_iter<Node3>, right_side_iter<Node16>,
     right_side_iter<Node48>, right_side_iter<Node256>};
 
-PRESERVE_NONE void begin(CheckJob *job, CheckContext *context) {
+PRESERVE_NONE void begin(Job *job, Context *context) {
   job->lcp = longestCommonPrefix(job->begin.data(), job->end.data(),
                                  std::min(job->begin.size(), job->end.size()));
   if (job->lcp == int(job->begin.size()) &&
       job->end.size() == job->begin.size() + 1 && job->end.back() == 0) {
     // Call directly since we have nothing to prefetch
-    MUSTTAIL return check_point_read_state_machine::begin(job, context);
+    MUSTTAIL return check::point_read_state_machine::begin(job, context);
   }
   if (job->lcp == int(job->begin.size() - 1) &&
       job->end.size() == job->begin.size() &&
       int(job->begin.back()) + 1 == int(job->end.back())) {
     // Call directly since we have nothing to prefetch
-    MUSTTAIL return check_prefix_read_state_machine::begin(job, context);
+    MUSTTAIL return check::prefix_read_state_machine::begin(job, context);
   }
 
   ++context->readContext.range_read_accum;
@@ -3514,8 +3643,7 @@ PRESERVE_NONE void begin(CheckJob *job, CheckContext *context) {
 }
 
 // Advance down common prefix, but stay on a physical path in the tree
-template <class NodeT>
-void common_prefix_iter(CheckJob *job, CheckContext *context) {
+template <class NodeT> void common_prefix_iter(Job *job, Context *context) {
 
   assert(NodeT::kType == job->child->getType());
   NodeT *child = static_cast<NodeT *>(job->child);
@@ -3559,8 +3687,7 @@ void common_prefix_iter(CheckJob *job, CheckContext *context) {
 }
 
 template <class NodeT>
-PRESERVE_NONE void done_common_prefix_iter(CheckJob *job,
-                                           CheckContext *context) {
+PRESERVE_NONE void done_common_prefix_iter(Job *job, Context *context) {
   assert(NodeT::kType == job->n->getType());
   NodeT *n = static_cast<NodeT *>(job->n);
 
@@ -3666,7 +3793,7 @@ PRESERVE_NONE void done_common_prefix_iter(CheckJob *job,
 // Return true if the max version among all keys that start with key[:prefixLen]
 // that are >= key is <= readVersion
 template <class NodeT>
-PRESERVE_NONE void left_side_iter(CheckJob *job, CheckContext *context) {
+PRESERVE_NONE void left_side_iter(Job *job, Context *context) {
   assert(NodeT::kType == job->n->getType());
   NodeT *n = static_cast<NodeT *>(job->n);
 
@@ -3765,7 +3892,7 @@ PRESERVE_NONE void left_side_iter(CheckJob *job, CheckContext *context) {
   MUSTTAIL return keepGoing(job, context);
 }
 
-PRESERVE_NONE void done_left_side_iter(CheckJob *job, CheckContext *context) {
+PRESERVE_NONE void done_left_side_iter(Job *job, Context *context) {
 
   job->n = job->commonPrefixNode;
   job->remaining = job->end;
@@ -3797,7 +3924,7 @@ PRESERVE_NONE void done_left_side_iter(CheckJob *job, CheckContext *context) {
 }
 
 template <class NodeT>
-void left_side_down_left_spine(CheckJob *job, CheckContext *context) {
+void left_side_down_left_spine(Job *job, Context *context) {
   assert(job->n->getType() == NodeT::kType);
   NodeT *n = static_cast<NodeT *>(job->n);
 
@@ -3818,7 +3945,7 @@ void left_side_down_left_spine(CheckJob *job, CheckContext *context) {
 // Return true if the max version among all keys that start with key[:prefixLen]
 // that are < key is <= readVersion
 template <class NodeT>
-PRESERVE_NONE void right_side_iter(CheckJob *job, CheckContext *context) {
+PRESERVE_NONE void right_side_iter(Job *job, Context *context) {
   assert(NodeT::kType == job->n->getType());
   NodeT *n = static_cast<NodeT *>(job->n);
 
@@ -3913,11 +4040,10 @@ PRESERVE_NONE void right_side_iter(CheckJob *job, CheckContext *context) {
   MUSTTAIL return keepGoing(job, context);
 }
 
-} // namespace check_range_read_state_machine
+} // namespace range_read_state_machine
 
-void CheckJob::init(const ConflictSet::ReadRange *read,
-                    ConflictSet::Result *result, Node *root,
-                    int64_t oldestVersionFullPrecision) {
+void Job::init(const ConflictSet::ReadRange *read, ConflictSet::Result *result,
+               Node *root, int64_t oldestVersionFullPrecision) {
   auto begin = std::span<const uint8_t>(read->begin.p, read->begin.len);
   auto end = std::span<const uint8_t>(read->end.p, read->end.len);
   if (read->readVersion < oldestVersionFullPrecision) [[unlikely]] {
@@ -3928,16 +4054,114 @@ void CheckJob::init(const ConflictSet::ReadRange *read,
     this->n = root;
     this->readVersion = InternalVersionT(read->readVersion);
     this->result = result;
-    continuation = check_point_read_state_machine::begin;
+    continuation = check::point_read_state_machine::begin;
   } else {
     this->begin = begin;
     this->end = end;
     this->n = root;
     this->readVersion = InternalVersionT(read->readVersion);
     this->result = result;
-    continuation = check_range_read_state_machine::begin;
+    continuation = check::range_read_state_machine::begin;
   }
 }
+} // namespace check
+
+namespace interleaved_insert {
+
+typedef PRESERVE_NONE void (*Continuation)(struct Job *, struct Context *);
+
+// State relevant to an individual insertion
+struct Job {
+  std::span<const uint8_t> remaining;
+  Node *n;
+  int index;
+
+  // State for context switching machinery - not application specific
+  Continuation continuation;
+  Job *prev;
+  Job *next;
+  void init(Context *, int index);
+};
+
+// Result of an insertion.  The search path of insertionPoint + remaining == the
+// original key, and there is existing node in the tree further along the search
+// path of the original key
+struct Result {
+  Node *insertionPoint;
+  std::span<const uint8_t> remaining;
+};
+
+// State relevant to every insertion
+struct Context {
+  int count;
+  int64_t started;
+  const ConflictSet::WriteRange *writes;
+  Node *root;
+  InternalVersionT writeVersion;
+  Result *results;
+};
+
+PRESERVE_NONE void keepGoing(Job *job, Context *context) {
+  job = job->next;
+  MUSTTAIL return job->continuation(job, context);
+}
+
+PRESERVE_NONE void complete(Job *job, Context *context) {
+  if (context->started == context->count) {
+    if (job->prev == job) {
+      return;
+    }
+    job->prev->next = job->next;
+    job->next->prev = job->prev;
+    job = job->next;
+    MUSTTAIL return job->continuation(job, context);
+  } else {
+    int temp = context->started++;
+    job->init(context, temp);
+    MUSTTAIL return job->continuation(job, context);
+  }
+}
+
+template <class NodeT> PRESERVE_NONE void iter(Job *, Context *);
+
+static Continuation iterTable[] = {iter<Node0>, iter<Node3>, iter<Node16>,
+                                   iter<Node48>, iter<Node256>};
+
+template <class NodeT> void iter(Job *job, Context *context) {
+  assert(NodeT::kType == job->n->getType());
+  NodeT *n = static_cast<NodeT *>(job->n);
+
+  TaggedNodePointer *child =
+      getChildUpdatingMaxVersion(n, job->remaining, context->writeVersion);
+  if (child == nullptr) [[unlikely]] {
+    context->results[job->index] = {job->n, job->remaining};
+    MUSTTAIL return complete(job, context);
+  }
+  job->n = *child;
+  if (job->remaining.size() == 0) [[unlikely]] {
+    context->results[job->index] = {job->n, job->remaining};
+    MUSTTAIL return complete(job, context);
+  }
+  job->continuation = iterTable[child->getType()];
+  __builtin_prefetch(job->n);
+  MUSTTAIL return keepGoing(job, context);
+}
+
+void Job::init(Context *context, int index) {
+  this->index = index;
+  remaining = std::span<const uint8_t>(context->writes[index].begin.p,
+                                       context->writes[index].begin.len);
+  n = context->root;
+
+  if (remaining.size() == 0) [[unlikely]] {
+    context->results[index] = {n, remaining};
+    continuation = interleaved_insert::complete;
+  } else {
+    continuation = iterTable[n->getType()];
+  }
+}
+
+} // namespace interleaved_insert
 
 // Sequential implementations
 namespace {
@@ -4352,7 +4576,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   // We still have the sequential implementation for compilers that don't
   // support preserve_none and musttail
   void useSequential(const ReadRange *reads, Result *result, int count,
-                     CheckContext &context) {
+                     check::Context &context) {
     for (int i = 0; i < count; ++i) {
       if (reads[i].readVersion < oldestVersionFullPrecision) [[unlikely]] {
         result[i] = TooOld;
@@ -4384,7 +4608,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     }
 
     int64_t check_byte_accum = 0;
-    CheckContext context;
+    check::Context context;
     context.readContext.impl = this;
 
 #if __has_attribute(preserve_none) && __has_attribute(musttail)
@@ -4392,7 +4616,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       useSequential(reads, result, count, context);
     } else {
       constexpr int kConcurrent = 16;
-      CheckJob inProgress[kConcurrent];
+      check::Job inProgress[kConcurrent];
       context.count = count;
       context.oldestVersionFullPrecision = oldestVersionFullPrecision;
       context.root = root;
@@ -4420,7 +4644,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
 #ifndef NDEBUG
       Arena arena;
       auto *results2 = new (arena) Result[count];
-      CheckContext context2;
+      check::Context context2;
       context2.readContext.impl = this;
       useSequential(reads, results2, count, context2);
       assert(memcmp(result, results2, count) == 0);
@@ -4465,6 +4689,67 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     check_bytes_total.add(check_byte_accum);
   }
 
+  void interleavedPointWrites(const WriteRange *writes, int count,
+                              InternalVersionT writeVersion) {
+    // Phase 1: Search for insertion points concurrently, without modifying the
+    // structure of the tree.
+
+    if (count == 0) {
+      return;
+    }
+
+    interleaved_insert::Result stackResults[100];
+
+    constexpr int kConcurrent = 16;
+    interleaved_insert::Job inProgress[kConcurrent];
+    interleaved_insert::Context context;
+    context.writeVersion = writeVersion;
+    context.count = count;
+    context.root = root;
+    context.writes = writes;
+    context.results = stackResults;
+    if (count > int(sizeof(stackResults) / sizeof(stackResults[0])))
+        [[unlikely]] {
+      context.results = (interleaved_insert::Result *)safe_malloc(
+          count * sizeof(interleaved_insert::Result));
+    }
+    int64_t started = std::min(kConcurrent, count);
+    context.started = started;
+    for (int i = 0; i < started; i++) {
+      inProgress[i].init(&context, i);
+    }
+    for (int i = 0; i < started - 1; i++) {
+      inProgress[i].next = inProgress + i + 1;
+    }
+    for (int i = 1; i < started; i++) {
+      inProgress[i].prev = inProgress + i - 1;
+    }
+    inProgress[0].prev = inProgress + started - 1;
+    inProgress[started - 1].next = inProgress;
+
+    // Kick off the sequence of tail calls that finally returns once all jobs
+    // are done
+    inProgress->continuation(inProgress, &context);
+
+    // Phase 2: Perform insertions. Nodes may be upsized during this phase, but
+    // old nodes get forwarding pointers installed and are released after
+    // phase 2.
+
+    for (int i = 0; i < count; ++i) {
+      while (context.results[i].insertionPoint->releaseDeferred) {
+        context.results[i].insertionPoint =
+            context.results[i].insertionPoint->forwardTo;
+      }
+      addPointWrite(getInTree(context.results[i].insertionPoint, this),
+                    context.results[i].remaining, writeVersion, &writeContext);
+    }
+
+    if (count > int(sizeof(stackResults) / sizeof(stackResults[0])))
+        [[unlikely]] {
+      safe_free(context.results, count * sizeof(interleaved_insert::Result));
+    }
+  }
+
   void addWrites(const WriteRange *writes, int count, int64_t writeVersion) {
 #if !USE_64_BIT
     // There could be other conflict sets in the same thread. We need
@@ -4506,19 +4791,36 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       }
     }
 
+#if __has_attribute(preserve_none) && __has_attribute(musttail)
+    bool allPointWrites = true;
     for (int i = 0; i < count; ++i) {
-      const auto &w = writes[i];
-      writeContext.accum.write_bytes += w.begin.len + w.end.len;
-      auto begin = std::span<const uint8_t>(w.begin.p, w.begin.len);
-      auto end = std::span<const uint8_t>(w.end.p, w.end.len);
-      if (w.end.len > 0) {
-        addWriteRange(root, begin, end, InternalVersionT(writeVersion),
-                      &writeContext, this);
-      } else {
-        addPointWrite(root, begin, InternalVersionT(writeVersion),
-                      &writeContext);
+      if (writes[i].end.len > 0) {
+        allPointWrites = false;
+        break;
       }
     }
+#else
+    bool allPointWrites = false;
+#endif
+    if (allPointWrites && count > 1) {
+      interleavedPointWrites(writes, count, InternalVersionT(writeVersion));
+    } else {
+      for (int i = 0; i < count; ++i) {
+        const auto &w = writes[i];
+        writeContext.accum.write_bytes += w.begin.len + w.end.len;
+        auto begin = std::span<const uint8_t>(w.begin.p, w.begin.len);
+        auto end = std::span<const uint8_t>(w.end.p, w.end.len);
+        if (w.end.len > 0) {
+          addWriteRange(root, begin, end, InternalVersionT(writeVersion),
+                        &writeContext, this);
+        } else {
+          addPointWrite(root, begin, InternalVersionT(writeVersion),
+                        &writeContext);
+        }
+      }
+    }
+
+    writeContext.releaseDeferred();
 
     // Run gc at least 200% the rate we're inserting entries
     keyUpdates += std::max<int64_t>(writeContext.accum.entries_inserted -