Disable debug symbols and frame pointer for macos

This causes some versions of clang to crash

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.18)
 project(
   conflict-set
-  VERSION 0.0.10
+  VERSION 0.0.11
   DESCRIPTION
     "A data structure for optimistic concurrency control on ranges of bitwise-lexicographically-ordered keys."
   HOMEPAGE_URL "https://git.weaselab.dev/weaselab/conflict-set"
@@ -31,14 +31,12 @@ if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
                                                "MinSizeRel" "RelWithDebInfo")
 endif()
 
-add_compile_options(
+add_compile_options(-fdata-sections -ffunction-sections -Wswitch-enum
-  -fdata-sections
+                    -Werror=switch-enum -fPIC)
-  -ffunction-sections
+if(NOT APPLE)
-  -Wswitch-enum
+  # This causes some versions of clang to crash on macos
-  -Werror=switch-enum
+  add_compile_options(-g -fno-omit-frame-pointer)
-  -fPIC
+endif()
-  -g
-  -fno-omit-frame-pointer)
 
 set(full_relro_flags "-pie;LINKER:-z,relro,-z,now,-z,noexecstack")
 cmake_push_check_state()
@@ -342,6 +340,11 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
   add_executable(driver_perf TestDriver.cpp)
   target_compile_definitions(driver_perf PRIVATE PERF_TEST=1)
   target_link_libraries(driver_perf PRIVATE ${PROJECT_NAME})
+
+  # server bench
+  add_executable(server_bench ServerBench.cpp)
+  target_link_libraries(server_bench PRIVATE ${PROJECT_NAME})
+  set_target_properties(server_bench PROPERTIES SKIP_BUILD_RPATH ON)
 endif()
 
 # packaging

ConflictSet.cpp

@@ -902,6 +902,7 @@ Node *&getChildExists(Node *self, uint8_t index) {
 }
 
 InternalVersionT maxVersion(Node *n, ConflictSet::Impl *);
+InternalVersionT exchangeMaxVersion(Node *n, InternalVersionT newMax);
 
 void setMaxVersion(Node *n, ConflictSet::Impl *, InternalVersionT maxVersion);
 
@@ -939,6 +940,54 @@ Node *getChild(Node *self, uint8_t index) {
   }
 }
 
+struct ChildAndMaxVersion {
+  Node *child;
+  InternalVersionT maxVersion;
+};
+
+ChildAndMaxVersion getChildAndMaxVersion(Node0 *, uint8_t) { return {}; }
+ChildAndMaxVersion getChildAndMaxVersion(Node3 *self, uint8_t index) {
+  int i = getNodeIndex(self, index);
+  if (i < 0) {
+    return {};
+  }
+  return {self->children[i], self->childMaxVersion[i]};
+}
+ChildAndMaxVersion getChildAndMaxVersion(Node16 *self, uint8_t index) {
+  int i = getNodeIndex(self, index);
+  if (i < 0) {
+    return {};
+  }
+  return {self->children[i], self->childMaxVersion[i]};
+}
+ChildAndMaxVersion getChildAndMaxVersion(Node48 *self, uint8_t index) {
+  int i = self->index[index];
+  if (i < 0) {
+    return {};
+  }
+  return {self->children[i], self->childMaxVersion[i]};
+}
+ChildAndMaxVersion getChildAndMaxVersion(Node256 *self, uint8_t index) {
+  return {self->children[index], self->childMaxVersion[index]};
+}
+
+ChildAndMaxVersion getChildAndMaxVersion(Node *self, uint8_t index) {
+  switch (self->getType()) {
+  case Type_Node0:
+    return getChildAndMaxVersion(static_cast<Node0 *>(self), index);
+  case Type_Node3:
+    return getChildAndMaxVersion(static_cast<Node3 *>(self), index);
+  case Type_Node16:
+    return getChildAndMaxVersion(static_cast<Node16 *>(self), index);
+  case Type_Node48:
+    return getChildAndMaxVersion(static_cast<Node48 *>(self), index);
+  case Type_Node256:
+    return getChildAndMaxVersion(static_cast<Node256 *>(self), index);
+  default:                   // GCOVR_EXCL_LINE
+    __builtin_unreachable(); // GCOVR_EXCL_LINE
+  }
+}
+
 template <class NodeT> Node *getChildGeqSimd(NodeT *self, int child) {
   static_assert(std::is_same_v<NodeT, Node3> || std::is_same_v<NodeT, Node16>);
 
@@ -1075,8 +1124,10 @@ Node *getFirstChildExists(Node *self) {
 }
 
 // Caller is responsible for assigning a non-null pointer to the returned
-// reference if null
+// reference if null. Updates child's max version to `newMaxVersion` if child
-Node *&getOrCreateChild(Node *&self, uint8_t index, WriteContext *tls) {
+// exists but does not have a partial key.
+Node *&getOrCreateChild(Node *&self, uint8_t index,
+                        InternalVersionT newMaxVersion, WriteContext *tls) {
 
   // Fast path for if it exists already
   switch (self->getType()) {
@@ -1086,6 +1137,9 @@ Node *&getOrCreateChild(Node *&self, uint8_t index, WriteContext *tls) {
     auto *self3 = static_cast<Node3 *>(self);
     int i = getNodeIndex(self3, index);
     if (i >= 0) {
+      if (self3->children[i]->partialKeyLen == 0) {
+        self3->childMaxVersion[i] = newMaxVersion;
+      }
       return self3->children[i];
     }
   } break;
@@ -1093,6 +1147,9 @@ Node *&getOrCreateChild(Node *&self, uint8_t index, WriteContext *tls) {
     auto *self16 = static_cast<Node16 *>(self);
     int i = getNodeIndex(self16, index);
     if (i >= 0) {
+      if (self16->children[i]->partialKeyLen == 0) {
+        self16->childMaxVersion[i] = newMaxVersion;
+      }
       return self16->children[i];
     }
   } break;
@@ -1100,12 +1157,23 @@ Node *&getOrCreateChild(Node *&self, uint8_t index, WriteContext *tls) {
     auto *self48 = static_cast<Node48 *>(self);
     int secondIndex = self48->index[index];
     if (secondIndex >= 0) {
+      if (self48->children[secondIndex]->partialKeyLen == 0) {
+        self48->childMaxVersion[secondIndex] = newMaxVersion;
+        self48->maxOfMax[secondIndex >> Node48::kMaxOfMaxShift] =
+            std::max(self48->maxOfMax[secondIndex >> Node48::kMaxOfMaxShift],
+                     newMaxVersion);
+      }
       return self48->children[secondIndex];
     }
   } break;
   case Type_Node256: {
     auto *self256 = static_cast<Node256 *>(self);
     if (auto &result = self256->children[index]; result != nullptr) {
+      if (self256->children[index]->partialKeyLen == 0) {
+        self256->childMaxVersion[index] = newMaxVersion;
+        self256->maxOfMax[index >> Node256::kMaxOfMaxShift] = std::max(
+            self256->maxOfMax[index >> Node256::kMaxOfMaxShift], newMaxVersion);
+      }
       return result;
     }
   } break;
@@ -1332,6 +1400,29 @@ void maybeDecreaseCapacity(Node *&self, WriteContext *tls,
   freeAndMakeCapacityAtLeast(self, maxCapacity, tls, impl, false);
 }
 
+#if defined(HAS_AVX) && !defined(__SANITIZE_THREAD__)
+// This gets covered in local development
+// GCOVR_EXCL_START
+__attribute__((target("avx512f"))) void rezero16(InternalVersionT *vs,
+                                                 InternalVersionT zero) {
+  uint32_t z;
+  memcpy(&z, &zero, sizeof(z));
+  const auto zvec = _mm512_set1_epi32(z);
+  auto m = _mm512_cmplt_epi32_mask(
+      _mm512_sub_epi32(_mm512_loadu_epi32(vs), zvec), _mm512_setzero_epi32());
+  _mm512_mask_storeu_epi32(vs, m, zvec);
+}
+// GCOVR_EXCL_STOP
+
+__attribute__((target("default")))
+#endif
+
+void rezero16(InternalVersionT *vs, InternalVersionT zero) {
+  for (int i = 0; i < 16; ++i) {
+    vs[i] = std::max(vs[i], zero);
+  }
+}
+
 void rezero(Node *n, InternalVersionT z) {
 #if DEBUG_VERBOSE && !defined(NDEBUG)
   fprintf(stderr, "rezero to %" PRId64 ": %s\n", z.toInt64(),
@@ -1352,14 +1443,12 @@ void rezero(Node *n, InternalVersionT z) {
   } break;
   case Type_Node16: {
     auto *self = static_cast<Node16 *>(n);
-    for (int i = 0; i < 16; ++i) {
+    rezero16(self->childMaxVersion, z);
-      self->childMaxVersion[i] = std::max(self->childMaxVersion[i], z);
-    }
   } break;
   case Type_Node48: {
     auto *self = static_cast<Node48 *>(n);
-    for (int i = 0; i < 48; ++i) {
+    for (int i = 0; i < 48; i += 16) {
-      self->childMaxVersion[i] = std::max(self->childMaxVersion[i], z);
+      rezero16(self->childMaxVersion + i, z);
     }
     for (auto &m : self->maxOfMax) {
       m = std::max(m, z);
@@ -1367,12 +1456,10 @@ void rezero(Node *n, InternalVersionT z) {
   } break;
   case Type_Node256: {
     auto *self = static_cast<Node256 *>(n);
-    for (int i = 0; i < 256; ++i) {
+    for (int i = 0; i < 256; i += 16) {
-      self->childMaxVersion[i] = std::max(self->childMaxVersion[i], z);
+      rezero16(self->childMaxVersion + i, z);
-    }
-    for (auto &m : self->maxOfMax) {
-      m = std::max(m, z);
     }
+    rezero16(self->maxOfMax, z);
   } break;
   default:                   // GCOVR_EXCL_LINE
     __builtin_unreachable(); // GCOVR_EXCL_LINE
@@ -1676,7 +1763,7 @@ int firstNeqStride(const uint8_t *ap, const uint8_t *bp) {
 // This gets covered in local development
 // GCOVR_EXCL_START
 #if defined(HAS_AVX) && !defined(__SANITIZE_THREAD__)
-__attribute__((target("avx512bw"))) int
+__attribute__((target("avx512f,avx512bw"))) int
 longestCommonPrefix(const uint8_t *ap, const uint8_t *bp, int cl) {
   int i = 0;
   int end = cl & ~63;
@@ -1761,41 +1848,6 @@ int longestCommonPrefix(const uint8_t *ap, const uint8_t *bp, int cl) {
   return i;
 }
 
-// Performs a physical search for remaining
-struct SearchStepWise {
-  Node *n;
-  std::span<const uint8_t> remaining;
-
-  SearchStepWise() {}
-  SearchStepWise(Node *n, std::span<const uint8_t> remaining)
-      : n(n), remaining(remaining) {
-    assert(n->partialKeyLen == 0);
-  }
-
-  bool step() {
-    if (remaining.size() == 0) {
-      return true;
-    }
-    auto *child = getChild(n, remaining[0]);
-    if (child == nullptr) {
-      return true;
-    }
-    if (child->partialKeyLen > 0) {
-      int cl = std::min<int>(child->partialKeyLen, remaining.size() - 1);
-      int i =
-          longestCommonPrefix(child->partialKey(), remaining.data() + 1, cl);
-      if (i != child->partialKeyLen) {
-        return true;
-      }
-    }
-    n = child;
-    remaining =
-        remaining.subspan(1 + child->partialKeyLen,
-                          remaining.size() - (1 + child->partialKeyLen));
-    return false;
-  }
-};
-
 // Logically this is the same as performing firstGeq and then checking against
 // point or range version according to cmp, but this version short circuits as
 // soon as it can prove that there's no conflict.
@@ -1806,12 +1858,7 @@ bool checkPointRead(Node *n, const std::span<const uint8_t> key,
   fprintf(stderr, "Check point read: %s\n", printable(key).c_str());
 #endif
   auto remaining = key;
-  auto *impl = tls->impl;
   for (;; ++tls->point_read_iterations_accum) {
-    if (maxVersion(n, impl) <= readVersion) {
-      ++tls->point_read_short_circuit_accum;
-      return true;
-    }
     if (remaining.size() == 0) {
       if (n->entryPresent) {
         return n->entry.pointVersion <= readVersion;
@@ -1820,7 +1867,7 @@ bool checkPointRead(Node *n, const std::span<const uint8_t> key,
       goto downLeftSpine;
     }
 
-    auto *child = getChild(n, remaining[0]);
+    auto [child, maxV] = getChildAndMaxVersion(n, remaining[0]);
     if (child == nullptr) {
       auto c = getChildGeq(n, remaining[0]);
       if (c != nullptr) {
@@ -1862,6 +1909,11 @@ bool checkPointRead(Node *n, const std::span<const uint8_t> key,
         goto downLeftSpine;
       }
     }
+
+    if (maxV <= readVersion) {
+      ++tls->point_read_short_circuit_accum;
+      return true;
+    }
   }
 downLeftSpine:
   for (; !n->entryPresent; n = getFirstChildExists(n)) {
@@ -1881,17 +1933,11 @@ bool checkPrefixRead(Node *n, const std::span<const uint8_t> key,
   auto remaining = key;
   auto *impl = tls->impl;
   for (;; ++tls->prefix_read_iterations_accum) {
-    auto m = maxVersion(n, impl);
     if (remaining.size() == 0) {
-      return m <= readVersion;
+      return maxVersion(n, impl) <= readVersion;
     }
 
-    if (m <= readVersion) {
+    auto [child, maxV] = getChildAndMaxVersion(n, remaining[0]);
-      ++tls->prefix_read_short_circuit_accum;
-      return true;
-    }
-
-    auto *child = getChild(n, remaining[0]);
     if (child == nullptr) {
       auto c = getChildGeq(n, remaining[0]);
       if (c != nullptr) {
@@ -1937,6 +1983,11 @@ bool checkPrefixRead(Node *n, const std::span<const uint8_t> key,
         goto downLeftSpine;
       }
     }
+
+    if (maxV <= readVersion) {
+      ++tls->prefix_read_short_circuit_accum;
+      return true;
+    }
   }
 downLeftSpine:
   for (; !n->entryPresent; n = getFirstChildExists(n)) {
@@ -2053,13 +2104,9 @@ bool scan16(const InternalVersionT *vs, const uint8_t *is, int begin, int end,
 }
 
 // Returns true if v[i] <= readVersion for all i such that begin <= i < end
-//
-// always_inline So that we can optimize when begin or end is a constant.
-// gcovr exclude annotation necessary because of always_inline?
 template <bool kAVX512>
-inline __attribute__((always_inline)) bool
+bool scan16(const InternalVersionT *vs, int begin, int end,
-scan16(const InternalVersionT *vs, int begin, int end, // GCOVR_EXCL_LINE
+            InternalVersionT readVersion) {
-       InternalVersionT readVersion) {                 // GCOVR_EXCL_LINE
   assert(0 <= begin && begin < 16);
   assert(0 <= end && end <= 16);
   assert(begin <= end);
@@ -2114,8 +2161,9 @@ scan16(const InternalVersionT *vs, int begin, int end, // GCOVR_EXCL_LINE
 // path of n + [child], where child in (begin, end) is <= readVersion. Does not
 // account for the range version of firstGt(searchpath(n) + [end - 1])
 template <bool kAVX512>
-bool checkMaxBetweenExclusive(Node *n, int begin, int end,
+bool checkMaxBetweenExclusiveImpl(Node *n, int begin, int end,
-                              InternalVersionT readVersion, ReadContext *tls) {
+                                  InternalVersionT readVersion,
+                                  ReadContext *tls) {
   ++tls->range_read_node_scan_accum;
   assume(-1 <= begin);
   assume(begin <= 256);
@@ -2147,7 +2195,7 @@ bool checkMaxBetweenExclusive(Node *n, int begin, int end,
     if (!mask) {
       return true;
     }
-    auto *child = self->children[__builtin_ctz(mask)];
+    auto *child = self->children[std::countr_zero(mask)];
     const bool firstRangeOk =
         !child->entryPresent || child->entry.rangeVersion <= readVersion;
     uint32_t compared = 0;
@@ -2182,7 +2230,7 @@ bool checkMaxBetweenExclusive(Node *n, int begin, int end,
     if (!mask) {
       return true;
     }
-    auto *child = self->children[__builtin_ctzll(mask) >> 2];
+    auto *child = self->children[std::countr_zero(mask) >> 2];
     const bool firstRangeOk =
         !child->entryPresent || child->entry.rangeVersion <= readVersion;
 
@@ -2222,7 +2270,7 @@ bool checkMaxBetweenExclusive(Node *n, int begin, int end,
     if (!mask) {
       return true;
     }
-    auto *child = self->children[__builtin_ctz(mask)];
+    auto *child = self->children[std::countr_zero(mask)];
     const bool firstRangeOk =
         !child->entryPresent || child->entry.rangeVersion <= readVersion;
 
@@ -2253,7 +2301,7 @@ bool checkMaxBetweenExclusive(Node *n, int begin, int end,
     if (!mask) {
       return true;
     }
-    auto *child = self->children[__builtin_ctz(mask)];
+    auto *child = self->children[std::countr_zero(mask)];
     const bool firstRangeOk =
         !child->entryPresent || child->entry.rangeVersion <= readVersion;
     uint32_t compared = 0;
@@ -2363,6 +2411,22 @@ bool checkMaxBetweenExclusive(Node *n, int begin, int end,
   }
 }
 
+#if defined(HAS_AVX) && !defined(__SANITIZE_THREAD__)
+// This gets covered in local development
+// GCOVR_EXCL_START
+__attribute__((target("avx512f"))) bool
+checkMaxBetweenExclusive(Node *n, int begin, int end,
+                         InternalVersionT readVersion, ReadContext *tls) {
+  return checkMaxBetweenExclusiveImpl<true>(n, begin, end, readVersion, tls);
+}
+// GCOVR_EXCL_STOP
+__attribute__((target("default")))
+#endif
+bool checkMaxBetweenExclusive(Node *n, int begin, int end,
+                         InternalVersionT readVersion, ReadContext *tls) {
+  return checkMaxBetweenExclusiveImpl<false>(n, begin, end, readVersion, tls);
+}
+
 Vector<uint8_t> getSearchPath(Arena &arena, Node *n) {
   assert(n != nullptr);
   auto result = vector<uint8_t>(arena);
@@ -2385,7 +2449,6 @@ Vector<uint8_t> getSearchPath(Arena &arena, Node *n) {
 //
 // Precondition: transitively, no child of n has a search path that's a longer
 // prefix of key than n
-template <bool kAVX512>
 bool checkRangeStartsWith(Node *n, std::span<const uint8_t> key, int begin,
                           int end, InternalVersionT readVersion,
                           ReadContext *tls) {
@@ -2395,7 +2458,7 @@ bool checkRangeStartsWith(Node *n, std::span<const uint8_t> key, int begin,
   auto remaining = key;
   auto *impl = tls->impl;
   if (remaining.size() == 0) {
-    return checkMaxBetweenExclusive<kAVX512>(n, begin, end, readVersion, tls);
+    return checkMaxBetweenExclusive(n, begin, end, readVersion, tls);
   }
 
   auto *child = getChild(n, remaining[0]);
@@ -2454,7 +2517,7 @@ downLeftSpine:
 namespace {
 // Return true if the max version among all keys that start with key[:prefixLen]
 // that are >= key is <= readVersion
-template <bool kAVX512> struct CheckRangeLeftSide {
+struct CheckRangeLeftSide {
   CheckRangeLeftSide(Node *n, std::span<const uint8_t> key, int prefixLen,
                      InternalVersionT readVersion, ReadContext *tls)
       : n(n), remaining(key), prefixLen(prefixLen), readVersion(readVersion),
@@ -2476,10 +2539,6 @@ template <bool kAVX512> struct CheckRangeLeftSide {
   bool ok;
 
   bool step() {
-    if (maxVersion(n, impl) <= readVersion) {
-      ok = true;
-      return true;
-    }
     if (remaining.size() == 0) {
       assert(searchPathLen >= prefixLen);
       ok = maxVersion(n, impl) <= readVersion;
@@ -2487,14 +2546,13 @@ template <bool kAVX512> struct CheckRangeLeftSide {
     }
 
     if (searchPathLen >= prefixLen) {
-      if (!checkMaxBetweenExclusive<kAVX512>(n, remaining[0], 256, readVersion,
+      if (!checkMaxBetweenExclusive(n, remaining[0], 256, readVersion, tls)) {
-                                             tls)) {
         ok = false;
         return true;
       }
     }
 
-    auto *child = getChild(n, remaining[0]);
+    auto [child, maxV] = getChildAndMaxVersion(n, remaining[0]);
     if (child == nullptr) {
       auto c = getChildGeq(n, remaining[0]);
       if (c != nullptr) {
@@ -2557,6 +2615,10 @@ template <bool kAVX512> struct CheckRangeLeftSide {
         return true;
       }
     }
+    if (maxV <= readVersion) {
+      ok = true;
+      return true;
+    }
     return false;
   }
 
@@ -2570,7 +2632,7 @@ template <bool kAVX512> struct CheckRangeLeftSide {
 
 // Return true if the max version among all keys that start with key[:prefixLen]
 // that are < key is <= readVersion
-template <bool kAVX512> struct CheckRangeRightSide {
+struct CheckRangeRightSide {
   CheckRangeRightSide(Node *n, std::span<const uint8_t> key, int prefixLen,
                       InternalVersionT readVersion, ReadContext *tls)
       : n(n), key(key), remaining(key), prefixLen(prefixLen),
@@ -2613,8 +2675,7 @@ template <bool kAVX512> struct CheckRangeRightSide {
         return true;
       }
 
-      if (!checkMaxBetweenExclusive<kAVX512>(n, -1, remaining[0], readVersion,
+      if (!checkMaxBetweenExclusive(n, -1, remaining[0], readVersion, tls)) {
-                                             tls)) {
         ok = false;
         return true;
       }
@@ -2701,10 +2762,9 @@ template <bool kAVX512> struct CheckRangeRightSide {
 };
 } // namespace
 
-template <bool kAVX512>
+bool checkRangeRead(Node *n, std::span<const uint8_t> begin,
-bool checkRangeReadImpl(Node *n, std::span<const uint8_t> begin,
+                    std::span<const uint8_t> end, InternalVersionT readVersion,
-                        std::span<const uint8_t> end,
+                    ReadContext *tls) {
-                        InternalVersionT readVersion, ReadContext *tls) {
   int lcp = longestCommonPrefix(begin.data(), end.data(),
                                 std::min(begin.size(), end.size()));
   if (lcp == int(begin.size()) && end.size() == begin.size() + 1 &&
@@ -2718,50 +2778,63 @@ bool checkRangeReadImpl(Node *n, std::span<const uint8_t> begin,
 
   ++tls->range_read_accum;
 
-  SearchStepWise search{n, begin.subspan(0, lcp)};
+  auto remaining = begin.subspan(0, lcp);
   Arena arena;
-  auto *impl = tls->impl;
+  // If the common prefix isn't a prefix of any physical entry in the tree, we
+  // can go to "downLeftSpine"
   for (;; ++tls->range_read_iterations_accum) {
-    assert(getSearchPath(arena, search.n) <=>
+    assert(getSearchPath(arena, n) <=>
-               begin.subspan(0, lcp - search.remaining.size()) ==
+               begin.subspan(0, lcp - remaining.size()) ==
            0);
-    if (maxVersion(search.n, impl) <= readVersion) {
+    if (remaining.size() == 0) {
+      break;
+    }
+    auto [child, v] = getChildAndMaxVersion(n, remaining[0]);
+    if (child == nullptr) {
+      break;
+    }
+
+    if (child->partialKeyLen > 0) {
+      int cl = std::min<int>(child->partialKeyLen, remaining.size() - 1);
+      int i =
+          longestCommonPrefix(child->partialKey(), remaining.data() + 1, cl);
+      if (i != child->partialKeyLen) {
+        break;
+      }
+    }
+    if (v <= readVersion) {
       ++tls->range_read_short_circuit_accum;
       return true;
     }
-    if (search.step()) {
+    n = child;
-      break;
+    remaining =
-    }
+        remaining.subspan(1 + child->partialKeyLen,
+                          remaining.size() - (1 + child->partialKeyLen));
   }
-  assert(getSearchPath(arena, search.n) <=>
+  assert(getSearchPath(arena, n) <=> begin.subspan(0, lcp - remaining.size()) ==
-             begin.subspan(0, lcp - search.remaining.size()) ==
          0);
 
-  const int consumed = lcp - search.remaining.size();
+  const int consumed = lcp - remaining.size();
   assume(consumed >= 0);
 
   begin = begin.subspan(consumed, int(begin.size()) - consumed);
   end = end.subspan(consumed, int(end.size()) - consumed);
-  n = search.n;
   lcp -= consumed;
 
   if (lcp == int(begin.size())) {
-    CheckRangeRightSide<kAVX512> checkRangeRightSide{n, end, lcp, readVersion,
+    CheckRangeRightSide checkRangeRightSide{n, end, lcp, readVersion, tls};
-                                                     tls};
     while (!checkRangeRightSide.step())
       ;
     return checkRangeRightSide.ok;
   }
 
-  if (!checkRangeStartsWith<kAVX512>(n, begin.subspan(0, lcp), begin[lcp],
+  if (!checkRangeStartsWith(n, begin.subspan(0, lcp), begin[lcp], end[lcp],
-                                     end[lcp], readVersion, tls)) {
+                            readVersion, tls)) {
     return false;
   }
 
-  CheckRangeLeftSide<kAVX512> checkRangeLeftSide{n, begin, lcp + 1, readVersion,
+  CheckRangeLeftSide checkRangeLeftSide{n, begin, lcp + 1, readVersion, tls};
-                                                 tls};
+  CheckRangeRightSide checkRangeRightSide{n, end, lcp + 1, readVersion, tls};
-  CheckRangeRightSide<kAVX512> checkRangeRightSide{n, end, lcp + 1, readVersion,
-                                                   tls};
 
   for (;;) {
     bool leftDone = checkRangeLeftSide.step();
@@ -2796,138 +2869,101 @@ bool checkRangeReadImpl(Node *n, std::span<const uint8_t> begin,
 template __attribute__((target("avx512f"))) bool
 scan16<true>(const InternalVersionT *vs, const uint8_t *is, int begin, int end,
              InternalVersionT readVersion);
-template __attribute__((always_inline, target("avx512f"))) bool
+template __attribute__((target("avx512f"))) bool
 scan16<true>(const InternalVersionT *vs, int begin, int end,
              InternalVersionT readVersion);
 template __attribute__((target("avx512f"))) bool
-checkMaxBetweenExclusive<true>(Node *n, int begin, int end,
+checkMaxBetweenExclusiveImpl<true>(Node *n, int begin, int end,
-                               InternalVersionT readVersion, ReadContext *);
+                                   InternalVersionT readVersion, ReadContext *);
-template __attribute__((target("avx512f"))) bool
-checkRangeStartsWith<true>(Node *n, std::span<const uint8_t> key, int begin,
-                           int end, InternalVersionT readVersion,
-                           ReadContext *);
-template __attribute__((target("avx512f"))) bool
-CheckRangeLeftSide<true>::step();
-template __attribute__((target("avx512f"))) bool
-CheckRangeRightSide<true>::step();
-template __attribute__((target("avx512f"))) bool
-checkRangeReadImpl<true>(Node *n, std::span<const uint8_t> begin,
-                         std::span<const uint8_t> end,
-                         InternalVersionT readVersion, ReadContext *);
 #endif
 
-#if defined(__SANITIZE_THREAD__) || !defined(__x86_64__)
+// Consume the partial key of `self` (which must exist), and update `self` and
-bool checkRangeRead(Node *n, std::span<const uint8_t> begin,
+// `key` such that `self` is along the search path of `key`
-                    std::span<const uint8_t> end, InternalVersionT readVersion,
+void consumePartialKey(Node *&self, std::span<const uint8_t> &key,
-                    ReadContext *tls) {
+                       InternalVersionT writeVersion, WriteContext *tls) {
-  return checkRangeReadImpl<false>(n, begin, end, readVersion, tls);
+  assert(self->partialKeyLen > 0);
+  // Handle an existing partial key
+  int commonLen = std::min<int>(self->partialKeyLen, key.size());
+  int partialKeyIndex =
+      longestCommonPrefix(self->partialKey(), key.data(), commonLen);
+  if (partialKeyIndex < self->partialKeyLen) {
+    auto *old = self;
+    // Since root cannot have a partial key
+    assert(old->parent != nullptr);
+    InternalVersionT oldMaxVersion = exchangeMaxVersion(old, writeVersion);
+
+    // *self will have one child (old)
+    auto *newSelf = tls->allocate<Node3>(partialKeyIndex);
+
+    newSelf->parent = old->parent;
+    newSelf->parentsIndex = old->parentsIndex;
+    newSelf->partialKeyLen = partialKeyIndex;
+    newSelf->entryPresent = false;
+    newSelf->numChildren = 1;
+
+    memcpy(newSelf->partialKey(), old->partialKey(), newSelf->partialKeyLen);
+
+    uint8_t oldDistinguishingByte = old->partialKey()[partialKeyIndex];
+    old->parent = newSelf;
+    old->parentsIndex = oldDistinguishingByte;
+    newSelf->index[0] = oldDistinguishingByte;
+    newSelf->children[0] = old;
+    newSelf->childMaxVersion[0] = oldMaxVersion;
+    self = newSelf;
+
+    memmove(old->partialKey(), old->partialKey() + partialKeyIndex + 1,
+            old->partialKeyLen - (partialKeyIndex + 1));
+    old->partialKeyLen -= partialKeyIndex + 1;
+
+    // We would consider decreasing capacity here, but we can't invalidate
+    // old since it's not on the search path. setOldestVersion will clean it
+    // up.
+  }
+  key = key.subspan(partialKeyIndex, key.size() - partialKeyIndex);
 }
-#else
-// Only one of these is ever exercised. I'm not worried about somehow not
-// calling one of these though.
-// GCOVR_EXCL_START
-__attribute__((target("default"))) bool
-checkRangeRead(Node *n, std::span<const uint8_t> begin,
-               std::span<const uint8_t> end, InternalVersionT readVersion,
-               ReadContext *tls) {
-  return checkRangeReadImpl<false>(n, begin, end, readVersion, tls);
-}
-__attribute__((target("avx512f"))) bool
-checkRangeRead(Node *n, std::span<const uint8_t> begin,
-               std::span<const uint8_t> end, InternalVersionT readVersion,
-               ReadContext *tls) {
-  return checkRangeReadImpl<true>(n, begin, end, readVersion, tls);
-}
-// GCOVR_EXCL_STOP
-#endif
 
 // Returns a pointer to the newly inserted node.  Caller must set
-// `entryPresent`, `entry` fields and `maxVersion` on the result.  The search
+// `entryPresent`, and `entry` fields.  All nodes along the search path of the
-// path of the result's parent will have `maxVersion` at least `writeVersion` as
+// result will have `maxVersion` set to `writeVersion` as a postcondition. Nodes
-// a postcondition. Nodes along the search path to `key` may be invalidated.
+// along the search path may be invalidated.
-template <bool kBegin>
+[[nodiscard]]
-[[nodiscard]] Node *insert(Node **self, std::span<const uint8_t> key,
+Node *insert(Node **self, std::span<const uint8_t> key,
-                           InternalVersionT writeVersion, WriteContext *tls,
+             InternalVersionT writeVersion, WriteContext *tls,
-                           ConflictSet::Impl *impl) {
+             ConflictSet::Impl *impl) {
+
+  if ((*self)->partialKeyLen > 0) {
+    consumePartialKey(*self, key, writeVersion, tls);
+  }
+  assert(maxVersion(*self, impl) <= writeVersion);
+  setMaxVersion(*self, impl, writeVersion);
 
   for (;; ++tls->accum.insert_iterations) {
 
-    if ((*self)->partialKeyLen > 0) {
-      // Handle an existing partial key
-      int commonLen = std::min<int>((*self)->partialKeyLen, key.size());
-      int partialKeyIndex =
-          longestCommonPrefix((*self)->partialKey(), key.data(), commonLen);
-      if (partialKeyIndex < (*self)->partialKeyLen) {
-        auto *old = *self;
-        InternalVersionT oldMaxVersion = maxVersion(old, impl);
-
-        // *self will have one child
-        *self = tls->allocate<Node3>(partialKeyIndex);
-
-        memcpy((char *)*self + kNodeCopyBegin, (char *)old + kNodeCopyBegin,
-               kNodeCopySize);
-        (*self)->partialKeyLen = partialKeyIndex;
-
-        // Not necessary to call removeKey here, since this node is "synthetic"
-        (*self)->entryPresent = false;
-
-        (*self)->numChildren = 0;
-        memcpy((*self)->partialKey(), old->partialKey(),
-               (*self)->partialKeyLen);
-
-        getOrCreateChild(*self, old->partialKey()[partialKeyIndex], tls) = old;
-        old->parent = *self;
-        old->parentsIndex = old->partialKey()[partialKeyIndex];
-        setMaxVersion(old, impl, oldMaxVersion);
-
-        memmove(old->partialKey(), old->partialKey() + partialKeyIndex + 1,
-                old->partialKeyLen - (partialKeyIndex + 1));
-        old->partialKeyLen -= partialKeyIndex + 1;
-
-        // We would consider decreasing capacity here, but we can't invalidate
-        // old since it's not on the search path. setOldestVersion will clean it
-        // up.
-      }
-      key = key.subspan(partialKeyIndex, key.size() - partialKeyIndex);
-
-    } else {
-      // Consider adding a partial key
-      if ((*self)->numChildren == 0 && !(*self)->entryPresent) {
-        assert((*self)->getCapacity() >= int(key.size()));
-        (*self)->partialKeyLen = key.size();
-        memcpy((*self)->partialKey(), key.data(), (*self)->partialKeyLen);
-        key = key.subspan((*self)->partialKeyLen,
-                          key.size() - (*self)->partialKeyLen);
-      }
-    }
-
-    if constexpr (kBegin) {
-      assert(maxVersion(*self, impl) <= writeVersion);
-      setMaxVersion(*self, impl, writeVersion);
-    }
-
     if (key.size() == 0) {
       return *self;
     }
 
-    if constexpr (!kBegin) {
+    auto &child = getOrCreateChild(*self, key.front(), writeVersion, tls);
-      assert(maxVersion(*self, impl) <= writeVersion);
-      setMaxVersion(*self, impl, writeVersion);
-    }
-
-    auto &child = getOrCreateChild(*self, key.front(), tls);
     if (!child) {
       child = tls->allocate<Node0>(key.size() - 1);
       child->numChildren = 0;
       child->entryPresent = false;
-      child->partialKeyLen = 0;
+      child->partialKeyLen = key.size() - 1;
       child->parent = *self;
       child->parentsIndex = key.front();
-      setMaxVersion(child, impl, kBegin ? writeVersion : tls->zero);
+      setMaxVersion(child, impl, writeVersion);
+      memcpy(child->partialKey(), key.data() + 1, child->partialKeyLen);
+      return child;
     }
 
     self = &child;
     key = key.subspan(1, key.size() - 1);
+
+    if ((*self)->partialKeyLen > 0) {
+      consumePartialKey(*self, key, writeVersion, tls);
+      assert(maxVersion(*self, impl) <= writeVersion);
+      setMaxVersion(*self, impl, writeVersion);
+    }
   }
 }
 
@@ -2960,7 +2996,7 @@ void addPointWrite(Node *&root, std::span<const uint8_t> key,
                    InternalVersionT writeVersion, WriteContext *tls,
                    ConflictSet::Impl *impl) {
   ++tls->accum.point_writes;
-  auto *n = insert<true>(&root, key, writeVersion, tls, impl);
+  auto *n = insert(&root, key, writeVersion, tls, impl);
   if (!n->entryPresent) {
     ++tls->accum.entries_inserted;
     auto *p = nextLogical(n);
@@ -2969,7 +3005,6 @@ void addPointWrite(Node *&root, std::span<const uint8_t> key,
     n->entryPresent = true;
 
     n->entry.pointVersion = writeVersion;
-    setMaxVersion(n, impl, writeVersion);
     n->entry.rangeVersion =
         p == nullptr ? tls->zero : std::max(p->entry.rangeVersion, tls->zero);
   } else {
@@ -2978,6 +3013,44 @@ void addPointWrite(Node *&root, std::span<const uint8_t> key,
   }
 }
 
+// Precondition: `node->entryPresent`
+void fixupMaxVersion(Node *node, ConflictSet::Impl *impl, WriteContext *tls) {
+  InternalVersionT max;
+  assert(node->entryPresent);
+  max = std::max(node->entry.pointVersion, tls->zero);
+  switch (node->getType()) {
+  case Type_Node0:
+    break;
+  case Type_Node3: {
+    auto *self3 = static_cast<Node3 *>(node);
+    for (int i = 0; i < self3->numChildren; ++i) {
+      max = std::max(self3->childMaxVersion[i], max);
+    }
+  } break;
+  case Type_Node16: {
+    auto *self16 = static_cast<Node16 *>(node);
+    for (int i = 0; i < self16->numChildren; ++i) {
+      max = std::max(self16->childMaxVersion[i], max);
+    }
+  } break;
+  case Type_Node48: {
+    auto *self48 = static_cast<Node48 *>(node);
+    for (auto v : self48->maxOfMax) {
+      max = std::max(v, max);
+    }
+  } break;
+  case Type_Node256: {
+    auto *self256 = static_cast<Node256 *>(node);
+    for (auto v : self256->maxOfMax) {
+      max = std::max(v, max);
+    }
+  } break;
+  default:                   // GCOVR_EXCL_LINE
+    __builtin_unreachable(); // GCOVR_EXCL_LINE
+  }
+  setMaxVersion(node, impl, max);
+}
+
 void addWriteRange(Node *&root, std::span<const uint8_t> begin,
                    std::span<const uint8_t> end, InternalVersionT writeVersion,
                    WriteContext *tls, ConflictSet::Impl *impl) {
@@ -3024,7 +3097,7 @@ void addWriteRange(Node *&root, std::span<const uint8_t> begin,
   begin = begin.subspan(consumed, begin.size() - consumed);
   end = end.subspan(consumed, end.size() - consumed);
 
-  auto *beginNode = insert<true>(useAsRoot, begin, writeVersion, tls, impl);
+  auto *beginNode = insert(useAsRoot, begin, writeVersion, tls, impl);
 
   const bool insertedBegin = !beginNode->entryPresent;
 
@@ -3037,14 +3110,11 @@ void addWriteRange(Node *&root, std::span<const uint8_t> begin,
     beginNode->entry.rangeVersion =
         p == nullptr ? tls->zero : std::max(p->entry.rangeVersion, tls->zero);
     beginNode->entry.pointVersion = writeVersion;
-    assert(maxVersion(beginNode, impl) <= writeVersion);
-    setMaxVersion(beginNode, impl, writeVersion);
   }
-  setMaxVersion(beginNode, impl, writeVersion);
   assert(writeVersion >= beginNode->entry.pointVersion);
   beginNode->entry.pointVersion = writeVersion;
 
-  auto *endNode = insert<false>(useAsRoot, end, writeVersion, tls, impl);
+  auto *endNode = insert(useAsRoot, end, writeVersion, tls, impl);
 
   const bool insertedEnd = !endNode->entryPresent;
 
@@ -3056,22 +3126,22 @@ void addWriteRange(Node *&root, std::span<const uint8_t> begin,
     auto *p = nextLogical(endNode);
     endNode->entry.pointVersion =
         p == nullptr ? tls->zero : std::max(p->entry.rangeVersion, tls->zero);
-    auto m = maxVersion(endNode, impl);
-    setMaxVersion(endNode, impl,
-                  std::max<InternalVersionT>(m, endNode->entry.pointVersion));
   }
   endNode->entry.rangeVersion = writeVersion;
 
   if (beginIsPrefix && insertedEnd) {
     // beginNode may have been invalidated when inserting end. TODO can we do
     // better?
-    beginNode = insert<true>(useAsRoot, begin, writeVersion, tls, impl);
+    beginNode = insert(useAsRoot, begin, writeVersion, tls, impl);
     assert(beginNode->entryPresent);
   }
 
   for (beginNode = nextLogical(beginNode); beginNode != endNode;
        beginNode = erase(beginNode, tls, impl, /*logical*/ true, endNode)) {
   }
+
+  // Inserting end trashed endNode's maxVersion. Fix that
+  fixupMaxVersion(endNode, impl, tls);
 }
 
 Node *firstGeqPhysical(Node *n, const std::span<const uint8_t> key) {
@@ -3488,6 +3558,39 @@ InternalVersionT maxVersion(Node *n, ConflictSet::Impl *impl) {
   }
 }
 
+// Precondition `n` is not the root
+InternalVersionT exchangeMaxVersion(Node *n, InternalVersionT newMax) {
+  int index = n->parentsIndex;
+  n = n->parent;
+  assert(n != nullptr);
+  switch (n->getType()) {
+  case Type_Node0:           // GCOVR_EXCL_LINE
+    __builtin_unreachable(); // GCOVR_EXCL_LINE
+  case Type_Node3: {
+    auto *n3 = static_cast<Node3 *>(n);
+    int i = getNodeIndex(n3, index);
+    return std::exchange(n3->childMaxVersion[i], newMax);
+  }
+  case Type_Node16: {
+    auto *n16 = static_cast<Node16 *>(n);
+    int i = getNodeIndex(n16, index);
+    return std::exchange(n16->childMaxVersion[i], newMax);
+  }
+  case Type_Node48: {
+    auto *n48 = static_cast<Node48 *>(n);
+    assert(n48->bitSet.test(index));
+    return std::exchange(n48->childMaxVersion[n48->index[index]], newMax);
+  }
+  case Type_Node256: {
+    auto *n256 = static_cast<Node256 *>(n);
+    assert(n256->bitSet.test(index));
+    return std::exchange(n256->childMaxVersion[index], newMax);
+  }
+  default:                   // GCOVR_EXCL_LINE
+    __builtin_unreachable(); // GCOVR_EXCL_LINE
+  }
+}
+
 void setMaxVersion(Node *n, ConflictSet::Impl *impl, InternalVersionT newMax) {
   int index = n->parentsIndex;
   n = n->parent;
@@ -3998,6 +4101,10 @@ checkMaxVersion(Node *root, Node *node, InternalVersionT oldestVersion,
                                        ConflictSet::Impl *impl) {
   bool success = true;
 
+  if (node->partialKeyLen > 0) {
+    fprintf(stderr, "Root cannot have a partial key");
+    success = false;
+  }
   checkParentPointers(node, success);
   checkMaxVersion(node, node, oldestVersion, success, impl);
   checkEntriesExist(node, success);

README.md

@@ -24,15 +24,15 @@ Hardware for all benchmarks is an AMD Ryzen 9 7900 with (2x32GB) 5600MT/s CL28-3
 
 |               ns/op |                op/s |    err% |          ins/op |          cyc/op |    IPC |         bra/op |   miss% |     total | benchmark
 |--------------------:|--------------------:|--------:|----------------:|----------------:|-------:|---------------:|--------:|----------:|:----------
-|               17.03 |       58,732,967.93 |    0.6% |          276.28 |           87.96 |  3.141 |          52.15 |    0.4% |      0.01 | `point reads`
+|               12.42 |       80,500,398.66 |    0.8% |          180.38 |           61.57 |  2.930 |          41.51 |    0.4% |      0.01 | `point reads`
-|               19.52 |       51,239,158.04 |    0.3% |          367.16 |          101.50 |  3.617 |          61.92 |    0.3% |      0.01 | `prefix reads`
+|               15.17 |       65,917,580.99 |    0.2% |          279.47 |           74.95 |  3.729 |          55.54 |    0.3% |      0.01 | `prefix reads`
-|               47.74 |       20,947,676.63 |    0.5% |          998.16 |          247.43 |  4.034 |         161.64 |    0.2% |      0.01 | `range reads`
+|               38.16 |       26,202,393.91 |    0.1% |          803.07 |          189.13 |  4.246 |         141.68 |    0.2% |      0.01 | `range reads`
-|               23.14 |       43,207,824.89 |    0.4% |          408.18 |          121.64 |  3.356 |          70.20 |    0.3% |      0.01 | `point writes`
+|               20.20 |       49,504,615.44 |    0.4% |          363.00 |          100.35 |  3.617 |          49.81 |    0.3% |      0.01 | `point writes`
-|               38.02 |       26,302,115.66 |    0.1% |          709.72 |          199.70 |  3.554 |         134.26 |    0.3% |      0.01 | `prefix writes`
+|               41.99 |       23,816,559.99 |    0.3% |          799.27 |          209.63 |  3.813 |         154.32 |    0.1% |      0.01 | `prefix writes`
-|               44.28 |       22,583,559.17 |    0.9% |          825.19 |          233.10 |  3.540 |         141.48 |    0.2% |      0.01 | `range writes`
+|               46.28 |       21,607,605.88 |    1.5% |          953.79 |          231.47 |  4.121 |         168.34 |    0.0% |      0.01 | `range writes`
-|               85.50 |       11,695,990.63 |    0.5% |        1,488.16 |          455.68 |  3.266 |         289.22 |    0.1% |      0.01 | `monotonic increasing point writes`
+|               80.99 |       12,347,449.98 |    0.9% |        1,501.97 |          406.50 |  3.695 |         281.89 |    0.1% |      0.01 | `monotonic increasing point writes`
-|          338,388.50 |            2,955.18 |    3.3% |    4,097,087.00 |    1,809,996.00 |  2.264 |     759,645.00 |    0.0% |      0.01 | `worst case for radix tree`
+|          318,010.00 |            3,144.56 |    1.0% |    3,994,511.50 |    1,657,831.50 |  2.409 |     805,969.50 |    0.0% |      0.01 | `worst case for radix tree`
-|               84.84 |       11,787,313.59 |    1.4% |        1,716.02 |          440.50 |  3.896 |         271.00 |    0.0% |      0.01 | `create and destroy`
+|               75.85 |       13,183,612.56 |    0.5% |        1,590.01 |          385.64 |  4.123 |         258.00 |    0.0% |      0.01 | `create and destroy`
 
 # "Real data" test
 
@@ -47,7 +47,7 @@ Check: 4.47891 seconds, 364.05 MB/s, Add: 4.55599 seconds, 123.058 MB/s, Gc rati
 ## radix tree
 
 ```
-Check: 1.05813 seconds, 1540.97 MB/s, Add: 1.32071 seconds, 424.508 MB/s, Gc ratio: 42.2067%
+Check: 0.963721 seconds, 1691.93 MB/s, Add: 1.3288 seconds, 421.924 MB/s, Gc ratio: 42.8819%
 ```
 
 ## hash table

ServerBench.cpp

@@ -0,0 +1,233 @@
+#include <atomic>
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <string>
+#include <string_view>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <thread>
+#include <unistd.h>
+
+#include "ConflictSet.h"
+#include "third_party/nadeau.h"
+
+std::atomic<int64_t> transactions;
+
+constexpr int kBaseSearchDepth = 32;
+constexpr int kWindowSize = 10000000;
+
+std::basic_string<uint8_t> numToKey(int64_t num) {
+  std::basic_string<uint8_t> result;
+  result.resize(kBaseSearchDepth + sizeof(int64_t));
+  memset(result.data(), 0, kBaseSearchDepth);
+  int64_t be = __builtin_bswap64(num);
+  memcpy(result.data() + kBaseSearchDepth, &be, sizeof(int64_t));
+  return result;
+}
+
+void workload(weaselab::ConflictSet *cs) {
+  int64_t version = kWindowSize;
+  cs->addWrites(nullptr, 0, version);
+  for (;; transactions.fetch_add(1, std::memory_order_relaxed)) {
+    // Reads
+    {
+      auto beginK = numToKey(version - kWindowSize);
+      auto endK = numToKey(version - 1);
+      auto pointRv = version - kWindowSize + rand() % kWindowSize + 1;
+      auto pointK = numToKey(pointRv);
+      weaselab::ConflictSet::ReadRange reads[] = {
+          {
+              {pointK.data(), int(pointK.size())},
+              {nullptr, 0},
+              pointRv,
+          },
+          {
+              {beginK.data(), int(beginK.size())},
+              {endK.data(), int(endK.size())},
+              version - 2,
+          },
+      };
+      weaselab::ConflictSet::Result result[sizeof(reads) / sizeof(reads[0])];
+      cs->check(reads, result, sizeof(reads) / sizeof(reads[0]));
+      // for (int i = 0; i < sizeof(reads) / sizeof(reads[0]); ++i) {
+      //   if (result[i] != weaselab::ConflictSet::Commit) {
+      //     fprintf(stderr, "Unexpected conflict: [%s, %s) @ %" PRId64 "\n",
+      //             printable(reads[i].begin).c_str(),
+      //             printable(reads[i].end).c_str(), reads[i].readVersion);
+      //     abort();
+      //   }
+      // }
+    }
+    // Writes
+    {
+      weaselab::ConflictSet::WriteRange w;
+      auto k = numToKey(version);
+      w.begin.p = k.data();
+      w.end.len = 0;
+      if (version % (kWindowSize / 2) == 0) {
+        for (int l = 0; l <= k.size(); ++l) {
+          w.begin.len = l;
+          cs->addWrites(&w, 1, version);
+        }
+      } else {
+        w.begin.len = k.size();
+        cs->addWrites(&w, 1, version);
+      }
+    }
+    // GC
+    cs->setOldestVersion(version - kWindowSize);
+    ++version;
+  }
+}
+
+// Adapted from getaddrinfo man page
+int getListenFd(const char *node, const char *service) {
+
+  struct addrinfo hints;
+  struct addrinfo *result, *rp;
+  int sfd, s;
+
+  memset(&hints, 0, sizeof(hints));
+  hints.ai_family = AF_UNSPEC;     /* Allow IPv4 or IPv6 */
+  hints.ai_socktype = SOCK_STREAM; /* stream socket */
+  hints.ai_flags = AI_PASSIVE;     /* For wildcard IP address */
+  hints.ai_protocol = 0;           /* Any protocol */
+  hints.ai_canonname = nullptr;
+  hints.ai_addr = nullptr;
+  hints.ai_next = nullptr;
+
+  s = getaddrinfo(node, service, &hints, &result);
+  if (s != 0) {
+    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
+    abort();
+  }
+
+  /* getaddrinfo() returns a list of address structures.
+     Try each address until we successfully bind(2).
+     If socket(2) (or bind(2)) fails, we (close the socket
+     and) try the next address. */
+
+  for (rp = result; rp != nullptr; rp = rp->ai_next) {
+    sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+    if (sfd == -1) {
+      continue;
+    }
+
+    int val = 1;
+    setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
+
+    if (bind(sfd, rp->ai_addr, rp->ai_addrlen) == 0) {
+      break; /* Success */
+    }
+
+    close(sfd);
+  }
+
+  freeaddrinfo(result); /* No longer needed */
+
+  if (rp == nullptr) { /* No address succeeded */
+    fprintf(stderr, "Could not bind\n");
+    abort();
+  }
+
+  int rv = listen(sfd, SOMAXCONN);
+  if (rv) {
+    perror("listen()");
+    abort();
+  }
+
+  return sfd;
+}
+
+// HTTP response
+//
+std::string_view part1 =
+    "HTTP/1.1 200 OK \r\nContent-type: text/plain; version=0.0.4; "
+    "charset=utf-8; escaping=values\r\nContent-Length: ";
+// Decimal content length
+std::string_view part2 = "\r\n\r\n";
+// Body
+
+double toSeconds(timeval t) {
+  return double(t.tv_sec) + double(t.tv_usec) * 1e-6;
+}
+
+int main(int argc, char **argv) {
+  if (argc != 3) {
+    goto fail;
+  }
+  {
+    int listenFd = getListenFd(argv[1], argv[2]);
+
+    weaselab::ConflictSet cs{0};
+    weaselab::ConflictSet::MetricsV1 *metrics;
+    int metricsCount;
+    cs.getMetricsV1(&metrics, &metricsCount);
+
+    auto w = std::thread{workload, &cs};
+
+    for (;;) {
+      struct sockaddr_storage peer_addr = {};
+      socklen_t peer_addr_len = sizeof(peer_addr);
+      const int connfd =
+          accept(listenFd, (struct sockaddr *)&peer_addr, &peer_addr_len);
+
+      std::string body;
+
+      rusage r;
+      getrusage(RUSAGE_SELF, &r);
+      body += "# HELP process_cpu_seconds_total Total user and system CPU time "
+              "spent in seconds.\n# TYPE process_cpu_seconds_total counter\n"
+              "process_cpu_seconds_total ";
+      body += std::to_string(toSeconds(r.ru_utime) + toSeconds(r.ru_stime));
+      body += "\n";
+      body += "# HELP process_resident_memory_bytes Resident memory size in "
+              "bytes.\n# TYPE process_resident_memory_bytes gauge\n"
+              "process_resident_memory_bytes ";
+      body += std::to_string(getCurrentRSS());
+      body += "\n";
+      body += "# HELP transactions_total Total number of transactions\n"
+              "# TYPE transactions_total counter\n"
+              "transactions_total ";
+      body += std::to_string(transactions.load(std::memory_order_relaxed));
+      body += "\n";
+
+      for (int i = 0; i < metricsCount; ++i) {
+        body += "# HELP ";
+        body += metrics[i].name;
+        body += " ";
+        body += metrics[i].help;
+        body += "\n";
+        body += "# TYPE ";
+        body += metrics[i].name;
+        body += " ";
+        body += metrics[i].type == metrics[i].Counter ? "counter" : "gauge";
+        body += "\n";
+        body += metrics[i].name;
+        body += " ";
+        body += std::to_string(metrics[i].getValue());
+        body += "\n";
+      }
+
+      auto len = std::to_string(body.size());
+      iovec iov[] = {
+          {(void *)part1.data(), part1.size()},
+          {(void *)len.data(), len.size()},
+          {(void *)part2.data(), part2.size()},
+          {(void *)body.data(), body.size()},
+      };
+      int written;
+      do {
+        written = writev(connfd, iov, sizeof(iov) / sizeof(iov[0]));
+      } while (written < 0 && errno == EINTR);
+      close(connfd);
+    }
+  }
+fail:
+  fprintf(stderr, "Expected ./%s <host> <port>\n", argv[0]);
+  return 1;
+}

corpus/0f5c5f28c31e44ee0ec085fec09adf0981065771

@@ -1,5 +0,0 @@
-
-<EFBFBD><EFBFBD>
-
-
-2

corpus/12bdd00fd4038756cbcf8ecdad1b0cd862603cd8

@@ -1 +0,0 @@
-<EFBFBD>