Bump version

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.gitea/workflows/ci.yml

@@ -0,0 +1,306 @@
+name: CI
+
+on: [push, pull_request]
+
+env:
+  CC: clang
+  CXX: clang++
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest-amd64
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/cache@v4
+        with:
+          path: /var/cache/apt/archives
+          key: apt-amd64-${{ hashFiles('.gitea/workflows/ci.yml') }}
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y git nodejs pre-commit
+
+      - uses: actions/cache@v4
+        with:
+          path: ~/.cache/pre-commit
+          key: pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
+
+      - name: Run pre-commit
+        run: |
+          git config --global --add safe.directory "$PWD"
+          pre-commit run --all-files --show-diff-on-failure
+
+  test:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: 64-bit-versions
+            cmake_args: -DCMAKE_CXX_FLAGS=-DUSE_64_BIT=1
+          - name: debug
+            cmake_args: -DCMAKE_BUILD_TYPE=Debug
+          - name: simd-fallback
+            cmake_args: -DUSE_SIMD_FALLBACK=ON
+          - name: gcc
+            cmake_args: -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++
+    runs-on: ubuntu-latest-amd64
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/cache@v4
+        with:
+          path: /var/cache/apt/archives
+          key: apt-amd64-${{ hashFiles('.gitea/workflows/ci.yml') }}
+
+      - name: Install common dependencies
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y \
+            build-essential ccache cmake gcc g++ libc6-dbg \
+            ninja-build python3 valgrind zstd
+          sudo curl -Ls "https://minio.weaselab.dev/public/$(uname -m)/mc.RELEASE.2025-08-13T08-35-41Z" \
+            -o /usr/local/bin/mc && sudo chmod +x /usr/local/bin/mc
+
+      - name: Install LLVM toolchain
+        if: matrix.name != 'gcc'
+        run: |
+          . /etc/os-release
+          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+          echo "deb http://apt.llvm.org/${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main" | sudo tee /etc/apt/sources.list.d/llvm.list
+          sudo apt-get update -qq
+          sudo apt-get install -y \
+            clang-21 llvm-21 lld-21 mold
+          for tool in clang clang++ llvm-ar llvm-nm llvm-ranlib llvm-objcopy llvm-cov llvm-symbolizer lld ld.lld; do
+            sudo update-alternatives --install /usr/bin/${tool} ${tool} /usr/bin/${tool}-21 100
+          done
+
+      - name: Build
+        run: |
+          export CCACHE_DIR="$GITHUB_WORKSPACE/.ccache"
+          rm -rf build
+          cmake -S . -B build -G Ninja -DCMAKE_CXX_COMPILER_LAUNCHER=ccache ${{ matrix.cmake_args }}
+          ninja -C build
+          ccache -s
+
+      - name: Test
+        run: |
+          cd build
+          ctest --no-compress-output --test-output-size-passed 100000 --test-output-size-failed 100000 -T Test -j "$(nproc)" --timeout 90 > /dev/null
+
+      - name: Upload test results to MinIO
+        if: always()
+        env:
+          MINIO_ACCESS_KEY: ${{ secrets.MINIO_ACCESS_KEY }}
+          MC_HOST_minio: https://${{ secrets.MINIO_ACCESS_KEY }}:${{ secrets.MINIO_SECRET_KEY }}@minio.weaselab.dev
+        run: |
+          if [ -z "$MINIO_ACCESS_KEY" ]; then
+            echo "MinIO credentials not configured; skipping upload"
+            exit 0
+          fi
+          zstd build/Testing/*/Test.xml
+          mc cp build/Testing/*/Test.xml.zst "minio/jenkins/conflict-set/${{ gitea.run_number }}/${{ matrix.name }}/"
+
+      - name: Test summary
+        if: always()
+        run: |
+          python3 ctest_summary.py build/Testing/*/Test.xml \
+            --link "https://minio.weaselab.dev/jenkins/conflict-set/${{ gitea.run_number }}/${{ matrix.name }}/Test.xml.zst" \
+            | tee -a "$GITHUB_STEP_SUMMARY"
+
+  release:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - runner: ubuntu-latest-amd64
+            arch: amd64
+          - runner: ubuntu-latest-arm64
+            arch: arm64
+    runs-on: ${{ matrix.runner }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/cache@v4
+        with:
+          path: /var/cache/apt/archives
+          key: apt-${{ matrix.arch }}-${{ hashFiles('.gitea/workflows/ci.yml') }}
+
+      - name: Install dependencies
+        run: |
+          . /etc/os-release
+          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+          echo "deb http://apt.llvm.org/${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main" | sudo tee /etc/apt/sources.list.d/llvm.list
+          sudo apt-get update -qq
+          sudo apt-get install -y \
+            build-essential ccache clang-21 cmake devscripts \
+            libc6-dbg llvm-21 lld-21 mold ninja-build rpm \
+            valgrind zstd
+          sudo curl -Ls "https://minio.weaselab.dev/public/$(uname -m)/mc.RELEASE.2025-08-13T08-35-41Z" \
+            -o /usr/local/bin/mc && sudo chmod +x /usr/local/bin/mc
+          for tool in clang clang++ llvm-ar llvm-nm llvm-ranlib llvm-objcopy llvm-cov llvm-symbolizer lld ld.lld; do
+            sudo update-alternatives --install /usr/bin/${tool} ${tool} /usr/bin/${tool}-21 100
+          done
+
+      - name: Install paper build dependencies
+        if: matrix.arch == 'amd64'
+        run: |
+          sudo apt-get install -y \
+            biber latexmk \
+            texlive-bibtex-extra texlive-fonts-recommended \
+            texlive-latex-extra texlive-pictures
+
+      - uses: actions/cache@v4
+        with:
+          path: .ccache
+          key: ccache-release-${{ matrix.arch }}-${{ gitea.sha }}
+          restore-keys: |
+            ccache-release-${{ matrix.arch }}-
+
+      - name: Build
+        run: |
+          export CCACHE_DIR="$GITHUB_WORKSPACE/.ccache"
+          rm -rf build
+          cmake -S . -B build -G Ninja -DCMAKE_CXX_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_FLAGS=-DNVALGRIND
+          ninja -C build
+          ccache -s
+
+      - name: Test
+        run: |
+          cd build
+          # On arm64, valgrind needs the MAKE_MEM_DEFINED client requests for
+          # https://git.weaselab.dev/weaselab/conflict-set/issues/39, but this
+          # build has -DNVALGRIND, which compiles them out. Skip valgrind
+          # tests here; they run annotated in the test job.
+          ctest --no-compress-output --test-output-size-passed 100000 --test-output-size-failed 100000 ${{ matrix.arch == 'arm64' && '-E valgrind' || '' }} -T Test -j "$(nproc)" --timeout 90 > /dev/null
+
+      - name: Package
+        run: |
+          cd build
+          cpack -G DEB
+          cpack -G RPM
+
+      - name: Build paper
+        if: matrix.arch == 'amd64'
+        run: |
+          cd paper
+          make
+
+      - name: Upload artifacts to MinIO
+        if: always()
+        shell: bash
+        env:
+          MINIO_ACCESS_KEY: ${{ secrets.MINIO_ACCESS_KEY }}
+          MC_HOST_minio: https://${{ secrets.MINIO_ACCESS_KEY }}:${{ secrets.MINIO_SECRET_KEY }}@minio.weaselab.dev
+        run: |
+          if [ -z "$MINIO_ACCESS_KEY" ]; then
+            echo "MinIO credentials not configured; skipping upload"
+            exit 0
+          fi
+          dest="minio/jenkins/conflict-set/${{ gitea.run_number }}/release-${{ matrix.arch }}/"
+          zstd build/Testing/*/Test.xml
+          mc cp build/Testing/*/Test.xml.zst "$dest"
+          if compgen -G "build/*.deb" > /dev/null; then
+            mc cp build/*.deb "$dest"
+          fi
+          if compgen -G "build/*.rpm" > /dev/null; then
+            mc cp build/*.rpm "$dest"
+          fi
+          if compgen -G "paper/*.pdf" > /dev/null; then
+            mc cp paper/*.pdf "$dest"
+          fi
+
+      - name: Test summary
+        if: always()
+        run: |
+          python3 ctest_summary.py build/Testing/*/Test.xml \
+            --link "https://minio.weaselab.dev/jenkins/conflict-set/${{ gitea.run_number }}/release-${{ matrix.arch }}/Test.xml.zst" \
+            | tee -a "$GITHUB_STEP_SUMMARY"
+
+  coverage:
+    runs-on: ubuntu-latest-amd64
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/cache@v4
+        with:
+          path: /var/cache/apt/archives
+          key: apt-amd64-${{ hashFiles('.gitea/workflows/ci.yml') }}
+
+      - name: Install dependencies
+        run: |
+          . /etc/os-release
+          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+          echo "deb http://apt.llvm.org/${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main" | sudo tee /etc/apt/sources.list.d/llvm.list
+          sudo apt-get update -qq
+          sudo apt-get install -y \
+            build-essential ccache clang-21 cmake gcovr \
+            libc6-dbg llvm-21 lld-21 mold ninja-build python3 valgrind zstd
+          sudo curl -Ls "https://minio.weaselab.dev/public/$(uname -m)/mc.RELEASE.2025-08-13T08-35-41Z" \
+            -o /usr/local/bin/mc && sudo chmod +x /usr/local/bin/mc
+          for tool in clang clang++ llvm-ar llvm-nm llvm-ranlib llvm-objcopy llvm-cov llvm-symbolizer lld ld.lld; do
+            sudo update-alternatives --install /usr/bin/${tool} ${tool} /usr/bin/${tool}-21 100
+          done
+
+      - uses: actions/cache@v4
+        with:
+          path: .ccache
+          key: ccache-coverage-${{ gitea.sha }}
+          restore-keys: |
+            ccache-coverage-
+
+      - name: Build
+        run: |
+          export CCACHE_DIR="$GITHUB_WORKSPACE/.ccache"
+          rm -rf build
+          cmake -S . -B build -G Ninja -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+            -DCMAKE_C_FLAGS=--coverage -DCMAKE_CXX_FLAGS=--coverage \
+            -DCMAKE_BUILD_TYPE=Debug -DDISABLE_TSAN=ON
+          ninja -C build
+          ccache -s
+
+      - name: Test
+        run: |
+          cd build
+          ctest --no-compress-output --test-output-size-passed 100000 --test-output-size-failed 100000 -T Test -j "$(nproc)" --timeout 90 > /dev/null
+
+      - name: Coverage report
+        shell: bash
+        run: |
+          gcov_args=(-f ConflictSet.cpp -f LongestCommonPrefix.h -f Metrics.h
+                     --gcov-executable "llvm-cov gcov" --exclude-noncode-lines)
+          gcovr "${gcov_args[@]}" --cobertura > build/coverage.xml
+          gcovr "${gcov_args[@]}"
+          mkdir -p build/coverage_html
+          gcovr "${gcov_args[@]}" --html-details build/coverage_html/index.html
+          gcovr "${gcov_args[@]}" --fail-under-line 100 > /dev/null
+
+      - name: Upload results to MinIO
+        if: always()
+        env:
+          MINIO_ACCESS_KEY: ${{ secrets.MINIO_ACCESS_KEY }}
+          MC_HOST_minio: https://${{ secrets.MINIO_ACCESS_KEY }}:${{ secrets.MINIO_SECRET_KEY }}@minio.weaselab.dev
+        run: |
+          if [ -z "$MINIO_ACCESS_KEY" ]; then
+            echo "MinIO credentials not configured; skipping upload"
+            exit 0
+          fi
+          dest="minio/jenkins/conflict-set/${{ gitea.run_number }}/coverage/"
+          zstd build/Testing/*/Test.xml
+          mc cp build/Testing/*/Test.xml.zst "$dest"
+          if [ -e build/coverage.xml ]; then
+            mc cp build/coverage.xml "$dest"
+          fi
+          if [ -d build/coverage_html ]; then
+            mc cp -r build/coverage_html "$dest"
+          fi
+
+      - name: Test summary
+        if: always()
+        run: |
+          python3 ctest_summary.py build/Testing/*/Test.xml \
+            --link "https://minio.weaselab.dev/jenkins/conflict-set/${{ gitea.run_number }}/coverage/Test.xml.zst" \
+            | tee -a "$GITHUB_STEP_SUMMARY"
+          echo "" | tee -a "$GITHUB_STEP_SUMMARY"
+          echo "📊 [Coverage report](https://minio.weaselab.dev/jenkins/conflict-set/${{ gitea.run_number }}/coverage/coverage_html/index.html)" | tee -a "$GITHUB_STEP_SUMMARY"

CMakeLists.txt

@@ -72,6 +72,12 @@ else()
   add_link_options(-Wl,--gc-sections)
 endif()
 
+if(EMSCRIPTEN)
+  # https://github.com/emscripten-core/emscripten/issues/15377#issuecomment-1285167486
+  add_link_options(-lnodefs.js -lnoderawfs.js)
+  add_link_options(-s ALLOW_MEMORY_GROWTH)
+endif()
+
 if(NOT USE_SIMD_FALLBACK)
   cmake_push_check_state()
   list(APPEND CMAKE_REQUIRED_FLAGS -mavx)

ConflictSet.cpp

@@ -17,9 +17,9 @@ limitations under the License.
 #include "ConflictSet.h"
 #include "Internal.h"
 #include "LongestCommonPrefix.h"
-#include "Metrics.h"
 
 #include <algorithm>
+#include <atomic>
 #include <bit>
 #include <cassert>
 #include <cstddef>
@@ -578,6 +578,39 @@ static_assert(kBytesPerKey - sizeof(Node0) >= kMinNodeSurplus);
 
 constexpr int64_t kFreeListMaxMemory = 1 << 20;
 
+struct Metric {
+  Metric *prev;
+  const char *name;
+  const char *help;
+  ConflictSet::MetricsV1::Type type;
+  std::atomic<int64_t> value;
+
+protected:
+  Metric(ConflictSet::Impl *impl, const char *name, const char *help,
+         ConflictSet::MetricsV1::Type type);
+};
+
+struct Gauge : private Metric {
+  Gauge(ConflictSet::Impl *impl, const char *name, const char *help)
+      : Metric(impl, name, help, ConflictSet::MetricsV1::Gauge) {}
+
+  void set(int64_t value) {
+    this->value.store(value, std::memory_order_relaxed);
+  }
+};
+
+struct Counter : private Metric {
+  Counter(ConflictSet::Impl *impl, const char *name, const char *help)
+      : Metric(impl, name, help, ConflictSet::MetricsV1::Counter) {}
+  // Expensive. Accumulate locally and then call add instead of repeatedly
+  // calling add.
+  void add(int64_t value) {
+    assert(value >= 0);
+    static_assert(std::atomic<int64_t>::is_always_lock_free);
+    this->value.fetch_add(value, std::memory_order_relaxed);
+  }
+};
+
 template <class T> struct BoundedFreeListAllocator {
 
   static_assert(sizeof(T) >= sizeof(void *));
@@ -2510,19 +2543,38 @@ downLeftSpine:
 namespace {
 // Return true if the max version among all keys that start with key[:prefixLen]
 // that are >= key is <= readVersion
-bool checkRangeLeftSide(Node *n, std::span<const uint8_t> key, int prefixLen,
+struct CheckRangeLeftSide {
-                        InternalVersionT readVersion, ReadContext *tls) {
+  CheckRangeLeftSide(Node *n, std::span<const uint8_t> key, int prefixLen,
-  auto remaining = key;
+                     InternalVersionT readVersion, ReadContext *tls)
+      : n(n), remaining(key), prefixLen(prefixLen), readVersion(readVersion),
+        impl(tls->impl), tls(tls) {
+#if DEBUG_VERBOSE && !defined(NDEBUG)
+    fprintf(stderr, "Check range left side from %s for keys starting with %s\n",
+            printable(key).c_str(),
+            printable(key.subspan(0, prefixLen)).c_str());
+#endif
+  }
+
+  Node *n;
+  std::span<const uint8_t> remaining;
+  int prefixLen;
+  InternalVersionT readVersion;
+  ConflictSet::Impl *impl;
+  ReadContext *tls;
   int searchPathLen = 0;
-  for (;; ++tls->range_read_iterations_accum) {
+  bool ok;
+
+  bool step() {
     if (remaining.size() == 0) {
       assert(searchPathLen >= prefixLen);
-      return maxVersion(n) <= readVersion;
+      ok = maxVersion(n) <= readVersion;
+      return true;
     }
 
     if (searchPathLen >= prefixLen) {
       if (!checkMaxBetweenExclusive(n, remaining[0], 256, readVersion, tls)) {
-        return false;
+        ok = false;
+        return true;
       }
     }
 
@@ -2532,16 +2584,18 @@ bool checkRangeLeftSide(Node *n, std::span<const uint8_t> key, int prefixLen,
       if (c != nullptr) {
         if (searchPathLen < prefixLen) {
           n = c;
-          goto downLeftSpine;
+          return downLeftSpine();
         }
         n = c;
-        return maxVersion(n) <= readVersion;
+        ok = maxVersion(n) <= readVersion;
+        return true;
       } else {
         n = nextSibling(n);
         if (n == nullptr) {
+          ok = true;
           return true;
         }
-        goto downLeftSpine;
+        return downLeftSpine();
       }
     }
 
@@ -2557,18 +2611,21 @@ bool checkRangeLeftSide(Node *n, std::span<const uint8_t> key, int prefixLen,
         auto c = n->partialKey()[i] <=> remaining[i];
         if (c > 0) {
           if (searchPathLen < prefixLen) {
-            goto downLeftSpine;
+            return downLeftSpine();
           }
           if (n->entryPresent && n->entry.rangeVersion > readVersion) {
-            return false;
+            ok = false;
+            return true;
           }
-          return maxVersion(n) <= readVersion;
+          ok = maxVersion(n) <= readVersion;
+          return true;
         } else {
           n = nextSibling(n);
           if (n == nullptr) {
+            ok = true;
             return true;
           }
-          goto downLeftSpine;
+          return downLeftSpine();
         }
       }
       if (commonLen == n->partialKeyLen) {
@@ -2577,47 +2634,83 @@ bool checkRangeLeftSide(Node *n, std::span<const uint8_t> key, int prefixLen,
       } else if (n->partialKeyLen > int(remaining.size())) {
         assert(searchPathLen >= prefixLen);
         if (n->entryPresent && n->entry.rangeVersion > readVersion) {
-          return false;
+          ok = false;
+          return true;
         }
-        return maxVersion(n) <= readVersion;
+        ok = maxVersion(n) <= readVersion;
-      }
-    }
-    if (maxV <= readVersion) {
         return true;
       }
     }
-downLeftSpine:
+    if (maxV <= readVersion) {
+      ok = true;
+      return true;
+    }
+    return false;
+  }
+
+  bool downLeftSpine() {
     for (; !n->entryPresent; n = getFirstChildExists(n)) {
     }
-  return n->entry.rangeVersion <= readVersion;
+    ok = n->entry.rangeVersion <= readVersion;
-}
+    return true;
+  }
+};
 
 // Return true if the max version among all keys that start with key[:prefixLen]
 // that are < key is <= readVersion
-bool checkRangeRightSide(Node *n, std::span<const uint8_t> key, int prefixLen,
+struct CheckRangeRightSide {
-                         InternalVersionT readVersion, ReadContext *tls) {
+  CheckRangeRightSide(Node *n, std::span<const uint8_t> key, int prefixLen,
-  auto remaining = key;
+                      InternalVersionT readVersion, ReadContext *tls)
-  int searchPathLen = 0;
+      : n(n), key(key), remaining(key), prefixLen(prefixLen),
+        readVersion(readVersion), impl(tls->impl), tls(tls) {
+#if DEBUG_VERBOSE && !defined(NDEBUG)
+    fprintf(stderr, "Check range right side to %s for keys starting with %s\n",
+            printable(key).c_str(),
+            printable(key.subspan(0, prefixLen)).c_str());
+#endif
+  }
+
+  Node *n;
+  std::span<const uint8_t> key;
+  std::span<const uint8_t> remaining;
+  int prefixLen;
+  InternalVersionT readVersion;
+  ConflictSet::Impl *impl;
+  ReadContext *tls;
+  int searchPathLen = 0;
+  bool ok;
+
+  bool step() {
+#if DEBUG_VERBOSE && !defined(NDEBUG)
+    fprintf(stderr,
+            "Search path: %s, searchPathLen: %d, prefixLen: %d, remaining: "
+            "%s\n",
+            getSearchPathPrintable(n).c_str(), searchPathLen, prefixLen,
+            printable(remaining).c_str());
+#endif
 
-  for (;; ++tls->range_read_iterations_accum) {
     assert(searchPathLen <= int(key.size()));
+
     if (remaining.size() == 0) {
-      goto downLeftSpine;
+      return downLeftSpine();
     }
 
     if (searchPathLen >= prefixLen) {
       if (n->entryPresent && n->entry.pointVersion > readVersion) {
-        return false;
+        ok = false;
+        return true;
       }
 
       if (!checkMaxBetweenExclusive(n, -1, remaining[0], readVersion, tls)) {
-        return false;
+        ok = false;
+        return true;
       }
     }
 
     if (searchPathLen > prefixLen && n->entryPresent &&
         n->entry.rangeVersion > readVersion) {
-      return false;
+      ok = false;
+      return true;
     }
 
     auto *child = getChild(n, remaining[0]);
@@ -2625,9 +2718,9 @@ bool checkRangeRightSide(Node *n, std::span<const uint8_t> key, int prefixLen,
       auto c = getChildGeq(n, remaining[0]);
       if (c != nullptr) {
         n = c;
-        goto downLeftSpine;
+        return downLeftSpine();
       } else {
-        goto backtrack;
+        return backtrack();
       }
     }
 
@@ -2643,30 +2736,35 @@ bool checkRangeRightSide(Node *n, std::span<const uint8_t> key, int prefixLen,
         ++searchPathLen;
         auto c = n->partialKey()[i] <=> remaining[i];
         if (c > 0) {
-          goto downLeftSpine;
+          return downLeftSpine();
         } else {
           if (searchPathLen > prefixLen && n->entryPresent &&
               n->entry.rangeVersion > readVersion) {
-            return false;
+            ok = false;
+            return true;
           }
-          goto backtrack;
+          return backtrack();
         }
       }
       if (commonLen == n->partialKeyLen) {
         // partial key matches
         remaining = remaining.subspan(commonLen, remaining.size() - commonLen);
       } else if (n->partialKeyLen > int(remaining.size())) {
-        goto downLeftSpine;
+        return downLeftSpine();
       }
     }
+    return false;
   }
-backtrack:
+
+  bool backtrack() {
     for (;;) {
       // searchPathLen > prefixLen implies n is not the root
       if (searchPathLen > prefixLen && maxVersion(n) > readVersion) {
-      return false;
+        ok = false;
+        return true;
       }
       if (n->parent == nullptr) {
+        ok = true;
         return true;
       }
       auto next = getChildGeq(n->parent, n->parentsIndex + 1);
@@ -2677,14 +2775,18 @@ backtrack:
         searchPathLen -= n->partialKeyLen;
         n = next;
         searchPathLen += n->partialKeyLen;
-      goto downLeftSpine;
+        return downLeftSpine();
       }
     }
-downLeftSpine:
+  }
+
+  bool downLeftSpine() {
     for (; !n->entryPresent; n = getFirstChildExists(n)) {
     }
-  return n->entry.rangeVersion <= readVersion;
+    ok = n->entry.rangeVersion <= readVersion;
-}
+    return true;
+  }
+};
 } // namespace
 
 bool checkRangeRead(Node *n, std::span<const uint8_t> begin,
@@ -2705,8 +2807,8 @@ bool checkRangeRead(Node *n, std::span<const uint8_t> begin,
 
   auto remaining = begin.subspan(0, lcp);
   Arena arena;
-
+  // If the common prefix isn't a prefix of any physical entry in the tree, we
-  // Advance down common prefix, but stay on a physical path in the tree
+  // can go to "downLeftSpine"
   for (;; ++tls->range_read_iterations_accum) {
     assert(getSearchPath(arena, n) <=>
                begin.subspan(0, lcp - remaining.size()) ==
@@ -2747,17 +2849,47 @@ bool checkRangeRead(Node *n, std::span<const uint8_t> begin,
   lcp -= consumed;
 
   if (lcp == int(begin.size())) {
-    return checkRangeRightSide(n, end, lcp, readVersion, tls);
+    CheckRangeRightSide checkRangeRightSide{n, end, lcp, readVersion, tls};
+    while (!checkRangeRightSide.step())
+      ;
+    return checkRangeRightSide.ok;
   }
 
-  // This makes it safe to check maxVersion within checkRangeLeftSide. If this
+  if (!checkRangeStartsWith(n, begin.subspan(0, lcp), begin[lcp], end[lcp],
+                            readVersion, tls)) {
+    return false;
+  }
+
+  // This makes it safe to check maxVersion within CheckRangeLeftSide. If this
   // were false, then we would have returned above since lcp == begin.size().
   assert(!(n->parent == nullptr && begin.size() == 0));
+  CheckRangeLeftSide checkRangeLeftSide{n, begin, lcp + 1, readVersion, tls};
+  CheckRangeRightSide checkRangeRightSide{n, end, lcp + 1, readVersion, tls};
 
-  return checkRangeStartsWith(n, begin.subspan(0, lcp), begin[lcp], end[lcp],
+  for (;;) {
-                              readVersion, tls) &&
+    bool leftDone = checkRangeLeftSide.step();
-         checkRangeLeftSide(n, begin, lcp + 1, readVersion, tls) &&
+    bool rightDone = checkRangeRightSide.step();
-         checkRangeRightSide(n, end, lcp + 1, readVersion, tls);
+    if (!leftDone && !rightDone) {
+      tls->range_read_iterations_accum += 2;
+      continue;
+    }
+    if (leftDone && rightDone) {
+      break;
+    } else if (leftDone) {
+      while (!checkRangeRightSide.step()) {
+        ++tls->range_read_iterations_accum;
+      }
+      break;
+    } else {
+      assert(rightDone);
+      while (!checkRangeLeftSide.step()) {
+        ++tls->range_read_iterations_accum;
+      }
+    }
+    break;
+  }
+
+  return checkRangeLeftSide.ok && checkRangeRightSide.ok;
 }
 
 #ifdef __x86_64__
@@ -3110,6 +3242,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
                           0) *
         2;
 
+    memory_bytes.set(totalBytes);
     point_writes_total.add(tls.accum.point_writes);
     range_writes_total.add(tls.accum.range_writes);
     nodes_allocated_total.add(tls.accum.nodes_allocated);
@@ -3198,6 +3331,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
 #endif
     keyUpdates = gcScanStep(keyUpdates);
 
+    memory_bytes.set(totalBytes);
     nodes_allocated_total.add(std::exchange(tls.accum.nodes_allocated, 0));
     nodes_released_total.add(std::exchange(tls.accum.nodes_released, 0));
     entries_inserted_total.add(std::exchange(tls.accum.entries_inserted, 0));
@@ -3245,7 +3379,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   explicit Impl(int64_t oldestVersion) {
     assert(oldestVersion >= 0);
     init(oldestVersion);
-    metrics = initMetrics(metricsList, metricsCount);
+    initMetrics();
   }
   ~Impl() {
     eraseTree(root, &tls);
@@ -3268,12 +3402,23 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
 
   MetricsV1 *metrics;
   int metricsCount = 0;
-  Metric *metricsList = nullptr;
+  void initMetrics() {
+    metrics = (MetricsV1 *)safe_malloc(metricsCount * sizeof(metrics[0]));
+    for (auto [i, m] = std::make_tuple(metricsCount - 1, metricList); i >= 0;
+         --i, m = m->prev) {
+      metrics[i].name = m->name;
+      metrics[i].help = m->help;
+      metrics[i].p = m;
+      metrics[i].type = m->type;
+    }
+  }
+
+  Metric *metricList = nullptr;
 
 #define GAUGE(name, help)                                                      \
-  Gauge name { metricsList, metricsCount, #name, help }
+  Gauge name { this, #name, help }
 #define COUNTER(name, help)                                                    \
-  Counter name { metricsList, metricsCount, #name, help }
+  Counter name { this, #name, help }
   // ==================== METRICS DEFINITIONS ====================
   COUNTER(point_read_total, "Total number of point reads checked");
   COUNTER(point_read_short_circuit_total,
@@ -3339,6 +3484,13 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   }
 };
 
+Metric::Metric(ConflictSet::Impl *impl, const char *name, const char *help,
+               ConflictSet::MetricsV1::Type type)
+    : prev(std::exchange(impl->metricList, this)), name(name), help(help),
+      type(type), value(0) {
+  ++impl->metricsCount;
+}
+
 Node *&getInTree(Node *n, ConflictSet::Impl *impl) {
   return n->parent == nullptr ? impl->root
                               : getChildExists(n->parent, n->parentsIndex);
@@ -3357,7 +3509,6 @@ void internal_addWrites(ConflictSet::Impl *impl,
   mallocBytesDelta = 0;
   impl->addWrites(writes, count, writeVersion);
   impl->totalBytes += mallocBytesDelta;
-  impl->memory_bytes.set(impl->totalBytes);
 #if SHOW_MEMORY
   if (impl->totalBytes != mallocBytes) {
     abort();
@@ -3369,7 +3520,6 @@ void internal_setOldestVersion(ConflictSet::Impl *impl, int64_t oldestVersion) {
   mallocBytesDelta = 0;
   impl->setOldestVersion(oldestVersion);
   impl->totalBytes += mallocBytesDelta;
-  impl->memory_bytes.set(impl->totalBytes);
 #if SHOW_MEMORY
   if (impl->totalBytes != mallocBytes) {
     abort();
@@ -3498,7 +3648,12 @@ ConflictSet::ConflictSet(ConflictSet &&other) noexcept
     : impl(std::exchange(other.impl, nullptr)) {}
 
 ConflictSet &ConflictSet::operator=(ConflictSet &&other) noexcept {
+  if (this != &other) {
+    if (impl) {
+      internal_destroy(impl);
+    }
     impl = std::exchange(other.impl, nullptr);
+  }
   return *this;
 }
 
@@ -3923,73 +4078,6 @@ struct __attribute__((visibility("default"))) PeakPrinter {
 
 #ifdef ENABLE_MAIN
 
-#define ANKERL_NANOBENCH_IMPLEMENT
-#include "third_party/nanobench.h"
-
-template <int kN> void benchRezero() {
-  static_assert(kN % 16 == 0);
-  ankerl::nanobench::Bench bench;
-  InternalVersionT vs[kN];
-  InternalVersionT zero;
-  bench.run("rezero" + std::to_string(kN), [&]() {
-    bench.doNotOptimizeAway(vs);
-    bench.doNotOptimizeAway(zero);
-    for (int i = 0; i < kN; i += 16) {
-      rezero16(vs + i, zero);
-    }
-  });
-}
-
-template <int kN> void benchScan1() {
-  static_assert(kN % 16 == 0);
-  ankerl::nanobench::Bench bench;
-  InternalVersionT vs[kN];
-  uint8_t is[kN];
-  uint8_t begin;
-  uint8_t end;
-  InternalVersionT v;
-  bench.run("scan" + std::to_string(kN), [&]() {
-    bench.doNotOptimizeAway(vs);
-    bench.doNotOptimizeAway(is);
-    bench.doNotOptimizeAway(begin);
-    bench.doNotOptimizeAway(end);
-    bench.doNotOptimizeAway(v);
-    for (int i = 0; i < kN; i += 16) {
-      scan16</*kAVX512=*/true>(vs + i, is + i, begin, end, v);
-    }
-  });
-}
-
-template <int kN> void benchScan2() {
-  static_assert(kN % 16 == 0);
-  ankerl::nanobench::Bench bench;
-  InternalVersionT vs[kN];
-  uint8_t is[kN];
-  uint8_t begin;
-  uint8_t end;
-  InternalVersionT v;
-  bench.run("scan" + std::to_string(kN), [&]() {
-    bench.doNotOptimizeAway(vs);
-    bench.doNotOptimizeAway(begin);
-    bench.doNotOptimizeAway(end);
-    bench.doNotOptimizeAway(v);
-    for (int i = 0; i < kN; i += 16) {
-      scan16</*kAVX512=*/true>(vs + i, begin, end, v);
-    }
-  });
-}
-
-void benchLCP(int len) {
-  ankerl::nanobench::Bench bench;
-  std::vector<uint8_t> lhs(len);
-  std::vector<uint8_t> rhs(len);
-  bench.run("lcp " + std::to_string(len), [&]() {
-    bench.doNotOptimizeAway(lhs);
-    bench.doNotOptimizeAway(rhs);
-    bench.doNotOptimizeAway(longestCommonPrefix(lhs.data(), rhs.data(), len));
-  });
-}
-
 void printTree() {
   int64_t writeVersion = 0;
   ConflictSet::Impl cs{writeVersion};
@@ -4011,11 +4099,7 @@ void printTree() {
   debugPrintDot(stdout, cs.root, &cs);
 }
 
-int main(void) {
+int main(void) { printTree(); }
-  for (int i = 0; i < 256; ++i) {
-    benchLCP(i);
-  }
-}
 #endif
 
 #ifdef ENABLE_FUZZ

HashTable.cpp

@@ -119,7 +119,13 @@ ConflictSet::ConflictSet(ConflictSet &&other) noexcept
     : impl(std::exchange(other.impl, nullptr)) {}
 
 ConflictSet &ConflictSet::operator=(ConflictSet &&other) noexcept {
+  if (this != &other) {
+    if (impl) {
+      impl->~Impl();
+      safe_free(impl, sizeof(Impl));
+    }
     impl = std::exchange(other.impl, nullptr);
+  }
   return *this;
 }
 

Jenkinsfile

@@ -129,7 +129,7 @@ pipeline {
             }
             steps {
                 script {
-                    filter_args = "-f ConflictSet.cpp -f LongestCommonPrefix.h -f Metrics.h"
+                    filter_args = "-f ConflictSet.cpp -f LongestCommonPrefix.h"
                 }
                 CleanBuildAndTest("-DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_C_FLAGS=--coverage -DCMAKE_CXX_FLAGS=--coverage -DCMAKE_BUILD_TYPE=Debug -DDISABLE_TSAN=ON")
                 sh """

LongestCommonPrefix.h

@@ -129,7 +129,7 @@ longestCommonPrefix(const uint8_t *ap, const uint8_t *bp, int cl) {
   }
 
   int i = 0;
-  int end;
+  int end; // GCOVR_EXCL_LINE
 
   // kStride * kUnrollCount at a time
   end = cl & ~(kStride * kUnrollFactor - 1);

Metrics.h

@@ -1,64 +0,0 @@
-#pragma once
-
-#include "ConflictSet.h"
-#include "Internal.h"
-
-#include <assert.h>
-#include <atomic>
-#include <tuple>
-
-struct Metric {
-  Metric *prev;
-  const char *name;
-  const char *help;
-  weaselab::ConflictSet::MetricsV1::Type type;
-  std::atomic<int64_t> value;
-
-protected:
-  Metric(Metric *&metricList, int &metricsCount, const char *name,
-         const char *help, weaselab::ConflictSet::MetricsV1::Type type)
-      : prev(std::exchange(metricList, this)), name(name), help(help),
-        type(type), value(0) {
-    ++metricsCount;
-  }
-};
-
-struct Gauge : private Metric {
-  Gauge(Metric *&metricList, int &metricsCount, const char *name,
-        const char *help)
-      : Metric(metricList, metricsCount, name, help,
-               weaselab::ConflictSet::MetricsV1::Gauge) {}
-
-  void set(int64_t value) {
-    this->value.store(value, std::memory_order_relaxed);
-  }
-};
-
-struct Counter : private Metric {
-  Counter(Metric *&metricList, int &metricsCount, const char *name,
-          const char *help)
-      : Metric(metricList, metricsCount, name, help,
-               weaselab::ConflictSet::MetricsV1::Counter) {}
-  // Expensive. Accumulate locally and then call add instead of repeatedly
-  // calling add.
-  void add(int64_t value) {
-    assert(value >= 0);
-    static_assert(std::atomic<int64_t>::is_always_lock_free);
-    this->value.fetch_add(value, std::memory_order_relaxed);
-  }
-};
-
-inline weaselab::ConflictSet::MetricsV1 *initMetrics(Metric *metricsList,
-                                                     int metricsCount) {
-  weaselab::ConflictSet::MetricsV1 *metrics =
-      (weaselab::ConflictSet::MetricsV1 *)safe_malloc(metricsCount *
-                                                      sizeof(metrics[0]));
-  for (auto [i, m] = std::make_tuple(metricsCount - 1, metricsList); i >= 0;
-       --i, m = m->prev) {
-    metrics[i].name = m->name;
-    metrics[i].help = m->help;
-    metrics[i].p = m;
-    metrics[i].type = m->type;
-  }
-  return metrics;
-}

README.md

@@ -2,7 +2,16 @@ A data structure for optimistic concurrency control on ranges of bitwise-lexicog
 
 Intended as an alternative to FoundationDB's skip list.
 
-Hardware for all benchmarks is an AMD Ryzen 9 7900 with (2x32GB) 5600MT/s CL28-34-34-89 1.35V RAM
+Hardware for all benchmarks is an AMD Ryzen 9 7900 with (2x32GB) 5600MT/s CL28-34-34-89 1.35V RAM.
+
+```
+$ clang++ --version
+
+Ubuntu clang version 21.1.8 (6ubuntu1)
+Target: x86_64-pc-linux-gnu
+Thread model: posix
+InstalledDir: /usr/lib/llvm-21/bin
+```
 
 # Microbenchmark
 
@@ -10,44 +19,45 @@ 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
 |--------------------:|--------------------:|--------:|----------------:|----------------:|-------:|---------------:|--------:|----------:|:----------
-|              172.03 |        5,812,791.77 |    0.4% |        3,130.62 |          879.00 |  3.562 |         509.23 |    0.0% |      0.01 | `point reads`
+|              171.37 |        5,835,467.28 |    0.5% |        2,915.46 |          629.31 |  4.633 |         502.91 |    0.0% |      0.01 | `point reads`
-|              167.44 |        5,972,130.71 |    0.2% |        3,065.14 |          862.27 |  3.555 |         494.30 |    0.0% |      0.01 | `prefix reads`
+|              168.16 |        5,946,774.62 |    0.5% |        2,859.73 |          619.03 |  4.620 |         488.59 |    0.0% |      0.01 | `prefix reads`
-|              238.77 |        4,188,130.84 |    0.9% |        3,589.93 |        1,259.30 |  2.851 |         637.12 |    0.0% |      0.01 | `range reads`
+|              245.86 |        4,067,294.63 |    0.3% |        3,508.97 |          904.82 |  3.878 |         627.73 |    0.0% |      0.01 | `range reads`
-|              424.01 |        2,358,426.70 |    0.2% |        5,620.05 |        2,242.35 |  2.506 |         854.80 |    1.7% |      0.01 | `point writes`
+|              381.14 |        2,623,691.76 |    0.2% |        5,127.16 |        1,402.60 |  3.655 |         830.59 |    1.7% |      0.01 | `point writes`
-|              418.45 |        2,389,780.56 |    0.4% |        5,525.07 |        2,211.05 |  2.499 |         831.71 |    1.7% |      0.01 | `prefix writes`
+|              376.24 |        2,657,887.07 |    0.3% |        5,062.85 |        1,381.07 |  3.666 |         811.68 |    1.6% |      0.01 | `prefix writes`
-|              254.87 |        3,923,568.88 |    2.6% |        3,187.01 |        1,366.50 |  2.332 |         529.11 |    2.7% |      0.02 | `range writes`
+|              257.09 |        3,889,688.44 |    3.8% |        3,010.09 |          949.42 |  3.170 |         521.34 |    2.9% |      0.01 | `range writes`
-|              675.96 |        1,479,374.50 |    3.3% |        7,735.41 |        3,468.60 |  2.230 |       1,386.02 |    1.8% |      0.01 | `monotonic increasing point writes`
+|              629.71 |        1,588,026.28 |    4.0% |        6,809.60 |        2,320.32 |  2.935 |       1,247.08 |    1.3% |      0.01 | `monotonic increasing point writes`
-|          137,986.20 |            7,247.10 |    0.6% |      789,752.33 |      699,462.00 |  1.129 |     144,824.14 |    0.0% |      0.01 | `worst case for radix tree`
+|          126,164.50 |            7,926.16 |    1.7% |      772,460.25 |      463,264.67 |  1.667 |     141,512.00 |    0.2% |      0.01 | `worst case for radix tree`
-|               21.63 |       46,231,564.03 |    1.0% |          448.00 |          107.14 |  4.181 |          84.00 |    0.0% |      0.01 | `create and destroy`
+|               15.33 |       65,217,669.23 |    0.4% |          299.00 |           56.45 |  5.297 |          64.00 |    0.0% |      0.01 | `create and destroy`
 
 ## Radix tree (this implementation)
 
+
 |               ns/op |                op/s |    err% |          ins/op |          cyc/op |    IPC |         bra/op |   miss% |     total | benchmark
 |--------------------:|--------------------:|--------:|----------------:|----------------:|-------:|---------------:|--------:|----------:|:----------
-|               12.88 |       77,653,350.77 |    0.5% |          185.37 |           64.45 |  2.876 |          41.51 |    0.4% |      0.01 | `point reads`
+|               12.81 |       78,088,759.03 |    0.7% |          187.38 |           47.15 |  3.974 |          33.70 |    0.5% |      0.01 | `point reads`
-|               14.67 |       68,179,354.49 |    0.1% |          271.44 |           73.40 |  3.698 |          53.70 |    0.3% |      0.01 | `prefix reads`
+|               16.77 |       59,626,501.14 |    0.4% |          277.61 |           61.74 |  4.497 |          44.76 |    0.4% |      0.01 | `prefix reads`
-|               34.84 |       28,701,444.36 |    0.3% |          715.74 |          175.27 |  4.084 |         127.30 |    0.2% |      0.01 | `range reads`
+|               42.45 |       23,556,818.87 |    0.4% |          856.96 |          156.09 |  5.490 |         126.22 |    0.2% |      0.01 | `range reads`
-|               17.12 |       58,422,988.28 |    0.2% |          314.30 |           86.11 |  3.650 |          39.82 |    0.4% |      0.01 | `point writes`
+|               15.76 |       63,453,196.94 |    0.3% |          249.89 |           58.04 |  4.306 |          33.21 |    0.5% |      0.01 | `point writes`
-|               31.42 |       31,830,804.65 |    0.1% |          591.06 |          158.07 |  3.739 |          82.67 |    0.2% |      0.01 | `prefix writes`
+|               29.71 |       33,662,499.39 |    0.1% |          509.14 |          109.33 |  4.657 |          70.26 |    0.5% |      0.01 | `prefix writes`
-|               37.37 |       26,759,432.70 |    2.2% |          681.98 |          188.95 |  3.609 |          96.10 |    0.1% |      0.01 | `range writes`
+|               35.77 |       27,956,388.03 |    0.8% |          614.18 |          131.72 |  4.663 |          85.57 |    0.1% |      0.01 | `range writes`
-|               76.72 |       13,035,140.63 |    2.3% |        1,421.28 |          387.17 |  3.671 |         257.76 |    0.1% |      0.01 | `monotonic increasing point writes`
+|               80.13 |       12,480,456.47 |    1.5% |        1,279.04 |          294.90 |  4.337 |         234.68 |    0.1% |      0.01 | `monotonic increasing point writes`
-|          297,452.00 |            3,361.89 |    0.9% |    3,508,083.00 |    1,500,834.67 |  2.337 |     727,525.33 |    0.1% |      0.01 | `worst case for radix tree`
+|          360,748.00 |            2,772.02 |    2.6% |    4,401,835.00 |    1,318,754.00 |  3.338 |     728,537.00 |    0.0% |      0.01 | `worst case for radix tree`
-|               87.70 |       11,402,490.60 |    1.0% |        1,795.00 |          442.09 |  4.060 |         297.00 |    0.0% |      0.01 | `create and destroy`
+|               90.69 |       11,027,103.45 |    1.0% |        1,686.00 |          333.80 |  5.051 |         284.00 |    0.0% |      0.01 | `create and destroy`
 
 # "Real data" test
 
-Point queries only, best of three runs. Gc ratio is the ratio of time spent doing garbage collection to time spent adding writes or doing garbage collection. Lower is better.
+Point queries only. Gc ratio is the ratio of time spent doing garbage collection to time spent adding writes or doing garbage collection. Lower is better.
 
 ## skip list
 
 ```
-Check: 4.47891 seconds, 364.05 MB/s, Add: 4.55599 seconds, 123.058 MB/s, Gc ratio: 37.1145%
+Check: 4.42779 seconds, 368.253 MB/s, Add: 4.64942 seconds, 120.586 MB/s, Gc ratio: 28.8784%, Peak idle memory: 5.51735e+06
 ```
 
 ## radix tree
 
 ```
-Check: 0.953012 seconds, 1710.94 MB/s, Add: 1.30025 seconds, 431.188 MB/s, Gc ratio: 43.9816%, Peak idle memory: 2.28375e+06
+Check: 0.891163 seconds, 1829.69 MB/s, Add: 1.23064 seconds, 455.579 MB/s, Gc ratio: 42.9417%, Peak idle memory: 2.28333e+06
 ```
 
 ## hash table
@@ -55,5 +65,6 @@ Check: 0.953012 seconds, 1710.94 MB/s, Add: 1.30025 seconds, 431.188 MB/s, Gc ra
 (The hash table implementation doesn't work on range queries, and its purpose is to provide an idea of how fast point queries can be)
 
 ```
-Check: 0.804094 seconds, 2027.81 MB/s, Add: 0.652952 seconds, 858.645 MB/s, Gc ratio: 35.3885%
+Check: 0.858484 seconds, 1899.33 MB/s, Add: 0.632886 seconds, 885.868 MB/s, Gc ratio: 41.252%, Peak idle memory: 0
 ```
+

ServerBench.cpp

@@ -21,7 +21,7 @@
 
 std::atomic<int64_t> transactions;
 
-constexpr int kBaseSearchDepth = 115;
+constexpr int kBaseSearchDepth = 32;
 constexpr int kWindowSize = 10000000;
 
 std::string numToKey(int64_t num) {

SkipList.cpp

@@ -22,7 +22,6 @@
 
 #include "ConflictSet.h"
 #include "Internal.h"
-#include "Metrics.h"
 
 #include <algorithm>
 #include <span>
@@ -435,14 +434,13 @@ public:
     return result;
   }
 
-  // Return number of iterations of main loop
+  void detectConflicts(ReadConflictRange *ranges, int count,
-  int detectConflicts(ReadConflictRange *ranges, int count,
                        ConflictSet::Result *transactionConflictStatus) const {
     const int M = 16;
     int nextJob[M];
     CheckMax inProgress[M];
     if (!count)
-      return 0;
+      return;
 
     int started = std::min(M, count);
     for (int i = 0; i < started; i++) {
@@ -453,9 +451,8 @@ public:
 
     int prevJob = started - 1;
     int job = 0;
-    int iters = 0;
     // vtune: 340 parts
-    for (;; ++iters) {
+    while (true) {
       if (inProgress[job].advance()) {
         if (started == count) {
           if (prevJob == job)
@@ -471,7 +468,6 @@ public:
       prevJob = job;
       job = nextJob[job];
     }
-    return iters;
   }
 
   void find(const StringRef *values, Finger *results, int *temp, int count) {
@@ -706,27 +702,15 @@ private:
   };
 };
 
-struct ReadContext {
-  int64_t commits_accum = 0;
-  int64_t conflicts_accum = 0;
-  int64_t too_olds_accum = 0;
-  int64_t check_bytes_accum = 0;
-};
-
 struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   Impl(int64_t oldestVersion)
       : oldestVersion(oldestVersion), newestVersion(oldestVersion),
-        skipList(oldestVersion) {
+        skipList(oldestVersion) {}
-    metrics = initMetrics(metricsList, metricsCount);
-  }
-  ~Impl() { safe_free(metrics, metricsCount * sizeof(metrics[0])); }
   void check(const ConflictSet::ReadRange *reads, ConflictSet::Result *results,
-             int count) {
+             int count) const {
-    ReadContext tls;
     Arena arena;
     auto *ranges = new (arena) ReadConflictRange[count];
     for (int i = 0; i < count; ++i) {
-      tls.check_bytes_accum += reads[i].begin.len + reads[i].end.len;
       ranges[i].begin = {reads[i].begin.p, size_t(reads[i].begin.len)};
       ranges[i].end = reads[i].end.len > 0
                           ? StringRef{reads[i].end.p, size_t(reads[i].end.len)}
@@ -734,22 +718,13 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       ranges[i].version = reads[i].readVersion;
       results[i] = ConflictSet::Commit;
     }
-    int iters = skipList.detectConflicts(ranges, count, results);
+    skipList.detectConflicts(ranges, count, results);
     for (int i = 0; i < count; ++i) {
       if (reads[i].readVersion < oldestVersion ||
           reads[i].readVersion < newestVersion - 2e9) {
         results[i] = TooOld;
       }
-      tls.commits_accum += results[i] == Commit;
-      tls.conflicts_accum += results[i] == Conflict;
-      tls.too_olds_accum += results[i] == TooOld;
     }
-    range_read_iterations_total.add(iters);
-    range_read_total.add(count);
-    commits_total.add(tls.commits_accum);
-    conflicts_total.add(tls.conflicts_accum);
-    too_olds_total.add(tls.too_olds_accum);
-    check_bytes_total.add(tls.check_bytes_accum);
   }
 
   void addWrites(const ConflictSet::WriteRange *writes, int count,
@@ -813,9 +788,6 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   }
 
   void setOldestVersion(int64_t oldestVersion) {
-    // This isn't 100% accurate. It overcounts if you hit the end
-    gc_iterations_total.add(keyUpdates);
-
     assert(oldestVersion >= this->oldestVersion);
     this->oldestVersion = oldestVersion;
     SkipList::Finger finger;
@@ -830,54 +802,6 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
 
   int64_t totalBytes = 0;
 
-  MetricsV1 *metrics;
-  int metricsCount = 0;
-  Metric *metricsList = nullptr;
-
-#define GAUGE(name, help)                                                      \
-  Gauge name { metricsList, metricsCount, #name, help }
-#define COUNTER(name, help)                                                    \
-  Counter name { metricsList, metricsCount, #name, help }
-  // ==================== METRICS DEFINITIONS ====================
-  COUNTER(range_read_total, "Total number of range reads checked");
-  COUNTER(range_read_iterations_total,
-          "Total number of iterations of the main loops for range read checks");
-  COUNTER(commits_total,
-          "Total number of checks where the result is \"commit\"");
-  COUNTER(conflicts_total,
-          "Total number of checks where the result is \"conflict\"");
-  COUNTER(too_olds_total,
-          "Total number of checks where the result is \"too old\"");
-  COUNTER(check_bytes_total, "Total number of key bytes checked");
-  GAUGE(memory_bytes, "Total number of bytes in use");
-  COUNTER(nodes_allocated_total,
-          "The total number of physical tree nodes allocated");
-  COUNTER(nodes_released_total,
-          "The total number of physical tree nodes released");
-  COUNTER(insert_iterations_total,
-          "The total number of iterations of the main loop for insertion. "
-          "Includes searches where the entry already existed, and so insertion "
-          "did not take place");
-  COUNTER(entries_inserted_total,
-          "The total number of entries inserted in the tree");
-  COUNTER(entries_erased_total,
-          "The total number of entries erased from the tree");
-  COUNTER(
-      gc_iterations_total,
-      "The total number of iterations of the main loop for garbage collection");
-  COUNTER(write_bytes_total, "Total number of key bytes in calls to addWrites");
-  GAUGE(oldest_version,
-        "The lowest version that doesn't result in \"TooOld\" for checks");
-  GAUGE(newest_version, "The version of the most recent call to addWrites");
-  // ==================== END METRICS DEFINITIONS ====================
-#undef GAUGE
-#undef COUNTER
-
-  void getMetricsV1(MetricsV1 **metrics, int *count) {
-    *metrics = this->metrics;
-    *count = metricsCount;
-  }
-
 private:
   int64_t keyUpdates = 0;
   Arena removalArena;
@@ -900,7 +824,6 @@ void internal_addWrites(ConflictSet::Impl *impl,
   mallocBytesDelta = 0;
   impl->addWrites(writes, count, writeVersion);
   impl->totalBytes += mallocBytesDelta;
-  impl->memory_bytes.set(impl->totalBytes);
 #if SHOW_MEMORY
   if (impl->totalBytes != mallocBytes) {
     abort();
@@ -912,7 +835,6 @@ void internal_setOldestVersion(ConflictSet::Impl *impl, int64_t oldestVersion) {
   mallocBytesDelta = 0;
   impl->setOldestVersion(oldestVersion);
   impl->totalBytes += mallocBytesDelta;
-  impl->memory_bytes.set(impl->totalBytes);
 #if SHOW_MEMORY
   if (impl->totalBytes != mallocBytes) {
     abort();
@@ -936,11 +858,12 @@ int64_t internal_getBytes(ConflictSet::Impl *impl) { return impl->totalBytes; }
 
 void internal_getMetricsV1(ConflictSet::Impl *impl,
                            ConflictSet::MetricsV1 **metrics, int *count) {
-  return impl->getMetricsV1(metrics, count);
+  *metrics = nullptr;
+  *count = 0;
 }
 
 double internal_getMetricValue(const ConflictSet::MetricsV1 *metric) {
-  return ((Metric *)metric->p)->value.load(std::memory_order_relaxed);
+  return 0;
 }
 
 void ConflictSet::check(const ReadRange *reads, Result *results,
@@ -980,7 +903,12 @@ ConflictSet::ConflictSet(ConflictSet &&other) noexcept
     : impl(std::exchange(other.impl, nullptr)) {}
 
 ConflictSet &ConflictSet::operator=(ConflictSet &&other) noexcept {
+  if (this != &other) {
+    if (impl) {
+      internal_destroy(impl);
+    }
     impl = std::exchange(other.impl, nullptr);
+  }
   return *this;
 }