Skip sorting if already sorted for skip list

This works around a weird error I was getting when trying to link a
translation unit that included Internal.h with libconflict-set-static.a
with clang + gnu objcopy

CMakeLists.txt

@@ -32,12 +32,7 @@ if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
 endif()
 
 add_compile_options(
-  -Werror=switch-enum
-  -Wswitch-enum
-  -Wunused-variable
-  -fPIC
-  -fdata-sections
-  -ffunction-sections
+  -Werror=switch-enum -Wswitch-enum -fPIC -fdata-sections -ffunction-sections
   -fno-jump-tables # https://github.com/llvm/llvm-project/issues/54247
 )
 
@@ -109,11 +104,19 @@ else()
   add_link_options(-Wl,--gc-sections)
 endif()
 
-if(USE_SIMD_FALLBACK)
-  add_compile_definitions(USE_SIMD_FALLBACK)
-else()
-  if(CMAKE_SYSTEM_PROCESSOR STREQUAL x86_64)
+if(NOT USE_SIMD_FALLBACK)
+  cmake_push_check_state()
+  list(APPEND CMAKE_REQUIRED_FLAGS -mavx)
+  check_include_file_cxx("immintrin.h" HAS_AVX)
+  if(HAS_AVX)
     add_compile_options(-mavx)
+    add_compile_definitions(HAS_AVX)
+  endif()
+  cmake_pop_check_state()
+
+  check_include_file_cxx("arm_neon.h" HAS_ARM_NEON)
+  if(HAS_ARM_NEON)
+    add_compile_definitions(HAS_ARM_NEON)
   endif()
 endif()
 
@@ -343,7 +346,8 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
   # c++98
   add_executable(conflict_set_cxx_api_test conflict_set_cxx_api_test.cpp)
   target_compile_options(conflict_set_cxx_api_test PRIVATE ${TEST_FLAGS})
-  target_link_libraries(conflict_set_cxx_api_test PRIVATE ${PROJECT_NAME})
+  target_link_libraries(conflict_set_cxx_api_test
+                        PRIVATE ${PROJECT_NAME}-static)
   set_target_properties(conflict_set_cxx_api_test PROPERTIES CXX_STANDARD 98)
   set_target_properties(conflict_set_cxx_api_test
                         PROPERTIES CXX_STANDARD_REQUIRED ON)

ConflictSet.cpp

@@ -14,16 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-#if !defined(USE_SIMD_FALLBACK) && defined(__has_include)
-#if defined(__x86_64__) && __has_include("immintrin.h")
-#define HAS_AVX 1
-#include <immintrin.h>
-#elif __has_include("arm_neon.h")
-#define HAS_ARM_NEON 1
-#include <arm_neon.h>
-#endif
-#endif
-
 #include "ConflictSet.h"
 #include "Internal.h"
 #include "LongestCommonPrefix.h"
@@ -44,6 +34,12 @@ limitations under the License.
 #include <type_traits>
 #include <utility>
 
+#ifdef HAS_AVX
+#include <immintrin.h>
+#elif defined(HAS_ARM_NEON)
+#include <arm_neon.h>
+#endif
+
 #ifndef __SANITIZE_THREAD__
 #if defined(__has_feature)
 #if __has_feature(thread_sanitizer)
@@ -700,6 +696,8 @@ constexpr int64_t kMaxFreeListBytes = 1 << 20;
 // doesn't meet the capacity constraints, it's freed and a new node is allocated
 // with the minimum capacity. The hope is that "unfit" nodes don't get stuck in
 // the free list.
+//
+// TODO valgrind annotations
 template <class T> struct NodeAllocator {
 
   static_assert(std::derived_from<T, Node>);
@@ -736,7 +734,6 @@ template <class T> struct NodeAllocator {
     p->parent = freeList;
     freeList = p;
     freeListSize += sizeof(T) + p->partialKeyCapacity;
-    VALGRIND_MAKE_MEM_NOACCESS(p, sizeof(T) + p->partialKeyCapacity);
   }
 
   void deferRelease(T *p, Node *forwardTo) {
@@ -758,13 +755,6 @@ template <class T> struct NodeAllocator {
   void releaseDeferred() {
     if (deferredList != nullptr) {
       deferredListFront->parent = freeList;
-#ifndef NVALGRIND
-      for (auto *iter = deferredList; iter != freeList;) {
-        auto *tmp = iter;
-        iter = (T *)iter->parent;
-        VALGRIND_MAKE_MEM_NOACCESS(tmp, sizeof(T) + tmp->partialKeyCapacity);
-      }
-#endif
       freeList = std::exchange(deferredList, nullptr);
     }
     for (T *n = std::exchange(deferredListOverflow, nullptr); n != nullptr;) {
@@ -785,7 +775,6 @@ template <class T> struct NodeAllocator {
     assert(deferredList == nullptr);
     assert(deferredListOverflow == nullptr);
     for (T *iter = freeList; iter != nullptr;) {
-      VALGRIND_MAKE_MEM_DEFINED(iter, sizeof(T));
       auto *tmp = iter;
       iter = (T *)iter->parent;
       removeNode(tmp);
@@ -803,7 +792,6 @@ private:
 
   T *allocate_helper(int minCapacity, int maxCapacity) {
     if (freeList != nullptr) {
-      VALGRIND_MAKE_MEM_DEFINED(freeList, sizeof(T));
       freeListSize -= sizeof(T) + freeList->partialKeyCapacity;
       assume(freeList->partialKeyCapacity >= 0);
       assume(minCapacity >= 0);
@@ -812,11 +800,6 @@ private:
           freeList->partialKeyCapacity <= maxCapacity) {
         auto *result = freeList;
         freeList = (T *)freeList->parent;
-        VALGRIND_MAKE_MEM_UNDEFINED(result,
-                                    sizeof(T) + result->partialKeyCapacity);
-        VALGRIND_MAKE_MEM_DEFINED(&result->partialKeyCapacity,
-                                  sizeof(result->partialKeyCapacity));
-        VALGRIND_MAKE_MEM_DEFINED(&result->type, sizeof(result->type));
         return result;
       } else {
         auto *p = freeList;
@@ -5347,11 +5330,6 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     gc_iterations_total.add(set_oldest_iterations_accum);
     if (n == nullptr) {
       removalKey = {};
-      if (removalBufferSize > kMaxRemovalBufferSize) {
-        safe_free(removalBuffer, removalBufferSize);
-        removalBufferSize = kMinRemovalBufferSize;
-        removalBuffer = (uint8_t *)safe_malloc(removalBufferSize);
-      }
       oldestExtantVersion = oldestVersionAtGcBegin;
       oldest_extant_version.set(oldestExtantVersion);
       oldestVersionAtGcBegin = oldestVersionFullPrecision;
@@ -5362,47 +5340,12 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
               oldestExtantVersion, oldestVersionAtGcBegin);
 #endif
     } else {
-      // Store the current search path to resume the scan later
-      saveRemovalKey(n);
+      removalKeyArena = Arena();
+      removalKey = getSearchPath(removalKeyArena, n);
     }
     return fuel;
   }
 
-  void saveRemovalKey(Node *n) {
-    uint8_t *cursor = removalBuffer + removalBufferSize;
-    int size = 0;
-    auto reserve = [&](int delta) {
-      if (size + delta > removalBufferSize) [[unlikely]] {
-        int newBufSize = std::max(removalBufferSize * 2, size + delta);
-        uint8_t *newBuf = (uint8_t *)safe_malloc(newBufSize);
-        memcpy(newBuf + newBufSize - size, cursor, size);
-        safe_free(removalBuffer, removalBufferSize);
-        removalBuffer = newBuf;
-        removalBufferSize = newBufSize;
-        cursor = newBuf + newBufSize - size;
-      }
-    };
-    for (;;) {
-      auto partialKey = TrivialSpan{n->partialKey(), n->partialKeyLen};
-      reserve(partialKey.size());
-      size += partialKey.size();
-      cursor -= partialKey.size();
-      memcpy(cursor, partialKey.data(), partialKey.size());
-
-      if (n->parent == nullptr) {
-        break;
-      }
-
-      reserve(1);
-      ++size;
-      --cursor;
-      *cursor = n->parentsIndex;
-
-      n = n->parent;
-    }
-    removalKey = {cursor, size};
-  }
-
   void setOldestVersion(int64_t newOldestVersion) {
     assert(newOldestVersion >= 0);
     assert(newOldestVersion <= newestVersionFullPrecision);
@@ -5453,7 +5396,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     writeContext.~WriteContext();
     new (&writeContext) WriteContext();
 
-    // Leave removalBuffer as is
+    removalKeyArena = Arena{};
     removalKey = {};
     keyUpdates = 10;
 
@@ -5485,16 +5428,11 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   ~Impl() {
     eraseTree(root, &writeContext);
     safe_free(metrics, metricsCount * sizeof(metrics[0]));
-    safe_free(removalBuffer, removalBufferSize);
   }
 
   WriteContext writeContext;
 
-  static constexpr int kMinRemovalBufferSize = 1 << 10;
-  // Eventually downsize if larger than this value
-  static constexpr int kMaxRemovalBufferSize = 1 << 16;
-  uint8_t *removalBuffer = (uint8_t *)safe_malloc(kMinRemovalBufferSize);
-  int removalBufferSize = kMinRemovalBufferSize;
+  Arena removalKeyArena;
   TrivialSpan removalKey;
   int64_t keyUpdates;
 
@@ -5920,13 +5858,13 @@ void checkVersionsGeqOldestExtant(Node *n,
   case Type_Node0: {
   } break;
   case Type_Node3: {
-    [[maybe_unused]] auto *self = static_cast<Node3 *>(n);
+    auto *self = static_cast<Node3 *>(n);
     for (int i = 0; i < 3; ++i) {
       assert(self->childMaxVersion[i] >= oldestExtantVersion);
     }
   } break;
   case Type_Node16: {
-    [[maybe_unused]] auto *self = static_cast<Node16 *>(n);
+    auto *self = static_cast<Node16 *>(n);
     for (int i = 0; i < 16; ++i) {
       assert(self->childMaxVersion[i] >= oldestExtantVersion);
     }
@@ -5936,7 +5874,7 @@ void checkVersionsGeqOldestExtant(Node *n,
     for (int i = 0; i < 48; ++i) {
       assert(self->childMaxVersion[i] >= oldestExtantVersion);
     }
-    for ([[maybe_unused]] auto m : self->maxOfMax) {
+    for (auto m : self->maxOfMax) {
       assert(m >= oldestExtantVersion);
     }
   } break;
@@ -5945,7 +5883,7 @@ void checkVersionsGeqOldestExtant(Node *n,
     for (int i = 0; i < 256; ++i) {
       assert(self->childMaxVersion[i] >= oldestExtantVersion);
     }
-    for ([[maybe_unused]] auto m : self->maxOfMax) {
+    for (auto m : self->maxOfMax) {
       assert(m >= oldestExtantVersion);
     }
   } break;

Jenkinsfile

@@ -91,7 +91,7 @@ pipeline {
                 minio bucket: 'jenkins', credentialsId: 'jenkins-minio', excludes: '', host: 'minio.weaselab.dev', includes: 'build/*.deb,build/*.rpm,paper/*.pdf', targetFolder: '${JOB_NAME}/${BUILD_NUMBER}/${STAGE_NAME}/'
             }
         }
-        stage('gcc') {
+        stage('Release [gcc]') {
             agent {
                 dockerfile {
                     args '-v /home/jenkins/ccache:/ccache'
@@ -99,7 +99,7 @@ pipeline {
                 }
             }
             steps {
-                CleanBuildAndTest("-DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++")
+                CleanBuildAndTest("-DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_CXX_FLAGS=-DNVALGRIND")
                 recordIssues(tools: [gcc()])
             }
         }

RealDataBench.cpp

@@ -5,7 +5,7 @@
 #include <cstdio>
 #include <cstring>
 #include <fcntl.h>
-#include <span>
+#include <string_view>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ -64,7 +64,7 @@ int main(int argc, const char **argv) {
     auto *const mapOriginal = begin;
     const auto sizeOriginal = size;
 
-    using StringView = std::span<const uint8_t>;
+    using StringView = std::basic_string_view<uint8_t>;
 
     StringView write;
     std::vector<StringView> reads;
@@ -78,9 +78,9 @@ int main(int argc, const char **argv) {
       end = (uint8_t *)memchr(begin, '\n', size);
 
       if (line.size() > 0 && line[0] == 'P') {
-        write = line.subspan(2, line.size());
+        write = line.substr(2, line.size());
       } else if (line.size() > 0 && line[0] == 'L') {
-        reads.push_back(line.subspan(2, line.size()));
+        reads.push_back(line.substr(2, line.size()));
       } else if (line.empty()) {
         {
           readRanges.resize(reads.size());

ServerBench.cpp

@@ -23,97 +23,6 @@
 #include "Internal.h"
 #include "third_party/nadeau.h"
 
-constexpr int kCacheLine = 64; // TODO mac m1 is 128
-
-template <class T> struct TxQueue {
-
-  explicit TxQueue(int lgSlotCount)
-      : slotCount(1 << lgSlotCount), slotCountMask(slotCount - 1),
-        slots(new T[slotCount]) {
-    // Otherwise we can't tell the difference between full and empty.
-    assert(!(slotCountMask & 0x80000000));
-  }
-
-  /// Call from producer thread, after ensuring consumer is no longer accessing
-  /// it somehow
-  ~TxQueue() { delete[] slots; }
-
-  /// Must be called from the producer thread
-  void push(T t) {
-    if (wouldBlock()) {
-      // Wait for pops to change and try again
-      consumer.pops.wait(producer.lastPopRead, std::memory_order_relaxed);
-      producer.lastPopRead = consumer.pops.load(std::memory_order_acquire);
-    }
-    slots[producer.pushesNonAtomic++ & slotCountMask] = std::move(t);
-    // seq_cst so that the notify can't be ordered before the store
-    producer.pushes.store(producer.pushesNonAtomic, std::memory_order_seq_cst);
-    // We have to notify every time, since we don't know if this is the last
-    // push ever
-    producer.pushes.notify_one();
-  }
-
-  /// Must be called from the producer thread
-  uint32_t outstanding() {
-    return producer.pushesNonAtomic -
-           consumer.pops.load(std::memory_order_relaxed);
-  }
-
-  /// Returns true if a call to push might block. Must be called from the
-  /// producer thread.
-  bool wouldBlock() {
-    // See if we can determine that overflow won't happen entirely from state
-    // local to the producer
-    if (producer.pushesNonAtomic - producer.lastPopRead == slotCount - 1) {
-      // Re-read pops with memory order
-      producer.lastPopRead = consumer.pops.load(std::memory_order_acquire);
-      return producer.pushesNonAtomic - producer.lastPopRead == slotCount - 1;
-    }
-    return false;
-  }
-
-  /// Valid until the next pop, or until this queue is destroyed.
-  T *pop() {
-    // See if we can determine that there's an entry we can pop entirely from
-    // state local to the consumer
-    if (consumer.lastPushRead - consumer.popsNonAtomic == 0) {
-      // Re-read pushes with memory order and try again
-      consumer.lastPushRead = producer.pushes.load(std::memory_order_acquire);
-      if (consumer.lastPushRead - consumer.popsNonAtomic == 0) {
-        // Wait for pushes to change and try again
-        producer.pushes.wait(consumer.lastPushRead, std::memory_order_relaxed);
-        consumer.lastPushRead = producer.pushes.load(std::memory_order_acquire);
-      }
-    }
-    auto result = &slots[consumer.popsNonAtomic++ & slotCountMask];
-    // We only have to write pops with memory order if we've run out of items.
-    // We know that we'll eventually run out.
-    if (consumer.lastPushRead - consumer.popsNonAtomic == 0) {
-      // seq_cst so that the notify can't be ordered before the store
-      consumer.pops.store(consumer.popsNonAtomic, std::memory_order_seq_cst);
-      consumer.pops.notify_one();
-    }
-    return result;
-  }
-
-private:
-  const uint32_t slotCount;
-  const uint32_t slotCountMask;
-  T *slots;
-  struct alignas(kCacheLine) ProducerState {
-    std::atomic<uint32_t> pushes{0};
-    uint32_t pushesNonAtomic{0};
-    uint32_t lastPopRead{0};
-  };
-  struct alignas(kCacheLine) ConsumerState {
-    std::atomic<uint32_t> pops{0};
-    uint32_t popsNonAtomic{0};
-    uint32_t lastPushRead{0};
-  };
-  ProducerState producer;
-  ConsumerState consumer;
-};
-
 std::atomic<int64_t> transactions;
 
 int64_t safeUnaryMinus(int64_t x) {
@@ -157,69 +66,49 @@ template <class... Ts> std::string tupleKey(const Ts &...ts) {
 
 constexpr int kTotalKeyRange = 1'000'000'000;
 constexpr int kWindowSize = 1'000'000;
-constexpr int kNumReadKeysPerTx = 10;
-constexpr int kNumWriteKeysPerTx = 5;
+constexpr int kNumKeys = 10;
 
-struct Transaction {
-  std::vector<std::string> keys;
-  std::vector<weaselab::ConflictSet::ReadRange> reads;
-  std::vector<weaselab::ConflictSet::WriteRange> writes;
-  int64_t version;
-  int64_t oldestVersion;
-  Transaction() = default;
-  explicit Transaction(int64_t version)
-      : version(version), oldestVersion(version - kWindowSize) {
+void workload(weaselab::ConflictSet *cs) {
+  int64_t version = kWindowSize;
+  for (;; transactions.fetch_add(1, std::memory_order_relaxed)) {
     std::vector<int64_t> keyIndices;
-    for (int i = 0; i < std::max(kNumReadKeysPerTx, kNumWriteKeysPerTx); ++i) {
+    for (int i = 0; i < kNumKeys; ++i) {
       keyIndices.push_back(rand() % kTotalKeyRange);
     }
     std::sort(keyIndices.begin(), keyIndices.end());
+    std::vector<std::string> keys;
     constexpr std::string_view fullString =
         "this is a string, where a prefix of it is used as an element of the "
         "tuple forming the key";
-    for (int i = 0; i < int(keyIndices.size()); ++i) {
+    for (int i = 0; i < kNumKeys; ++i) {
       keys.push_back(
           tupleKey(0x100, keyIndices[i] / fullString.size(),
                    fullString.substr(0, keyIndices[i] % fullString.size())));
       // printf("%s\n", printable(keys.back()).c_str());
     }
-    for (int i = 0; i < kNumWriteKeysPerTx; ++i) {
+
+    std::vector<weaselab::ConflictSet::ReadRange> reads;
+    std::vector<weaselab::ConflictSet::WriteRange> writes;
+    std::vector<weaselab::ConflictSet::Result> results;
+    for (int i = 0; i < kNumKeys; ++i) {
       writes.push_back({{(const uint8_t *)keys[i].data(), int(keys[i].size())},
                         {nullptr, 0}});
-    }
-    reads.push_back({{(const uint8_t *)keys[0].data(), int(keys[0].size())},
-                     {(const uint8_t *)keys[1].data(), int(keys[1].size())},
-                     version - kWindowSize});
-    static_assert(kNumReadKeysPerTx >= 3);
-    for (int i = 2; i < kNumReadKeysPerTx; ++i) {
       reads.push_back({{(const uint8_t *)keys[i].data(), int(keys[i].size())},
                        {nullptr, 0},
                        version - kWindowSize});
     }
+    results.resize(reads.size());
+
+    cs->check(reads.data(), results.data(), reads.size());
+    bool ok = true;
+    for (auto result : results) {
+      ok &= result == weaselab::ConflictSet::Commit;
+    }
+    cs->addWrites(writes.data(), ok ? writes.size() : 0, version);
+    cs->setOldestVersion(version - kWindowSize);
+    ++version;
   }
-
-  Transaction(Transaction &&) = default;
-  Transaction &operator=(Transaction &&) = default;
-  Transaction(Transaction const &) = delete;
-  Transaction const &operator=(Transaction const &) = delete;
-};
-
-struct Resolver {
-
-  void resolve(const weaselab::ConflictSet::ReadRange *reads, int readCount,
-               const weaselab::ConflictSet::WriteRange *writes, int writeCount,
-               int64_t newVersion, int64_t newOldestVersion) {
-    results.resize(readCount);
-    cs.check(reads, results.data(), readCount);
-    cs.addWrites(writes, writeCount, newVersion);
-    cs.setOldestVersion(newOldestVersion);
-  }
-
-  ConflictSet cs{0};
-
-private:
-  std::vector<weaselab::ConflictSet::Result> results;
-};
+}
 
 // Adapted from getaddrinfo man page
 int getListenFd(const char *node, const char *service) {
@@ -362,8 +251,7 @@ int main(int argc, char **argv) {
   {
     int listenFd = getListenFd(argv[1], argv[2]);
 
-    Resolver resolver;
-    auto &cs = resolver.cs;
+    weaselab::ConflictSet cs{0};
     weaselab::ConflictSet::MetricsV1 *metrics;
     int metricsCount;
     cs.getMetricsV1(&metrics, &metricsCount);
@@ -412,23 +300,7 @@ int main(int argc, char **argv) {
     }
 #endif
 
-    TxQueue<std::unique_ptr<Transaction>> queue{10};
-
-    auto workloadThread = std::thread{[&]() {
-      for (int64_t version = kWindowSize;;
-           ++version, transactions.fetch_add(1, std::memory_order_relaxed)) {
-        auto tx = std::make_unique<Transaction>(version);
-        queue.push(std::move(tx));
-      }
-    }};
-
-    auto resolverThread = std::thread{[&]() {
-      for (;;) {
-        auto tx = queue.pop()->get();
-        resolver.resolve(tx->reads.data(), tx->reads.size(), tx->writes.data(),
-                         tx->writes.size(), tx->version, tx->oldestVersion);
-      }
-    }};
+    auto w = std::thread{workload, &cs};
 
     for (;;) {
       struct sockaddr_storage peer_addr = {};

SkipList.cpp

@@ -796,6 +796,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     int temp[stripeSize];
     int stripes = (stringCount + stripeSize - 1) / stripeSize;
     StringRef values[stripeSize];
+    int64_t writeVersions[stripeSize / 2];
     int ss = stringCount - (stripes - 1) * stripeSize;
     int64_t entryDelta = 0;
     for (int s = stripes - 1; s >= 0; s--) {

apple-symbol-imports.txt

@@ -1,4 +1,3 @@
-___chkstk_darwin
 ___stack_chk_fail
 ___stack_chk_guard
 __tlv_bootstrap
@@ -6,7 +5,6 @@ _abort
 _bzero
 _free
 _malloc
-_memcmp
 _memcpy
 _memmove
 dyld_stub_binder

package_macos.sh

@@ -8,7 +8,7 @@ SRC_DIR="${0%/*}"
 BUILD_ARM="$(mktemp -d -t conflict-set-arm)"
 BUILD_X86="$(mktemp -d -t conflict-set-x86)"
 
-cmake_args=(-DCMAKE_CXX_FLAGS=-DNVALGRIND -DCPACK_PACKAGING_INSTALL_PREFIX=/usr/local -DCMAKE_CXX_COMPILER=/opt/homebrew/opt/llvm/bin/clang++)
+cmake_args=(-DCMAKE_CXX_FLAGS=-DNVALGRIND -DCPACK_PACKAGING_INSTALL_PREFIX=/usr/local)
 
 cmake -S"$SRC_DIR" -B"$BUILD_ARM" -DCMAKE_OSX_ARCHITECTURES=arm64 "${cmake_args[@]}"
 cmake --build "$BUILD_ARM" --target conflict-set --target conflict-set-static

test_conflict_set.py

@@ -1,4 +1,3 @@
-import struct
 from conflict_set import *
 
 
@@ -165,16 +164,6 @@ def test_fixup_256():
         cs.check(read(0, bytes([1]), bytes([2])))
 
 
-def test_large_removal_buffer():
-    with DebugConflictSet() as cs:
-        for i in range(1000):
-            # create extra gc work
-            for j in range(100):
-                cs.addWrites(1000 + i)
-            cs.addWrites(1000 + i, write(struct.pack(">l", i) + bytes([0] * 100000)))
-            cs.setOldestVersion(i)
-
-
 if __name__ == "__main__":
     # budget "pytest" for ctest integration without pulling in a dependency. You can of course still use pytest in local development.
     import argparse