Add cycles_total

If numChildren + entryPresent is enough, we don't have to copy even if
it would fit in a smaller node.

If we have to copy, we might as well use the smallest acceptable node
type.

Bench.cpp

@@ -7,6 +7,7 @@
 void showMemory(const ConflictSet &cs);
 #endif
 
+#define ANKERL_NANOBENCH_IMPLEMENT
 #include "third_party/nanobench.h"
 
 constexpr int kNumKeys = 1000000;
@@ -360,7 +361,21 @@ void benchWorstCaseForRadixRangeRead() {
 void benchCreateAndDestroy() {
   ankerl::nanobench::Bench bench;
 
-  bench.run("create and destroy", [&]() { ConflictSet cs{0}; });
+  bench.run("create and destroy", [&]() {
+    ConflictSet cs{0};
+    ConflictSet::WriteRange w;
+    uint8_t b[9];
+    b[8] = 0;
+    for (int64_t i = 0; i < 1000; i += 7) {
+      auto x = __builtin_bswap64(i);
+      memcpy(b, &x, 8);
+      w.begin.p = b;
+      w.begin.len = 8;
+      w.end.len = 0;
+      w.end.p = b;
+      cs.addWrites(&w, 1, 1);
+    }
+  });
 }
 
 int main(void) {

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.18)
 project(
   conflict-set
-  VERSION 0.0.14
+  VERSION 0.0.12
   DESCRIPTION
     "A data structure for optimistic concurrency control on ranges of bitwise-lexicographically-ordered keys."
   HOMEPAGE_URL "https://git.weaselab.dev/weaselab/conflict-set"
@@ -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)
@@ -138,8 +144,6 @@ include(CTest)
 # disable tests if this is being used through e.g. FetchContent
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
 
-  add_library(nanobench ${CMAKE_CURRENT_SOURCE_DIR}/nanobench.cpp)
-
   set(TEST_FLAGS -Wall -Wextra -Wunreachable-code -Wpedantic -UNDEBUG)
 
   # corpus tests, which are tests curated by libfuzzer. The goal is to get broad
@@ -187,7 +191,6 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
   target_include_directories(conflict_set_main
                              PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include)
   target_compile_definitions(conflict_set_main PRIVATE ENABLE_MAIN)
-  target_link_libraries(conflict_set_main PRIVATE nanobench)
 
   if(NOT APPLE)
     # libfuzzer target, to generate/manage corpus
@@ -248,19 +251,6 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
     add_test(NAME conflict_set_blackbox_${hash} COMMAND driver ${TEST})
   endforeach()
 
-  find_program(VALGRIND_EXE valgrind)
-  if(VALGRIND_EXE AND NOT CMAKE_CROSSCOMPILING)
-    list(LENGTH CORPUS_TESTS len)
-    math(EXPR last "${len} - 1")
-    set(partition_size 100)
-    foreach(i RANGE 0 ${last} ${partition_size})
-      list(SUBLIST CORPUS_TESTS ${i} ${partition_size} partition)
-      add_test(NAME conflict_set_blackbox_valgrind_${i}
-               COMMAND ${VALGRIND_EXE} --error-exitcode=99 --
-                       $<TARGET_FILE:driver> ${partition})
-    endforeach()
-  endif()
-
   # scripted tests. Written manually to fill in anything libfuzzer couldn't
   # find.
   if(NOT CMAKE_CROSSCOMPILING)
@@ -281,17 +271,16 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
           ${Python3_EXECUTABLE}
           ${CMAKE_CURRENT_SOURCE_DIR}/test_conflict_set.py test ${TEST}
           --build-dir ${CMAKE_CURRENT_BINARY_DIR})
-      if(VALGRIND_EXE AND NOT CMAKE_CROSSCOMPILING)
-        add_test(
-          NAME script_test_${TEST}_valgrind
-          COMMAND
-            ${VALGRIND_EXE} ${Python3_EXECUTABLE}
-            ${CMAKE_CURRENT_SOURCE_DIR}/test_conflict_set.py test ${TEST}
-            --build-dir ${CMAKE_CURRENT_BINARY_DIR})
-      endif()
     endforeach()
   endif()
 
+  find_program(VALGRIND_EXE valgrind)
+  if(VALGRIND_EXE AND NOT CMAKE_CROSSCOMPILING)
+    add_test(NAME conflict_set_blackbox_valgrind
+             COMMAND ${VALGRIND_EXE} --error-exitcode=99 --
+                     $<TARGET_FILE:driver> ${CORPUS_TESTS})
+  endif()
+
   # api smoke tests
 
   # c90
@@ -341,7 +330,7 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
 
   # bench
   add_executable(conflict_set_bench Bench.cpp)
-  target_link_libraries(conflict_set_bench PRIVATE ${PROJECT_NAME} nanobench)
+  target_link_libraries(conflict_set_bench PRIVATE ${PROJECT_NAME})
   set_target_properties(conflict_set_bench PROPERTIES SKIP_BUILD_RPATH ON)
   add_executable(real_data_bench RealDataBench.cpp)
   target_link_libraries(real_data_bench PRIVATE ${PROJECT_NAME})
@@ -356,9 +345,6 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND BUILD_TESTING)
   add_executable(server_bench ServerBench.cpp)
   target_link_libraries(server_bench PRIVATE ${PROJECT_NAME})
   set_target_properties(server_bench PROPERTIES SKIP_BUILD_RPATH ON)
-
-  add_executable(interleaving_test InterleavingTest.cpp)
-  target_link_libraries(interleaving_test PRIVATE nanobench)
 endif()
 
 # packaging

InterleavingTest.cpp

@@ -1,178 +0,0 @@
-#include <alloca.h>
-#include <cassert>
-#ifdef __x86_64__
-#include <immintrin.h>
-#endif
-
-#include "third_party/nanobench.h"
-
-struct Job {
-  int *input;
-  // Returned void* is a function pointer to the next continuation. We have to
-  // use void* because otherwise the type would be recursive.
-  typedef void *(*continuation)(Job *);
-  continuation next;
-};
-
-void *stepJob(Job *j) {
-  auto done = --(*j->input) == 0;
-#ifdef __x86_64__
-  _mm_clflush(j->input);
-#endif
-  return done ? nullptr : (void *)stepJob;
-}
-
-// So we can look at the disassembly more easily
-
-extern "C" {
-void sequential(Job **jobs, int count) {
-  for (int i = 0; i < count; ++i) {
-    do {
-      jobs[i]->next = (Job::continuation)jobs[i]->next(jobs[i]);
-    } while (jobs[i]->next);
-  }
-}
-
-void sequentialNoFuncPtr(Job **jobs, int count) {
-  for (int i = 0; i < count; ++i) {
-    while (stepJob(jobs[i]))
-      ;
-  }
-}
-
-void interleaveSwapping(Job **jobs, int remaining) {
-  int current = 0;
-  while (remaining > 0) {
-    auto next = (Job::continuation)jobs[current]->next(jobs[current]);
-    jobs[current]->next = next;
-    if (next == nullptr) {
-      jobs[current] = jobs[remaining - 1];
-      --remaining;
-    } else {
-      ++current;
-    }
-    if (current == remaining) {
-      current = 0;
-    }
-  }
-}
-
-void interleaveBoundedCyclicList(Job **jobs, int count) {
-  if (count == 0) {
-    return;
-  }
-
-  constexpr int kConcurrent = 32;
-  Job *inProgress[kConcurrent];
-  int nextJob[kConcurrent];
-
-  int started = std::min(kConcurrent, count);
-  for (int i = 0; i < started; i++) {
-    inProgress[i] = jobs[i];
-    nextJob[i] = i + 1;
-  }
-  nextJob[started - 1] = 0;
-
-  int prevJob = started - 1;
-  int job = 0;
-  for (;;) {
-    auto next = (Job::continuation)inProgress[job]->next(inProgress[job]);
-    inProgress[job]->next = next;
-    if (next == nullptr) {
-      if (started == count) {
-        if (prevJob == job)
-          break;
-        nextJob[prevJob] = nextJob[job];
-        job = prevJob;
-      } else {
-        int temp = started++;
-        inProgress[job] = jobs[temp];
-      }
-    }
-    prevJob = job;
-    job = nextJob[job];
-  }
-}
-
-void interleaveCyclicList(Job **jobs, int count) {
-  auto *nextJob = (int *)alloca(sizeof(int) * count);
-
-  for (int i = 0; i < count - 1; ++i) {
-    nextJob[i] = i + 1;
-  }
-  nextJob[count - 1] = 0;
-
-  int prevJob = count - 1;
-  int job = 0;
-  for (;;) {
-    auto next = (Job::continuation)jobs[job]->next(jobs[job]);
-    jobs[job]->next = next;
-    if (next == nullptr) {
-      if (prevJob == job)
-        break;
-      nextJob[prevJob] = nextJob[job];
-      job = prevJob;
-    }
-    prevJob = job;
-    job = nextJob[job];
-  }
-}
-}
-
-int main() {
-  ankerl::nanobench::Bench bench;
-
-  constexpr int kNumJobs = 100;
-  bench.relative(true);
-
-  Job jobs[kNumJobs];
-  Job jobsCopy[kNumJobs];
-  int iters = 0;
-  int originalInput[kNumJobs];
-  for (int i = 0; i < kNumJobs; ++i) {
-    originalInput[i] = rand() % 5 + 3;
-    jobs[i].input = new int{originalInput[i]};
-    jobs[i].next = stepJob;
-    iters += *jobs[i].input;
-  }
-  bench.batch(iters);
-
-  for (auto [scheduler, name] :
-       {std::make_pair(sequentialNoFuncPtr, "sequentialNoFuncPtr"),
-        std::make_pair(sequential, "sequential"),
-        std::make_pair(interleaveSwapping, "interleavingSwapping"),
-        std::make_pair(interleaveBoundedCyclicList,
-                       "interleaveBoundedCyclicList"),
-        std::make_pair(interleaveCyclicList, "interleaveCyclicList")}) {
-    for (int i = 0; i < kNumJobs; ++i) {
-      *jobs[i].input = originalInput[i];
-    }
-    memcpy(jobsCopy, jobs, sizeof(jobs));
-    Job *ps[kNumJobs];
-    for (int i = 0; i < kNumJobs; ++i) {
-      ps[i] = jobsCopy + i;
-    }
-    scheduler(ps, kNumJobs);
-    for (int i = 0; i < kNumJobs; ++i) {
-      if (*jobsCopy[i].input != 0) {
-        fprintf(stderr, "%s failed\n", name);
-        abort();
-      }
-    }
-
-    bench.run(name, [&]() {
-      for (int i = 0; i < kNumJobs; ++i) {
-        *jobs[i].input = originalInput[i];
-      }
-      memcpy(jobsCopy, jobs, sizeof(jobs));
-      Job *ps[kNumJobs];
-      for (int i = 0; i < kNumJobs; ++i) {
-        ps[i] = jobsCopy + i;
-      }
-      scheduler(ps, kNumJobs);
-    });
-  }
-  for (int i = 0; i < kNumJobs; ++i) {
-    delete jobs[i].input;
-  }
-}

Internal.h

@@ -20,6 +20,7 @@ using namespace weaselab;
 #include <thread>
 #include <unordered_set>
 #include <utility>
+#include <vector>
 
 #include <callgrind.h>
 
@@ -747,10 +748,7 @@ struct TestDriver {
       fprintf(stderr, "%p Set oldest version: %" PRId64 "\n", this,
               oldestVersion);
 #endif
-      CALLGRIND_START_INSTRUMENTATION;
       cs.setOldestVersion(oldestVersion);
-      CALLGRIND_STOP_INSTRUMENTATION;
-
       if constexpr (kEnableAssertions) {
         refImpl.setOldestVersion(oldestVersion);
       }

Jenkinsfile

@@ -48,17 +48,6 @@ pipeline {
                 recordIssues(tools: [clang()])
             }
         }
-        stage('64 bit versions') {
-            agent {
-                dockerfile {
-                    args '-v /home/jenkins/ccache:/ccache'
-                    reuseNode true
-                }
-            }
-            steps {
-                CleanBuildAndTest("-DCMAKE_CXX_FLAGS=-DUSE_64_BIT=1")
-            }
-        }
         stage('Debug') {
             agent {
                 dockerfile {
@@ -129,7 +118,7 @@ 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 """

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

@@ -24,15 +24,16 @@ 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
 |--------------------:|--------------------:|--------:|----------------:|----------------:|-------:|---------------:|--------:|----------:|:----------
-|               12.88 |       77,653,350.77 |    0.5% |          185.37 |           64.45 |  2.876 |          41.51 |    0.4% |      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`
-|               34.84 |       28,701,444.36 |    0.3% |          715.74 |          175.27 |  4.084 |         127.30 |    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`
-|               31.42 |       31,830,804.65 |    0.1% |          591.06 |          158.07 |  3.739 |          82.67 |    0.2% |      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`
-|               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`
-|          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`
-|               87.70 |       11,402,490.60 |    1.0% |        1,795.00 |          442.09 |  4.060 |         297.00 |    0.0% |      0.01 | `create and destroy`
+|               10.80 |       92,600,541.52 |    0.6% |          180.38 |           54.49 |  3.310 |          41.51 |    0.4% |      0.01 | `point reads`
+|               15.00 |       66,687,691.68 |    0.4% |          278.44 |           76.44 |  3.642 |          55.56 |    0.3% |      0.01 | `prefix reads`
+|               36.81 |       27,163,394.61 |    0.4% |          795.06 |          187.91 |  4.231 |         142.67 |    0.2% |      0.01 | `range reads`
+|               18.14 |       55,137,674.01 |    1.2% |          338.19 |           92.86 |  3.642 |          42.81 |    0.4% |      0.01 | `point writes`
+|               33.19 |       30,127,119.71 |    0.1% |          681.03 |          170.05 |  4.005 |          98.68 |    0.2% |      0.01 | `prefix writes`
+|               37.37 |       26,759,432.70 |    1.9% |          779.70 |          195.45 |  3.989 |         114.21 |    0.0% |      0.01 | `range writes`
+|               74.36 |       13,448,582.47 |    1.9% |        1,425.68 |          389.08 |  3.664 |         258.88 |    0.1% |      0.01 | `monotonic increasing point writes`
+|          316,928.00 |            3,155.29 |    1.5% |    3,992,986.00 |    1,699,813.00 |  2.349 |     806,226.50 |    0.0% |      0.01 | `worst case for radix tree`
+|               75.26 |       13,286,517.16 |    0.5% |        1,590.01 |          386.67 |  4.112 |         258.00 |    0.0% |      0.01 | `create and destroy`
+
 
 # "Real data" test
 
@@ -47,7 +48,7 @@ Check: 4.47891 seconds, 364.05 MB/s, Add: 4.55599 seconds, 123.058 MB/s, Gc rati
 ## 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: 0.910234 seconds, 1791.35 MB/s, Add: 1.25908 seconds, 445.287 MB/s, Gc ratio: 44.0415%
 ```
 
 ## hash table

ServerBench.cpp

@@ -6,26 +6,22 @@
 #include <string.h>
 #include <string>
 #include <string_view>
-#include <sys/ioctl.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
-#include <sys/types.h>
 #include <sys/uio.h>
 #include <thread>
 #include <unistd.h>
-#include <utility>
-#include <vector>
 
 #include "ConflictSet.h"
 #include "third_party/nadeau.h"
 
 std::atomic<int64_t> transactions;
 
-constexpr int kBaseSearchDepth = 115;
+constexpr int kBaseSearchDepth = 32;
 constexpr int kWindowSize = 10000000;
 
-std::string numToKey(int64_t num) {
-  std::string result;
+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);
@@ -45,13 +41,13 @@ void workload(weaselab::ConflictSet *cs) {
       auto pointK = numToKey(pointRv);
       weaselab::ConflictSet::ReadRange reads[] = {
           {
-              {(const uint8_t *)pointK.data(), int(pointK.size())},
+              {pointK.data(), int(pointK.size())},
               {nullptr, 0},
               pointRv,
           },
           {
-              {(const uint8_t *)beginK.data(), int(beginK.size())},
-              {(const uint8_t *)endK.data(), int(endK.size())},
+              {beginK.data(), int(beginK.size())},
+              {endK.data(), int(endK.size())},
               version - 2,
           },
       };
@@ -70,7 +66,7 @@ void workload(weaselab::ConflictSet *cs) {
     {
       weaselab::ConflictSet::WriteRange w;
       auto k = numToKey(version);
-      w.begin.p = (const uint8_t *)k.data();
+      w.begin.p = k.data();
       w.end.len = 0;
       if (version % (kWindowSize / 2) == 0) {
         for (int l = 0; l <= k.size(); ++l) {
@@ -83,9 +79,9 @@ void workload(weaselab::ConflictSet *cs) {
         int64_t beginN = version - kWindowSize + rand() % kWindowSize;
         auto b = numToKey(beginN);
         auto e = numToKey(beginN + 1000);
-        w.begin.p = (const uint8_t *)b.data();
+        w.begin.p = b.data();
         w.begin.len = b.size();
-        w.end.p = (const uint8_t *)e.data();
+        w.end.p = e.data();
         w.end.len = e.size();
         cs->addWrites(&w, 1, version);
       }
@@ -168,29 +164,36 @@ double toSeconds(timeval t) {
   return double(t.tv_sec) + double(t.tv_usec) * 1e-6;
 }
 
-#ifdef __linux__
 #include <linux/perf_event.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#ifdef __linux__
 struct PerfCounter {
-  PerfCounter(int type, int config, const std::string &labels = {},
-              int groupLeaderFd = -1)
-      : labels(labels) {
+  explicit PerfCounter(int event) {
     struct perf_event_attr pe;
 
     memset(&pe, 0, sizeof(pe));
-    pe.type = type;
+    pe.type = PERF_TYPE_HARDWARE;
     pe.size = sizeof(pe);
-    pe.config = config;
+    pe.config = event;
     pe.inherit = 1;
     pe.exclude_kernel = 1;
     pe.exclude_hv = 1;
 
-    fd = perf_event_open(&pe, 0, -1, groupLeaderFd, 0);
-    if (fd < 0 && errno != ENOENT && errno != EINVAL) {
-      perror(labels.c_str());
+    fd = perf_event_open(&pe, 0, -1, -1, 0);
+    if (fd == -1) {
+      fprintf(stderr, "Error opening leader %llx\n", pe.config);
+      exit(EXIT_FAILURE);
     }
   }
 
-  int64_t total() const {
+  int64_t total() {
     int64_t count;
     if (read(fd, &count, sizeof(count)) != sizeof(count)) {
       perror("read instructions from perf");
@@ -199,27 +202,10 @@ struct PerfCounter {
     return count;
   }
 
-  PerfCounter(PerfCounter &&other)
-      : fd(std::exchange(other.fd, -1)), labels(std::move(other.labels)) {}
-  PerfCounter &operator=(PerfCounter &&other) {
-    fd = std::exchange(other.fd, -1);
-    labels = std::move(other.labels);
-    return *this;
-  }
-
-  ~PerfCounter() {
-    if (fd >= 0) {
-      close(fd);
-    }
-  }
-
-  bool ok() const { return fd >= 0; }
-  const std::string &getLabels() const { return labels; }
-  int getFd() const { return fd; }
+  ~PerfCounter() { close(fd); }
 
 private:
   int fd;
-  std::string labels;
   static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid,
                               int cpu, int group_fd, unsigned long flags) {
     int ret;
@@ -228,6 +214,11 @@ private:
     return ret;
   }
 };
+#else
+struct PerfCounter {
+  explicit PerPerfCounter(int) {}
+  int64_t total() { return 0; }
+};
 #endif
 
 int main(int argc, char **argv) {
@@ -242,50 +233,8 @@ int main(int argc, char **argv) {
     int metricsCount;
     cs.getMetricsV1(&metrics, &metricsCount);
 
-#ifdef __linux__
-    PerfCounter instructions{PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS};
-    PerfCounter cycles{PERF_TYPE_HARDWARE, PERF_COUNT_HW_CPU_CYCLES, "",
-                       instructions.getFd()};
-
-    std::vector<PerfCounter> cacheCounters;
-    for (auto [id, idStr] : std::initializer_list<std::pair<int, std::string>>{
-             {PERF_COUNT_HW_CACHE_L1D, "l1d"},
-             {PERF_COUNT_HW_CACHE_L1I, "l1i"},
-             {PERF_COUNT_HW_CACHE_LL, "ll"},
-             {PERF_COUNT_HW_CACHE_DTLB, "dtlb"},
-             {PERF_COUNT_HW_CACHE_ITLB, "itlb"},
-             {PERF_COUNT_HW_CACHE_BPU, "bpu"},
-             {PERF_COUNT_HW_CACHE_NODE, "node"},
-         }) {
-      for (auto [op, opStr] :
-           std::initializer_list<std::pair<int, std::string>>{
-               {PERF_COUNT_HW_CACHE_OP_READ, "read"},
-               {PERF_COUNT_HW_CACHE_OP_WRITE, "write"},
-               {PERF_COUNT_HW_CACHE_OP_PREFETCH, "prefetch"},
-           }) {
-        int groupLeaderFd = -1;
-        for (auto [result, resultStr] :
-             std::initializer_list<std::pair<int, std::string>>{
-                 {PERF_COUNT_HW_CACHE_RESULT_MISS, "miss"},
-                 {PERF_COUNT_HW_CACHE_RESULT_ACCESS, "access"},
-             }) {
-          auto labels = "{id=\"" + idStr + "\", op=\"" + opStr +
-                        "\", result=\"" + resultStr + "\"}";
-          cacheCounters.emplace_back(PERF_TYPE_HW_CACHE,
-                                     id | (op << 8) | (result << 16), labels,
-                                     groupLeaderFd);
-          if (!cacheCounters.back().ok()) {
-            cacheCounters.pop_back();
-          } else {
-            if (groupLeaderFd == -1) {
-              groupLeaderFd = cacheCounters.back().getFd();
-            }
-          }
-        }
-      }
-    }
-#endif
-
+    PerfCounter instructions{PERF_COUNT_HW_INSTRUCTIONS};
+    PerfCounter cycles{PERF_COUNT_HW_CPU_CYCLES};
     auto w = std::thread{workload, &cs};
 
     for (;;) {
@@ -313,7 +262,6 @@ int main(int argc, char **argv) {
               "transactions_total ";
       body += std::to_string(transactions.load(std::memory_order_relaxed));
       body += "\n";
-#ifdef __linux__
       body += "# HELP instructions_total Total number of instructions\n"
               "# TYPE instructions_total counter\n"
               "instructions_total ";
@@ -324,13 +272,6 @@ int main(int argc, char **argv) {
               "cycles_total ";
       body += std::to_string(cycles.total());
       body += "\n";
-      body += "# HELP cache_event_total Total number of cache events\n"
-              "# TYPE cache_event_total counter\n";
-      for (const auto &counter : cacheCounters) {
-        body += "cache_event_total" + counter.getLabels() + " " +
-                std::to_string(counter.total()) + "\n";
-      }
-#endif
 
       for (int i = 0; i < metricsCount; ++i) {
         body += "# HELP ";

SkipList.cpp

@@ -22,11 +22,9 @@
 
 #include "ConflictSet.h"
 #include "Internal.h"
-#include "Metrics.h"
 
 #include <algorithm>
 #include <span>
-#include <vector>
 
 std::span<const uint8_t> keyAfter(Arena &arena, std::span<const uint8_t> key) {
   auto result =
@@ -117,6 +115,15 @@ bool operator==(const KeyInfo &lhs, const KeyInfo &rhs) {
   return !(lhs < rhs || rhs < lhs);
 }
 
+void swapSort(std::vector<KeyInfo> &points, int a, int b) {
+  if (points[b] < points[a]) {
+    KeyInfo temp;
+    temp = points[a];
+    points[a] = points[b];
+    points[b] = temp;
+  }
+}
+
 struct SortTask {
   int begin;
   int size;
@@ -176,6 +183,13 @@ void sortPoints(std::vector<KeyInfo> &points) {
   }
 }
 
+static thread_local uint32_t g_seed = 0;
+
+static inline int skfastrand() {
+  g_seed = g_seed * 1664525L + 1013904223L;
+  return g_seed;
+}
+
 static int compare(const StringRef &a, const StringRef &b) {
   int c = memcmp(a.data(), b.data(), std::min(a.size(), b.size()));
   if (c < 0)
@@ -201,24 +215,20 @@ struct ReadConflictRange {
   }
 };
 
-static constexpr int MaxLevels = 26;
-
-struct RandomLevel {
-  explicit RandomLevel(uint32_t seed) : seed(seed) {}
-
-  int next() {
-    int result = __builtin_clz(seed | (uint32_t(-1) >> (MaxLevels - 1)));
-    seed = seed * 1664525L + 1013904223L;
-    return result;
-  }
-
-private:
-  uint32_t seed;
-};
-
 class SkipList {
 private:
-  RandomLevel randomLevel{0};
+  static constexpr int MaxLevels = 26;
+
+  int randomLevel() const {
+    uint32_t i = uint32_t(skfastrand()) >> (32 - (MaxLevels - 1));
+    int level = 0;
+    while (i & 1) {
+      i >>= 1;
+      level++;
+    }
+    assert(level < MaxLevels);
+    return level;
+  }
 
   // Represent a node in the SkipList. The node has multiple (i.e., level)
   // pointers to other nodes, and keeps a record of the max versions for each
@@ -416,33 +426,27 @@ public:
   }
   void swap(SkipList &other) { std::swap(header, other.header); }
 
-  // Returns the change in the number of entries
-  int64_t addConflictRanges(const Finger *fingers, int rangeCount,
-                            Version version) {
-    int64_t result = rangeCount;
+  void addConflictRanges(const Finger *fingers, int rangeCount,
+                         Version version) {
     for (int r = rangeCount - 1; r >= 0; r--) {
       const Finger &startF = fingers[r * 2];
       const Finger &endF = fingers[r * 2 + 1];
 
-      if (endF.found() == nullptr) {
-        ++result;
+      if (endF.found() == nullptr)
         insert(endF, endF.finger[0]->getMaxVersion(0));
-      }
 
-      result -= remove(startF, endF);
+      remove(startF, endF);
       insert(startF, version);
     }
-    return result;
   }
 
-  // Return number of iterations of main loop
-  int detectConflicts(ReadConflictRange *ranges, int count,
-                      ConflictSet::Result *transactionConflictStatus) const {
+  void 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 +457,8 @@ 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 +474,6 @@ public:
       prevJob = job;
       job = nextJob[job];
     }
-    return iters;
   }
 
   void find(const StringRef *values, Finger *results, int *temp, int count) {
@@ -565,10 +567,9 @@ public:
   }
 
 private:
-  // Returns the number of entries removed
-  int64_t remove(const Finger &start, const Finger &end) {
+  void remove(const Finger &start, const Finger &end) {
     if (start.finger[0] == end.finger[0])
-      return 0;
+      return;
 
     Node *x = start.finger[0]->getNext(0);
 
@@ -577,20 +578,17 @@ private:
       if (start.finger[i] != end.finger[i])
         start.finger[i]->setNext(i, end.finger[i]->getNext(i));
 
-    int64_t result = 0;
     while (true) {
       Node *next = x->getNext(0);
       x->destroy();
-      ++result;
       if (x == end.finger[0])
         break;
       x = next;
     }
-    return result;
   }
 
   void insert(const Finger &f, Version version) {
-    int level = randomLevel.next();
+    int level = randomLevel();
     // std::cout << std::string((const char*)value,length) << " level: " <<
     // level << std::endl;
     Node *x = Node::create(f.value, level);
@@ -706,27 +704,17 @@ 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 SkipListConflictSet {};
 
 struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   Impl(int64_t oldestVersion)
       : oldestVersion(oldestVersion), newestVersion(oldestVersion),
-        skipList(oldestVersion) {
-    metrics = initMetrics(metricsList, metricsCount);
-  }
-  ~Impl() { safe_free(metrics, metricsCount * sizeof(metrics[0])); }
+        skipList(oldestVersion) {}
   void check(const ConflictSet::ReadRange *reads, ConflictSet::Result *results,
-             int count) {
-    ReadContext tls;
+             int count) const {
     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 +722,13 @@ 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,
@@ -796,33 +775,27 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     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--) {
       for (int i = 0; i * 2 < ss; ++i) {
         const auto &w = combinedWriteConflictRanges[s * stripeSize / 2 + i];
         values[i * 2] = w.first;
         values[i * 2 + 1] = w.second;
+        keyUpdates += 3;
       }
       skipList.find(values, fingers, temp, ss);
-      entryDelta += skipList.addConflictRanges(fingers, ss / 2, writeVersion);
+      skipList.addConflictRanges(fingers, ss / 2, writeVersion);
       ss = stripeSize;
     }
-
-    // Run gc at least 200% the rate we're inserting entries
-    keyUpdates += std::max<int64_t>(entryDelta, 0) * 2;
   }
 
   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;
     int temp;
     std::span<const uint8_t> key = removalKey;
     skipList.find(&key, &finger, &temp, 1);
-    skipList.removeBefore(oldestVersion, finger, std::exchange(keyUpdates, 0));
+    skipList.removeBefore(oldestVersion, finger, std::exchange(keyUpdates, 10));
     removalArena = Arena();
     removalKey = copyToArena(
         removalArena, {finger.getValue().data(), finger.getValue().size()});
@@ -830,56 +803,8 @@ 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;
+  int64_t keyUpdates = 10;
   Arena removalArena;
   std::span<const uint8_t> removalKey;
   int64_t oldestVersion;
@@ -900,7 +825,6 @@ 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 +836,6 @@ 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 +859,12 @@ 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,