WIP adding metrics to skiplist

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>
@@ -578,39 +578,6 @@ 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 *));
@@ -3242,7 +3209,6 @@ 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);
@@ -3331,7 +3297,6 @@ 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));
@@ -3379,7 +3344,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   explicit Impl(int64_t oldestVersion) {
     assert(oldestVersion >= 0);
     init(oldestVersion);
-    initMetrics();
+    metrics = initMetrics(metricsList, metricsCount);
   }
   ~Impl() {
     eraseTree(root, &tls);
@@ -3402,23 +3367,12 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
 
   MetricsV1 *metrics;
   int metricsCount = 0;
-  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;
+  Metric *metricsList = nullptr;
 
 #define GAUGE(name, help)                                                      \
-  Gauge name { this, #name, help }
+  Gauge name { metricsList, metricsCount, #name, help }
 #define COUNTER(name, help)                                                    \
-  Counter name { this, #name, help }
+  Counter name { metricsList, metricsCount, #name, help }
   // ==================== METRICS DEFINITIONS ====================
   COUNTER(point_read_total, "Total number of point reads checked");
   COUNTER(point_read_short_circuit_total,
@@ -3484,13 +3438,6 @@ 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);
@@ -3509,6 +3456,7 @@ 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();
@@ -3520,6 +3468,7 @@ 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();