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+/*****************************************************************************
+
+Copyright (c) 2012, 2015, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, 2022, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file include/ut0counter.h
+
+Counter utility class
+
+Created 2012/04/12 by Sunny Bains
+*******************************************************/
+
+#ifndef ut0counter_h
+#define ut0counter_h
+
+#include "univ.i"
+#include "my_rdtsc.h"
+
+/** Use the result of my_timer_cycles(), which mainly uses RDTSC for cycles
+as a random value. See the comments for my_timer_cycles() */
+/** @return result from RDTSC or similar functions. */
+static inline size_t
+get_rnd_value()
+{
+	size_t c = static_cast<size_t>(my_timer_cycles());
+
+	if (c != 0) {
+		return c;
+	}
+
+	/* We may go here if my_timer_cycles() returns 0,
+	so we have to have the plan B for the counter. */
+#if !defined(_WIN32)
+	return (size_t)pthread_self();
+#else
+	LARGE_INTEGER cnt;
+	QueryPerformanceCounter(&cnt);
+
+	return static_cast<size_t>(cnt.QuadPart);
+#endif /* !_WIN32 */
+}
+
+/** Atomic which occupies whole CPU cache line.
+Note: We rely on the default constructor of std::atomic and
+do not explicitly initialize the contents. This works for us,
+because ib_counter_t is only intended for usage with global
+memory that is allocated from the .bss and thus guaranteed to
+be zero-initialized by the run-time environment.
+@see srv_stats */
+template <typename Type>
+struct ib_atomic_counter_element_t {
+  alignas(CPU_LEVEL1_DCACHE_LINESIZE) Atomic_relaxed<Type> value;
+};
+
+template <typename Type>
+struct ib_counter_element_t {
+  alignas(CPU_LEVEL1_DCACHE_LINESIZE) Type value;
+};
+
+
+/** Class for using fuzzy counters. The counter is multi-instance relaxed atomic
+so the results are not guaranteed to be 100% accurate but close
+enough. */
+template <typename Type,
+          template <typename T> class Element = ib_atomic_counter_element_t,
+          int N = 128 >
+struct ib_counter_t {
+	/** Increment the counter by 1. */
+	void inc() { add(1); }
+	ib_counter_t& operator++() { inc(); return *this; }
+
+	/** Increment the counter by 1.
+	@param[in]	index	a reasonably thread-unique identifier */
+	void inc(size_t index) { add(index, 1); }
+
+	/** Add to the counter.
+	@param[in]	n	amount to be added */
+	void add(Type n) { add(get_rnd_value(), n); }
+
+	/** Add to the counter.
+	@param[in]	index	a reasonably thread-unique identifier
+	@param[in]	n	amount to be added */
+	TPOOL_SUPPRESS_TSAN void add(size_t index, Type n) {
+		index = index % N;
+
+		ut_ad(index < UT_ARR_SIZE(m_counter));
+
+		m_counter[index].value += n;
+	}
+
+	/* @return total value - not 100% accurate, since it is relaxed atomic*/
+	operator Type() const {
+		Type	total = 0;
+
+		for (const auto &counter : m_counter) {
+			total += counter.value;
+		}
+
+		return(total);
+	}
+
+private:
+	static_assert(sizeof(Element<Type>) == CPU_LEVEL1_DCACHE_LINESIZE, "");
+	/** Array of counter elements */
+	alignas(CPU_LEVEL1_DCACHE_LINESIZE) Element<Type> m_counter[N];
+};
+
+#endif /* ut0counter_h */