Adding upstream version 1:10.11.6.upstream/1%10.11.6

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 203 insertions, 0 deletions

diff --git a/storage/rocksdb/ut0counter.h b/storage/rocksdb/ut0counter.h
new file mode 100644
index 00000000..5267508f
--- /dev/null
+++ b/storage/rocksdb/ut0counter.h
@@ -0,0 +1,203 @@
+/*
+Copyright (c) 2012, Oracle and/or its affiliates. All Rights Reserved.
+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, Suite 500, 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 <string.h>
+
+/** CPU cache line size */
+#define UT_CACHE_LINE_SIZE		64
+
+/** Default number of slots to use in ib_counter_t */
+#define IB_N_SLOTS		64
+
+#ifdef _WIN32
+#define get_curr_thread_id() GetCurrentThreadId()
+#else
+#define get_curr_thread_id() pthread_self()
+#endif
+
+#define UT_ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+
+/** Get the offset into the counter array. */
+template <typename Type, int N>
+struct generic_indexer_t {
+	/** Default constructor/destructor should be OK. */
+
+        /** @return offset within m_counter */
+        size_t offset(size_t index) const {
+                return(((index % N) + 1) * (UT_CACHE_LINE_SIZE / sizeof(Type)));
+        }
+};
+
+#ifdef HAVE_SCHED_GETCPU
+//#include <utmpx.h>  // Including this causes problems with EMPTY symbol
+#include <sched.h>  // Include this instead
+/** Use the cpu id to index into the counter array. If it fails then
+use the thread id. */
+template <typename Type, int N>
+struct get_sched_indexer_t : public generic_indexer_t<Type, N> {
+	/** Default constructor/destructor should be OK. */
+
+	/* @return result from sched_getcpu(), the thread id if it fails. */
+	size_t get_rnd_index() const {
+
+		size_t	cpu = sched_getcpu();
+		if (cpu == (size_t) -1) {
+			cpu = (size_t) get_curr_thread_id();
+		}
+
+		return(cpu);
+	}
+};
+#endif /* HAVE_SCHED_GETCPU */
+
+/** Use the thread id to index into the counter array. */
+template <typename Type, int N>
+struct thread_id_indexer_t : public generic_indexer_t<Type, N> {
+	/** Default constructor/destructor should are OK. */
+
+	/* @return a random number, currently we use the thread id. Where
+	thread id is represented as a pointer, it may not work as
+	effectively. */
+	size_t get_rnd_index() const {
+		return (size_t)get_curr_thread_id();
+	}
+};
+
+/** For counters wher N=1 */
+template <typename Type, int N=1>
+struct single_indexer_t {
+	/** Default constructor/destructor should are OK. */
+
+        /** @return offset within m_counter */
+        size_t offset(size_t index) const {
+		DBUG_ASSERT(N == 1);
+                return((UT_CACHE_LINE_SIZE / sizeof(Type)));
+        }
+
+	/* @return 1 */
+	size_t get_rnd_index() const {
+		DBUG_ASSERT(N == 1);
+		return(1);
+	}
+};
+
+/** Class for using fuzzy counters. The counter is not protected by any
+mutex and the results are not guaranteed to be 100% accurate but close
+enough. Creates an array of counters and separates each element by the
+UT_CACHE_LINE_SIZE bytes */
+template <
+	typename Type,
+	int N = IB_N_SLOTS,
+	template<typename, int> class Indexer = thread_id_indexer_t>
+class ib_counter_t {
+public:
+	ib_counter_t() { memset(m_counter, 0x0, sizeof(m_counter)); }
+
+	~ib_counter_t()
+	{
+		DBUG_ASSERT(validate());
+	}
+
+	bool validate() {
+#ifdef UNIV_DEBUG
+		size_t	n = (UT_CACHE_LINE_SIZE / sizeof(Type));
+
+		/* Check that we aren't writing outside our defined bounds. */
+		for (size_t i = 0; i < UT_ARRAY_SIZE(m_counter); i += n) {
+			for (size_t j = 1; j < n - 1; ++j) {
+				DBUG_ASSERT(m_counter[i + j] == 0);
+			}
+		}
+#endif /* UNIV_DEBUG */
+		return(true);
+	}
+
+	/** If you can't use a good index id. Increment by 1. */
+	void inc() { add(1); }
+
+	/** If you can't use a good index id.
+	* @param n  - is the amount to increment */
+	void add(Type n) {
+		size_t	i = m_policy.offset(m_policy.get_rnd_index());
+
+		DBUG_ASSERT(i < UT_ARRAY_SIZE(m_counter));
+
+		m_counter[i] += n;
+	}
+
+	/** Use this if you can use a unique indentifier, saves a
+	call to get_rnd_index().
+	@param i - index into a slot
+	@param n - amount to increment */
+	void add(size_t index, Type n) {
+		size_t	i = m_policy.offset(index);
+
+		DBUG_ASSERT(i < UT_ARRAY_SIZE(m_counter));
+
+		m_counter[i] += n;
+	}
+
+	/** If you can't use a good index id. Decrement by 1. */
+	void dec() { sub(1); }
+
+	/** If you can't use a good index id.
+	* @param - n is the amount to decrement */
+	void sub(Type n) {
+		size_t	i = m_policy.offset(m_policy.get_rnd_index());
+
+		DBUG_ASSERT(i < UT_ARRAY_SIZE(m_counter));
+
+		m_counter[i] -= n;
+	}
+
+	/** Use this if you can use a unique indentifier, saves a
+	call to get_rnd_index().
+	@param i - index into a slot
+	@param n - amount to decrement */
+	void sub(size_t index, Type n) {
+		size_t	i = m_policy.offset(index);
+
+		DBUG_ASSERT(i < UT_ARRAY_SIZE(m_counter));
+
+		m_counter[i] -= n;
+	}
+
+	/* @return total value - not 100% accurate, since it is not atomic. */
+	operator Type() const {
+		Type	total = 0;
+
+		for (size_t i = 0; i < N; ++i) {
+			total += m_counter[m_policy.offset(i)];
+		}
+
+		return(total);
+	}
+
+private:
+	/** Indexer into the array */
+	Indexer<Type, N>m_policy;
+
+        /** Slot 0 is unused. */
+	Type		m_counter[(N + 1) * (UT_CACHE_LINE_SIZE / sizeof(Type))];
+};
+
+#endif /* UT0COUNTER_H */