diff options
Diffstat (limited to 'storage/innobase/include/ut0counter.h')
| -rw-r--r-- | storage/innobase/include/ut0counter.h | 78 |
1 files changed, 41 insertions, 37 deletions
diff --git a/storage/innobase/include/ut0counter.h b/storage/innobase/include/ut0counter.h index d2a6c1eb3e3..a04a674751c 100644 --- a/storage/innobase/include/ut0counter.h +++ b/storage/innobase/include/ut0counter.h @@ -1,7 +1,7 @@ /***************************************************************************** -Copyright (c) 2012, Oracle and/or its affiliates. All Rights Reserved. -Copyright (c) 2017, MariaDB Corporation. +Copyright (c) 2012, 2015, Oracle and/or its affiliates. All Rights Reserved. +Copyright (c) 2017, 2018, 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 @@ -25,15 +25,20 @@ Counter utility class Created 2012/04/12 by Sunny Bains *******************************************************/ -#ifndef UT0COUNTER_H -#define UT0COUNTER_H +#ifndef ut0counter_h +#define ut0counter_h -#include "univ.i" -#include <string.h> #include "os0thread.h" -#include "os0sync.h" +#include "my_rdtsc.h" #include "my_atomic.h" +/** CPU cache line size */ +#ifdef CPU_LEVEL1_DCACHE_LINESIZE +# define CACHE_LINE_SIZE CPU_LEVEL1_DCACHE_LINESIZE +#else +# error CPU_LEVEL1_DCACHE_LINESIZE is undefined +#endif /* CPU_LEVEL1_DCACHE_LINESIZE */ + /** Default number of slots to use in ib_counter_t */ #define IB_N_SLOTS 64 @@ -41,47 +46,46 @@ Created 2012/04/12 by Sunny Bains template <typename Type, int N> struct generic_indexer_t { /** @return offset within m_counter */ - size_t offset(size_t index) const UNIV_NOTHROW { + static size_t offset(size_t index) UNIV_NOTHROW + { return(((index % N) + 1) * (CACHE_LINE_SIZE / sizeof(Type))); } }; -#ifdef HAVE_SCHED_GETCPU -#include <utmpx.h> -/** 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> { - /* @return result from sched_getcpu(), the thread id if it fails. */ - size_t get_rnd_index() const UNIV_NOTHROW { - - size_t cpu = sched_getcpu(); - if (cpu == -1) { - cpu = (lint) os_thread_get_curr_id(); +/** Use the result of my_timer_cycles(), which mainly uses RDTSC for cycles, +to index into the counter array. See the comments for my_timer_cycles() */ +template <typename Type=ulint, int N=1> +struct counter_indexer_t : public generic_indexer_t<Type, N> { + /** @return result from RDTSC or similar functions. */ + static size_t get_rnd_index() UNIV_NOTHROW + { + size_t c = static_cast<size_t>(my_timer_cycles()); + + if (c != 0) { + return(c); + } else { + /* 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(os_thread_get_curr_id())); +#else + LARGE_INTEGER cnt; + QueryPerformanceCounter(&cnt); + + return(static_cast<size_t>(cnt.QuadPart)); +#endif /* !_WIN32 */ } - - 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> { - /* @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 UNIV_NOTHROW { - return((lint) os_thread_get_curr_id()); } /** @return a random offset to the array */ - size_t get_rnd_offset() const UNIV_NOTHROW + static size_t get_rnd_offset() UNIV_NOTHROW { return(generic_indexer_t<Type, N>::offset(get_rnd_index())); } }; +#define default_indexer_t counter_indexer_t + /** Class for using fuzzy counters. The counter is relaxed atomic so the results are not guaranteed to be 100% accurate but close enough. Creates an array of counters and separates each element by the @@ -89,7 +93,7 @@ CACHE_LINE_SIZE bytes */ template < typename Type, int N = IB_N_SLOTS, - template<typename, int> class Indexer = thread_id_indexer_t> + template<typename, int> class Indexer = default_indexer_t> struct MY_ALIGNED(CACHE_LINE_SIZE) ib_counter_t { /** Increment the counter by 1. */ @@ -154,4 +158,4 @@ private: Type m_counter[(N + 1) * (CACHE_LINE_SIZE / sizeof(Type))]; }; -#endif /* UT0COUNTER_H */ +#endif /* ut0counter_h */ |