1/* Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License as published by
5 the Free Software Foundation; version 2 of the License.
6
7 This program is distributed in the hope that it will be useful,
8 but WITHOUT ANY WARRANTY; without even the implied warranty of
9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 GNU General Public License for more details.
11
12 You should have received a copy of the GNU General Public License
13 along with this program; if not, write to the Free Software Foundation,
14 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
15
16#ifndef PFS_GLOBAL_H
17#define PFS_GLOBAL_H
18
19#include "my_compiler.h"
20
21/**
22 @file storage/perfschema/pfs_global.h
23 Miscellaneous global dependencies (declarations).
24*/
25
26/** True when the performance schema is initialized. */
27extern bool pfs_initialized;
28
29/** Total memory allocated by the performance schema, in bytes. */
30extern size_t pfs_allocated_memory;
31
32#if defined(HAVE_POSIX_MEMALIGN) || defined(HAVE_MEMALIGN) || defined(HAVE_ALIGNED_MALLOC)
33#define PFS_ALIGNEMENT CPU_LEVEL1_DCACHE_LINESIZE
34#define PFS_ALIGNED MY_ALIGNED(PFS_ALIGNEMENT)
35#else
36/*
37 Known platforms that do not provide aligned memory:
38 - MacOSX Darwin (osx10.5)
39 For these platforms, compile without the alignment optimization.
40*/
41#define PFS_ALIGNED
42#endif /* HAVE_POSIX_MEMALIGN || HAVE_MEMALIGN || HAVE_ALIGNED_MALLOC */
43
44void *pfs_malloc(size_t size, myf flags);
45
46/** Allocate an array of structures with overflow check. */
47void *pfs_malloc_array(size_t n, size_t size, myf flags);
48
49/**
50 Helper, to allocate an array of structures.
51 @param n number of elements in the array
52 @param s size of array element
53 @param T type of an element
54 @param f flags to use when allocating memory
55*/
56#define PFS_MALLOC_ARRAY(n, s, T, f) \
57 reinterpret_cast<T*>(pfs_malloc_array((n), (s), (f)))
58
59/** Free memory allocated with @sa pfs_malloc. */
60void pfs_free(void *ptr);
61
62/** Detect multiplication overflow. */
63bool is_overflow(size_t product, size_t n1, size_t n2);
64
65uint pfs_get_socket_address(char *host,
66 uint host_len,
67 uint *port,
68 const struct sockaddr_storage *src_addr,
69 socklen_t src_len);
70
71/**
72 Compute a random index value in an interval.
73 @param ptr seed address
74 @param max_size maximun size of the interval
75 @return a random value in [0, max_size-1]
76*/
77inline uint randomized_index(const void *ptr, uint max_size)
78{
79 static uint seed1= 0;
80 static uint seed2= 0;
81 uint result;
82 intptr value;
83
84 if (unlikely(max_size == 0))
85 return 0;
86
87 /*
88 ptr is typically an aligned structure, and can be in an array.
89 - The last bits are not random because of alignment,
90 so we divide by 8.
91 - The high bits are mostly constant, especially with 64 bits architectures,
92 but we keep most of them anyway, by doing computation in intptr.
93 The high bits are significant depending on where the data is
94 stored (the data segment, the stack, the heap, ...).
95 - To spread consecutive cells in an array further, we multiply by
96 a factor A. This factor should not be too high, which would cause
97 an overflow and cause loss of randomness (droping the top high bits).
98 The factor is a prime number, to help spread the distribution.
99 - To add more noise, and to be more robust if the calling code is
100 passing a constant value instead of a random identity,
101 we add the previous results, for hysteresys, with a degree 2 polynom,
102 X^2 + X + 1.
103 - Last, a modulo is applied to be within the [0, max_size - 1] range.
104 Note that seed1 and seed2 are static, and are *not* thread safe,
105 which is even better.
106 Effect with arrays: T array[N]
107 - ptr(i) = & array[i] = & array[0] + i * sizeof(T)
108 - ptr(i+1) = ptr(i) + sizeof(T).
109 What we want here, is to have index(i) and index(i+1) fall into
110 very different areas in [0, max_size - 1], to avoid locality.
111 */
112 value= (reinterpret_cast<intptr> (ptr)) >> 3;
113 value*= 1789;
114 value+= seed2 + seed1 + 1;
115
116 result= (static_cast<uint> (value)) % max_size;
117
118 seed2= seed1*seed1;
119 seed1= result;
120
121 DBUG_ASSERT(result < max_size);
122 return result;
123}
124
125void pfs_print_error(const char *format, ...);
126
127/**
128 Given an array defined as T ARRAY[MAX],
129 check that an UNSAFE pointer actually points to an element
130 within the array.
131*/
132#define SANITIZE_ARRAY_BODY(T, ARRAY, MAX, UNSAFE) \
133 intptr offset; \
134 if ((&ARRAY[0] <= UNSAFE) && \
135 (UNSAFE < &ARRAY[MAX])) \
136 { \
137 offset= ((intptr) UNSAFE - (intptr) ARRAY) % sizeof(T); \
138 if (offset == 0) \
139 return UNSAFE; \
140 } \
141 return NULL
142
143#endif
144
145