Ring buffer: use shmp (shared-memory pointers) for per-channel shm structures
[lttng-ust.git] / include / ust / core.h
1 /* Copyright (C) 2010 Pierre-Marc Fournier
2 *
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
7 *
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16 */
17
18 #ifndef UST_CORE_H
19 #define UST_CORE_H
20
21 #include <sys/types.h>
22 #include <ust/config.h>
23 #include <urcu/arch.h>
24
25 #define likely(x) __builtin_expect(!!(x), 1)
26 #define unlikely(x) __builtin_expect(!!(x), 0)
27
28 /* ARRAYS */
29
30 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
31
32
33 /* ALIGNMENT SHORTCUTS */
34
35 #include <unistd.h>
36
37 #define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1)
38 #define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
39 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
40 #define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
41 #define PAGE_MASK (~(PAGE_SIZE-1))
42
43 /* ERROR OPS */
44 #define MAX_ERRNO 4095
45
46 #define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
47
48 static inline void *ERR_PTR(long error)
49 {
50 return (void *) error;
51 }
52
53 static inline long PTR_ERR(const void *ptr)
54 {
55 return (long) ptr;
56 }
57
58 static inline long IS_ERR(const void *ptr)
59 {
60 return IS_ERR_VALUE((unsigned long)ptr);
61 }
62
63
64 /* Min / Max */
65
66 #define min_t(type, x, y) ({ \
67 type __min1 = (x); \
68 type __min2 = (y); \
69 __min1 < __min2 ? __min1: __min2; })
70
71 #define max_t(type, x, y) ({ \
72 type __max1 = (x); \
73 type __max2 = (y); \
74 __max1 > __max2 ? __max1: __max2; })
75
76
77 /* MUTEXES */
78
79 #include <pthread.h>
80
81 #define DEFINE_MUTEX(m) pthread_mutex_t (m) = PTHREAD_MUTEX_INITIALIZER;
82 #define DECLARE_MUTEX(m) extern pthread_mutex_t (m);
83
84 /* MALLOCATION */
85
86 #include <stdlib.h>
87
88 static inline
89 void *zmalloc(size_t len)
90 {
91 return calloc(1, len);
92 }
93
94 static inline
95 void *malloc_align(size_t len)
96 {
97 return malloc(ALIGN(len, CAA_CACHE_LINE_SIZE));
98 }
99
100 static inline
101 void *zmalloc_align(size_t len)
102 {
103 return calloc(1, ALIGN(len, CAA_CACHE_LINE_SIZE));
104 }
105
106 /* MATH */
107
108 #include <ust/processor.h>
109 static inline unsigned int hweight32(unsigned int w)
110 {
111 unsigned int res = w - ((w >> 1) & 0x55555555);
112 res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
113 res = (res + (res >> 4)) & 0x0F0F0F0F;
114 res = res + (res >> 8);
115 return (res + (res >> 16)) & 0x000000FF;
116 }
117
118 static __inline__ int get_count_order(unsigned int count)
119 {
120 int order;
121
122 order = fls(count) - 1;
123 if (count & (count - 1))
124 order++;
125 return order;
126 }
127
128 #define _ust_container_of(ptr, type, member) ({ \
129 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
130 (type *)( (char *)__mptr - offsetof(type,member) );})
131
132 #ifndef inline_memcpy
133 #define inline_memcpy memcpy
134 #endif
135
136 #ifndef __same_type
137 #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
138 #endif
139
140 #endif /* UST_CORE_H */
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