include/lttng/core.h

   1 #ifndef UST_CORE_H
   2 #define UST_CORE_H
   3
   4 /*
   5  * Copyright (C) 2010  Pierre-Marc Fournier
   6  * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; version 2.1 of
  11  * the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  21  */
  22
  23 #include <sys/types.h>
  24 #include <lttng/config.h>
  25 #include <urcu/arch.h>
  26 #include <urcu/compiler.h>
  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) caa_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 <lttng/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 #ifndef UST_VALGRIND
 141
 142 static __inline__ int ust_get_cpu(void)
 143 {
 144         int cpu;
 145
 146         cpu = sched_getcpu();
 147         if (caa_likely(cpu >= 0))
 148                 return cpu;
 149         /*
 150          * If getcpu(2) is not implemented in the Kernel use CPU 0 as fallback.
 151          */
 152         return 0;
 153 }
 154
 155 #else   /* #else #ifndef UST_VALGRIND */
 156
 157 static __inline__ int ust_get_cpu(void)
 158 {
 159         /*
 160          * Valgrind does not support the sched_getcpu() vsyscall.
 161          * It causes it to detect a segfault in the program and stop it.
 162          * So if we want to check libust with valgrind, we have to refrain
 163          * from using this call. TODO: it would probably be better to return
 164          * other values too, to better test it.
 165          */
 166         return 0;
 167 }
 168
 169 #endif  /* #else #ifndef UST_VALGRIND */
 170
 171 #endif /* UST_CORE_H */