src/urcu-utils.h

   1 #ifndef _URCU_UTILS_H
   2 #define _URCU_UTILS_H
   3
   4 /*
   5  * urcu-utils.h
   6  *
   7  * Userspace RCU library internal utils
   8  *
   9  * Copyright (c) 2018 Michael Jeanson <mjeanson@efficios.com>
  10  *
  11  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2.1 of the License, or (at your option) any later version.
  15  *
  16  * This library is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with this library; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  24  */
  25
  26 #define urcu_stringify(a) _urcu_stringify(a)
  27 #define _urcu_stringify(a) #a
  28
  29 #define max_t(type, x, y)                               \
  30         ({                                              \
  31                 type __max1 = (x);                      \
  32                 type __max2 = (y);                      \
  33                 __max1 > __max2 ? __max1: __max2;       \
  34         })
  35
  36 #define min_t(type, x, y)                               \
  37         ({                                              \
  38                 type __min1 = (x);                      \
  39                 type __min2 = (y);                      \
  40                 __min1 <= __min2 ? __min1: __min2;      \
  41         })
  42
  43 /* There is no concept of symbol aliases on MacOS */
  44 #ifdef __APPLE__
  45 #define URCU_ATTR_ALIAS(x)
  46 #else
  47 #define URCU_ATTR_ALIAS(x) __attribute__((alias(x)))
  48 #endif
  49
  50 #ifdef CONFIG_RCU_TLS
  51 #define DEFINE_URCU_TLS_ALIAS_1(type, name, alias)              \
  52         URCU_ATTR_ALIAS(#name)                                  \
  53         extern type alias
  54
  55 #else
  56 #define DEFINE_URCU_TLS_ALIAS_1(type, name, alias)              \
  57         URCU_ATTR_ALIAS("*__tls_access_" #name)                 \
  58         type *__tls_access_ ## alias()
  59 #endif
  60
  61 #define DEFINE_URCU_TLS_ALIAS(type, name, alias)                \
  62         DEFINE_URCU_TLS_ALIAS_1(type, name, alias)
  63
  64 #endif /* _URCU_UTILS_H */