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 #include <urcu/config.h>
  27
  28 #define urcu_stringify(a) _urcu_stringify(a)
  29 #define _urcu_stringify(a) #a
  30
  31 #define max_t(type, x, y)                               \
  32         ({                                              \
  33                 type __max1 = (x);                      \
  34                 type __max2 = (y);                      \
  35                 __max1 > __max2 ? __max1: __max2;       \
  36         })
  37
  38 #define min_t(type, x, y)                               \
  39         ({                                              \
  40                 type __min1 = (x);                      \
  41                 type __min2 = (y);                      \
  42                 __min1 <= __min2 ? __min1: __min2;      \
  43         })
  44
  45 /* There is no concept of symbol aliases on MacOS */
  46 #ifdef __APPLE__
  47 #define URCU_ATTR_ALIAS(x)
  48 #else
  49 #define URCU_ATTR_ALIAS(x) __attribute__((alias(x)))
  50 #endif
  51
  52 #ifdef CONFIG_RCU_TLS
  53 #define DEFINE_URCU_TLS_ALIAS_1(type, name, alias)              \
  54         URCU_ATTR_ALIAS(#name)                                  \
  55         extern type alias
  56
  57 #else
  58 #define DEFINE_URCU_TLS_ALIAS_1(type, name, alias)              \
  59         URCU_ATTR_ALIAS("*__tls_access_" #name)                 \
  60         type *__tls_access_ ## alias()
  61 #endif
  62
  63 #define DEFINE_URCU_TLS_ALIAS(type, name, alias)                \
  64         DEFINE_URCU_TLS_ALIAS_1(type, name, alias)
  65
  66 #endif /* _URCU_UTILS_H */