The Tcpdump Group git mirrors - libpcap/blob - thread-local.h

   1 /*
   2  * Copyright (c) 1994, 1995, 1996
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the Computer Systems
  16  *      Engineering Group at Lawrence Berkeley Laboratory.
  17  * 4. Neither the name of the University nor of the Laboratory may be used
  18  *    to endorse or promote products derived from this software without
  19  *    specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef thread_local_h
  35 #define thread_local_h
  36
  37 /*
  38  * This defines thread_local to specify thread-local storage, if it
  39  * is not already defined.
  40  *
  41  * C11, if __STDC_NO_THREADS__ is not defined to be 1, defines
  42  * _Thread_local to indicate thread-local storage.  (You can also
  43  * include <threads.h> to so define it, but we don't use any of
  44  * the other stuff there.)
  45  *
  46  * Otherwise, we define it ourselves, based on the compiler.
  47  *
  48  * This is taken from https://stackoverflow.com/a/18298965/16139739.
  49  */
  50 #ifndef thread_local
  51   #if __STDC_VERSION__ >= 201112 && !defined __STDC_NO_THREADS__
  52     #define thread_local _Thread_local
  53   #elif defined __TINYC__
  54     #define thread_local
  55     #warning "Some libpcap calls will not be thread-safe."
  56   #elif defined _WIN32 && ( \
  57          defined _MSC_VER || \
  58          defined __ICL || \
  59          defined __DMC__ || \
  60          defined __BORLANDC__ )
  61     #define thread_local __declspec(thread)
  62   /* note that ICC (linux) and Clang are covered by __GNUC__ */
  63   #elif defined __GNUC__ || \
  64          defined __SUNPRO_C || \
  65          defined __xlC__ || \
  66          defined __HP_cc
  67     #define thread_local __thread
  68   #else
  69     #error "Cannot define thread_local"
  70   #endif
  71 #endif
  72
  73 #endif