libstdc++-v3/src/mutex.cc

   1 // mutex -*- C++ -*-
   2
   3 // Copyright (C) 2008 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 #include <mutex>
  31
  32 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
  33
  34 namespace std
  35 {
  36   const defer_lock_t defer_lock = defer_lock_t();
  37   const try_to_lock_t try_to_lock = try_to_lock_t();
  38   const adopt_lock_t adopt_lock = adopt_lock_t();
  39
  40   const char*
  41   lock_error::what() const throw()
  42   { return "std::lock_error"; }
  43
  44 #ifdef _GLIBCXX_HAVE_TLS
  45   __thread void* __once_callable;
  46   __thread void (*__once_call)();
  47 #else
  48   // explicit instantiation due to -fno-implicit-instantiation
  49   template class function<void()>;
  50   function<void()> __once_functor;
  51   mutex __once_mutex;
  52   unique_lock<mutex> __once_functor_lock(__once_mutex, defer_lock);
  53 #endif
  54
  55   extern "C"
  56   {
  57     void __once_proxy()
  58     {
  59 #ifndef _GLIBCXX_HAVE_TLS
  60       function<void()> __once_call = std::move(__once_functor);
  61       __once_functor_lock.unlock();
  62 #endif
  63       __once_call();
  64     }
  65   }
  66 }
  67
  68 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1