libstdc++-v3/testsuite/30_threads/call_once/39909.cc

   1 // { dg-do run }
   2 // { dg-options "-pthread"  }
   3 // { dg-require-effective-target c++11 }
   4 // { dg-require-effective-target pthread }
   5 // { dg-require-cstdint "" }
   6 // { dg-require-gthreads "" }
   7
   8 // Copyright (C) 2009-2018 Free Software Foundation, Inc.
   9 //
  10 // This file is part of the GNU ISO C++ Library.  This library is free
  11 // software; you can redistribute it and/or modify it under the
  12 // terms of the GNU General Public License as published by the
  13 // Free Software Foundation; either version 3, or (at your option)
  14 // 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
  19 // GNU General Public License for more details.
  20
  21 // You should have received a copy of the GNU General Public License along
  22 // with this library; see the file COPYING3.  If not see
  23 // <http://www.gnu.org/licenses/>.
  24
  25
  26 #include <mutex>
  27 #include <thread>
  28 #include <testsuite_hooks.h>
  29
  30 std::once_flag flag;
  31 int value = 0;
  32
  33 struct Inc { void operator()() const { ++value; } };
  34
  35 struct Func
  36 {
  37    void operator()() const
  38    {
  39        Inc inc;
  40        for (int i = 0; i < 10000;  ++i)
  41            std::call_once(flag, inc);
  42    }
  43 };
  44
  45 int main()
  46 {
  47    Func f;
  48    std::thread t1(f);
  49    std::thread t2(f);
  50    std::thread t3(f);
  51    t1.join();
  52    t2.join();
  53    t3.join();
  54    VERIFY( value == 1 );
  55    return 0;
  56 }