libstdc++-v3/testsuite/30_threads/lock/4.cc

   1 // { dg-do run { target *-*-freebsd* *-*-netbsd* *-*-linux* *-*-solaris* *-*-cygwin *-*-darwin* alpha*-*-osf* mips-sgi-irix6* } }
   2 // { dg-options " -std=gnu++0x -pthread" { target *-*-freebsd* *-*-netbsd* *-*-linux* alpha*-*-osf* mips-sgi-irix6* } }
   3 // { dg-options " -std=gnu++0x -pthreads" { target *-*-solaris* } }
   4 // { dg-options " -std=gnu++0x " { target *-*-cygwin *-*-darwin* } }
   5 // { dg-require-cstdint "" }
   6 // { dg-require-gthreads "" }
   7
   8 // Copyright (C) 2010 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 <testsuite_hooks.h>
  28
  29 struct unreliable_lock
  30 {
  31   std::mutex m;
  32   std::unique_lock<std::mutex> l;
  33
  34   static int count;
  35   static int throw_on;
  36   static int lock_on;
  37
  38   unreliable_lock() : l(m, std::defer_lock) { }
  39
  40   ~unreliable_lock()
  41   {
  42     bool test __attribute__((unused)) = true;
  43     VERIFY( !l.owns_lock() );
  44   }
  45
  46   void lock()
  47   {
  48     if (count == throw_on)
  49       throw throw_on;
  50     ++count;
  51     l.lock();
  52   }
  53   bool try_lock()
  54   {
  55     if (count == throw_on)
  56       throw throw_on;
  57     std::unique_lock<std::mutex> l2(m, std::defer_lock);
  58     if (count == lock_on)
  59       l2.lock();
  60     ++count;
  61     return l.try_lock();
  62   }
  63
  64   void unlock()
  65   {
  66     bool test __attribute__((unused)) = true;
  67     VERIFY( l.owns_lock() );
  68     l.unlock();
  69   }
  70
  71 };
  72
  73 int unreliable_lock::count = 0;
  74 int unreliable_lock::throw_on = -1;
  75 int unreliable_lock::lock_on = -1;
  76
  77 void test01()
  78 {
  79   bool test __attribute__((unused)) = true;
  80
  81   unreliable_lock l1, l2, l3;
  82
  83   try
  84     {
  85       unreliable_lock::count = 0;
  86       std::lock(l1, l2, l3);
  87       VERIFY( unreliable_lock::count == 3 );
  88       l1.unlock();
  89       l2.unlock();
  90       l3.unlock();
  91     }
  92   catch (...)
  93     {
  94       VERIFY( false );
  95     }
  96 }
  97
  98 void test02()
  99 {
 100   bool test __attribute__((unused)) = true;
 101
 102   // test behaviour when a lock is already held
 103   try
 104     {
 105       unreliable_lock::lock_on = 1;
 106       while (unreliable_lock::lock_on < 3)
 107       {
 108         unreliable_lock::count = 0;
 109         unreliable_lock l1, l2, l3;
 110         std::lock(l1, l2, l3);
 111         VERIFY( unreliable_lock::count > 3 );
 112         l1.unlock();
 113         l2.unlock();
 114         l3.unlock();
 115         ++unreliable_lock::lock_on;
 116       }
 117     }
 118   catch (...)
 119     {
 120       VERIFY( false );
 121     }
 122 }
 123
 124 void test03()
 125 {
 126   // test behaviour when an exception is thrown
 127   unreliable_lock::throw_on = 0;
 128   while (unreliable_lock::throw_on < 3)
 129   {
 130     unreliable_lock::count = 0;
 131     unreliable_lock l1, l2, l3;
 132     bool test = false;
 133     try
 134       {
 135         std::lock(l1, l2, l3);
 136       }
 137     catch (...)
 138       {
 139         test = true;
 140       }
 141     VERIFY( test );
 142     ++unreliable_lock::throw_on;
 143   }
 144 }
 145
 146 int main()
 147 {
 148   test01();
 149   test02();
 150   test03();
 151   return 0;
 152 }