libstdc++-v3/testsuite/30_threads/try_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       int result = std::try_lock(l1, l2, l3);
  87       VERIFY( result == -1 );
  88       VERIFY( unreliable_lock::count == 3 );
  89       l1.unlock();
  90       l2.unlock();
  91       l3.unlock();
  92     }
  93   catch (...)
  94     {
  95       VERIFY( false );
  96     }
  97 }
  98
  99 void test02()
 100 {
 101   bool test __attribute__((unused)) = true;
 102
 103   unreliable_lock l1, l2, l3;
 104
 105   try
 106     {
 107       // test behaviour when a lock is already held
 108       unreliable_lock::lock_on = 0;
 109       while (unreliable_lock::lock_on < 3)
 110       {
 111         unreliable_lock::count = 0;
 112         int failed = std::try_lock(l1, l2, l3);
 113         VERIFY( failed == unreliable_lock::lock_on );
 114         ++unreliable_lock::lock_on;
 115       }
 116     }
 117   catch (...)
 118     {
 119       VERIFY( false );
 120     }
 121 }
 122
 123 void test03()
 124 {
 125   bool test __attribute__((unused)) = true;
 126
 127   unreliable_lock l1, l2, l3;
 128
 129   try
 130     {
 131       // test behaviour when an exception is thrown
 132       unreliable_lock::throw_on = 0;
 133       while (unreliable_lock::throw_on < 3)
 134       {
 135         unreliable_lock::count = 0;
 136         int failed = std::try_lock(l1, l2, l3);
 137         VERIFY( failed == unreliable_lock::throw_on );
 138         ++unreliable_lock::throw_on;
 139       }
 140     }
 141   catch (...)
 142     {
 143       VERIFY( false );
 144     }
 145 }
 146
 147 int main()
 148 {
 149   test01();
 150   test02();
 151   test03();
 152   return 0;
 153 }