libstdc++-v3/testsuite/20_util/shared_ptr/thread/default_weaktoshared.cc

   1 // Copyright (C) 2006-2016 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // 20.6.6.2 Template class shared_ptr [util.smartptr.shared]
  19
  20 // { dg-do run { target *-*-freebsd* *-*-dragonfly* *-*-netbsd* *-*-linux* *-*-gnu* *-*-solaris* *-*-cygwin *-*-rtems* *-*-darwin* } }
  21 // { dg-options "-pthread" { target *-*-freebsd* *-*-dragonfly* *-*-netbsd* *-*-linux* *-*-gnu* *-*-solaris* } }
  22 // { dg-require-effective-target c++11 }
  23
  24 #include <memory>
  25 #include <random>
  26 #include <vector>
  27 #include <iostream>
  28 #include <cstdlib>
  29 #include <thread>
  30 #include <atomic>
  31 #include <testsuite_hooks.h>
  32
  33 #ifdef _GLIBCXX_HAVE_UNISTD_H
  34 #include <unistd.h>     // To test for _POSIX_THREAD_PRIORITY_SCHEDULING
  35 #endif
  36
  37 /* This (brute-force) tests the atomicity and thus thread safety of the
  38  * shared_ptr <- weak_ptr
  39  * assignment operation by allocating a test object, retrieving a weak
  40  * reference to it, and letting a number of threads repeatedly create strong
  41  * references from the weak reference.
  42  * Specifically, this tests the function _Sp_counted_base<true>::add_ref_lock()
  43  */
  44
  45
  46 const unsigned int HAMMER_MAX_THREADS = 10;
  47 const unsigned int POOL_SIZE = 1000;
  48 const unsigned long HAMMER_REPEAT = 100000;
  49 const unsigned long KILL_ONE_IN = 1000;
  50
  51 struct A
  52 {
  53   static std::atomic<int> counter;
  54   A() { counter.fetch_add(1, std::memory_order_relaxed); }
  55  ~A() { counter.fetch_sub(1, std::memory_order_relaxed); }
  56 };
  57
  58 std::atomic<int> A::counter{ 0 };
  59
  60 typedef std::shared_ptr<A> sp_A_t;
  61 typedef std::weak_ptr<A> wp_A_t;
  62
  63 typedef std::vector<sp_A_t> sp_vector_t;
  64 typedef std::vector<wp_A_t> wp_vector_t;
  65
  66 struct shared_and_weak_pools
  67 {
  68   sp_vector_t& shared_pool;
  69   wp_vector_t& weak_pool;
  70
  71   shared_and_weak_pools(sp_vector_t& _shared_pool, wp_vector_t& _weak_pool)
  72     : shared_pool(_shared_pool), weak_pool(_weak_pool)
  73     { }
  74 };
  75
  76 void thread_hammer_and_kill(shared_and_weak_pools& pools)
  77 {
  78   std::mt19937 urbg;
  79   std::uniform_int_distribution<> dist(0, KILL_ONE_IN - 1);
  80
  81   sp_vector_t::iterator cur_shared = pools.shared_pool.begin();
  82   wp_vector_t::iterator cur_weak = pools.weak_pool.begin();
  83
  84   for (unsigned int i = 0; i < HAMMER_REPEAT; ++i)
  85     {
  86       try
  87       {
  88         sp_A_t strong(*cur_weak);
  89       }
  90       catch (std::bad_weak_ptr& exception)
  91       {
  92         ++cur_weak;
  93         if (cur_weak == pools.weak_pool.end())
  94           break;
  95       }
  96
  97       if (dist(urbg) == 0)
  98       {
  99         cur_shared->reset();
 100         ++cur_shared;
 101       }
 102     }
 103 }
 104
 105 void thread_hammer(wp_vector_t& weak_pool)
 106 {
 107   wp_vector_t::iterator cur_weak = weak_pool.begin();
 108
 109   for (unsigned int i = 0; i < HAMMER_REPEAT; ++i)
 110     {
 111       try
 112       {
 113         sp_A_t strong(*cur_weak);
 114       }
 115       catch (std::bad_weak_ptr& exception)
 116       {
 117         ++cur_weak;
 118         if (cur_weak == weak_pool.end())
 119           break;
 120       }
 121     }
 122 }
 123
 124 void
 125 test01()
 126 {
 127   sp_vector_t obj_pool(POOL_SIZE);
 128
 129   for(auto& obj : obj_pool)
 130     obj.reset(new A);
 131
 132   // Obtain weak references.
 133   std::vector<wp_vector_t> weak_pool(HAMMER_MAX_THREADS, wp_vector_t(obj_pool.begin(), obj_pool.end()));
 134
 135   // Launch threads with pointer to weak reference.
 136   std::thread threads[HAMMER_MAX_THREADS];
 137 #if defined(__sun) && defined(__svr4__) && _XOPEN_VERSION >= 500
 138   pthread_setconcurrency (HAMMER_MAX_THREADS);
 139 #endif
 140
 141   shared_and_weak_pools pools(obj_pool, weak_pool[0]);
 142   threads[0] = std::thread(thread_hammer_and_kill, std::ref(pools));
 143   for (unsigned int worker = 1; worker < HAMMER_MAX_THREADS; worker++)
 144     threads[worker] = std::thread(thread_hammer, std::ref(weak_pool[worker]));
 145
 146   // Wait for threads to complete, then check integrity of reference.
 147   for (auto& thread : threads)
 148     thread.join();
 149
 150   obj_pool.clear();
 151
 152   VERIFY( A::counter == 0 );
 153 }
 154
 155 int
 156 main()
 157 {
 158   test01();
 159   return 0;
 160 }