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

   1 // Copyright (C) 2006-2019 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 }
  21 // { dg-options "-pthread"  }
  22 // { dg-require-effective-target c++11 }
  23 // { dg-require-effective-target pthread }
  24 // { dg-require-cstdint "" }
  25
  26 #include <memory>
  27 #include <random>
  28 #include <vector>
  29 #include <iostream>
  30 #include <cstdlib>
  31 #include <thread>
  32 #include <atomic>
  33 #include <functional>
  34 #include <testsuite_hooks.h>
  35
  36 #ifdef _GLIBCXX_HAVE_UNISTD_H
  37 #include <unistd.h>     // To test for _POSIX_THREAD_PRIORITY_SCHEDULING
  38 #endif
  39
  40 /* This (brute-force) tests the atomicity and thus thread safety of the
  41  * shared_ptr <- weak_ptr
  42  * assignment operation by allocating a test object, retrieving a weak
  43  * reference to it, and letting a number of threads repeatedly create strong
  44  * references from the weak reference.
  45  * Specifically, this tests the function _Sp_counted_base<true>::add_ref_lock()
  46  */
  47
  48
  49 const unsigned int HAMMER_MAX_THREADS = 10;
  50 const unsigned int POOL_SIZE = 1000;
  51 const unsigned long HAMMER_REPEAT = 100000;
  52 const unsigned long KILL_ONE_IN = 1000;
  53
  54 struct A
  55 {
  56   static std::atomic<int> counter;
  57   A() { counter.fetch_add(1, std::memory_order_relaxed); }
  58  ~A() { counter.fetch_sub(1, std::memory_order_relaxed); }
  59 };
  60
  61 std::atomic<int> A::counter{ 0 };
  62
  63 typedef std::shared_ptr<A> sp_A_t;
  64 typedef std::weak_ptr<A> wp_A_t;
  65
  66 typedef std::vector<sp_A_t> sp_vector_t;
  67 typedef std::vector<wp_A_t> wp_vector_t;
  68
  69 struct shared_and_weak_pools
  70 {
  71   sp_vector_t& shared_pool;
  72   wp_vector_t& weak_pool;
  73
  74   shared_and_weak_pools(sp_vector_t& _shared_pool, wp_vector_t& _weak_pool)
  75     : shared_pool(_shared_pool), weak_pool(_weak_pool)
  76     { }
  77 };
  78
  79 void thread_hammer_and_kill(shared_and_weak_pools& pools)
  80 {
  81   std::mt19937 urbg;
  82   std::uniform_int_distribution<> dist(0, KILL_ONE_IN - 1);
  83
  84   sp_vector_t::iterator cur_shared = pools.shared_pool.begin();
  85   wp_vector_t::iterator cur_weak = pools.weak_pool.begin();
  86
  87   for (unsigned int i = 0; i < HAMMER_REPEAT; ++i)
  88     {
  89       try
  90       {
  91         sp_A_t strong(*cur_weak);
  92       }
  93       catch (std::bad_weak_ptr& exception)
  94       {
  95         ++cur_weak;
  96         if (cur_weak == pools.weak_pool.end())
  97           break;
  98       }
  99
 100       if (dist(urbg) == 0)
 101       {
 102         cur_shared->reset();
 103         ++cur_shared;
 104       }
 105     }
 106 }
 107
 108 void thread_hammer(wp_vector_t& weak_pool)
 109 {
 110   wp_vector_t::iterator cur_weak = weak_pool.begin();
 111
 112   for (unsigned int i = 0; i < HAMMER_REPEAT; ++i)
 113     {
 114       try
 115       {
 116         sp_A_t strong(*cur_weak);
 117       }
 118       catch (std::bad_weak_ptr& exception)
 119       {
 120         ++cur_weak;
 121         if (cur_weak == weak_pool.end())
 122           break;
 123       }
 124     }
 125 }
 126
 127 void
 128 test01()
 129 {
 130   sp_vector_t obj_pool(POOL_SIZE);
 131
 132   for(auto& obj : obj_pool)
 133     obj.reset(new A);
 134
 135   // Obtain weak references.
 136   std::vector<wp_vector_t> weak_pool(HAMMER_MAX_THREADS, wp_vector_t(obj_pool.begin(), obj_pool.end()));
 137
 138   // Launch threads with pointer to weak reference.
 139   std::thread threads[HAMMER_MAX_THREADS];
 140 #if defined(__sun) && defined(__svr4__) && _XOPEN_VERSION >= 500
 141   pthread_setconcurrency (HAMMER_MAX_THREADS);
 142 #endif
 143
 144   shared_and_weak_pools pools(obj_pool, weak_pool[0]);
 145   threads[0] = std::thread(thread_hammer_and_kill, std::ref(pools));
 146   for (unsigned int worker = 1; worker < HAMMER_MAX_THREADS; worker++)
 147     threads[worker] = std::thread(thread_hammer, std::ref(weak_pool[worker]));
 148
 149   // Wait for threads to complete, then check integrity of reference.
 150   for (auto& thread : threads)
 151     thread.join();
 152
 153   obj_pool.clear();
 154
 155   VERIFY( A::counter == 0 );
 156 }
 157
 158 int
 159 main()
 160 {
 161   test01();
 162   return 0;
 163 }