libstdc++-v3/testsuite/20_util/synchronized_pool_resource/multithreaded.cc

   1 // Copyright (C) 2018-2024 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 // { dg-do run { target c++17 } }
  19 // { dg-additional-options "-pthread" { target pthread } }
  20 // { dg-require-gthreads "" }
  21
  22 #include <memory_resource>
  23 #include <future>
  24 #include <testsuite_allocator.h>
  25 #include <testsuite_hooks.h>
  26
  27 void
  28 test01()
  29 {
  30   __gnu_test::memory_resource test_mr;
  31   std::pmr::synchronized_pool_resource smr(&test_mr);
  32
  33   const std::size_t largest_pool = smr.options().largest_required_pool_block;
  34
  35   auto do_alloc = [&smr](void*& p, size_t n) {
  36     // perform some other allocations and deallocations on the same thread:
  37     void* p2 = smr.allocate(n);
  38     smr.deallocate(p2, n);
  39     p2 = smr.allocate(n);
  40     p = smr.allocate(n);
  41     smr.deallocate(p2, n);
  42   };
  43   auto do_dealloc = [&smr](void* p, size_t n) { smr.deallocate(p, n); };
  44
  45   void* p1;
  46   void* p2;
  47   void* p3;
  48   auto f1 = std::async(std::launch::async, do_alloc, std::ref(p1), 8);
  49   auto f2 = std::async(std::launch::async, do_alloc, std::ref(p2), 64);
  50   auto f3 = std::async(std::launch::async, do_alloc, std::ref(p3),
  51                        largest_pool* 2);
  52
  53   f1.get();
  54   f2.get();
  55   f3.get();
  56   VERIFY( p1 != nullptr );
  57   VERIFY( p2 != nullptr );
  58   VERIFY( p3 != nullptr );
  59   size_t nallocs = test_mr.number_of_active_allocations();
  60   VERIFY( nallocs >= 4 );
  61
  62   // deallocate on different threads from allocation:
  63   f1 = std::async(std::launch::async, do_dealloc, p1, 8);
  64   f2 = std::async(std::launch::async, do_dealloc, p2, 64);
  65   f1.get();
  66   f2.get();
  67   // No additional memory is allocated by deallocating on new threads:
  68   VERIFY( test_mr.number_of_active_allocations() == nallocs );
  69
  70   // Deallocate large unpooled allocation:
  71   f3 = std::async(std::launch::async, do_dealloc, p3, largest_pool * 2);
  72   f3.get();
  73   // The large allocation should have been returned upstream:
  74   VERIFY( test_mr.number_of_active_allocations() == nallocs - 1 );
  75
  76   smr.release();
  77   VERIFY( test_mr.number_of_active_allocations() == 0 );
  78 }
  79
  80 int
  81 main()
  82 {
  83   test01();
  84 }