libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc

   1 // Copyright (C) 2018-2019 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 // { dg-options "-std=gnu++17" }
  19 // { dg-do run { target c++17 } }
  20
  21 #include <memory_resource>
  22 #include <testsuite_allocator.h>
  23
  24 struct resource : __gnu_test::memory_resource
  25 {
  26   int allocate_calls = 0;
  27   int deallocate_calls = 0;
  28
  29   void*
  30   do_allocate(std::size_t bytes, std::size_t align) override
  31   {
  32     ++allocate_calls;
  33     return __gnu_test::memory_resource::do_allocate(bytes, align);
  34   }
  35
  36   void
  37   do_deallocate(void* p, std::size_t bytes, std::size_t align) override
  38   {
  39     ++deallocate_calls;
  40     __gnu_test::memory_resource::do_deallocate(p, bytes, align);
  41   }
  42 };
  43
  44 void
  45 test01()
  46 {
  47   resource r;
  48   std::pmr::monotonic_buffer_resource mbr(&r);
  49   auto p = mbr.allocate(10, 16);
  50   mbr.deallocate(p, 1, 2);
  51   VERIFY( r.deallocate_calls == 0 );
  52   p = mbr.allocate(10, 16);
  53   p = mbr.allocate(10, 16);
  54   p = mbr.allocate(10, 16);
  55   p = mbr.allocate(1024, 64);
  56   p = mbr.allocate(1024, 64);
  57   p = mbr.allocate(128, 8);
  58   p = mbr.allocate(128, 8);
  59   p = mbr.allocate(128, 8);
  60   p = mbr.allocate(128, 8);
  61   p = mbr.allocate(128, 8);
  62   p = mbr.allocate(128, 8);
  63   p = mbr.allocate(128, 8);
  64   mbr.deallocate(p, 1, 2);
  65   p = mbr.allocate(1024, 16);
  66   p = mbr.allocate(1024, 16);
  67   mbr.deallocate(p, 1, 2);
  68   VERIFY( r.deallocate_calls == 0 );
  69   mbr.release();
  70   VERIFY( r.deallocate_calls != 0 );
  71   VERIFY( r.deallocate_calls == r.allocate_calls );
  72   VERIFY( mbr.upstream_resource() == &r );
  73   VERIFY( r.number_of_active_allocations() == 0 );
  74 }
  75
  76 void
  77 test02()
  78 {
  79   std::pmr::monotonic_buffer_resource mbr; // uses get_default_resource()
  80   auto* const upstream = mbr.upstream_resource();
  81   resource r;
  82   __gnu_test::default_resource_mgr _(&r); // calls set_default_resource(&r)
  83   mbr.release();
  84   // release() doesn't change upstream resource:
  85   VERIFY( mbr.upstream_resource() == upstream );
  86 }
  87
  88 void
  89 test03()
  90 {
  91   resource r;
  92   __gnu_test::default_resource_mgr _(&r);
  93   std::pmr::monotonic_buffer_resource mbr(16);
  94   for (int i = 0; i < 100; ++i)
  95     (void) mbr.allocate(4, 1);
  96   const int allocations = r.allocate_calls;
  97   VERIFY( allocations != 0 );
  98   mbr.release();
  99   VERIFY( r.allocate_calls == r.deallocate_calls );
 100   VERIFY( r.number_of_active_allocations() == 0 );
 101
 102   // next_buffer_size should have been reset to the initial value,
 103   // so the allocations from upstream should be the same as before.
 104   r.allocate_calls = 0;
 105   r.deallocate_calls = 0;
 106   for (int i = 0; i < 100; ++i)
 107     (void) mbr.allocate(4,1);
 108   VERIFY( allocations == r.allocate_calls );
 109 }
 110
 111 void
 112 test04()
 113 {
 114   resource r;
 115   unsigned char buffer[1024];
 116   std::pmr::monotonic_buffer_resource mbr(buffer, sizeof(buffer), &r);
 117   void* p = mbr.allocate(800, 16);
 118   VERIFY( p >= buffer && p < (buffer + 16) );
 119   void* const p_in_buffer = p;
 120   VERIFY( r.allocate_calls == 0 );
 121   p = mbr.allocate(300, 1);
 122   VERIFY( p != buffer );
 123   VERIFY( p != buffer );
 124   VERIFY( r.allocate_calls == 1 );
 125   mbr.release();
 126   VERIFY( r.deallocate_calls == 1 );
 127   VERIFY( mbr.upstream_resource() == &r );
 128   VERIFY( r.number_of_active_allocations() == 0 );
 129   // initial buffer should be used again now:
 130   p = mbr.allocate(1000, 16);
 131   VERIFY( p == p_in_buffer );
 132   VERIFY( r.allocate_calls == 1 );
 133 }
 134
 135 void
 136 test05() // LWG 3120
 137 {
 138   char buffer[100];
 139   {
 140     std::pmr::monotonic_buffer_resource mr(buffer, sizeof(buffer),
 141                                             std::pmr::null_memory_resource());
 142     mr.release();
 143     (void) mr.allocate(60);
 144   }
 145
 146   {
 147     std::pmr::monotonic_buffer_resource mr(buffer, sizeof(buffer),
 148                                             std::pmr::null_memory_resource());
 149     (void) mr.allocate(60);
 150     mr.release();
 151     (void) mr.allocate(60);
 152   }
 153
 154   {
 155     resource r;
 156     std::pmr::monotonic_buffer_resource mr(&r);
 157     for (int i = 0; i < 100; ++i)
 158     {
 159       (void) mr.allocate(1);
 160       mr.release();
 161     }
 162     VERIFY( r.number_of_active_allocations() == 0 );
 163   }
 164 }
 165
 166 int
 167 main()
 168 {
 169   test01();
 170   test02();
 171   test03();
 172   test04();
 173   test05();
 174 }