sal/cpprt/operators_new_delete.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
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   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <algorithm>
  21 #include <new>
  22 #include <string.h>
  23 #include <osl/diagnose.h>
  24 #include <rtl/alloc.h>
  25
  26 // AllocatorTraits
  27
  28 namespace
  29 {
  30
  31 struct AllocatorTraits
  32 {
  33     typedef char const signature_type[8];
  34     const signature_type & m_signature;
  35
  36     explicit AllocatorTraits (signature_type const & s)
  37         : m_signature (s)
  38     {}
  39
  40     std::size_t size (std::size_t n) const
  41     {
  42         n = std::max(n, std::size_t(1));
  43 #if OSL_DEBUG_LEVEL > 0
  44         n += sizeof(signature_type);
  45 #endif  /* OSL_DEBUG_LEVEL  */
  46         return n;
  47     }
  48
  49     void* init (void * p) const
  50     {
  51 #if OSL_DEBUG_LEVEL > 0
  52         memcpy (p, m_signature, sizeof(signature_type));
  53         p = static_cast<char*>(p) + sizeof(signature_type);
  54 #endif  /* OSL_DEBUG_LEVEL */
  55         return p;
  56     }
  57
  58     void* fini (void * p) const
  59     {
  60 #if OSL_DEBUG_LEVEL > 0
  61         p = static_cast<char*>(p) - sizeof(signature_type);
  62         if (memcmp (p, m_signature, sizeof(signature_type)) != 0)
  63         {
  64             OSL_FAIL("operator delete mismatch");
  65         }
  66 #endif  /* OSL_DEBUG_LEVEL */
  67         return p;
  68     }
  69 };
  70
  71 struct VectorTraits : public AllocatorTraits
  72 {
  73     static const signature_type g_signature;
  74
  75     VectorTraits()
  76         : AllocatorTraits (g_signature)
  77     {}
  78 };
  79
  80 struct ScalarTraits : public AllocatorTraits
  81 {
  82     static const signature_type g_signature;
  83
  84     ScalarTraits()
  85         : AllocatorTraits (g_signature)
  86     {}
  87 };
  88
  89 const AllocatorTraits::signature_type VectorTraits::g_signature = "new[]()";
  90 const AllocatorTraits::signature_type ScalarTraits::g_signature = "new()  ";
  91
  92 } // anonymous namespace
  93
  94 // Allocator
  95
  96 static void default_handler()
  97 {
  98     // Multithreading race in 'std::set_new_handler()' call sequence below.
  99     throw std::bad_alloc();
 100 }
 101
 102 static void* allocate (
 103     std::size_t n, AllocatorTraits const & rTraits)
 104 {
 105     n = rTraits.size (n);
 106     for (;;)
 107     {
 108         void * p = rtl_allocateMemory (sal_Size(n));
 109         if (p != 0)
 110             return rTraits.init (p);
 111
 112         std::new_handler d = default_handler, f = std::set_new_handler (d);
 113         if (f != d)
 114             std::set_new_handler (f);
 115
 116         if (f == 0)
 117             throw std::bad_alloc();
 118         (*f)();
 119     }
 120 }
 121
 122 static void* allocate_nothrow (
 123     std::size_t n, AllocatorTraits const & rTraits)
 124 {
 125     try
 126     {
 127         return allocate (n, rTraits);
 128     }
 129     catch (std::bad_alloc const &)
 130     {
 131         return 0;
 132     }
 133 }
 134
 135 static void deallocate (void * p, AllocatorTraits const & rTraits)
 136 {
 137     if (p)
 138     {
 139         rtl_freeMemory (rTraits.fini(p));
 140     }
 141 }
 142
 143 // T * p = new T; delete p;
 144
 145 void* SAL_CALL operator new (std::size_t n) throw (std::bad_alloc)
 146 {
 147     return allocate (n, ScalarTraits());
 148 }
 149
 150 void SAL_CALL operator delete (void * p) throw ()
 151 {
 152     deallocate (p, ScalarTraits());
 153 }
 154
 155 // T * p = new(nothrow) T; delete(nothrow) p;
 156
 157 void* SAL_CALL operator new (std::size_t n, std::nothrow_t const &) throw ()
 158 {
 159     return allocate_nothrow (n, ScalarTraits());
 160 }
 161
 162 void SAL_CALL operator delete (void * p, std::nothrow_t const &) throw ()
 163 {
 164     deallocate (p, ScalarTraits());
 165 }
 166
 167 // T * p = new T[n]; delete[] p;
 168
 169 void* SAL_CALL operator new[] (std::size_t n) throw (std::bad_alloc)
 170 {
 171     return allocate (n, VectorTraits());
 172 }
 173
 174 void SAL_CALL operator delete[] (void * p) throw ()
 175 {
 176     deallocate (p, VectorTraits());
 177 }
 178
 179 // T * p = new(nothrow) T[n]; delete(nothrow)[] p;
 180
 181 void* SAL_CALL operator new[] (std::size_t n, std::nothrow_t const &) throw ()
 182 {
 183     return allocate_nothrow (n, VectorTraits());
 184 }
 185
 186 void SAL_CALL operator delete[] (void * p, std::nothrow_t const &) throw ()
 187 {
 188     deallocate (p, VectorTraits());
 189 }
 190
 191 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */