cdsa/cdsa_utilities/cssmalloc.cpp

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 //
  20 // cssmalloc - memory allocation in the CDSA world.
  21 //
  22 // Don't eat heavily before inspecting this code.
  23 //
  24 #include <Security/cssmalloc.h>
  25 #include <Security/memutils.h>
  26 #include <Security/globalizer.h>
  27 #include <stdlib.h>
  28 #include <errno.h>
  29
  30 using LowLevelMemoryUtilities::alignof;
  31 using LowLevelMemoryUtilities::increment;
  32 using LowLevelMemoryUtilities::alignUp;
  33
  34
  35 //
  36 // Features of the CssmAllocator root class
  37 //
  38 bool CssmAllocator::operator == (const CssmAllocator &alloc) const
  39 {
  40         return this == &alloc;
  41 }
  42
  43 CssmAllocator::~CssmAllocator()
  44 {
  45 }
  46
  47
  48 //
  49 // Standard CssmAllocator variants.
  50 // Note that all calls to CssmAllocator::standard(xxx) with the same xxx argument
  51 // must produce compatible allocators (i.e. they must be work on a common memory
  52 // pool). This is trivially achieved here by using singletons.
  53 //
  54 struct DefaultCssmAllocator : public CssmAllocator {
  55         void *malloc(size_t size);
  56         void free(void *addr);
  57         void *realloc(void *addr, size_t size);
  58 };
  59
  60 static ModuleNexus<DefaultCssmAllocator> defaultAllocator;
  61
  62
  63 CssmAllocator &CssmAllocator::standard(uint32)
  64 {
  65         return defaultAllocator();
  66 }
  67
  68 void *DefaultCssmAllocator::malloc(size_t size)
  69 {
  70         if (void *result = ::malloc(size))
  71                 return result;
  72         throw std::bad_alloc();
  73 }
  74
  75 void DefaultCssmAllocator::free(void *addr)
  76 {
  77         ::free(addr);
  78 }
  79
  80 void *DefaultCssmAllocator::realloc(void *addr, size_t newSize)
  81 {
  82         if (void *result = ::realloc(addr, newSize))
  83                 return result;
  84         throw std::bad_alloc();
  85 }
  86
  87 TrackingAllocator::~TrackingAllocator()
  88 {
  89         AllocSet::iterator first = mAllocSet.begin(), last = mAllocSet.end();
  90         for (; first != last; ++first)
  91                 mAllocator.free(*first);
  92 }
  93
  94 //
  95 // CssmMemoryFunctionsAllocators
  96 //
  97 void *CssmMemoryFunctionsAllocator::malloc(size_t size)
  98 { return functions.malloc(size); }
  99
 100 void CssmMemoryFunctionsAllocator::free(void *addr)
 101 { return functions.free(addr); }
 102
 103 void *CssmMemoryFunctionsAllocator::realloc(void *addr, size_t size)
 104 { return functions.realloc(addr, size); }
 105
 106
 107 //
 108 // CssmAllocatorMemoryFunctions
 109 //
 110 CssmAllocatorMemoryFunctions::CssmAllocatorMemoryFunctions(CssmAllocator &alloc)
 111 {
 112         AllocRef = &alloc;
 113         malloc_func = relayMalloc;
 114         free_func = relayFree;
 115         realloc_func = relayRealloc;
 116         calloc_func = relayCalloc;
 117 }
 118
 119 void *CssmAllocatorMemoryFunctions::relayMalloc(size_t size, void *ref)
 120 { return allocator(ref).malloc(size); }
 121
 122 void CssmAllocatorMemoryFunctions::relayFree(void *mem, void *ref)
 123 { allocator(ref).free(mem); }
 124
 125 void *CssmAllocatorMemoryFunctions::relayRealloc(void *mem, size_t size, void *ref)
 126 { return allocator(ref).realloc(mem, size); }
 127
 128 void *CssmAllocatorMemoryFunctions::relayCalloc(uint32 count, size_t size, void *ref)
 129 {
 130         // CssmAllocator doesn't have a calloc() method
 131         void *mem = allocator(ref).malloc(size * count);
 132         memset(mem, 0, size * count);
 133         return mem;
 134 }
 135
 136
 137 //
 138 // Memory allocators for CssmHeap objects.
 139 // This implementation stores a pointer to the allocator used into memory
 140 // *after* the object's proper storage block. This allows the usual free()
 141 // functions to safely free our (hidden) pointer without knowing about it.
 142 // An allocator argument of NULL is interpreted as the standard allocator.
 143 //
 144 void *CssmHeap::operator new (size_t size, CssmAllocator *alloc)
 145 {
 146         if (alloc == NULL)
 147                 alloc = &CssmAllocator::standard();
 148         size = alignUp(size, alignof<CssmAllocator *>());
 149         size_t totalSize = size + sizeof(CssmAllocator *);
 150         void *addr = alloc->malloc(totalSize);
 151         *(CssmAllocator **)increment(addr, size) = alloc;
 152         return addr;
 153 }
 154
 155 void CssmHeap::operator delete (void *addr, size_t size, CssmAllocator *alloc)
 156 {
 157         alloc->free(addr);      // as per C++ std, called (only) if construction fails
 158 }
 159
 160 void CssmHeap::operator delete (void *addr, size_t size)
 161 {
 162         void *end = increment(addr, alignUp(size, alignof<CssmAllocator *>()));
 163         (*(CssmAllocator **)end)->free(addr);
 164 }