1 | /* -*- C++ -*- */ |
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2 | |
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3 | #include <map> |
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4 | #include "stlallocator.h" |
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5 | |
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6 | #ifndef _SANITYCHECKHEAP_H_ |
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7 | #define _SANITYCHECKHEAP_H_ |
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8 | |
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9 | /** |
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10 | * @class SanityCheckHeap |
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11 | * @brief Checks for memory allocation usage errors at runtime. |
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12 | * See the "error messages" for the kinds of errors this layer can catch. |
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13 | * @author Emery Berger |
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14 | */ |
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15 | |
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16 | #include "mallocheap.h" |
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17 | #include "zoneheap.h" |
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18 | #include "stlallocator.h" |
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19 | #include "mmapheap.h" |
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20 | |
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21 | namespace HL { |
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22 | |
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23 | template <class SuperHeap> |
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24 | class SanityCheckHeap : public SuperHeap { |
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25 | private: |
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26 | |
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27 | /// Define a local allocator that lets us use the SuperHeap for the map. |
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28 | /// This approach lets us use SanityCheckHeaps when we're replacing malloc. |
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29 | |
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30 | // The objects are pairs, mapping void * pointers to sizes. |
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31 | typedef std::pair<const void *, int> objType; |
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32 | |
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33 | // The heap is a simple freelist heap. |
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34 | typedef HL::FreelistHeap<HL::ZoneHeap<HL::MmapHeap, 16384> > heapType; |
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35 | |
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36 | // And we wrap it up so it can be used as an STL allocator. |
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37 | typedef HL::STLAllocator<objType, heapType> localAllocator; |
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38 | |
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39 | typedef std::less<void *> localComparator; |
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40 | |
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41 | /// A map of pointers to objects and their allocated sizes. |
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42 | typedef std::map<void *, int, localComparator, localAllocator> mapType; |
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43 | |
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44 | /// A freed object has a special size, -1. |
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45 | enum { FREED = -1 }; |
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46 | |
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47 | /** |
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48 | * @brief "Error messages", used in asserts. |
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49 | * These must all equal zero. |
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50 | */ |
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51 | enum { MALLOC_RETURNED_ALLOCATED_OBJECT = 0, |
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52 | FREE_CALLED_ON_OBJECT_I_NEVER_ALLOCATED = 0, |
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53 | FREE_CALLED_TWICE_ON_SAME_OBJECT = 0 }; |
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54 | |
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55 | public: |
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56 | |
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57 | inline void * malloc (size_t sz) { |
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58 | void * ptr = SuperHeap::malloc (sz); |
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59 | if (ptr == NULL) { |
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60 | return NULL; |
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61 | } |
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62 | // Fill the space with a known value. |
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63 | memset (ptr, 'A', sz); |
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64 | // Record this object as allocated. |
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65 | mapType::iterator i; |
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66 | // Look for this object in the map of allocated objects. |
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67 | i = allocatedObjects.find (ptr); |
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68 | if (i == allocatedObjects.end()) { |
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69 | // We didn't find it (this is good). |
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70 | // Add the tuple (ptr, sz). |
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71 | allocatedObjects.insert (std::pair<void *, int>(ptr, sz)); |
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72 | } else { |
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73 | // We found it. |
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74 | // It really should have been freed. |
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75 | if ((*i).second != FREED) { |
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76 | // This object is still in use! |
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77 | assert ( MALLOC_RETURNED_ALLOCATED_OBJECT ); |
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78 | return NULL; |
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79 | } else { |
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80 | // This object has been freed. Mark it as allocated. |
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81 | (*i).second = sz; |
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82 | } |
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83 | } |
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84 | return ptr; |
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85 | } |
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86 | |
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87 | inline void free (void * ptr) { |
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88 | // Look for this object in the list of allocated objects. |
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89 | mapType::iterator i; |
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90 | i = allocatedObjects.find (ptr); |
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91 | if (i == allocatedObjects.end()) { |
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92 | assert ( FREE_CALLED_ON_OBJECT_I_NEVER_ALLOCATED ); |
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93 | return; |
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94 | } |
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95 | // We found the object. It should not have been freed already. |
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96 | if ((*i).second == FREED) { |
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97 | // Oops, this object WAS freed before. |
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98 | assert ( FREE_CALLED_TWICE_ON_SAME_OBJECT ); |
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99 | return; |
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100 | } |
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101 | // Fill the space with a known value. |
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102 | memset (ptr, 'F', (*i).second); |
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103 | // Really free the pointer. |
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104 | (*i).second = FREED; |
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105 | SuperHeap::free (ptr); |
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106 | } |
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107 | |
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108 | private: |
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109 | |
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110 | /// A map of tuples: (obj address, size). |
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111 | mapType allocatedObjects; |
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112 | }; |
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113 | |
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114 | }; |
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115 | |
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116 | #endif |
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