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1 /* $Id$ */ |
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2 |
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3 /** @file alloc_func.hpp Functions related to the allocation of memory */ |
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4 |
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5 #ifndef ALLOC_FUNC_HPP |
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6 #define ALLOC_FUNC_HPP |
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7 |
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8 /** |
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9 * Simplified allocation function that allocates the specified number of |
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10 * elements of the given type. It also explicitly casts it to the requested |
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11 * type. |
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12 * @note throws an error when there is no memory anymore. |
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13 * @note the memory contains garbage data (i.e. possibly non-zero values). |
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14 * @param T the type of the variable(s) to allocation. |
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15 * @param num_elements the number of elements to allocate of the given type. |
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16 * @return NULL when num_elements == 0, non-NULL otherwise. |
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17 */ |
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18 template <typename T> FORCEINLINE T* MallocT(size_t num_elements) |
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19 { |
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20 /* |
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21 * MorphOS cannot handle 0 elements allocations, or rather that always |
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22 * returns NULL. So we do that for *all* allocations, thus causing it |
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23 * to behave the same on all OSes. |
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24 */ |
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25 if (num_elements == 0) return NULL; |
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26 |
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27 T *t_ptr = (T*)malloc(num_elements * sizeof(T)); |
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28 if (t_ptr == NULL) error("Out of memory. Cannot allocate %i bytes", num_elements * sizeof(T)); |
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29 return t_ptr; |
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30 } |
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31 |
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32 /** |
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33 * Simplified allocation function that allocates the specified number of |
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34 * elements of the given type. It also explicitly casts it to the requested |
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35 * type. |
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36 * @note throws an error when there is no memory anymore. |
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37 * @note the memory contains all zero values. |
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38 * @param T the type of the variable(s) to allocation. |
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39 * @param num_elements the number of elements to allocate of the given type. |
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40 * @return NULL when num_elements == 0, non-NULL otherwise. |
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41 */ |
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42 template <typename T> FORCEINLINE T* CallocT(size_t num_elements) |
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43 { |
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44 /* |
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45 * MorphOS cannot handle 0 elements allocations, or rather that always |
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46 * returns NULL. So we do that for *all* allocations, thus causing it |
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47 * to behave the same on all OSes. |
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48 */ |
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49 if (num_elements == 0) return NULL; |
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50 |
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51 T *t_ptr = (T*)calloc(num_elements, sizeof(T)); |
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52 if (t_ptr == NULL) error("Out of memory. Cannot allocate %i bytes", num_elements * sizeof(T)); |
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53 return t_ptr; |
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54 } |
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55 |
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56 /** |
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57 * Simplified reallocation function that allocates the specified number of |
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58 * elements of the given type. It also explicitly casts it to the requested |
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59 * type. It extends/shrinks the memory allocation given in t_ptr. |
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60 * @note throws an error when there is no memory anymore. |
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61 * @note the memory contains all zero values. |
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62 * @param T the type of the variable(s) to allocation. |
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63 * @param t_ptr the previous allocation to extend/shrink. |
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64 * @param num_elements the number of elements to allocate of the given type. |
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65 * @return NULL when num_elements == 0, non-NULL otherwise. |
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66 */ |
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67 template <typename T> FORCEINLINE T* ReallocT(T *t_ptr, size_t num_elements) |
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68 { |
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69 /* |
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70 * MorphOS cannot handle 0 elements allocations, or rather that always |
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71 * returns NULL. So we do that for *all* allocations, thus causing it |
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72 * to behave the same on all OSes. |
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73 */ |
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74 if (num_elements == 0) { |
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75 free(t_ptr); |
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76 return NULL; |
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77 } |
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78 |
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79 t_ptr = (T*)realloc(t_ptr, num_elements * sizeof(T)); |
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80 if (t_ptr == NULL) error("Out of memory. Cannot reallocate %i bytes", num_elements * sizeof(T)); |
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81 return t_ptr; |
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82 } |
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83 |
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84 /** |
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85 * A small 'wrapper' for allocations that can be done on most OSes on the |
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86 * stack, but are just too large to fit in the stack on devices with a small |
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87 * stack such as the NDS. |
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88 * So when it is possible a stack allocation is made, otherwise a heap |
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89 * allocation is made and this is freed once the struct goes out of scope. |
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90 * @param T the type to make the allocation for |
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91 * @param length the amount of items to allocate |
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92 */ |
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93 template <typename T, size_t length> |
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94 struct SmallStackSafeStackAlloc { |
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95 #if !defined(__NDS__) |
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96 /** Storing the data on the stack */ |
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97 T data[length]; |
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98 #else |
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99 /** Storing it on the heap */ |
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100 T *data; |
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101 |
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102 /** Allocating the memory */ |
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103 SmallStackSafeStackAlloc() : data(MallocT<T>(length)) {} |
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104 /** And freeing when it goes out of scope */ |
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105 ~SmallStackSafeStackAlloc() { free(data); } |
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106 #endif |
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107 |
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108 /** |
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109 * Gets a pointer to the data stored in this wrapper. |
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110 * @return the pointer. |
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111 */ |
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112 operator T* () { return data; } |
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113 }; |
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114 |
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115 #endif /* ALLOC_FUNC_HPP */ |