1 | /* -*- C++ -*- */ |
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2 | |
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3 | #ifndef _FIFODLFREELIST_H_ |
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4 | #define _FIFODLFREELIST_H_ |
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5 | |
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6 | #include <assert.h> |
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7 | |
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8 | template <class Super> |
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9 | class FIFODLFreelistHeap : public Super { |
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10 | public: |
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11 | |
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12 | FIFODLFreelistHeap (void) |
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13 | { |
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14 | head.prev = &head; |
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15 | head.next = &tail; |
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16 | tail.prev = &head; |
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17 | tail.next = &tail; |
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18 | assert (isEmpty()); |
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19 | } |
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20 | |
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21 | ~FIFODLFreelistHeap (void) |
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22 | { |
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23 | // Delete everything on the free list. |
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24 | freeObject * ptr = head.next; |
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25 | while (ptr != &tail) { |
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26 | void * oldptr = ptr; |
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27 | ptr = ptr->next; |
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28 | Super::free (oldptr); |
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29 | } |
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30 | } |
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31 | |
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32 | inline void * malloc (size_t sz) { |
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33 | //printf ("flist malloc %d\n", sz); |
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34 | // Check the free list first. |
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35 | freeObject * ptr = tail.prev; |
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36 | if (ptr == &head) { |
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37 | assert (isEmpty()); |
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38 | ptr = (freeObject *) Super::malloc (sz); |
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39 | } else { |
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40 | ptr->prev->next = &tail; |
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41 | tail.prev = ptr->prev; |
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42 | #if 0 |
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43 | ptr->prev = NULL; |
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44 | ptr->next = NULL; |
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45 | #endif |
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46 | } |
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47 | assert (getSize(ptr) >= sz); |
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48 | assert (getSize(ptr) >= sizeof(freeObject)); |
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49 | return (void *) ptr; |
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50 | } |
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51 | |
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52 | inline void free (void * ptr) { |
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53 | // Add this object to the free list. |
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54 | assert (ptr != NULL); |
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55 | freeObject * p = (freeObject *) ptr; |
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56 | p->next = head.next; |
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57 | p->next->prev = p; |
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58 | p->prev = &head; |
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59 | head.next = p; |
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60 | assert (!isEmpty()); |
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61 | } |
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62 | |
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63 | #if 0 |
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64 | // Returns the entire linked list of freed objects. |
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65 | inline void * multimalloc (size_t sz) { |
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66 | freeObject * ptr = head.next; |
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67 | ptr->prev = NULL; |
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68 | tail.prev->next = NULL; |
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69 | head.next = &tail; |
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70 | tail.prev = &head; |
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71 | return ptr; |
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72 | } |
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73 | #endif |
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74 | |
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75 | inline static void remove (void * rptr) |
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76 | { |
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77 | freeObject * p = (freeObject *) rptr; |
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78 | assert (p->next != NULL); |
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79 | assert (p->prev != NULL); |
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80 | p->prev->next = p->next; |
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81 | p->next->prev = p->prev; |
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82 | p->prev = p->next = NULL; |
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83 | } |
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84 | |
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85 | |
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86 | private: |
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87 | |
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88 | int isEmpty (void) { |
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89 | return (head.next == &tail); |
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90 | } |
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91 | |
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92 | class freeObject { |
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93 | public: |
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94 | freeObject * prev; |
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95 | freeObject * next; |
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96 | }; |
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97 | |
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98 | freeObject head, tail; |
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99 | }; |
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100 | |
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101 | #endif |
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