1 | // -*- C++ -*- |
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2 | |
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3 | #ifndef _HEAPMANAGER_H_ |
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4 | #define _HEAPMANAGER_H_ |
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5 | |
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6 | #include <stdlib.h> |
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7 | |
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8 | #include "guard.h" |
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9 | #include "cpuinfo.h" |
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10 | |
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11 | namespace Hoard { |
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12 | |
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13 | template <typename LockType, |
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14 | typename HeapType> |
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15 | class HeapManager : public HeapType { |
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16 | public: |
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17 | |
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18 | HeapManager (void) |
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19 | { |
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20 | HL::Guard<LockType> g (heapLock); |
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21 | |
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22 | /// Initialize all heap maps (nothing yet assigned). |
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23 | int i; |
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24 | for (i = 0; i < HeapType::MaxThreads; i++) { |
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25 | HeapType::setTidMap (i, 0); |
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26 | } |
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27 | for (i = 0; i < HeapType::MaxHeaps; i++) { |
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28 | HeapType::setInusemap (i, 0); |
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29 | } |
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30 | } |
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31 | |
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32 | /// Set this thread's heap id to 0. |
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33 | void chooseZero (void) { |
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34 | HL::Guard<LockType> g (heapLock); |
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35 | HeapType::setTidMap ((int) HL::CPUInfo::getThreadId() % MaxThreads, 0); |
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36 | } |
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37 | |
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38 | int findUnusedHeap (void) { |
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39 | |
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40 | HL::Guard<LockType> g (heapLock); |
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41 | |
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42 | unsigned int tid_original = HL::CPUInfo::getThreadId(); |
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43 | unsigned int tid = tid_original % HeapType::MaxThreads; |
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44 | |
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45 | int i = 0; |
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46 | while ((i < HeapType::MaxHeaps) && (HeapType::getInusemap(i))) |
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47 | i++; |
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48 | if (i >= HeapType::MaxHeaps) { |
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49 | // Every heap is in use: pick heap one. |
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50 | i = 0; |
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51 | } |
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52 | |
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53 | HeapType::setInusemap (i, 1); |
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54 | HeapType::setTidMap (tid, i); |
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55 | |
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56 | return i; |
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57 | } |
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58 | |
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59 | void releaseHeap (void) { |
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60 | // Decrement the ref-count on the current heap. |
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61 | |
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62 | HL::Guard<LockType> g (heapLock); |
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63 | |
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64 | // Statically ensure that the number of threads is a power of two. |
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65 | enum { VerifyPowerOfTwo = 1 / ((HeapType::MaxThreads & ~(HeapType::MaxThreads-1))) }; |
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66 | |
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67 | int tid = HL::CPUInfo::getThreadId() & (HeapType::MaxThreads - 1); |
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68 | int heapIndex = HeapType::getTidMap (tid); |
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69 | |
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70 | HeapType::setInusemap (heapIndex, 0); |
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71 | |
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72 | // Prevent underruns (defensive programming). |
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73 | |
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74 | if (HeapType::getInusemap (heapIndex) < 0) { |
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75 | HeapType::setInusemap (heapIndex, 0); |
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76 | } |
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77 | } |
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78 | |
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79 | |
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80 | private: |
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81 | |
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82 | // Disable copying. |
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83 | |
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84 | HeapManager (const HeapManager&); |
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85 | HeapManager& operator= (const HeapManager&); |
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86 | |
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87 | /// The lock, to ensure mutual exclusion. |
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88 | LockType heapLock; |
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89 | }; |
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90 | |
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91 | }; |
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92 | |
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93 | #endif |
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