[176] | 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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