[176] | 1 | /* -*- C++ -*- */ |
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| 2 | |
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| 3 | #ifndef _THREADHEAP_H_ |
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| 4 | #define _THREADHEAP_H_ |
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| 5 | |
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| 6 | #include <assert.h> |
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| 7 | #include <new.h> |
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| 8 | |
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| 9 | /* |
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| 10 | |
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| 11 | A ThreadHeap comprises NumHeaps "per-thread" heaps. |
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| 12 | |
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| 13 | To pick a per-thread heap, the current thread id is hashed (mod NumHeaps). |
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| 14 | |
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| 15 | malloc gets memory from its hashed per-thread heap. |
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| 16 | free returns memory to its hashed per-thread heap. |
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| 17 | |
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| 18 | (This allows the per-thread heap to determine the return |
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| 19 | policy -- 'pure private heaps', 'private heaps with ownership', |
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| 20 | etc.) |
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| 21 | |
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| 22 | NB: We assume that the thread heaps are 'locked' as needed. */ |
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| 23 | |
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| 24 | |
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| 25 | template <int NumHeaps, class PerThreadHeap> |
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| 26 | class ThreadHeap : public PerThreadHeap { |
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| 27 | public: |
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| 28 | |
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| 29 | ThreadHeap (void) |
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| 30 | { |
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| 31 | } |
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| 32 | |
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| 33 | inline void * malloc (size_t sz) { |
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| 34 | int tid = getThreadId() % NumHeaps; |
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| 35 | return getHeap(tid)->malloc (sz); |
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| 36 | } |
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| 37 | |
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| 38 | inline void free (void * ptr) { |
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| 39 | int tid = getThreadId() % NumHeaps; |
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| 40 | getHeap(tid)->free (ptr); |
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| 41 | } |
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| 42 | |
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| 43 | |
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| 44 | private: |
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| 45 | |
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| 46 | // Access the given heap within the buffer. |
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| 47 | PerThreadHeap * getHeap (int index) { |
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| 48 | assert (index >= 0); |
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| 49 | assert (index < NumHeaps); |
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| 50 | return &ptHeaps[index]; |
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| 51 | } |
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| 52 | |
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| 53 | // Get a suitable thread id number. |
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| 54 | inline static volatile int getThreadId (void); |
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| 55 | |
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| 56 | PerThreadHeap ptHeaps[NumHeaps]; |
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| 57 | |
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| 58 | }; |
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| 59 | |
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| 60 | |
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| 61 | // A platform-dependent way to get a thread id. |
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| 62 | |
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| 63 | // Include the necessary platform-dependent crud. |
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| 64 | #if defined(WIN32) || defined(__WIN32__) || defined(_WIN32) |
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| 65 | #ifndef WIN32 |
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| 66 | #define WIN32 1 |
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| 67 | #endif |
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| 68 | #include <windows.h> |
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| 69 | #include <process.h> |
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| 70 | #endif |
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| 71 | |
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| 72 | template <int NumHeaps, class PerThreadHeap> |
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| 73 | inline volatile int |
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| 74 | ThreadHeap<NumHeaps, PerThreadHeap>::getThreadId (void) { |
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| 75 | #if WIN32 |
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| 76 | return GetCurrentThreadId(); |
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| 77 | #endif |
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| 78 | #if defined(__BEOS__) |
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| 79 | return find_thread(0); |
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| 80 | #endif |
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| 81 | #if defined(__linux) |
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| 82 | // Consecutive thread id's in Linux are 1024 apart; |
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| 83 | // dividing off the 1024 gives us an appropriate thread id. |
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| 84 | return (int) pthread_self() >> 10; // (>> 10 = / 1024) |
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| 85 | #endif |
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| 86 | #if defined(__SVR4) |
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| 87 | return (int) lwp_self(); |
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| 88 | #endif |
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| 89 | #if defined(POSIX) |
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| 90 | return (int) pthread_self(); |
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| 91 | #endif |
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| 92 | #if USE_SPROC |
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| 93 | // This hairiness has the same effect as calling getpid(), |
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| 94 | // but it's MUCH faster since it avoids making a system call |
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| 95 | // and just accesses the sproc-local data directly. |
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| 96 | int pid = (int) PRDA->sys_prda.prda_sys.t_pid; |
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| 97 | return pid; |
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| 98 | #endif |
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| 99 | } |
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| 100 | |
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| 101 | |
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| 102 | #endif |
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