[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> |
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| 8 | |
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| 9 | #if !defined(_WIN32) |
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| 10 | #include <pthread.h> |
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| 11 | #endif |
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| 12 | |
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| 13 | #if defined(__SVR4) // Solaris |
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| 14 | extern "C" unsigned int lwp_self(void); |
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| 15 | #endif |
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| 16 | |
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| 17 | /* |
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| 18 | |
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| 19 | A ThreadHeap comprises NumHeaps "per-thread" heaps. |
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| 20 | |
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| 21 | To pick a per-thread heap, the current thread id is hashed (mod NumHeaps). |
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| 22 | |
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| 23 | malloc gets memory from its hashed per-thread heap. |
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| 24 | free returns memory to its hashed per-thread heap. |
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| 25 | |
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| 26 | (This allows the per-thread heap to determine the return |
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| 27 | policy -- 'pure private heaps', 'private heaps with ownership', |
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| 28 | etc.) |
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| 29 | |
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| 30 | NB: We assume that the thread heaps are 'locked' as needed. */ |
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| 31 | |
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| 32 | namespace HL { |
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| 33 | |
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| 34 | template <int NumHeaps, class PerThreadHeap> |
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| 35 | class ThreadHeap : public PerThreadHeap { |
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| 36 | public: |
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| 37 | |
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| 38 | inline void * malloc (size_t sz) { |
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| 39 | int tid = getThreadId() % NumHeaps; |
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| 40 | assert (tid >= 0); |
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| 41 | assert (tid < NumHeaps); |
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| 42 | return getHeap(tid)->malloc (sz); |
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| 43 | } |
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| 44 | |
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| 45 | inline void free (void * ptr) { |
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| 46 | int tid = getThreadId() % NumHeaps; |
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| 47 | assert (tid >= 0); |
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| 48 | assert (tid < NumHeaps); |
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| 49 | getHeap(tid)->free (ptr); |
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| 50 | } |
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| 51 | |
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| 52 | inline size_t getSize (void * ptr) { |
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| 53 | int tid = getThreadId() % NumHeaps; |
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| 54 | assert (tid >= 0); |
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| 55 | assert (tid < NumHeaps); |
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| 56 | return getHeap(tid)->getSize (ptr); |
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| 57 | } |
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| 58 | |
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| 59 | |
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| 60 | private: |
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| 61 | |
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| 62 | // Access the given heap within the buffer. |
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| 63 | inline PerThreadHeap * getHeap (int index) { |
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| 64 | assert (index >= 0); |
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| 65 | assert (index < NumHeaps); |
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| 66 | return &ptHeaps[index]; |
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| 67 | } |
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| 68 | |
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| 69 | // Get a suitable thread id number. |
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| 70 | inline static volatile int getThreadId (void); |
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| 71 | |
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| 72 | PerThreadHeap ptHeaps[NumHeaps]; |
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| 73 | |
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| 74 | }; |
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| 75 | |
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| 76 | } |
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| 77 | |
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| 78 | |
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| 79 | // A platform-dependent way to get a thread id. |
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| 80 | |
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| 81 | // Include the necessary platform-dependent crud. |
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| 82 | #if defined(WIN32) || defined(__WIN32__) || defined(_WIN32) |
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| 83 | #ifndef WIN32 |
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| 84 | #define WIN32 1 |
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| 85 | #endif |
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| 86 | #include <windows.h> |
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| 87 | #include <process.h> |
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| 88 | #endif |
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| 89 | |
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| 90 | template <int NumHeaps, class PerThreadHeap> |
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| 91 | inline volatile int |
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| 92 | HL::ThreadHeap<NumHeaps, PerThreadHeap>::getThreadId (void) { |
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| 93 | #if defined(WIN32) |
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| 94 | // It looks like thread id's are always multiples of 4, so... |
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| 95 | int tid = GetCurrentThreadId() >> 2; |
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| 96 | // Now hash in some of the first bits. |
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| 97 | // return (tid & ~(1024-1)) ^ tid; |
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| 98 | return tid; |
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| 99 | #endif |
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| 100 | #if defined(__BEOS__) |
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| 101 | return find_thread(0); |
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| 102 | #endif |
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| 103 | #if defined(__linux) |
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| 104 | // Consecutive thread id's in Linux are 1024 apart; |
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| 105 | // dividing off the 1024 gives us an appropriate thread id. |
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| 106 | return (int) pthread_self() >> 10; // (>> 10 = / 1024) |
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| 107 | #endif |
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| 108 | #if defined(__SVR4) |
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| 109 | // printf ("lwp_self = %d\n", (int) lwp_self()); |
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| 110 | return (int) lwp_self(); |
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| 111 | #endif |
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| 112 | #if defined(__APPLE__) |
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| 113 | return (int) pthread_self(); |
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| 114 | #endif |
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| 115 | #if defined(POSIX) |
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| 116 | return (int) pthread_self(); |
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| 117 | #endif |
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| 118 | #if USE_SPROC |
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| 119 | // This hairiness has the same effect as calling getpid(), |
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| 120 | // but it's MUCH faster since it avoids making a system call |
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| 121 | // and just accesses the sproc-local data directly. |
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| 122 | int pid = (int) PRDA->sys_prda.prda_sys.t_pid; |
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| 123 | return pid; |
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| 124 | #endif |
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| 125 | } |
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| 126 | |
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| 127 | |
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| 128 | #endif |
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