[b2a37b0] | 1 | #include "processor_list.hpp" |
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| 2 | |
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| 3 | #include <iostream> |
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| 4 | #include <string> |
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| 5 | #include <thread> |
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| 6 | |
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| 7 | unsigned num() { |
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| 8 | return 0x1000000; |
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| 9 | } |
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| 10 | |
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| 11 | // Barrier from |
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| 12 | class barrier_t { |
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| 13 | public: |
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| 14 | barrier_t(size_t total) |
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| 15 | : waiting(0) |
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| 16 | , total(total) |
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| 17 | {} |
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| 18 | |
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| 19 | void wait(unsigned) { |
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| 20 | size_t target = waiting++; |
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| 21 | target = (target - (target % total)) + total; |
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| 22 | while(waiting < target) |
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[7f5683e] | 23 | Pause(); |
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[b2a37b0] | 24 | |
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| 25 | assert(waiting < (1ul << 60)); |
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| 26 | } |
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| 27 | |
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| 28 | private: |
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| 29 | std::atomic<size_t> waiting; |
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| 30 | size_t total; |
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| 31 | }; |
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| 32 | |
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| 33 | class Random { |
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| 34 | private: |
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| 35 | unsigned int seed; |
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| 36 | public: |
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| 37 | Random(int seed) { |
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| 38 | this->seed = seed; |
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| 39 | } |
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| 40 | |
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| 41 | /** returns pseudorandom x satisfying 0 <= x < n. **/ |
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| 42 | unsigned int next() { |
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| 43 | seed ^= seed << 6; |
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| 44 | seed ^= seed >> 21; |
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| 45 | seed ^= seed << 7; |
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| 46 | return seed; |
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| 47 | } |
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| 48 | }; |
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| 49 | |
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| 50 | //------------------- |
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| 51 | |
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| 52 | struct processor { |
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| 53 | unsigned id; |
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| 54 | }; |
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| 55 | |
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| 56 | // Stage 1 |
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| 57 | // Make sure that the early registration works correctly |
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| 58 | // Registration uses a different process if the act of |
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| 59 | // registering the processor makes it the highest processor count |
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| 60 | // seen yet. |
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| 61 | void stage1(unsigned nthread, unsigned repeats) { |
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| 62 | const int n = repeats; |
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| 63 | const int nproc = 10; |
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| 64 | |
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| 65 | // List being tested |
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| 66 | processor_list list; |
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| 67 | |
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| 68 | // Barrier for synchronization |
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| 69 | barrier_t barrier(nthread + 1); |
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| 70 | |
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| 71 | // Seen values to detect duplicattion |
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| 72 | std::atomic<processor *> ids[nthread * nproc]; |
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| 73 | for(auto & i : ids) { |
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| 74 | i = nullptr; |
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| 75 | } |
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| 76 | |
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| 77 | // Can't pass VLA to lambda |
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| 78 | std::atomic<processor *> * idsp = ids; |
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| 79 | |
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| 80 | // Threads which will run the code |
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| 81 | std::thread * threads[nthread]; |
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| 82 | unsigned i = 1; |
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| 83 | for(auto & t : threads) { |
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| 84 | // Each thread will try to register a processor then add it to the |
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| 85 | // list of registerd processor |
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| 86 | t = new std::thread([&list, &barrier, idsp, n](unsigned tid){ |
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| 87 | processor proc[nproc]; |
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| 88 | for(int i = 0; i < n; i++) { |
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| 89 | for(auto & p : proc) { |
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| 90 | // Register the thread |
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| 91 | p.id = list.doregister(&p); |
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| 92 | } |
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| 93 | |
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| 94 | for(auto & p : proc) { |
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| 95 | // Make sure no one got this id before |
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| 96 | processor * prev = idsp[p.id].exchange(&p); |
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| 97 | assert(nullptr == prev); |
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| 98 | |
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| 99 | // Make sure id is still consistend |
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| 100 | assert(&p == list.get(p.id)); |
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| 101 | } |
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| 102 | |
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| 103 | // wait for round to finish |
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| 104 | barrier.wait(tid); |
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| 105 | |
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| 106 | // wait for reset |
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| 107 | barrier.wait(tid); |
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| 108 | } |
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| 109 | }, i++); |
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| 110 | } |
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| 111 | |
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| 112 | for(int i = 0; i < n; i++) { |
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| 113 | //Wait for round to finish |
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| 114 | barrier.wait(0); |
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| 115 | |
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| 116 | // Reset list |
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| 117 | list.reset(); |
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| 118 | |
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| 119 | std::cout << i << "\r"; |
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| 120 | |
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| 121 | // Reset seen values |
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| 122 | for(auto & i : ids) { |
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| 123 | i = nullptr; |
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| 124 | } |
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| 125 | |
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| 126 | // Start next round |
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| 127 | barrier.wait(0); |
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| 128 | } |
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| 129 | |
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| 130 | for(auto t : threads) { |
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| 131 | t->join(); |
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| 132 | delete t; |
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| 133 | } |
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| 134 | } |
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| 135 | |
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| 136 | // Stage 2 |
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| 137 | // Check that once churning starts, registration is still consistent. |
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| 138 | void stage2(unsigned nthread, unsigned repeats) { |
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| 139 | // List being tested |
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| 140 | processor_list list; |
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| 141 | |
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| 142 | // Threads which will run the code |
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| 143 | std::thread * threads[nthread]; |
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| 144 | unsigned i = 1; |
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| 145 | for(auto & t : threads) { |
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| 146 | // Each thread will try to register a few processors and |
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| 147 | // unregister them, making sure that the registration is |
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| 148 | // consistent |
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| 149 | t = new std::thread([&list, repeats](unsigned tid){ |
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| 150 | processor procs[10]; |
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| 151 | for(unsigned i = 0; i < repeats; i++) { |
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| 152 | // register the procs and note the id |
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| 153 | for(auto & p : procs) { |
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| 154 | p.id = list.doregister(&p); |
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| 155 | } |
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| 156 | |
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| 157 | if(1 == tid) std::cout << i << "\r"; |
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| 158 | |
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| 159 | // check the id is still consistent |
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| 160 | for(const auto & p : procs) { |
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| 161 | assert(&p == list.get(p.id)); |
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| 162 | } |
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| 163 | |
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| 164 | // unregister and check the id is consistent |
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| 165 | for(const auto & p : procs) { |
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| 166 | assert(&p == list.unregister(p.id)); |
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| 167 | } |
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| 168 | } |
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| 169 | }, i++); |
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| 170 | } |
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| 171 | |
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| 172 | for(auto t : threads) { |
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| 173 | t->join(); |
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| 174 | delete t; |
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| 175 | } |
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| 176 | } |
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| 177 | |
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| 178 | bool is_writer(); |
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| 179 | |
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| 180 | // Stage 3 |
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| 181 | // Check that the reader writer lock works. |
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| 182 | void stage3(unsigned nthread, unsigned repeats) { |
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| 183 | // List being tested |
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| 184 | processor_list list; |
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| 185 | |
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| 186 | size_t before = 0; |
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| 187 | |
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| 188 | std::unique_ptr<size_t> after( new size_t(0) ); |
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| 189 | |
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| 190 | std::atomic<bool> done ( false ); |
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| 191 | |
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| 192 | // Threads which will run the code |
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| 193 | std::thread * threads[nthread]; |
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| 194 | unsigned i = 1; |
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| 195 | for(auto & t : threads) { |
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| 196 | // Each thread will try to register a few processors and |
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| 197 | // unregister them, making sure that the registration is |
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| 198 | // consistent |
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| 199 | t = new std::thread([&list, repeats, &before, &after, &done](unsigned tid){ |
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| 200 | Random rng(tid); |
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| 201 | processor proc; |
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| 202 | proc.id = list.doregister(&proc); |
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| 203 | while(!done) { |
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| 204 | |
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| 205 | if( (rng.next() % 100) == 0 ) { |
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| 206 | auto r = list.write_lock(); |
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| 207 | |
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| 208 | auto b = before++; |
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| 209 | |
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| 210 | std::cout << b << "\r"; |
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| 211 | |
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| 212 | (*after)++; |
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| 213 | |
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| 214 | if(b >= repeats) done = true; |
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| 215 | |
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| 216 | list.write_unlock(r); |
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| 217 | } |
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| 218 | else { |
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| 219 | list.read_lock(proc.id); |
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| 220 | assert(before == *after); |
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| 221 | list.read_unlock(proc.id); |
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| 222 | } |
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| 223 | |
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| 224 | } |
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| 225 | |
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| 226 | list.unregister(proc.id); |
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| 227 | }, i++); |
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| 228 | } |
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| 229 | |
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| 230 | for(auto t : threads) { |
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| 231 | t->join(); |
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| 232 | delete t; |
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| 233 | } |
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| 234 | } |
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| 235 | |
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| 236 | int main(int argc, char * argv[]) { |
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| 237 | |
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| 238 | unsigned nthreads = 1; |
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| 239 | if( argc >= 3 ) { |
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| 240 | size_t idx; |
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| 241 | nthreads = std::stoul(argv[2], &idx); |
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| 242 | assert('\0' == argv[2][idx]); |
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| 243 | } |
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| 244 | |
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| 245 | unsigned repeats = 100; |
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| 246 | if( argc >= 2 ) { |
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| 247 | size_t idx; |
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| 248 | repeats = std::stoul(argv[1], &idx); |
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| 249 | assert('\0' == argv[1][idx]); |
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| 250 | } |
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| 251 | |
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| 252 | processor_list::check_cache_line_size(); |
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| 253 | |
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| 254 | std::cout << "Running " << repeats << " repetitions on " << nthreads << " threads" << std::endl; |
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| 255 | std::cout << "Checking registration - early" << std::endl; |
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| 256 | stage1(nthreads, repeats); |
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| 257 | std::cout << "Done " << std::endl; |
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| 258 | |
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| 259 | std::cout << "Checking registration - churn" << std::endl; |
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| 260 | stage2(nthreads, repeats); |
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| 261 | std::cout << "Done " << std::endl; |
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| 262 | |
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| 263 | std::cout << "Checking RW lock " << std::endl; |
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| 264 | stage3(nthreads, repeats); |
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| 265 | std::cout << "Done " << std::endl; |
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| 266 | |
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| 267 | |
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| 268 | return 0; |
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| 269 | } |
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