1 // Synthetic benchmark for __tsan_read/write{1,2,4,8}. 2 // As compared to mini_bench_local/shared.cc this benchmark passes through 3 // deduplication logic (ContainsSameAccess). 4 // First argument is access size (1, 2, 4, 8). Second optional arg switches 5 // from writes to reads. 6 7 #include <pthread.h> 8 #include <stdlib.h> 9 #include <stdio.h> 10 #include <unistd.h> 11 #include <linux/futex.h> 12 #include <sys/syscall.h> 13 #include <sys/time.h> 14 15 template<typename T, bool write> 16 void* thread(void *arg) { 17 const int kSize = 2 << 10; 18 static volatile long data[kSize]; 19 static volatile long turn; 20 const int kRepeat = 1 << 17; 21 const int id = !!arg; 22 for (int i = 0; i < kRepeat; i++) { 23 for (;;) { 24 int t = __atomic_load_n(&turn, __ATOMIC_ACQUIRE); 25 if (t == id) 26 break; 27 syscall(SYS_futex, &turn, FUTEX_WAIT, t, 0, 0, 0); 28 } 29 for (int j = 0; j < kSize; j++) { 30 if (write) { 31 ((volatile T*)&data[j])[0] = 1; 32 ((volatile T*)&data[j])[sizeof(T) == 8 ? 0 : 1] = 1; 33 } else { 34 T v0 = ((volatile T*)&data[j])[0]; 35 T v1 = ((volatile T*)&data[j])[sizeof(T) == 8 ? 0 : 1]; 36 (void)v0; 37 (void)v1; 38 } 39 } 40 __atomic_store_n(&turn, 1 - id, __ATOMIC_RELEASE); 41 syscall(SYS_futex, &turn, FUTEX_WAKE, 0, 0, 0, 0); 42 } 43 return 0; 44 } 45 46 template<typename T, bool write> 47 void test() { 48 pthread_t th; 49 pthread_create(&th, 0, thread<T, write>, (void*)1); 50 thread<T, write>(0); 51 pthread_join(th, 0); 52 } 53 54 template<bool write> 55 void testw(int size) { 56 switch (size) { 57 case 1: return test<char, write>(); 58 case 2: return test<short, write>(); 59 case 4: return test<int, write>(); 60 case 8: return test<long long, write>(); 61 } 62 } 63 64 int main(int argc, char** argv) { 65 int size = 8; 66 bool write = true; 67 if (argc > 1) { 68 size = atoi(argv[1]); 69 if (size != 1 && size != 2 && size != 4 && size != 8) 70 size = 8; 71 } 72 if (argc > 2) 73 write = false; 74 printf("%s%d\n", write ? "write" : "read", size); 75 if (write) 76 testw<true>(size); 77 else 78 testw<false>(size); 79 return 0; 80 } 81