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.
11 #include <linux/futex.h>
12 #include <sys/syscall.h>
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;
22 for (int i = 0; i < kRepeat; i++) {
24 int t = __atomic_load_n(&turn, __ATOMIC_ACQUIRE);
27 syscall(SYS_futex, &turn, FUTEX_WAIT, t, 0, 0, 0);
29 for (int j = 0; j < kSize; j++) {
31 ((volatile T*)&data[j])[0] = 1;
32 ((volatile T*)&data[j])[sizeof(T) == 8 ? 0 : 1] = 1;
34 T v0 = ((volatile T*)&data[j])[0];
35 T v1 = ((volatile T*)&data[j])[sizeof(T) == 8 ? 0 : 1];
40 __atomic_store_n(&turn, 1 - id, __ATOMIC_RELEASE);
41 syscall(SYS_futex, &turn, FUTEX_WAKE, 0, 0, 0, 0);
46 template<typename T, bool write>
49 pthread_create(&th, 0, thread<T, write>, (void*)1);
55 void testw(int 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>();
64 int main(int argc, char** argv) {
69 if (size != 1 && size != 2 && size != 4 && size != 8)
74 printf("%s%d\n", write ? "write" : "read", size);