aligned_vs_unaligned_race.cpp
895 Bytes
// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
// Race between an aligned access and an unaligned access, which
// touches the same memory region.
#include "test.h"
#include <stdint.h>
uint64_t Global[2];
void *Thread1(void *x) {
Global[1]++;
barrier_wait(&barrier);
return NULL;
}
void *Thread2(void *x) {
barrier_wait(&barrier);
char *p1 = reinterpret_cast<char *>(&Global[0]);
struct __attribute__((packed, aligned(1))) u_uint64_t { uint64_t val; };
u_uint64_t *p4 = reinterpret_cast<u_uint64_t *>(p1 + 1);
(*p4).val++;
return NULL;
}
int main() {
barrier_init(&barrier, 2);
pthread_t t[2];
pthread_create(&t[0], NULL, Thread1, NULL);
pthread_create(&t[1], NULL, Thread2, NULL);
pthread_join(t[0], NULL);
pthread_join(t[1], NULL);
fprintf(stderr, "Pass\n");
// CHECK: ThreadSanitizer: data race
// CHECK: Pass
return 0;
}