blob: e61c5b8caac978787faafe2ad561a9ef7a64b70f [file] [log] [blame]
// RUN: %clang_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
#include "test.h"
// We want to establish the following sequence of accesses to X:
// - main thread writes X
// - thread2 reads X, this read happens-before the write in main thread
// - thread1 reads X, this read is concurrent with the write in main thread
// Write in main thread and read in thread1 should be detected as a race.
// Previously tsan replaced write by main thread with read by thread1,
// as the result the race was not detected.
volatile long X, Y, Z;
void *Thread1(void *x) {
Y = X;
return NULL;
void *Thread2(void *x) {
Z = X;
return NULL;
int main() {
barrier_init(&barrier, 2);
pthread_t t[2];
pthread_create(&t[0], 0, Thread1, 0);
X = 42;
pthread_create(&t[1], 0, Thread2, 0);
pthread_join(t[0], 0);
pthread_join(t[1], 0);
return 0;
// CHECK: WARNING: ThreadSanitizer: data race