llvm-project/compiler-rt/test/tsan/annotate_happens_before.cpp

42 lines
836 B
C++

// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
#include "test.h"
/*
Annotations usage example.
Tsan does not see synchronization in barrier_wait.
ANNOTATE_HAPPENS_BEFORE/AFTER communicate the synchronization to tsan
and prevent the race report.
*/
int Global;
void *Thread1(void *x) {
barrier_wait(&barrier);
ANNOTATE_HAPPENS_AFTER(&barrier);
Global++;
return NULL;
}
void *Thread2(void *x) {
Global--;
ANNOTATE_HAPPENS_BEFORE(&barrier);
barrier_wait(&barrier);
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, "DONE\n");
return 0;
}
// CHECK-NOT: WARNING: ThreadSanitizer: data race
// CHECK: DONE