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| // 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.
If the compiler does not support __has_feature macro, then you can build with
CFLAGS="-fsanitize=thread -DTHREAD_SANITIZER" and then use
#ifdef THREAD_SANITIZER to enabled annotations.
*/
#if defined(__has_feature) && __has_feature(thread_sanitizer)
# define ANNOTATE_HAPPENS_BEFORE(addr) \
AnnotateHappensBefore(__FILE__, __LINE__, (void*)(addr))
# define ANNOTATE_HAPPENS_AFTER(addr) \
AnnotateHappensAfter(__FILE__, __LINE__, (void*)(addr))
extern "C" void AnnotateHappensBefore(const char *f, int l, void *addr);
extern "C" void AnnotateHappensAfter(const char *f, int l, void *addr);
#else
# define ANNOTATE_HAPPENS_BEFORE(addr)
# define ANNOTATE_HAPPENS_AFTER(addr)
#endif
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
|