File: annotate_happens_before.cpp

package info (click to toggle)
swiftlang 6.0.3-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 2,519,992 kB
  • sloc: cpp: 9,107,863; ansic: 2,040,022; asm: 1,135,751; python: 296,500; objc: 82,456; f90: 60,502; lisp: 34,951; pascal: 19,946; sh: 18,133; perl: 7,482; ml: 4,937; javascript: 4,117; makefile: 3,840; awk: 3,535; xml: 914; fortran: 619; cs: 573; ruby: 573
file content (41 lines) | stat: -rw-r--r-- 836 bytes parent folder | download | duplicates (27) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
 
// 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