File: write_in_reader_lock.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 (36 lines) | stat: -rw-r--r-- 960 bytes parent folder | download | duplicates (29) 
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
 
// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
#include "test.h"

pthread_rwlock_t rwlock;
int GLOB;

void *Thread1(void *p) {
  (void)p;
  pthread_rwlock_rdlock(&rwlock);
  barrier_wait(&barrier);
  // Write under reader lock.
  GLOB++;
  pthread_rwlock_unlock(&rwlock);
  return 0;
}

int main(int argc, char *argv[]) {
  barrier_init(&barrier, 2);
  pthread_rwlock_init(&rwlock, NULL);
  pthread_rwlock_rdlock(&rwlock);
  pthread_t t;
  pthread_create(&t, 0, Thread1, 0);
  volatile int x = GLOB;
  (void)x;
  pthread_rwlock_unlock(&rwlock);
  barrier_wait(&barrier);
  pthread_join(t, 0);
  pthread_rwlock_destroy(&rwlock);
  return 0;
}

// CHECK: WARNING: ThreadSanitizer: data race
// CHECK:   Write of size 4 at {{.*}} by thread T1{{.*}}:
// CHECK:     #0 Thread1(void*) {{.*}}write_in_reader_lock.cpp:12
// CHECK:   Previous read of size 4 at {{.*}} by main thread{{.*}}:
// CHECK:     #0 main {{.*}}write_in_reader_lock.cpp:23