Instrumented program hangs at exit if one of the threads is running getline()

[ramosian-glider]

Originally reported on Google Code with ID 47

$ cat t.c
#include <pthread.h>
#include <stdio.h>

void *thread(void *unused) {
  char *line = NULL;
  size_t size;
  getline(&line, &size, stdin);
  return NULL;
}

int main() {
  pthread_t t;
  pthread_create(&t, NULL, thread, NULL);
  return 0;
}
$ clang t.c -o t -lpthread
$ ./t
(everything ok)
$ clang t.c -o t -lpthread -fsanitize=thread
% ./t
(hangs)

Reported by glider@google.com on 2014-02-06 11:59:54

[ramosian-glider]

This happens because TSan calls fflush(0) at program shutdown, while the child thread
is holding a lock on the file stream.
Dima's suggestion is to replace the call to fflush(0) with "fflush(stdout); fflush(stderr);"

Reported by glider@google.com on 2014-02-06 12:15:09

[ramosian-glider]

I don't see how I can make this test reliable enough to commit it.
Turns out that the program may exit before the call to getline(), and we can't synchronize
that call with the program exit, because getline() never ends.
I'm gonna submit the fix without this test.

Reported by glider@google.com on 2014-02-06 13:39:00

[ramosian-glider]

sleep(1) will help you to write the test
also it's not necessary for a test to fail 100% of time

Reported by dvyukov@google.com on 2014-02-06 13:46:00

[ramosian-glider]

Coped with an infinite loop in thread() instead of a sleep.
r200922 fixes the issue and r200923 adds the test.

Reported by glider@google.com on 2014-02-06 14:12:04

• Status changed: Fixed

[ramosian-glider]

Adding Project:ThreadSanitizer as part of GitHub migration.

Reported by glider@google.com on 2015-07-30 09:21:31

• Labels added: ProjectThreadSanitizer