[tor-bugs] #18025 [Tor]: test_util_touch_file is racy and *does* fail

[Tor Bug Tracker & Wiki]

#18025: test_util_touch_file is racy and *does* fail
------------------------+--------------------------
     Reporter:  weasel  |      Owner:
         Type:  defect  |     Status:  new
     Priority:  Medium  |  Milestone:
    Component:  Tor     |    Version:  Tor: 0.2.7.6
     Severity:  Normal  |   Keywords:
Actual Points:          |  Parent ID:
       Points:          |    Sponsor:
------------------------+--------------------------
 Tor's master has a broken test:

 https://jenkins.torproject.org/job/tor-debian-master-nightly-
 binaries/630/ARCHITECTURE=i386,SUITE=wily/console

 {{{
 00:30:38 util/get_avail_disk_space: OK
 00:30:38 util/touch_file:
 00:30:38   FAIL ../src/test/test_util.c:4615: assert(st.st_mtime OP_GE
 now): 1452299437 vs 1452299438
 00:30:38   [touch_file FAILED]
 00:30:38 util/pwdb: [forking] OK
 }}}

 from test_util.c:
 {{{
   const time_t now = time(NULL);
   struct stat st;
   write_bytes_to_file(fname, "abc", 3, 1);
   tt_int_op(0, OP_EQ, stat(fname, &st));
   tt_i64_op(st.st_mtime, OP_GE, now);
 }}}

 The test is flawed to begin with, there's no guarantee for how much or
 little time is between the time() call and the write().

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18025>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online