[tor-bugs] #25113 [Core Tor/Tor]: monotonic_time unit test fail, 0.3.3.1-alpha debian armel

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#25113: monotonic_time unit test fail, 0.3.3.1-alpha debian armel
--------------------------+------------------------------------
 Reporter:  arma          |          Owner:  (none)
     Type:  defect        |         Status:  needs_information
 Priority:  Medium        |      Milestone:  Tor: 0.3.3.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.3.3.1-alpha
 Severity:  Normal        |     Resolution:
 Keywords:  tor-test      |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
--------------------------+------------------------------------
Changes (by dgoulet):

 * status:  new => needs_information
 * keywords:   => tor-test


Comment:

 Wow ok so there is literally a 4msec gap between the `nsecc1` and `msecc1`
 function call on armel.

 {{{
   nsecc1 = monotime_coarse_absolute_nsec();
   [usecc1 = monotime_coarse_absolute_usec();]
   msecc1 = monotime_coarse_absolute_msec();
 }}}

 So this test is doomed to fail on slow system because we get `nsecc1`
 before `msecc1` so shouldn't be `msecc1 >= nsecc1` instead?

 {{{
   tt_u64_op(msecc1, OP_LE, nsecc1 / 1000000 + 1);
   -> msecc1 <= nsecc1
 }}}

 Actually the whole set of checks between the `1` variables seems a bit
 weird, it assumes the clock gettime calls to be in the same msec range.

 Also, `clock_gettime()` is a vdso in ARM exported since Linux 4.1 so if
 the build machine has an older kernel, the time gaps can be bigger.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/25113#comment:1>
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