[tor-bugs] #17724 [Tor]: Unreliable rend_cache_purge test

[Tor Bug Tracker & Wiki]

#17724: Unreliable rend_cache_purge test
--------------------------------------+------------------------------------
 Reporter:  cypherpunks               |          Owner:
     Type:  defect                    |         Status:  needs_review
 Priority:  Medium                    |      Milestone:  Tor: 0.2.8.x-final
Component:  Tor                       |        Version:  Tor: unspecified
 Severity:  Minor                     |     Resolution:
 Keywords:  TorCoreTeam201512, tests  |  Actual Points:
Parent ID:                            |         Points:
  Sponsor:                            |
--------------------------------------+------------------------------------
Changes (by teor):

 * keywords:   => TorCoreTeam201512, tests
 * status:  new => needs_review
 * milestone:   => Tor: 0.2.8.x-final


Comment:

 Replying to [ticket:17724 cypherpunks]:
 > The `test_rend_cache_purge` function contains an assertion which
 verifies that the internal strmap does not change after a purge
 (`src/test/test_rendcache.c:1044` on
 0a701e537778ac9da31049f4efebf7cb2bf9c285).
 >
 > However, the `rend_cache_purge` function frees the internal strmap and
 allocates a new one. This turns the assertion in a check whether memory
 allocation returns the same address as was just freed. The C11 standard
 mentions that a previous call to `free` is synchronized with a call to
 `malloc` [0].
 > ...
 > I am suggesting to remove the assertion because it verifies behavior
 that does not affect normal operation and (in my case) interferes with
 testing.

 Relying on the internals of malloc in unit tests is unhelpful.

 Please see my branch bug17724 in https://github.com/teor2345/tor.git

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/17724#comment:1>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online