[lwip-devel] [bug #19167] tcp timeout handler can cause crash being invoked by sys_sem_wait()

[Dmitry Potapov]

Follow-up Comment #9, bug #19167 (project lwip):

Another problem Andreas Becker's proposal is that timeout handler can  be
invoked before the actual timeout expired. Here is what happens:
1. call to sys_mbox_fetch(), which remebers the current in
timeouts->remember
2. get blocked ona  semaphore or by sys_msleep()
3. do some job and add insert a new timeout handler
4. call to sys_mbox_fetch() again

In this case, timeout will be measured incorrectly from the moment #1. which
may be significantly earlier than #3 and as result the timeout will be
expired much earlier than it should.

So, it seems, the only reliable solution is to use 'expires' timestamp in the
timeout queue.

    _______________________________________________________

Reply to this item at:

  <http://savannah.nongnu.org/bugs/?19167>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.nongnu.org/