[libvirt] [PATCH v2] [TCK] nwfilter: add a test case using concurrency

[Stefan Berger]

On 11/19/2010 02:09 PM, Eric Blake wrote:
> On 11/18/2010 04:49 AM, Stefan Berger wrote:
>> V2:
>>     - following Eric's suggestions from review of V1
>>     - all scripts started by the main script trap on signal 2 and clean up
>>     - the main program waits for all child processes to have terminated
>>     - the test now requires each child process to do 10 steps:
>>        - 1 VM start-destroy cycle is 1 step
>>        - 50 filter changes are considered 1 step
>>     - the test terminates after 3 minutes (in case the test system is
>> very slow / busy) with a bail out message
>>
>> Now that the existing scripts are cleaned up and my POSIX compliancy
>> shell-scripting skills have temporarily:-)  improved, I am now adding a
>> test case that exercises concurrency. The test case creates and destroys
>> 2 VMs concurrently as well as changes their referenced filters in a
>> tight loop. This kind of test previously uncovered
>>
>> - deadlocks in libvirt due to lock-ordering in the nwfilter subsystem
>> - libvirt termination bug in libaugeas due to doubly closed file
>> descriptors and the side effects
>>
>> All of these have been fixed recently.
>>
>> The test script is known to run in bash, dash and ksh shells.
> They are still Linux-specific (things like date +%s aren't required by
> POSIX), but so is the functionality we're testing, so no need to come up
> with an alternate timeout method.  I only have a couple of trivial nits:
>
>> +  # Test runs for a maximum of 3 minutes
>> +  now=`date +%s`
>> +  test_end=$(($now + 3 * 60))
>> +
>> +  while :;
>> +  do
>> +    # The logs give us the number of cycles the VMs were created
>> +    # and destroyed.
>> +    val=$(cat "${logvm1}" 2>/dev/null | tail -n 1)
> Useless use of cat.  val=$(tail -n1 "${logvm1}" 2>/dev/null)
>
>> +    val=$(cat "${logvm2}" 2>/dev/null | tail -n 1)
> Likewise.

Removed the cat's.
> ACK with that fixed.
>
Pushed.

    Stefan