RFR: 8240222: [TESTBUG] gtest/jfr/test_networkUtilization.cpp failed when the number of tests is greater than or equal to 2

Tue Mar 10 11:37:25 UTC 2020

Thanks Markus.

Best regards,
Jia

在 2020/3/10 18:15, Markus Gronlund 写道:
> Hi Jia,
>
> Looks like it could work.
>
> Thanks
> Markus
>
> -----Original Message-----
> From: Jia Huang <huangjia at loongson.cn>
> Sent: den 10 mars 2020 02:30
> To: Markus Gronlund <markus.gronlund at oracle.com>
> Cc: hotspot-jfr-dev at openjdk.java.net; hotspot-dev at openjdk.java.net
> Subject: Re: RFR: 8240222: [TESTBUG] gtest/jfr/test_networkUtilization.cpp failed when the number of tests is greater than or equal to 2
>
> Thanks Markus.
>
> Could you give some comments or advice on this one:
> Webrev:  http://cr.openjdk.java.net/~jiahuang/8240222/webrev.00/ ?
>
> Best regards,
> Jia
>
> 在 2020/3/9 19:41, Markus Gronlund 写道:
>> The interface_id assigns a unique primary key for each interface.
>>
>> To support GTEST=REPEAT, I think the easiest way is to add a corresponding counter in the gtest itself that mirror the production code:
>>
>> That is, as an example, instead of the "add_interface("eth0", 1), that
>> hardcodes the traceid = 1, have it take a value from the corresponding
>> counter, i.e. "add_interface("eth0", next_id++)";
>>
>> Thanks
>> Markus
>>
>>
>>
>> -----Original Message-----
>> From: Jia Huang <huangjia at loongson.cn>
>> Sent: den 9 mars 2020 10:57
>> To: hotspot-dev at openjdk.java.net; hotspot-jfr-dev at openjdk.java.net
>> Subject: Re: RFR: 8240222: [TESTBUG]
>> gtest/jfr/test_networkUtilization.cpp failed when the number of tests
>> is greater than or equal to 2
>>
>> In addition, the static local variable "id" is assigned in the function of "new_entry", that is in share/jfr/periodic/jfrNetworkUtilization.cpp.
>>
>> ---------------------------------------------------------------
>> share/jfr/periodic/jfrNetworkUtilization.cpp
>>
>> static InterfaceEntry& new_entry(const NetworkInterface* iface,
>> GrowableArray<InterfaceEntry>* interfaces) {
>>      assert(iface != NULL, "invariant");
>>      assert(interfaces != NULL, "invariant");
>>
>>      // single threaded premise
>>      static traceid interface_id = 0;                       // this is
>> the static local variable
>>
>>      const char* name = iface->get_name();
>>      assert(name != NULL, "invariant");
>>
>>      InterfaceEntry entry;
>>      const size_t length = strlen(name);
>>      entry.name = NEW_C_HEAP_ARRAY(char, length + 1, mtInternal);
>>      strncpy(entry.name, name, length + 1);
>>      entry.id = ++interface_id;
>>      entry.bytes_in = iface->get_bytes_in();
>>      entry.bytes_out = iface->get_bytes_out();
>>      entry.written = false;
>>      return _interfaces->at(_interfaces->append(entry));
>> }
>> ---------------------------------------------------------------
>>
>> 在 2020/3/9 15:29, Jia Huang 写道:
>>> Haha, I'm also trying to email hotspot-jfr-dev.
>>> Thank you, David.
>>>
>>> 在 2020/3/9 13:03, David Holmes 写道:
>>>> Hi Jia,
>>>>
>>>> I see this is getting no response so have cc'd hotspot-jfr-dev as
>>>> they should have a better idea of how this gtest can and cannot be used.
>>>>
>>>> Just because the GTest framework supports "REPEAT" it doesn't mean
>>>> all tests can, or should, be repeatable.
>>>>
>>>> Cheers,
>>>> David
>>>>
>>>> On 29/02/2020 1:53 pm, Jia Huang wrote:
>>>>> Hi David,
>>>>>
>>>>> 在 2020/2/28 21:16, David Holmes 写道:
>>>>>> Hi Jia,
>>>>>>
>>>>>> On 28/02/2020 11:08 pm, Jia Huang wrote:
>>>>>>> Hi all,
>>>>>>>
>>>>>>> JBS: https://bugs.openjdk.java.net/browse/JDK-8240222
>>>>>>> Webrev: http://cr.openjdk.java.net/~jiahuang/8240222/webrev.00/
>>>>>>>
>>>>>>> gtest/jfr/test_networkUtilization.cpp failed when the number of
>>>>>>> tests is greater than or equal to 2.
>>>>>>> As shown in the following code, the test failed because "traceid
>>>>>>> id" is a static local variable.
>>>>>>> When the test runs a second time, "id" continues to grow,
>>>>>>> resulting in the return value of "i" being "_interfaces.end()".
>>>>>> Interesting! I'm not at all familiar with the details of gtest and
>>>>>> how it actually runs things. But I would expect that we have many
>>>>>> tests that rely on starting from a cleanly initialized VM state,
>>>>>> or test state, and so can't simply be repeated (it would be like
>>>>>> editing an arbitrary test and putting the body of main into a
>>>>>> for-loop!).
>>>>> I'm sorry that my last description may be a little incomplete.
>>>>> JfrTestNetworkUtilization is a group of tests,it includes four
>>>>> individual tests:
>>>>>      --JfrTestNetworkUtilization.RequestFunctionBasic_test_vm
>>>>>      --JfrTestNetworkUtilization.RequestFunctionMultiple_test_vm
>>>>>      --JfrTestNetworkUtilization.InterfaceRemoved_test_vm
>>>>>      --JfrTestNetworkUtilization.InterfaceReset_test_vm
>>>>>
>>>>> If you only run a individual test once, such as the following
>>>>> Testing, it still fails.
>>>>> The reason for the failure, as I said last time, is also because of
>>>>> static local variables.
>>>>> In the "RequestFunctionMultiple_test_vm" test, the sequence number
>>>>> of "eth0" is 2.
>>>>> However, the initial value of the static local variable "id" is 0.
>>>>>
>>>>> Testting:
>>>>>       --make run-test
>>>>> TEST=gtest:JfrTestNetworkUtilization.RequestFunctionMultiple_test_v
>>>>> m
>>>>> GTEST=REPEAT=1 CONF=release
>>>>>       --make run-test
>>>>> TEST=gtest:JfrTestNetworkUtilization.InterfaceRemoved_test_vm
>>>>> GTEST=REPEAT=1 CONF=release
>>>>>       --make run-test
>>>>> TEST=gtest:JfrTestNetworkUtilization.InterfaceReset_test_vm
>>>>> GTEST=REPEAT=1 CONF=release
>>>>>
>>>>>> So I'm not sure what the right way to fix this is:
>>>>>> - don't use REPEAT?
>>>>>> - declare the test as not repeatable somehow?
>>>>>> - change the test to make it repeatable?
>>>>> In the doc/testing.md or doc/testing.html, Gtest keywords inclue
>>>>> "REPEAT", so I think this means that all GTEST tests should be able
>>>>> to use the "REPEAT parameter.
>>>>>
>>>>>
>>>>> Best regards,
>>>>> Jia
>>>>>
>>>>>
>>>>>> Cheers,
>>>>>> David
>>>>>>
>>>>>>> -----------------------------------------------------------------
>>>>>>> -----------
>>>>>>>
>>>>>>> test/hotspot/gtest/jfr/test_networkUtilization.cpp
>>>>>>>
>>>>>>> static const MockNetworkInterface& get_interface(traceid id) {
>>>>>>>      std::list<MockNetworkInterface>::const_iterator i =
>>>>>>> _interfaces.begin();
>>>>>>>      for (; i != _interfaces.end(); ++i) {
>>>>>>>        if (i->id == id) {
>>>>>>>          break;
>>>>>>>        }
>>>>>>>      }
>>>>>>>      return *i;
>>>>>>> }
>>>>>>> -----------------------------------------------------------------
>>>>>>> -----------
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Testing:
>>>>>>>        - make run-test TEST=gtest:JfrTestNetworkUtilization
>>>>>>> GTEST=REPEAT=2 CONF=server-release
>>>>>>>        - make run-test TEST=gtest:JfrTestNetworkUtilization
>>>>>>> GTEST=REPEAT=2 CONF=server-fastdebug
>>>>>>>
>>>>>>> Thanks a lot
>>>>>>>
>>>>>>> Best regards,
>>>>>>> Jia
>>>>>>>