RFR(s): 8149036: Add UL tracing for thread related events at os level

Coleen Phillimore coleen.phillimore at oracle.com
Mon Feb 22 23:09:45 UTC 2016


Oh, also, I am willing to sponsor this.
Thanks,
Coleen

On 2/22/16 5:45 PM, Coleen Phillimore wrote:
>
>
> On 2/22/16 3:53 PM, Coleen Phillimore wrote:
>>
>> Hi Thomas,
>> I think the logging conversion looks really good.  The errno stuff is 
>> very ugly though.  Can you call strerrno_r - the thread safe 
>> version?  I didn't see discussion around this.
>
> Hi Thomas, I was talking to Kim.  You should use strerror() and not 
> add this code to os.cpp. The rationale is in this bug:
>
> https://bugs.openjdk.java.net/browse/JDK-6223913
>
> It seems like the errors would have standard errno at this point and 
> wouldn't be susceptible to the race in strerror().
>
> +        log.warning("Failed to start thread - pthread_create failed 
> (%s) for attributes: %s.",
> +          os::errno_name(errno), 
> os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
>
> It seems the chance of a race creating different errno at this early 
> point in the jvm is very low.
>
> Coleen
>
>> Thanks,
>> Coleen
>>
>> On 2/22/16 11:54 AM, Thomas Stüfe wrote:
>>> Dear all,
>>>
>>> please take a look at this proposed addition to UL. This adds a 
>>> number of
>>> trace points to thread creation. In detail:
>>>
>>> - it traces thread creation and thread creation errors, including 
>>> pthread
>>> attributes (for Posix platforms)
>>> - it traces stack location and creation/removal of stack guard pages.
>>>
>>> This all was first AIX-only tracing, but I converted this to UL and 
>>> made it
>>> available on all platforms.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8149036
>>> Webrev:
>>> http://cr.openjdk.java.net/~stuefe/webrevs/8149036-add-tracing-for-thread-events/webrev.00/webrev/ 
>>>
>>>
>>> Note also that I added a helper function, os::errno_name(), which is 
>>> a very
>>> simple replacement for strerror() without its problems (thread safety,
>>> unwanted localizations...).
>>>
>>> What do you think?
>>>
>>> Kind Regards, Thomas
>>
>



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