[PING] RFR: JDK-8152690: main thread does not have native thread name
Yasumasa Suenaga
yasuenag at gmail.com
Mon Apr 11 09:25:29 UTC 2016
PING: Could you review and sponsor it?
> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.01/
Thanks,
Yasumasa
On 2016/03/31 8:49, Yasumasa Suenaga wrote:
> Thanks Robbin,
>
> I'm waiting a sponsor and more reviewer :-)
>
> Yasumasa
>
> 2016/03/31 5:58 "Robbin Ehn" <robbin.ehn at oracle.com <mailto:robbin.ehn at oracle.com>>:
>
> FYI: I'm not a Reviewer.
>
> /Robbin
>
> On 03/30/2016 10:55 PM, Robbin Ehn wrote:
>
> Thanks, looks good.
>
> /Robbin
>
> On 03/30/2016 03:47 PM, Yasumasa Suenaga wrote:
>
> Hi,
>
> I uploaded new webrev.
> Could you review it?
>
> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.01/
>
>
> Thanks,
>
> Yasumasa
>
>
> On 2016/03/30 19:10, Robbin Ehn wrote:
>
> Hi,
>
> On 03/30/2016 11:41 AM, Yasumasa Suenaga wrote:
>
> Hi Robbin,
>
> 2016/03/30 18:22 "Robbin Ehn" <robbin.ehn at oracle.com <mailto:robbin.ehn at oracle.com>
> <mailto:robbin.ehn at oracle.com <mailto:robbin.ehn at oracle.com>>>:
> >
> > Hi Yasumasa,
> >
> >
> > On 03/25/2016 12:48 AM, Yasumasa Suenaga wrote:
> >>
> >> Hi Robbin,
> >> 2016/03/25 1:51 "Robbin Ehn" <robbin.ehn at oracle.com <mailto:robbin.ehn at oracle.com>
> <mailto:robbin.ehn at oracle.com <mailto:robbin.ehn at oracle.com>>
> >> <mailto:robbin.ehn at oracle.com <mailto:robbin.ehn at oracle.com> <mailto:robbin.ehn at oracle.com <mailto:robbin.ehn at oracle.com>>>>:
> >>
> >> >
> >> > Hi Yasumasa,
> >> >
> >> > I'm not sure why you don't set it:
> >> >
> >> > diff -r ded6ef79c770 src/share/vm/runtime/thread.cpp
> >> > --- a/src/share/vm/runtime/thread.cpp Thu Mar 24 13:09:16 2016
> +0000
> >> > +++ b/src/share/vm/runtime/thread.cpp Thu Mar 24 17:40:09 2016
> +0100
> >> > @@ -3584,6 +3584,7 @@
> >> > JavaThread* main_thread = new JavaThread();
> >> > main_thread->set_thread_state(_thread_in_vm);
> >> > main_thread->initialize_thread_current();
> >> > + main_thread->set_native_thread_name("main");
> >> > // must do this before set_active_handles
> >> > main_thread->record_stack_base_and_size();
> >> >
> main_thread->set_active_handles(JNIHandleBlock::allocate_block());
> >> >
> >> > here instead? Am I missing something?
> >>
> >> Native thread name is the same to thread name in Thread class.
> >> It is set in c'tor in Thread or setName().
> >> If you create new thread in Java app, native thread name will be
> set at
> >> startup. However, main thread is already starte in VM.
> >> Thread name for "main" is set in create_initial_thread().
> >> I think that the place of setting thrrad name should be the same.
> >
> >
> > Yes, I see your point. But then something like this is nicer, no?
> >
> > --- a/src/share/vm/runtime/thread.cpp Tue Mar 29 09:43:05 2016
> +0200
> > +++ b/src/share/vm/runtime/thread.cpp Wed Mar 30 10:51:12 2016
> +0200
> > @@ -981,6 +981,7 @@
> > // Creates the initial Thread
> > static oop create_initial_thread(Handle thread_group, JavaThread*
> thread,
> > TRAPS) {
> > + static const char* initial_thread_name = "main";
> > Klass* k =
> SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true,
> CHECK_NULL);
> > instanceKlassHandle klass (THREAD, k);
> > instanceHandle thread_oop =
> klass->allocate_instance_handle(CHECK_NULL);
> > @@ -988,8 +989,10 @@
> > java_lang_Thread::set_thread(thread_oop(), thread);
> > java_lang_Thread::set_priority(thread_oop(), NormPriority);
> > thread->set_threadObj(thread_oop());
> > -
> > - Handle string = java_lang_String::create_from_str("main",
> CHECK_NULL);
> > +
> > + thread->set_native_thread_name(initial_thread_name);
> > +
> > + Handle string =
> java_lang_String::create_from_str(initial_thread_name, CHECK_NULL);
> >
> > JavaValue result(T_VOID);
> > JavaCalls::call_special(&result, thread_oop,
>
> Okay, I will upload new webrev later.
>
>
> Thanks!
>
>
> >> > The launcher seem to name itself 'java' and naming this thread
> just
> >> > 'main' is confusing to me.
> >> >
> >> > E.g. so main thread of the process (and thus the process) is
> 'java' but
> >> > first JavaThread is 'main'.
> >>
> >> The native main thread in the process is not JavaThread. It is
> waiting
> >> for ending of Java main thread with pthread_join().
> >> set_native_thread_name() is for JavaThread. So I think that we do
> not
> >> need to call it for native main thread.
> >
> >
> > Not sure if we can change it anyhow, since we want java and native
> name to be the same and java thread name might have some dependents.
> >
> > The name is visible in e.g. /proc.
> >
> > $ ps H -C java -o 'pid tid comm' | head -4
> > PID TID COMMAND
> > 6423 6423 java
> > 6423 6424 main
> > 6423 6425 GC Thread#0
> >
> > It would be nice with something like 'Java Main Thread'.
>
> I do not think so.
> Native main thread might not be a Java launcher - e.g. Apache
> commons-daemon, JNI application, etc.
>
> If you want to change native main thread name, I think that we have to
> change Java launcher code.
> Should I include it in new webrev?
>
>
> No
>
> Thanks again!
>
> /Robbin
>
>
> Thanks,
>
> Yasumasa
>
> > Thanks
> >
> > /Robbin
> >
> >
> >>
> >> Thanks,
> >>
> >> Yasumasa
> >>
> >> > Thanks!
> >> >
> >> > /Robbin
> >> >
> >> > On 03/24/2016 03:26 PM, Yasumasa Suenaga wrote:
> >> > > Hi all,
> >> > >
> >> > > HotSpot for Linux will set thread name via
> pthread_setname_np().
> >> > > However, main thread does not have it.
> >> > >
> >> > > All JavaThread have native name, and main thread is
> JavaThread.
> >> > > For consistency, main thread should have native thread name.
> >> > >
> >> > > I uploaded a webrev. Could you review it?
> >> > >
> >> > > http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.00/
> >> > >
> >> > > I cannot access JPRT.
> >> > > So I need a sponsor.
> >> > >
> >> > >
> >> > > Thanks,
> >> > >
> >> > > Yasumasa
> >> > >
> >>
>
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