RFR: JDK-8152690: main thread does not have native thread name
David Holmes
david.holmes at oracle.com
Tue Apr 26 02:16:00 UTC 2016
Hi Yasumasa, Kumar,
Turns out this change breaks the behaviour of the launcher in the case
that main() completes by throwing an exception.
What we have in the launcher is:
(*env)->CallStaticVoidMethod(env, mainClass, mainID, mainArgs);
ret = (*env)->ExceptionOccurred(env) == NULL ? 0 : 1;
LEAVE();
where LEAVE would have expanded to:
if ((*vm)->DetachCurrentThread(vm) != JNI_OK) { \
JLI_ReportErrorMessage(JVM_ERROR2); \
ret = 1; \
} \
if (JNI_TRUE) { \
(*vm)->DestroyJavaVM(vm); \
return ret; \
} \
so note that we are potentially calling DetachCurrentThread with an
exception pending - which is prohibited by JNI**, but which we actually
rely on for desired operation as DetachCurrentThread calls
thread->exit() which performs uncaught exception handling (ie it prints
the exception message and stacktrace) and then clears the exception!
(Hence DestroyJavaVM is not called with any pending exceptions.)
**JNI spec needs to be modified here.
With the current change we have now inserted the following at the start
of LEAVE:
SetNativeThreadName(env, "DestroyJavaVM"); \
if ((*env)->ExceptionOccurred(env)) { \
(*env)->ExceptionClear(env); \
} \
this has two unintended consequences:
1. SetNativeThreadName itself calls a number of JNI methods, with the
exception pending - which is not permitted. So straight away where we have:
NULL_CHECK(cls = FindBootStrapClass(env, "java/lang/Thread"));
FindBootStrapClass calls JVM_FindClassFromBootLoader, which make calls
using the VM's CHECK_NULL macro - which checks for a pending exception
(which it finds) and returns NULL. So the jli NULL_CHECK macro then
reports a JNI error:
Error: A JNI error has occurred, please check your installation and try
again
2. There is no longer an exception from main() for DetachCurrentThread
to report, so we exit with a return code of 1 as required, but don't
report the exception message/stacktrace.
I don't see a reasonable solution for this other than abandoning the
attempt to change the name from "main" to "DestroyJavaVM" - which if we
can't do, I question the utility of setting the name in the first place
(while it might be useful in some circumstances [when main() is running]
it will cause confusion in others [when main() has exited]).
David
-----
On 25/04/2016 3:47 PM, David Holmes wrote:
> Looks good to me.
>
> I'll sponsor this "tomorrow".
>
> Thanks,
> David
>
> On 23/04/2016 11:24 PM, Yasumasa Suenaga wrote:
>> Hi Kumar,
>>
>> Thank you for your comment!
>> I've fixed them and uploaded new webrev. Could you review again?
>>
>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.06/hotspot/
>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.06/jdk/
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>> On 2016/04/23 1:14, Kumar Srinivasan wrote:
>>>
>>> Also a couple of minor suggestions:
>>>
>>> - * Set native thread name as possible.
>>> + * Set native thread name if possible.
>>>
>>>
>>> + /*
>>> - * We can clear pending exception because exception at this point
>>> - * is not critical.
>>> + */
>>>
>>> + /*
>>> + * Clear non critical pending exceptions at this point.
>>> + */
>>>
>>> Thanks
>>> Kumar
>>>
>>>> Hi,
>>>>
>>>> This is in the wrong place:
>>>>
>>>> 1715 if ((*env)->ExceptionOccurred(env)) {
>>>> 1716 /*
>>>> 1717 * We can clear pending exception because exception at
>>>> this point
>>>> 1718 * is not critical.
>>>> 1719 */
>>>> 1720 (*env)->ExceptionClear(env);
>>>> 1721 }
>>>>
>>>> This above needs to be after
>>>> 391 SetNativeThreadName(env, "main");
>>>> 392
>>>>
>>>> Here is why, supposing 1704 through 1711, returns a NULL,
>>>> but have also encountered an exception. In which case
>>>> the method SetNativeThreadName will return to the caller, as
>>>> if nothing has happened, because NULL_CHECK simply checks for NULL
>>>> and returns to the caller. This will cause the caller to enter
>>>> the VM with exceptions.
>>>>
>>>> Kumar
>>>>
>>>>
>>>> On 4/22/2016 5:11 AM, Yasumasa Suenaga wrote:
>>>>> Hi David,
>>>>>
>>>>>> I don't think we need to report the exception, but can just ignore
>>>>>> it. Either way we have to clear the exception before continuing.
>>>>>
>>>>> I've fixed it in new webrev:
>>>>>
>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.05/hotspot/
>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.05/jdk/
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Yasumasa
>>>>>
>>>>>
>>>>> On 2016/04/22 15:33, David Holmes wrote:
>>>>>> On 22/04/2016 1:36 PM, Yasumasa Suenaga wrote:
>>>>>>> Hi all,
>>>>>>>
>>>>>>> I have uploaded webrev.04 as below.
>>>>>>> Could you review again?
>>>>>>>
>>>>>>> > - hotspot:
>>>>>>> >
>>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.04/hotspot/
>>>>>>
>>>>>> Looks fine.
>>>>>>
>>>>>>> >
>>>>>>> > - jdk:
>>>>>>> > http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.04/jdk/
>>>>>>
>>>>>> As per private email (but repeated here on the record) in java.c:
>>>>>>
>>>>>> 715 if ((*env)->ExceptionOccurred(env)) {
>>>>>> 1716 JLI_ReportExceptionDescription(env);
>>>>>> 1717 }
>>>>>>
>>>>>> I don't think we need to report the exception, but can just ignore
>>>>>> it. Either way we have to clear the exception before continuing.
>>>>>>
>>>>>> Thanks,
>>>>>> David
>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Yasumasa
>>>>>>>
>>>>>>> 2016/04/19 22:43 "Yasumasa Suenaga" <yasuenag at gmail.com
>>>>>>> <mailto:yasuenag at gmail.com>>:
>>>>>>> >
>>>>>>> > Hi David,
>>>>>>> >
>>>>>>> > Thank you for your comment.
>>>>>>> > I uploaded new webrev. Could you review again?
>>>>>>> >
>>>>>>> > - hotspot:
>>>>>>> >
>>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.04/hotspot/
>>>>>>> >
>>>>>>> > - jdk:
>>>>>>> > http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.04/jdk/
>>>>>>> >
>>>>>>> >
>>>>>>> >> That aside I'm not sure why you do this so late in the
>>>>>>> process, I
>>>>>>> would have done it immediately after here:
>>>>>>> >
>>>>>>> >
>>>>>>> > I think that native thread name ("main") should be set just
>>>>>>> before
>>>>>>> > main method call.
>>>>>>> > However, main thread is already started, so I moved it as you
>>>>>>> suggested.
>>>>>>> >
>>>>>>> >
>>>>>>> >> One thing I dislike about the current structure is that we
>>>>>>> have to
>>>>>>> go from char* to java.lang.String to call setNativeName which then
>>>>>>> calls
>>>>>>> JVM_SetNativeThreadName which converts the j.l.String back to a
>>>>>>> char* !
>>>>>>> >
>>>>>>> >
>>>>>>> > SoI proposed to export new JVM function to set native thread
>>>>>>> name with
>>>>>>> > const char *.
>>>>>>> >
>>>>>>> >
>>>>>>> > Thanks,
>>>>>>> >
>>>>>>> > Yasumasa
>>>>>>> >
>>>>>>> >
>>>>>>> >
>>>>>>> > On 2016/04/19 14:04, David Holmes wrote:
>>>>>>> >>
>>>>>>> >> Hi Yasumasa,
>>>>>>> >>
>>>>>>> >> Thanks for persevering with this to get it into the current
>>>>>>> form.
>>>>>>> Sorry I haven't been able to do a detailed review until now.
>>>>>>> >>
>>>>>>> >> On 19/04/2016 9:28 AM, Yasumasa Suenaga wrote:
>>>>>>> >>>
>>>>>>> >>> Hi Gerard,
>>>>>>> >>>
>>>>>>> >>> 2016/04/19 3:14 "Gerard Ziemski" <gerard.ziemski at oracle.com
>>>>>>> <mailto:gerard.ziemski at oracle.com>
>>>>>>> >>> <mailto:gerard.ziemski at oracle.com
>>>>>>> <mailto:gerard.ziemski at oracle.com>>>:
>>>>>>> >>> >
>>>>>>> >>> > hi Yasumasa,
>>>>>>> >>> >
>>>>>>> >>> > Nice work. I have 2 questions:
>>>>>>> >>> >
>>>>>>> >>> > ========
>>>>>>> >>> > File: java.c
>>>>>>> >>> >
>>>>>>> >>> > #1 Shouldn’t we be checking for
>>>>>>> “(*env)->ExceptionOccurred(env)”
>>>>>>> >>> after every single JNI call? In this example instead of
>>>>>>> NULL_CHECK,
>>>>>>> >>> should we be using CHECK_EXCEPTION_NULL_LEAVE macro?
>>>>>>> >>>
>>>>>>> >>> It is not critical if we encounter error at JNI function call
>>>>>>> because
>>>>>>> >>> we cannot set native thread name only.
>>>>>>> >>> So I think that we do not need to leave from launcher process.
>>>>>>> >>
>>>>>>> >>
>>>>>>> >> I agree we do not need to abort if an exception occurs (and in
>>>>>>> fact
>>>>>>> I don't think an exception is even possible from this code), but we
>>>>>>> should ensure any pending exception is cleared before any futher JNI
>>>>>>> calls might be made. Note that NULL_CHECK is already used
>>>>>>> extensively
>>>>>>> throughout the launcher code - so if this usage is wrong then it
>>>>>>> is all
>>>>>>> wrong! More on this code below ...
>>>>>>> >>
>>>>>>> >> Other comments:
>>>>>>> >>
>>>>>>> >> hotspot/src/share/vm/prims/jvm.cpp
>>>>>>> >>
>>>>>>> >> Please add a comment to the method now that you removed the
>>>>>>> internal
>>>>>>> comment:
>>>>>>> >>
>>>>>>> >> // Sets the native thread name for a JavaThread. If specifically
>>>>>>> >> // requested JNI-attached threads can also have their native
>>>>>>> name set;
>>>>>>> >> // otherwise we do not modify JNI-attached threads as it may
>>>>>>> interfere
>>>>>>> >> // with the application that created them.
>>>>>>> >>
>>>>>>> >> ---
>>>>>>> >>
>>>>>>> >> jdk/src/java.base/share/classes/java/lang/Thread.java
>>>>>>> >>
>>>>>>> >> Please add the following comments:
>>>>>>> >>
>>>>>>> >> + // Don't modify JNI-attached threads
>>>>>>> >> setNativeName(name, false);
>>>>>>> >>
>>>>>>> >> + // May be called directly via JNI or reflection (when
>>>>>>> permitted) to
>>>>>>> >> + // allow JNI-attached threads to set their native name
>>>>>>> >> private native void setNativeName(String name, boolean
>>>>>>> allowAttachedThread);
>>>>>>> >>
>>>>>>> >> ---
>>>>>>> >>
>>>>>>> >> jd/src/java.base/share/native/libjli/java.c
>>>>>>> >>
>>>>>>> >> 328 #define LEAVE() \
>>>>>>> >> 329 SetNativeThreadName(env, "DestroyJavaVM"); \
>>>>>>> >>
>>>>>>> >> I was going to suggest this be set later, but realized we have
>>>>>>> to be
>>>>>>> attached to do this and that happens inside DestroyJavaVM. :)
>>>>>>> >>
>>>>>>> >> + /* Set native thread name. */
>>>>>>> >> + SetNativeThreadName(env, "main");
>>>>>>> >>
>>>>>>> >> The comment is redundant given the name of the method. That
>>>>>>> aside
>>>>>>> I'm not sure why you do this so late in the process, I would have
>>>>>>> done
>>>>>>> it immediately after here:
>>>>>>> >>
>>>>>>> >> 386 if (!InitializeJVM(&vm, &env, &ifn)) {
>>>>>>> >> 387 JLI_ReportErrorMessage(JVM_ERROR1);
>>>>>>> >> 388 exit(1);
>>>>>>> >> 389 }
>>>>>>> >> + SetNativeThreadName(env, "main");
>>>>>>> >>
>>>>>>> >>
>>>>>>> >> + /**
>>>>>>> >> + * Set native thread name as possible.
>>>>>>> >> + */
>>>>>>> >>
>>>>>>> >> Other than the as->if change I'm unclear where the "possible"
>>>>>>> bit
>>>>>>> comes into play - why would it not be possible?
>>>>>>> >>
>>>>>>> >> 1705 NULL_CHECK(cls = FindBootStrapClass(env,
>>>>>>> "java/lang/Thread"));
>>>>>>> >> 1706 NULL_CHECK(currentThreadID =
>>>>>>> (*env)->GetStaticMethodID(env,
>>>>>>> cls,
>>>>>>> >> 1707 "currentThread",
>>>>>>> "()Ljava/lang/Thread;"));
>>>>>>> >> 1708 NULL_CHECK(currentThread =
>>>>>>> (*env)->CallStaticObjectMethod(env, cls,
>>>>>>> >> 1709 currentThreadID));
>>>>>>> >> 1710 NULL_CHECK(setNativeNameID = (*env)->GetMethodID(env,
>>>>>>> cls,
>>>>>>> >> 1711 "setNativeName",
>>>>>>> "(Ljava/lang/String;Z)V"));
>>>>>>> >> 1712 NULL_CHECK(nameString = (*env)->NewStringUTF(env,
>>>>>>> name));
>>>>>>> >> 1713 (*env)->CallVoidMethod(env, currentThread,
>>>>>>> setNativeNameID,
>>>>>>> >> 1714 nameString, JNI_TRUE);
>>>>>>> >>
>>>>>>> >> As above NULL_CHECK is fine here, but we should check for and
>>>>>>> clear
>>>>>>> any pending exception after CallVoidMethod.
>>>>>>> >>
>>>>>>> >> One thing I dislike about the current structure is that we
>>>>>>> have to
>>>>>>> go from char* to java.lang.String to call setNativeName which then
>>>>>>> calls
>>>>>>> JVM_SetNativeThreadName which converts the j.l.String back to a
>>>>>>> char* !
>>>>>>> Overall I wonder about the affect on startup cost. But if there
>>>>>>> is an
>>>>>>> issue we can revisit this.
>>>>>>> >>
>>>>>>> >> Thanks,
>>>>>>> >> David
>>>>>>> >> -----
>>>>>>> >>
>>>>>>> >>
>>>>>>> >>> > #2 Should the comment for “SetNativeThreadName” be “Set
>>>>>>> native
>>>>>>> thread
>>>>>>> >>> name if possible.” not "Set native thread name as possible.”?
>>>>>>> >>>
>>>>>>> >>> Sorry for my bad English :-)
>>>>>>> >>>
>>>>>>> >>> Thanks,
>>>>>>> >>>
>>>>>>> >>> Yasumasa
>>>>>>> >>>
>>>>>>> >>> > cheers
>>>>>>> >>> >
>>>>>>> >>> > > On Apr 16, 2016, at 4:29 AM, Yasumasa Suenaga
>>>>>>> <yasuenag at gmail.com <mailto:yasuenag at gmail.com>
>>>>>>> >>> <mailto:yasuenag at gmail.com <mailto:yasuenag at gmail.com>>> wrote:
>>>>>>> >>> > >
>>>>>>> >>> > > Hi David,
>>>>>>> >>> > >
>>>>>>> >>> > > I uploaded new webrev:
>>>>>>> >>> > >
>>>>>>> >>> > > - hotspot:
>>>>>>> >>> > >
>>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.03/hotspot/
>>>>>>> >>> > >
>>>>>>> >>> > > - jdk:
>>>>>>> >>> > >
>>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.03/jdk/
>>>>>>> >>> > >
>>>>>>> >>> > >
>>>>>>> >>> > >> it won't work unless you change the semantics of
>>>>>>> setName so I'm
>>>>>>> >>> not sure what you were thinking here. To take advantage of an
>>>>>>> arg
>>>>>>> taking
>>>>>>> >>> JVM_SetNativThreadName you would need to call it directly as
>>>>>>> no Java
>>>>>>> >>> code will call it . ???
>>>>>>> >>> > >
>>>>>>> >>> > > I added a flag for setting native thread name to
>>>>>>> JNI-attached
>>>>>>> thread.
>>>>>>> >>> > > This change can set native thread name if main thread
>>>>>>> changes to
>>>>>>> >>> JNI-attached thread.
>>>>>>> >>> > >
>>>>>>> >>> > >
>>>>>>> >>> > > Thanks,
>>>>>>> >>> > >
>>>>>>> >>> > > Yasumasa
>>>>>>> >>> > >
>>>>>>> >>> > >
>>>>>>> >>> > > On 2016/04/16 16:11, David Holmes wrote:
>>>>>>> >>> > >> On 16/04/2016 3:27 PM, Yasumasa Suenaga wrote:
>>>>>>> >>> > >>> Hi David,
>>>>>>> >>> > >>>
>>>>>>> >>> > >>>> That change in behaviour may be a problem, it could be
>>>>>>> considered a
>>>>>>> >>> > >>>> regression that setName stops setting the native thread
>>>>>>> main, even
>>>>>>> >>> > >>>> though we never really intended it to work in the
>>>>>>> first place.
>>>>>>> >>> :( Such
>>>>>>> >>> > >>>> a change needs to go through CCC.
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> I understood.
>>>>>>> >>> > >>> Can I send CCC request?
>>>>>>> >>> > >>> (I'm jdk 9 commiter, but I'm not employee at Oracle.)
>>>>>>> >>> > >>
>>>>>>> >>> > >> Sorry you can't file a CCC request, you would need a
>>>>>>> sponsor for
>>>>>>> >>> that. But at this stage I don't think I agree with the
>>>>>>> proposed change
>>>>>>> >>> because of the change in behaviour - there's no way to
>>>>>>> restore the
>>>>>>> >>> "broken" behaviour.
>>>>>>> >>> > >>
>>>>>>> >>> > >>> I want to continue to discuss about it on JDK-8154331
>>>>>>> [1].
>>>>>>> >>> > >>
>>>>>>> >>> > >> Okay we can do that.
>>>>>>> >>> > >>
>>>>>>> >>> > >>>
>>>>>>> >>> > >>>> Further, we expect the launcher to use the supported
>>>>>>> JNI
>>>>>>> >>> interface (as
>>>>>>> >>> > >>>> other processes would), not the internal JVM
>>>>>>> interface that
>>>>>>> >>> exists for
>>>>>>> >>> > >>>> the JDK sources to communicate with the JVM.
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> I think that we do not use JVM interface if we add new
>>>>>>> method in
>>>>>>> >>> > >>> LauncherHelper as below:
>>>>>>> >>> > >>> ----------------
>>>>>>> >>> > >>> diff -r f02139a1ac84
>>>>>>> >>> > >>>
>>>>>>> src/java.base/share/classes/sun/launcher/LauncherHelper.java
>>>>>>> >>> > >>> ---
>>>>>>> a/src/java.base/share/classes/sun/launcher/LauncherHelper.java
>>>>>>> >>> > >>> Wed Apr 13 14:19:30 2016 +0000
>>>>>>> >>> > >>> +++
>>>>>>> b/src/java.base/share/classes/sun/launcher/LauncherHelper.java
>>>>>>> >>> > >>> Sat Apr 16 11:25:53 2016 +0900
>>>>>>> >>> > >>> @@ -960,4 +960,8 @@
>>>>>>> >>> > >>> else
>>>>>>> >>> > >>> return md.toNameAndVersion() + " (" + loc
>>>>>>> + ")";
>>>>>>> >>> > >>> }
>>>>>>> >>> > >>> +
>>>>>>> >>> > >>> + static void setNativeThreadName(String name) {
>>>>>>> >>> > >>> + Thread.currentThread().setName(name);
>>>>>>> >>> > >>> + }
>>>>>>> >>> > >>
>>>>>>> >>> > >> You could also make that call via JNI directly, so not
>>>>>>> sure the
>>>>>>> >>> helper adds much here. But it won't work unless you change the
>>>>>>> semantics
>>>>>>> >>> of setName so I'm not sure what you were thinking here. To take
>>>>>>> >>> advantage of an arg taking JVM_SetNativThreadName you would
>>>>>>> need to
>>>>>>> call
>>>>>>> >>> it directly as no Java code will call it . ???
>>>>>>> >>> > >>
>>>>>>> >>> > >> David
>>>>>>> >>> > >> -----
>>>>>>> >>> > >>
>>>>>>> >>> > >>> }
>>>>>>> >>> > >>> diff -r f02139a1ac84
>>>>>>> src/java.base/share/native/libjli/java.c
>>>>>>> >>> > >>> --- a/src/java.base/share/native/libjli/java.c Wed
>>>>>>> Apr 13
>>>>>>> 14:19:30
>>>>>>> >>> > >>> 2016 +0000
>>>>>>> >>> > >>> +++ b/src/java.base/share/native/libjli/java.c Sat
>>>>>>> Apr 16
>>>>>>> 11:25:53
>>>>>>> >>> > >>> 2016 +0900
>>>>>>> >>> > >>> @@ -125,6 +125,7 @@
>>>>>>> >>> > >>> static void PrintUsage(JNIEnv* env, jboolean doXUsage);
>>>>>>> >>> > >>> static void ShowSettings(JNIEnv* env, char *optString);
>>>>>>> >>> > >>> static void ListModules(JNIEnv* env, char *optString);
>>>>>>> >>> > >>> +static void SetNativeThreadName(JNIEnv* env, char
>>>>>>> *name);
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> static void SetPaths(int argc, char **argv);
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> @@ -325,6 +326,7 @@
>>>>>>> >>> > >>> * mainThread.isAlive() to work as expected.
>>>>>>> >>> > >>> */
>>>>>>> >>> > >>> #define LEAVE() \
>>>>>>> >>> > >>> + SetNativeThreadName(env, "DestroyJavaVM"); \
>>>>>>> >>> > >>> do { \
>>>>>>> >>> > >>> if ((*vm)->DetachCurrentThread(vm) != JNI_OK)
>>>>>>> { \
>>>>>>> >>> > >>> JLI_ReportErrorMessage(JVM_ERROR2); \
>>>>>>> >>> > >>> @@ -488,6 +490,9 @@
>>>>>>> >>> > >>> mainArgs = CreateApplicationArgs(env, argv, argc);
>>>>>>> >>> > >>> CHECK_EXCEPTION_NULL_LEAVE(mainArgs);
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> + /* Set native thread name. */
>>>>>>> >>> > >>> + SetNativeThreadName(env, "main");
>>>>>>> >>> > >>> +
>>>>>>> >>> > >>> /* Invoke main method. */
>>>>>>> >>> > >>> (*env)->CallStaticVoidMethod(env, mainClass, mainID,
>>>>>>> mainArgs);
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> @@ -1686,6 +1691,22 @@
>>>>>>> >>> > >>> joptString);
>>>>>>> >>> > >>> }
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> +/**
>>>>>>> >>> > >>> + * Set native thread name as possible.
>>>>>>> >>> > >>> + */
>>>>>>> >>> > >>> +static void
>>>>>>> >>> > >>> +SetNativeThreadName(JNIEnv *env, char *name)
>>>>>>> >>> > >>> +{
>>>>>>> >>> > >>> + jmethodID setNativeThreadNameID;
>>>>>>> >>> > >>> + jstring nameString;
>>>>>>> >>> > >>> + jclass cls = GetLauncherHelperClass(env);
>>>>>>> >>> > >>> + NULL_CHECK(cls);
>>>>>>> >>> > >>> + NULL_CHECK(setNativeThreadNameID =
>>>>>>> >>> (*env)->GetStaticMethodID(env, cls,
>>>>>>> >>> > >>> + "setNativeThreadName", "(Ljava/lang/String;)V"));
>>>>>>> >>> > >>> + NULL_CHECK(nameString = (*env)->NewStringUTF(env,
>>>>>>> name));
>>>>>>> >>> > >>> + (*env)->CallStaticVoidMethod(env, cls,
>>>>>>> setNativeThreadNameID,
>>>>>>> >>> > >>> nameString);
>>>>>>> >>> > >>> +}
>>>>>>> >>> > >>> +
>>>>>>> >>> > >>> /*
>>>>>>> >>> > >>> * Prints default usage or the Xusage message, see
>>>>>>> >>> > >>> sun.launcher.LauncherHelper.java
>>>>>>> >>> > >>> */
>>>>>>> >>> > >>> ----------------
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> So I want to add new arg to JVM_SetNativeThreadName().
>>>>>>> >>> > >>>
>>>>>>> >>> > >>>> However this is still a change to the exported JVM
>>>>>>> interface and so
>>>>>>> >>> > >>>> has to be approved.
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> Do you mean that this change needs CCC?
>>>>>>> >>> > >>>
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> Thanks,
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> Yasumasa
>>>>>>> >>> > >>>
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> [1]
>>>>>>> >>> > >>>
>>>>>>> >>>
>>>>>>> http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2016-April/019034.html
>>>>>>>
>>>>>>>
>>>>>>> >>> > >>>
>>>>>>> >>> > >>>
>>>>>>> >>> > >>>
>>>>>>> >>> > >>> On 2016/04/16 7:26, David Holmes wrote:
>>>>>>> >>> > >>>> On 15/04/2016 11:20 PM, Yasumasa Suenaga wrote:
>>>>>>> >>> > >>>>> Hi David,
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>>> I think it is a bug based on the comment here:
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> JavaThread(bool is_attaching_via_jni = false); //
>>>>>>> for main
>>>>>>> >>> thread and
>>>>>>> >>> > >>>>>> JNI attached threads
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> I filed it to JBS as JDK-8154331.
>>>>>>> >>> > >>>>> I will send review request to hotspot-runtime-dev.
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>>> Though that will introduce a change in behaviour by
>>>>>>> itself as
>>>>>>> >>> setName
>>>>>>> >>> > >>>>>> will no longer set the native name for the main
>>>>>>> thread.
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> I know.
>>>>>>> >>> > >>>>
>>>>>>> >>> > >>>> That change in behaviour may be a problem, it could be
>>>>>>> considered a
>>>>>>> >>> > >>>> regression that setName stops setting the native thread
>>>>>>> main, even
>>>>>>> >>> > >>>> though we never really intended it to work in the
>>>>>>> first place.
>>>>>>> >>> :( Such
>>>>>>> >>> > >>>> a change needs to go through CCC.
>>>>>>> >>> > >>>>
>>>>>>> >>> > >>>>> I checked changeset history.
>>>>>>> >>> > >>>>> JVM_SetNativeThreadName() was introduced in
>>>>>>> JDK-7098194,
>>>>>>> and it is
>>>>>>> >>> > >>>>> backported JDK 8.
>>>>>>> >>> > >>>>
>>>>>>> >>> > >>>> Yes this all came in as part of the OSX port in 7u2.
>>>>>>> >>> > >>>>
>>>>>>> >>> > >>>>> However, this function seems to be called from
>>>>>>> >>> Thread#setNativeName()
>>>>>>> >>> > >>>>> only.
>>>>>>> >>> > >>>>> In addition, Thread#setNativeName() is private method.
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> Thus I think that we can add an argument to
>>>>>>> >>> JVM_SetNativeThreadName()
>>>>>>> >>> > >>>>> for force setting.
>>>>>>> >>> > >>>>> (e.g. "bool forced")
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> It makes a change of JVM API.
>>>>>>> >>> > >>>>> However, this function is NOT public, so I think we
>>>>>>> can
>>>>>>> add one
>>>>>>> >>> more
>>>>>>> >>> > >>>>> argument.
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> What do you think about this?
>>>>>>> >>> > >>>>> If it is accepted, we can set native thread name
>>>>>>> from Java
>>>>>>> >>> launcher.
>>>>>>> >>> > >>>>
>>>>>>> >>> > >>>> The private/public aspect of the Java API is not
>>>>>>> really at
>>>>>>> >>> issue. Yes
>>>>>>> >>> > >>>> we would add another arg to the JVM function to allow
>>>>>>> it to
>>>>>>> apply to
>>>>>>> >>> > >>>> JNI-attached threads as well (I'd prefer the arg
>>>>>>> reflect that
>>>>>>> >>> not just
>>>>>>> >>> > >>>> "force"). However this is still a change to the
>>>>>>> exported JVM
>>>>>>> >>> interface
>>>>>>> >>> > >>>> and so has to be approved. Further, we expect the
>>>>>>> launcher to
>>>>>>> >>> use the
>>>>>>> >>> > >>>> supported JNI interface (as other processes would),
>>>>>>> not the
>>>>>>> internal
>>>>>>> >>> > >>>> JVM interface that exists for the JDK sources to
>>>>>>> communicate
>>>>>>> >>> with the
>>>>>>> >>> > >>>> JVM.
>>>>>>> >>> > >>>>
>>>>>>> >>> > >>>> David
>>>>>>> >>> > >>>> -----
>>>>>>> >>> > >>>>
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> Thanks,
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> Yasumasa
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>>
>>>>>>> >>> > >>>>> On 2016/04/15 19:16, David Holmes wrote:
>>>>>>> >>> > >>>>>> Hi Yasumasa,
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> On 15/04/2016 6:53 PM, Yasumasa Suenaga wrote:
>>>>>>> >>> > >>>>>>> Hi David,
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>>> The fact that the "main" thread is not tagged as
>>>>>>> being a
>>>>>>> >>> JNI-attached
>>>>>>> >>> > >>>>>>>> thread seems accidental to me
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> Should I file it to JBS?
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> I think it is a bug based on the comment here:
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> JavaThread(bool is_attaching_via_jni = false); //
>>>>>>> for main
>>>>>>> >>> thread and
>>>>>>> >>> > >>>>>> JNI attached threads
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> Though that will introduce a change in behaviour by
>>>>>>> itself as
>>>>>>> >>> setName
>>>>>>> >>> > >>>>>> will no longer set the native name for the main
>>>>>>> thread.
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>>> I think that we can fix as below:
>>>>>>> >>> > >>>>>>> ---------------
>>>>>>> >>> > >>>>>>> diff -r 52aa0ee93b32 src/share/vm/runtime/thread.cpp
>>>>>>> >>> > >>>>>>> --- a/src/share/vm/runtime/thread.cpp Thu Apr 14
>>>>>>> 13:31:11
>>>>>>> >>> 2016 +0200
>>>>>>> >>> > >>>>>>> +++ b/src/share/vm/runtime/thread.cpp Fri Apr 15
>>>>>>> 17:50:10
>>>>>>> >>> 2016 +0900
>>>>>>> >>> > >>>>>>> @@ -3592,7 +3592,7 @@
>>>>>>> >>> > >>>>>>> #endif // INCLUDE_JVMCI
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> // Attach the main thread to this os thread
>>>>>>> >>> > >>>>>>> - JavaThread* main_thread = new JavaThread();
>>>>>>> >>> > >>>>>>> + JavaThread* main_thread = new JavaThread(true);
>>>>>>> >>> > >>>>>>> main_thread->set_thread_state(_thread_in_vm);
>>>>>>> >>> > >>>>>>> main_thread->initialize_thread_current();
>>>>>>> >>> > >>>>>>> // must do this before set_active_handles
>>>>>>> >>> > >>>>>>> @@ -3776,6 +3776,9 @@
>>>>>>> >>> > >>>>>>> // Notify JVMTI agents that VM initialization
>>>>>>> is complete
>>>>>>> >>> - nop if
>>>>>>> >>> > >>>>>>> no agents.
>>>>>>> >>> > >>>>>>> JvmtiExport::post_vm_initialized();
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> + // Change attach status to "attached"
>>>>>>> >>> > >>>>>>> + main_thread->set_done_attaching_via_jni();
>>>>>>> >>> > >>>>>>> +
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> I think we can do this straight after the JavaThread
>>>>>>> constructor.
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>>> if (TRACE_START() != JNI_OK) {
>>>>>>> >>> > >>>>>>> vm_exit_during_initialization("Failed to start
>>>>>>> tracing
>>>>>>> >>> > >>>>>>> backend.");
>>>>>>> >>> > >>>>>>> }
>>>>>>> >>> > >>>>>>> ---------------
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>>> If it wants to name its native threads then it is
>>>>>>> free
>>>>>>> to do so,
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> Currently, JVM_SetNativeThreadName() cannot change
>>>>>>> native
>>>>>>> >>> thread name
>>>>>>> >>> > >>>>>>> when the caller thread is JNI-attached thread.
>>>>>>> >>> > >>>>>>> However, I think that it should be changed if Java
>>>>>>> developer
>>>>>>> >>> calls
>>>>>>> >>> > >>>>>>> Thread#setName() explicitly.
>>>>>>> >>> > >>>>>>> It is not the same of changing native thread name at
>>>>>>> >>> > >>>>>>> Threads::create_vm().
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> If it is allowed, I want to fix
>>>>>>> SetNativeThreadName() as
>>>>>>> below.
>>>>>>> >>> > >>>>>>> What do you think about this?
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> The decision to not change the name of JNI-attached
>>>>>>> threads was a
>>>>>>> >>> > >>>>>> deliberate one** - this functionality originated
>>>>>>> with the OSX
>>>>>>> >>> port and
>>>>>>> >>> > >>>>>> it was reported that the initial feedback with this
>>>>>>> feature was to
>>>>>>> >>> > >>>>>> ensure it didn't mess with thread names that had
>>>>>>> been set by
>>>>>>> >>> the host
>>>>>>> >>> > >>>>>> process. If we do as you propose then we will just
>>>>>>> have an
>>>>>>> >>> > >>>>>> inconsistency for people to complain about: "why
>>>>>>> does my
>>>>>>> >>> native thread
>>>>>>> >>> > >>>>>> only have a name if I call
>>>>>>> cur.setName(cur.getName()) ?"
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> ** If you follow the bugs and related discussions on
>>>>>>> this, the
>>>>>>> >>> > >>>>>> semantics and limitations (truncation, current
>>>>>>> thread only,
>>>>>>> >>> non-JNI
>>>>>>> >>> > >>>>>> threads only) of setting the native thread name
>>>>>>> were supposed
>>>>>>> >>> to be
>>>>>>> >>> > >>>>>> documented in the release notes - but as far as I
>>>>>>> can see
>>>>>>> that
>>>>>>> >>> never
>>>>>>> >>> > >>>>>> happened. :(
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> My position on this remains that if it is desirable
>>>>>>> for
>>>>>>> the main
>>>>>>> >>> > >>>>>> thread (and DestroyJavaVM thread) to have native
>>>>>>> names
>>>>>>> then the
>>>>>>> >>> > >>>>>> launcher needs to be setting them using the available
>>>>>>> platform
>>>>>>> >>> APIs.
>>>>>>> >>> > >>>>>> Unfortunately this is complicated - as evidenced by
>>>>>>> the VM
>>>>>>> >>> code for
>>>>>>> >>> > >>>>>> this - due to the need to verify API availability.
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> Any change in behaviour in relation to
>>>>>>> Thread.setName would
>>>>>>> >>> have to go
>>>>>>> >>> > >>>>>> through our CCC process I think. But a change in
>>>>>>> the launcher
>>>>>>> >>> would
>>>>>>> >>> > >>>>>> not.
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> Sorry.
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>> David
>>>>>>> >>> > >>>>>> -----
>>>>>>> >>> > >>>>>>
>>>>>>> >>> > >>>>>>> ---------------
>>>>>>> >>> > >>>>>>> --- a/src/share/vm/prims/jvm.cpp Thu Apr 14
>>>>>>> 13:31:11
>>>>>>> >>> 2016 +0200
>>>>>>> >>> > >>>>>>> +++ b/src/share/vm/prims/jvm.cpp Fri Apr 15
>>>>>>> 17:50:10
>>>>>>> >>> 2016 +0900
>>>>>>> >>> > >>>>>>> @@ -3187,7 +3187,7 @@
>>>>>>> >>> > >>>>>>> JavaThread* thr =
>>>>>>> java_lang_Thread::thread(java_thread);
>>>>>>> >>> > >>>>>>> // Thread naming only supported for the current
>>>>>>> thread,
>>>>>>> >>> doesn't
>>>>>>> >>> > >>>>>>> work
>>>>>>> >>> > >>>>>>> for
>>>>>>> >>> > >>>>>>> // target threads.
>>>>>>> >>> > >>>>>>> - if (Thread::current() == thr &&
>>>>>>> >>> !thr->has_attached_via_jni()) {
>>>>>>> >>> > >>>>>>> + if (Thread::current() == thr) {
>>>>>>> >>> > >>>>>>> // we don't set the name of an attached
>>>>>>> thread to avoid
>>>>>>> >>> stepping
>>>>>>> >>> > >>>>>>> // on other programs
>>>>>>> >>> > >>>>>>> const char *thread_name =
>>>>>>> >>> > >>>>>>>
>>>>>>> >>>
>>>>>>> java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
>>>>>>>
>>>>>>> >>> > >>>>>>> ---------------
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> Thanks,
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> Yasumasa
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>>
>>>>>>> >>> > >>>>>>> On 2016/04/15 13:32, David Holmes wrote:
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>> On 15/04/2016 1:11 AM, Yasumasa Suenaga wrote:
>>>>>>> >>> > >>>>>>>>> Roger,
>>>>>>> >>> > >>>>>>>>> Thanks for your comment!
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>> David,
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>> I'll wait to see what Kumar thinks about
>>>>>>> this. I
>>>>>>> don't like
>>>>>>> >>> > >>>>>>>>>>>> exposing
>>>>>>> >>> > >>>>>>>>>>>> a new JVM function this way.
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>> I tried to call Thread#setName() after
>>>>>>> initializing VM
>>>>>>> (before
>>>>>>> >>> > >>>>>>>>> calling
>>>>>>> >>> > >>>>>>>>> main method),
>>>>>>> >>> > >>>>>>>>> I could set native thread name.
>>>>>>> >>> > >>>>>>>>> However, DestroyJavaVM() calls
>>>>>>> AttachCurrentThread().
>>>>>>> So we
>>>>>>> >>> can't
>>>>>>> >>> > >>>>>>>>> set
>>>>>>> >>> > >>>>>>>>> native thread name for DestroyJavaVM.
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>> Right - I came to the same realization earlier this
>>>>>>> morning.
>>>>>>> >>> Which,
>>>>>>> >>> > >>>>>>>> unfortunately, takes me back to the basic premise
>>>>>>> here that
>>>>>>> >>> we don't
>>>>>>> >>> > >>>>>>>> set the name of threads not created by the JVM.
>>>>>>> The fact
>>>>>>> >>> that the
>>>>>>> >>> > >>>>>>>> "main" thread is not tagged as being a JNI-attached
>>>>>>> thread seems
>>>>>>> >>> > >>>>>>>> accidental to me - so JVM_SetNativeThreadName is
>>>>>>> only
>>>>>>> working by
>>>>>>> >>> > >>>>>>>> accident for the initial attach, and can't be
>>>>>>> used for the
>>>>>>> >>> > >>>>>>>> DestroyJavaVM part - which leaves the thread
>>>>>>> inconsistently
>>>>>>> >>> named at
>>>>>>> >>> > >>>>>>>> the native level.
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>> I'm afraid my view here is that the launcher has
>>>>>>> to be
>>>>>>> >>> treated like
>>>>>>> >>> > >>>>>>>> any other process that might host a JVM. If it
>>>>>>> wants to
>>>>>>> name its
>>>>>>> >>> > >>>>>>>> native threads then it is free to do so, but I
>>>>>>> would not be
>>>>>>> >>> exporting
>>>>>>> >>> > >>>>>>>> a function from the JVM to do that - it would
>>>>>>> have to
>>>>>>> use the OS
>>>>>>> >>> > >>>>>>>> specific API's for that on a platform-by-platform
>>>>>>> basis.
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>> Sorry.
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>> David
>>>>>>> >>> > >>>>>>>> -----
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>>
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>> Thanks,
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>> Yasumasa
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>>
>>>>>>> >>> > >>>>>>>>> On 2016/04/14 23:24, Roger Riggs wrote:
>>>>>>> >>> > >>>>>>>>>> Hi,
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> Comments:
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> jvm.h: The function names are too similar but
>>>>>>> perform
>>>>>>> >>> different
>>>>>>> >>> > >>>>>>>>>> functions:
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> -JVM_SetNativeThreadName0 vs
>>>>>>> JVM_SetNativeThreadName
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> - The first function applies to the current
>>>>>>> thread, the
>>>>>>> >>> second
>>>>>>> >>> > >>>>>>>>>> one a
>>>>>>> >>> > >>>>>>>>>> specific java thread.
>>>>>>> >>> > >>>>>>>>>> It would seem useful for there to be a comment
>>>>>>> somewhere
>>>>>>> >>> about
>>>>>>> >>> > >>>>>>>>>> what
>>>>>>> >>> > >>>>>>>>>> the new function does.
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> windows/native/libjli/java_md.c: line 408
>>>>>>> casts to
>>>>>>> (void*)
>>>>>>> >>> > >>>>>>>>>> instead of
>>>>>>> >>> > >>>>>>>>>> (SetNativeThreadName0_t)
>>>>>>> >>> > >>>>>>>>>> as is done on unix and mac.
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> - macosx/native/libjli/java_md_macosx.c:
>>>>>>> >>> > >>>>>>>>>> - 737: looks wrong to
>>>>>>> overwriteifn->GetCreatedJavaVMs
>>>>>>> >>> used at
>>>>>>> >>> > >>>>>>>>>> line 730
>>>>>>> >>> > >>>>>>>>>> - 738 Incorrect indentation; if possible keep
>>>>>>> the cast
>>>>>>> >>> on the
>>>>>>> >>> > >>>>>>>>>> same
>>>>>>> >>> > >>>>>>>>>> line as dlsym...
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> $.02, Roger
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>> On 4/14/2016 9:32 AM, Yasumasa Suenaga wrote:
>>>>>>> >>> > >>>>>>>>>>>> That is an interesting question which I
>>>>>>> haven't had
>>>>>>> time to
>>>>>>> >>> > >>>>>>>>>>>> check -
>>>>>>> >>> > >>>>>>>>>>>> sorry. If the main thread is considered a
>>>>>>> JNI-attached
>>>>>>> >>> thread
>>>>>>> >>> > >>>>>>>>>>>> then
>>>>>>> >>> > >>>>>>>>>>>> my suggestion wont work. If it isn't then my
>>>>>>> suggestion
>>>>>>> >>> should
>>>>>>> >>> > >>>>>>>>>>>> work
>>>>>>> >>> > >>>>>>>>>>>> (but it means we have an inconsistency in our
>>>>>>> treatment of
>>>>>>> >>> > >>>>>>>>>>>> JNI-attached threads :( )
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>> I ran following program on JDK 9 EA b112, and I
>>>>>>> confirmed
>>>>>>> >>> native
>>>>>>> >>> > >>>>>>>>>>> thread name (test) was set.
>>>>>>> >>> > >>>>>>>>>>> ---------
>>>>>>> >>> > >>>>>>>>>>> public class Sleep{
>>>>>>> >>> > >>>>>>>>>>> public static void main(String[] args) throws
>>>>>>> Exception{
>>>>>>> >>> > >>>>>>>>>>> Thread.currentThread().setName("test");
>>>>>>> >>> > >>>>>>>>>>> Thread.sleep(3600000);
>>>>>>> >>> > >>>>>>>>>>> }
>>>>>>> >>> > >>>>>>>>>>> }
>>>>>>> >>> > >>>>>>>>>>> ---------
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>> I'll wait to see what Kumar thinks about
>>>>>>> this. I
>>>>>>> don't like
>>>>>>> >>> > >>>>>>>>>>>> exposing
>>>>>>> >>> > >>>>>>>>>>>> a new JVM function this way.
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>> I will update webrev after hearing Kumar's
>>>>>>> comment.
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>> Thanks,
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>> Yasumasa
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>> On 2016/04/14 21:32, David Holmes wrote:
>>>>>>> >>> > >>>>>>>>>>>> On 14/04/2016 1:52 PM, Yasumasa Suenaga wrote:
>>>>>>> >>> > >>>>>>>>>>>>> Hi,
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> On 2016/04/14 9:34, David Holmes wrote:
>>>>>>> >>> > >>>>>>>>>>>>>> Hi,
>>>>>>> >>> > >>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>> On 14/04/2016 1:28 AM, Yasumasa Suenaga
>>>>>>> wrote:
>>>>>>> >>> > >>>>>>>>>>>>>>> Hi David,
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> Thanks for your comment.
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> I exported new JVM function to set native
>>>>>>> thread
>>>>>>> >>> name, and JLI
>>>>>>> >>> > >>>>>>>>>>>>>>> uses it
>>>>>>> >>> > >>>>>>>>>>>>>>> in new webrev.
>>>>>>> >>> > >>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>> First the launcher belongs to another team so
>>>>>>> >>> core-libs will
>>>>>>> >>> > >>>>>>>>>>>>>> need to
>>>>>>> >>> > >>>>>>>>>>>>>> review and approve this (in particular
>>>>>>> Kumar) -
>>>>>>> now cc'd.
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> Thanks!
>>>>>>> >>> > >>>>>>>>>>>>> I'm waiting to review :-)
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>> Personally I would have used a Java upcall to
>>>>>>> >>> Thread.setName
>>>>>>> >>> > >>>>>>>>>>>>>> rather
>>>>>>> >>> > >>>>>>>>>>>>>> than exporting JVM_SetNativeThreadName. No
>>>>>>> hotspot changes
>>>>>>> >>> > >>>>>>>>>>>>>> needed in
>>>>>>> >>> > >>>>>>>>>>>>>> that case.
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> As I wrote [1] in JBS, I changed to use
>>>>>>> Thread#setName() in
>>>>>>> >>> > >>>>>>>>>>>>> Thread#init(),
>>>>>>> >>> > >>>>>>>>>>>>> but I could not change native thread name.
>>>>>>> >>> > >>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>> At Thread.init time the thread is not alive,
>>>>>>> which is
>>>>>>> >>> why the
>>>>>>> >>> > >>>>>>>>>>>> native
>>>>>>> >>> > >>>>>>>>>>>> name is not set.
>>>>>>> >>> > >>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> I guess that caller of main() is JNI
>>>>>>> attached thread.
>>>>>>> >>> > >>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>> That is an interesting question which I
>>>>>>> haven't had
>>>>>>> time to
>>>>>>> >>> > >>>>>>>>>>>> check -
>>>>>>> >>> > >>>>>>>>>>>> sorry. If the main thread is considered a
>>>>>>> JNI-attached
>>>>>>> >>> thread
>>>>>>> >>> > >>>>>>>>>>>> then
>>>>>>> >>> > >>>>>>>>>>>> my suggestion wont work. If it isn't then my
>>>>>>> suggestion
>>>>>>> >>> should
>>>>>>> >>> > >>>>>>>>>>>> work
>>>>>>> >>> > >>>>>>>>>>>> (but it means we have an inconsistency in our
>>>>>>> treatment of
>>>>>>> >>> > >>>>>>>>>>>> JNI-attached threads :( )
>>>>>>> >>> > >>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>> I'll wait to see what Kumar thinks about
>>>>>>> this. I
>>>>>>> don't like
>>>>>>> >>> > >>>>>>>>>>>> exposing
>>>>>>> >>> > >>>>>>>>>>>> a new JVM function this way.
>>>>>>> >>> > >>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>> Thanks,
>>>>>>> >>> > >>>>>>>>>>>> David
>>>>>>> >>> > >>>>>>>>>>>> -----
>>>>>>> >>> > >>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> Thus I think that we have to provide a
>>>>>>> function to set
>>>>>>> >>> native
>>>>>>> >>> > >>>>>>>>>>>>> thread name.
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> Thanks,
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> Yasumasa
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>> [1]
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>>
>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8152690?focusedCommentId=13926851&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13926851
>>>>>>>
>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>> Thanks,
>>>>>>> >>> > >>>>>>>>>>>>>> David
>>>>>>> >>> > >>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> Could you review again?
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> - hotspot:
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>>
>>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.02/hotspot/
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> - jdk:
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> http://cr.openjdk.java.net/~ysuenaga/JDK-8152690/webrev.02/jdk/
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> Thanks,
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> Yasumasa
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>> On 2016/04/13 22:00, David Holmes wrote:
>>>>>>> >>> > >>>>>>>>>>>>>>>> I'll answer on this original thread as
>>>>>>> well ...
>>>>>>> >>> > >>>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>> Hi Yasumasa,
>>>>>>> >>> > >>>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>> Please see my updates to the bug (sorry
>>>>>>> have
>>>>>>> been on
>>>>>>> >>> > >>>>>>>>>>>>>>>> vacation).
>>>>>>> >>> > >>>>>>>>>>>>>>>> This
>>>>>>> >>> > >>>>>>>>>>>>>>>> needs to be done in the launcher to be
>>>>>>> correct
>>>>>>> as we
>>>>>>> >>> do not
>>>>>>> >>> > >>>>>>>>>>>>>>>> set the
>>>>>>> >>> > >>>>>>>>>>>>>>>> name of threads that attach via JNI, which
>>>>>>> includes the
>>>>>>> >>> > >>>>>>>>>>>>>>>> "main"
>>>>>>> >>> > >>>>>>>>>>>>>>>> thread.
>>>>>>> >>> > >>>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>> David
>>>>>>> >>> > >>>>>>>>>>>>>>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>> On 31/03/2016 9:49 AM, 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>
>>>>>>> >>> <mailto: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>>
>>>>>>> >>> > >>>>>>>>>>>>>>>>>>>>>> <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,
>>>>>>> >>> > >>>>>>>>>>>>>>>>>>>>>> >
>>>>>>> >>> > >>>>>>>>>>>>>>>>>>>>>> >
>>>>>>> >>> > >>>>>>>>>>>>>>>>>>>>>> > 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>>>
>>>>>>> >>> > >>>>>>>>>>>>>>>>>>>>>> >> <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
>>>>>>> <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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