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" <yasue...@gmail.com
<mailto:yasue...@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.ziem...@oracle.com
<mailto:gerard.ziem...@oracle.com>
 >>> <mailto:gerard.ziem...@oracle.com <mailto:gerard.ziem...@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
<yasue...@gmail.com <mailto:yasue...@gmail.com>
 >>> <mailto:yasue...@gmail.com <mailto:yasue...@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....@oracle.com <mailto:robbin....@oracle.com>
 >>> <mailto:robbin....@oracle.com <mailto:robbin....@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....@oracle.com <mailto:robbin....@oracle.com>
<mailto:robbin....@oracle.com <mailto:robbin....@oracle.com>>
 >>>  > >>>>>>>>>>>>>>>>>>>>>> <mailto:robbin....@oracle.com
<mailto:robbin....@oracle.com>
 >>> <mailto:robbin....@oracle.com <mailto:robbin....@oracle.com>>>>:
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  >
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  > Hi Yasumasa,
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  >
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  >
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  > On 03/25/2016 12:48 AM, Yasumasa
Suenaga wrote:
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  >>
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  >> Hi Robbin,
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  >> 2016/03/25 1:51 "Robbin Ehn"
 >>>  > >>>>>>>>>>>>>>>>>>>>>> <robbin....@oracle.com
<mailto:robbin....@oracle.com>
 >>> <mailto:robbin....@oracle.com <mailto:robbin....@oracle.com>>
 >>>  > >>>>>>>>>>>>>>>>>>>>>> <mailto:robbin....@oracle.com
<mailto:robbin....@oracle.com>
 >>> <mailto:robbin....@oracle.com <mailto:robbin....@oracle.com>>>
 >>>  > >>>>>>>>>>>>>>>>>>>>>>  >> <mailto:robbin....@oracle.com
<mailto:robbin....@oracle.com>
 >>> <mailto:robbin....@oracle.com <mailto:robbin....@oracle.com>>
 >>>  > >>>>>>>>>>>>>>>>>>>>>> <mailto:robbin....@oracle.com
<mailto:robbin....@oracle.com>
 >>> <mailto:robbin....@oracle.com <mailto:robbin....@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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