RFR (XS) 8213992: Rename and make DieOnSafepointTimeout the diagnostic option

[Aleksey Shipilev]

On 11/19/18 3:43 PM, Daniel D. Daugherty wrote:
> On 11/19/18 6:23 AM, Aleksey Shipilev wrote:
>> On 11/19/18 6:08 AM, David Holmes wrote:
>>>> David suggested making the option "product", but I don't like it very much: "product" option
>>>> suggests this is a production-grade feature and it comes with expectations of support, which is
>>>> interesting in itself when product feature crashes the VM. "diagnostic" keeps this mode
>>>> available in
>>>> product builds without the attached notion of support. Users that want fail-fast VM crash can then
>>>> use that option on "we know what we are doing" basis.
>>> I feel a little uncomfortable that "diagnostic" is being used as a synonym for "unsupported
>>> product". If you really want to fail-fast in production then you're looking for a production flag
>>> not a "diagnostic" one IMHO. I won't fight it but I'd like to know what others think.
>> Yup, let's hear it. I don't want to bikeshed this too much :)
> 
> If I was doing the work on this bug, I would have made it a diagnostic option
> also. I have a bias towards adding options as diagnostic for two reasons:
> 
> 1) Easier to get rid of the option if it's a bad idea.
> 2) You have to use the '-XX:UnlockDiagnosticVMOption' option to use it
>    which makes unintentional use more difficult.

Thanks. No further comments? David, are you happy? I am pushing this:

diff -r 0811cc0ab16e src/hotspot/share/runtime/globals.hpp
--- a/src/hotspot/share/runtime/globals.hpp     Tue Nov 20 16:18:12 2018 +0100
+++ b/src/hotspot/share/runtime/globals.hpp     Tue Nov 20 17:17:35 2018 +0100
@@ -496,12 +496,12 @@
                                                                             \
   product(bool, SafepointTimeout, false,                                    \
           "Time out and warn or fail after SafepointTimeoutDelay "          \
           "milliseconds if failed to reach safepoint")                      \
                                                                             \
-  develop(bool, DieOnSafepointTimeout, false,                               \
-          "Die upon failure to reach safepoint (see SafepointTimeout)")     \
+  diagnostic(bool, AbortVMOnSafepointTimeout, false,                        \
+          "Abort upon failure to reach safepoint (see SafepointTimeout)")   \
                                                                             \
   /* 50 retries * (5 * current_retry_count) millis = ~6.375 seconds */      \
   /* typically, at most a few retries are needed                    */      \
   product(intx, SuspendRetryCount, 50,                                      \
           "Maximum retry count for an external suspend request")            \
diff -r 0811cc0ab16e src/hotspot/share/runtime/safepoint.cpp
--- a/src/hotspot/share/runtime/safepoint.cpp   Tue Nov 20 16:18:12 2018 +0100
+++ b/src/hotspot/share/runtime/safepoint.cpp   Tue Nov 20 17:17:35 2018 +0100
@@ -976,13 +976,13 @@
       }
       ls.print_cr("# SafepointSynchronize::begin: (End of list)");
     }
   }

-  // To debug the long safepoint, specify both DieOnSafepointTimeout &
+  // To debug the long safepoint, specify both AbortVMOnSafepointTimeout &
   // ShowMessageBoxOnError.
-  if (DieOnSafepointTimeout) {
+  if (AbortVMOnSafepointTimeout) {
     fatal("Safepoint sync time longer than " INTX_FORMAT "ms detected when executing %s.",
           SafepointTimeoutDelay, VMThread::vm_safepoint_description());
   }
 }


Thanks,
-Aleksey