RFR (XS): 8208480: Fix for test failure: assert(is_bound() || is_unused()) after JDK-8206075 in C1

[Liu Xin]

hi, Lutz and Gunter,

Thank you for providing the information.
I met the full codecache in C1 in compiler/codegen/TestCharVect2.java
In my understanding,  Compilation::emit_code_epilog(LIR_Assembler*
assembler) checks bailout for every statement.
Do you meet the problem only on s390?

I am not object to your patch. if you need to reset  the label in
c1_LIRAssember's dtor, I think bailout  change  is redundant.
Remove it make code clearer.

diff -r fbb62267e5e9 src/hotspot/share/c1/c1_LIRAssembler.cpp
--- a/src/hotspot/share/c1/c1_LIRAssembler.cpp Thu Aug 09 15:52:23 2018
-0700
+++ b/src/hotspot/share/c1/c1_LIRAssembler.cpp Fri Aug 17 11:57:21 2018
-0700
@@ -112,6 +112,9 @@


 LIR_Assembler::~LIR_Assembler() {
+  // The unwind handler label may be unbound if this destructor is invoked
because of a bail-out.
+  // Reset it here to avoid an assertion.
+  _unwind_handler_entry.reset();
 }


diff -r fbb62267e5e9 src/hotspot/share/c1/c1_LIRAssembler.hpp
--- a/src/hotspot/share/c1/c1_LIRAssembler.hpp Thu Aug 09 15:52:23 2018
-0700
+++ b/src/hotspot/share/c1/c1_LIRAssembler.hpp Fri Aug 17 11:57:21 2018
-0700
@@ -71,11 +71,7 @@
   void record_non_safepoint_debug_info();

   // unified bailout support
-  void bailout(const char* msg) {
-    // reset the label in case it hits assertion in destructor.
-    _unwind_handler_entry.reset();
-    compilation()->bailout(msg);
-  }
+  void bailout(const char* msg) const { compilation()->bailout(msg); }
   bool bailed_out() const                        { return
compilation()->bailed_out(); }

   // code emission patterns and accessors


On Fri, Aug 17, 2018 at 8:35 AM Schmidt, Lutz <lutz.schmidt at sap.com> wrote:

> Hi,
>
>
>
> I’m responding on Gunter’s behalf. He just left the office a few minutes
> ago.
>
>
>
> The bailout case was a “codecache full” condition. For the error to occur,
> you must run into that condition when a reference to the label is already
> generated, but the label is not bound yet. This is not JCK test specific.
> We just happened to hit “codecache full” there.
>
>
>
> “jck_simple_api” is a subset of the api suite we compiled for our own
> purposes. The tests contained therein are just “simple” tests: they do not
> run too long, they can run massively parallel, they do not depend on
> specific resources (like ports, addresses, …).
>
>
>
> I’m afraid this doesn’t help you much. At least I tried. �� If you can’t
> reproduce on your own, please let us know what tracing you need. We could
> then try to produce the output on our test systems.
>
>
>
> Thanks,
>
> Lutz
>
>
>
> *From: *Liu Xin <navy.xliu at gmail.com>
> *Date: *Friday, 17. August 2018 at 17:15
> *To: *"Haug, Gunter" <gunter.haug at sap.com>
> *Cc**: *"hotspot-runtime-dev at openjdk.java.net" <
> hotspot-runtime-dev at openjdk.java.net>, Lutz Schmidt <lutz.schmidt at sap.com>,
> "Doerr, Martin (martin.doerr at sap.com)" <martin.doerr at sap.com>, "
> xxinliu at amazon.com" <xxinliu at amazon.com>
> *Subject: *Re: RFR (XS): 8208480: Fix for test failure: assert(is_bound()
> || is_unused()) after JDK-8206075 in C1
>
>
> hi, Gunter,
>
> I do consider bailout case. why didn't it catch your case?
>
> c1_LIRAssember.hpp
>
>  // unified bailout support
>
>   void bailout(const char* msg) {
>
>     // reset the label in case it hits assertion in destructor.
>
>     _unwind_handler_entry.reset();
>
>     compilation()->bailout(msg);
>
>   }
>
>
>
> can I reproduce this jck_simple_api_work?
>
>
> /priv/jvmtests/output_sapjvm12_o_jdk-test_dbgU_linuxs390x/jck_simple_api_work/hs_err_pid108809.log
>
>
>
> On Fri, Aug 17, 2018 at 6:39 AM Haug, Gunter <gunter.haug at sap.com> wrote:
>
> Hi all,
>
> could I please have  a review and a sponsor for this tiny fix:
>
> https://bugs.openjdk.java.net/browse/JDK-8208480
> http://cr.openjdk.java.net/~ghaug/webrevs/8208480
>
> C1 holds a label to the unwind handler during compilation. There are
> bail-out paths where a branch to this label has already been emitted but
> the handler hasn't (e.g. code cache full). The label is therefore unbound
> when the destructor is invoked and the assertion fires.
>
> Thanks,
> Gunter
>
>