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8264711: More runtime TRAPS cleanups #3345

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@hseigel hseigel commented Apr 5, 2021

Please review this additional cleanup of use of TRAPS in hotspot runtime code. The changes were tested with Mach5 tiers 1-2 on Linux, Mac OS, and Windows and Mach5 tiers 3-5 on Linux x64.

Thanks, Harold


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@bridgekeeper bridgekeeper bot commented Apr 5, 2021

👋 Welcome back hseigel! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

@openjdk openjdk bot added the rfr label Apr 5, 2021
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@hseigel The following labels will be automatically applied to this pull request:

  • hotspot
  • serviceability

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

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@mlbridge mlbridge bot commented Apr 5, 2021

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lfoltan approved these changes Apr 5, 2021
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@lfoltan lfoltan left a comment

Looks good Harold. One minor comment for the file jfrJavaSupport.cpp.

Thanks,
Lois

src/hotspot/share/jfr/jni/jfrJavaSupport.cpp Outdated Show resolved Hide resolved
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@openjdk openjdk bot commented Apr 5, 2021

@hseigel This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8264711: More runtime TRAPS cleanups

Reviewed-by: lfoltan, pchilanomate, dholmes, dcubed

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 39 new commits pushed to the master branch:

  • ec599da: 8264633: Add missing logging to PlatformRecording#stop
  • e89542f: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE
  • 016db40: 8263907: Specification of CellRendererPane::paintComponent(..Rectangle) should clearly mention which method it delegates the call to
  • 78d1164: 8214455: Relocate CDS archived regions to the top of the G1 heap
  • 88eb291: 8264809: test-lib fails to build due to some warnings in ASN1Formatter and jfr
  • a863ab6: 8264551: Unexpected warning when jpackage creates an exe
  • 6e2b82a: 8264731: Introduce InstanceKlass::method_at_itable_or_null()
  • 22b20f8: 8264424: Support OopStorage bulk allocation
  • ab3be72: 8264863: Update JCov version to support JDK 17
  • 774e5ae: 8264742: member variable _monitor of MonitorLocker is redundant
  • ... and 29 more: https://git.openjdk.java.net/jdk/compare/104e925dfdac0af3b1c6862f9a7d3442484f9241...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

@openjdk openjdk bot added the ready label Apr 5, 2021
@@ -2735,7 +2735,7 @@ JNI_ENTRY(jint, jni_MonitorExit(JNIEnv *env, jobject jobj))
}

Handle obj(THREAD, JNIHandles::resolve_non_null(jobj));
ObjectSynchronizer::jni_exit(obj(), CHECK_(JNI_ERR));
ObjectSynchronizer::jni_exit(THREAD->as_Java_thread(), obj());

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pchilano Apr 5, 2021
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Here we would return JNI_ERR if we throw IMSE from jni_exit().

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@pchilano pchilano left a comment

Hi Harold,

I looked at the changes to synchronization code and looks good except for one issue below.

Thanks,
Patricio

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@hseigel hseigel commented Apr 5, 2021

Thanks Lois and Patricio for reviewing the change!
I removed my bogus change to ObjectSynchronizer::jni_exit() which also made calls consistent in jfrJavaSupport.cpp.
Harold

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@pchilano pchilano commented Apr 5, 2021

Thanks Lois and Patricio for reviewing the change!
I removed my bogus change to ObjectSynchronizer::jni_exit() which also made calls consistent in jfrJavaSupport.cpp.
Harold
Thanks Harold! Fix looks good.

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@dholmes-ora dholmes-ora left a comment

Hi Harold,

Lots of good cleanup here but also a couple of things that I think are incorrect. Platform string creation can throw exceptions; and I also believe the ClassFileLoadHook can too.

Thanks,
David

@@ -393,7 +393,7 @@ Handle java_lang_String::create_from_symbol(Symbol* symbol, TRAPS) {
}

// Converts a C string to a Java String based on current encoding
Handle java_lang_String::create_from_platform_dependent_str(const char* str, TRAPS) {
Handle java_lang_String::create_from_platform_dependent_str(JavaThread* current, const char* str) {

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This change is incorrect. JNU_NewStringPlatform can raise an exception so TRAPS here is correct.

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hseigel Apr 7, 2021
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Thanks for finding this. I reverted this change and the change to as_platform_dependent_str() because it calls GetStringPlatformChars() which calls JNU_GetStringPlatformChars() which can throw an exception.

Symbol* name,
ClassLoaderData* loader_data,
Handle protection_domain,
JvmtiCachedClassFileData** cached_class_file,
TRAPS) {

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I don't think this removal of TRAPS is correct. The ClassFileLoadHook could result in an exception becoming pending.

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Thanks! This change was reverted.

@@ -706,7 +706,7 @@ JvmtiEnv::AddToSystemClassLoaderSearch(const char* segment) {
ObjectLocker ol(loader, THREAD);

// need the path as java.lang.String
Handle path = java_lang_String::create_from_platform_dependent_str(segment, THREAD);
Handle path = java_lang_String::create_from_platform_dependent_str(THREAD, segment);

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This change will need reverting as an exception is possible as previously noted.

But note that if there was no possibility of exception here then the following check of HAS_PENDING_EXCEPTION should also have been removed.

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hseigel Apr 7, 2021
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Reverted.

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@mlbridge mlbridge bot commented Apr 5, 2021

Mailing list message from David Holmes on serviceability-dev:

On 6/04/2021 5:14 am, Patricio Chilano Mateo wrote:

src/hotspot/share/prims/jni.cpp line 2738:

2736:
2737: Handle obj(THREAD, JNIHandles::resolve_non_null(jobj));
2738: ObjectSynchronizer::jni_exit(THREAD->as_Java_thread(), obj());

Here we would return JNI_ERR if we throw IMSE from jni_exit().

Strictly speaking we probably should return JNI_ERR in that case, but
the spec (as usual) is non-specific about the relationship between error
codes and throwing exceptions. I would not suggest making such a change
now. Note that we would have to be careful to only return JNI_ERR in the
single case of IMSE, and even then we would have to be certain that the
IMSE came from the actual "exit" and not e.g.

err = MonitorEnter(obj);
...
throwIMSE()
...
err = MonitorExit(obj)

Cheers,
David

hseigel added 2 commits Apr 7, 2021
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@hseigel hseigel commented Apr 7, 2021

Please review this latest version of this change containing reviewer suggested changes.

Thanks, Harold

@@ -157,15 +157,6 @@ Method* Bytecode_invoke::static_target(TRAPS) {
return LinkResolver::resolve_method_statically(bc, constants, index(), THREAD);
}

Handle Bytecode_invoke::appendix(TRAPS) {

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dcubed-ojdk Apr 7, 2021
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You might want to mention the removal of this function in
the bug report so that it will show up in a JBS search.

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@dcubed-ojdk dcubed-ojdk commented Apr 7, 2021

Thumbs up.

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@dholmes-ora dholmes-ora left a comment

Hi Harold,

Updates seem fine.

Thanks,
David

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@hseigel hseigel commented Apr 8, 2021

Thanks Lois, Patricio, David, and Dan for reviewing this!

/integrate

@openjdk openjdk bot closed this Apr 8, 2021
@openjdk openjdk bot added integrated and removed ready rfr labels Apr 8, 2021
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@openjdk openjdk bot commented Apr 8, 2021

@hseigel Since your change was applied there have been 41 commits pushed to the master branch:

  • 3aec2d9: 8264718: Shenandoah: enable string deduplication during root scanning
  • 255afbe: 8264672: runtime/ParallelLoad/ParallelSuperTest.java timed out
  • ec599da: 8264633: Add missing logging to PlatformRecording#stop
  • e89542f: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE
  • 016db40: 8263907: Specification of CellRendererPane::paintComponent(..Rectangle) should clearly mention which method it delegates the call to
  • 78d1164: 8214455: Relocate CDS archived regions to the top of the G1 heap
  • 88eb291: 8264809: test-lib fails to build due to some warnings in ASN1Formatter and jfr
  • a863ab6: 8264551: Unexpected warning when jpackage creates an exe
  • 6e2b82a: 8264731: Introduce InstanceKlass::method_at_itable_or_null()
  • 22b20f8: 8264424: Support OopStorage bulk allocation
  • ... and 31 more: https://git.openjdk.java.net/jdk/compare/104e925dfdac0af3b1c6862f9a7d3442484f9241...master

Your commit was automatically rebased without conflicts.

Pushed as commit af13c64.

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