URGENT RFR 8153673 [BACKOUT] JDWP: Memory Leak: GlobalRefs never deleted when processing invokeMethod command

[Daniel D. Daugherty]

On 4/6/16 5:45 PM, serguei.spitsyn at oracle.com wrote:
> Hi Dan,
>
> The fix looks right.

Thanks!


> Thank you for taking care about the hs-rt stability!

You are very welcome.


> It makes sense to back the fix of the 4858370 out at least because
> it introduced new test that started failing intermittently.
>
> The following 3 bugs have similar manifestation and related to the 
> remote invocation
> of a method or a constructor in the target VM:
> https://bugs.openjdk.java.net/browse/JDK-8152586
> https://bugs.openjdk.java.net/browse/JDK-8152686
> https://bugs.openjdk.java.net/browse/JDK-8152985

I wasn't sure that JDK-8152586 was part of the mix because I
thought it was first spotted before JDK-4858370 was pushed...
but I based that guess on your notes...

I suspect that the cleanup of the global refs is happening
too early and some things that were relying on those globals
refs are now unhappy... but it has been a long time since I've
been in that code...

Dan


>
>
> I'm still in process of isolation of the JDK-8152586 regression.
> I took a wrong path at some point and need to redo some of my steps.
>
> Thanks,
> Serguei
>
>
> On 4/6/16 16:34, Daniel D. Daugherty wrote:
>> Resending with Jesper and Serguei on directly...
>>
>> Greetings,
>>
>> It appears that the fix for this bug:
>>
>>     JDK-4858370 JDWP: Memory Leak: GlobalRefs never deleted when 
>> processing
>>                 invokeMethod command
>> https://bugs.openjdk.java.net/browse/JDK-4858370
>>
>> has been causing intermittent test failures in the JDK9-hs-rt nightly.
>>
>>
>> ************************************************************
>> I need reviews from Jesper Wilhelmsson and Serguei Spitsyn.
>> ************************************************************
>>
>>
>> This bug is being using to backout JDK-4858370:
>>
>>     JDK-8153673 [BACKOUT] JDWP: Memory Leak: GlobalRefs never deleted 
>> when
>>                 processing invokeMethod command
>> https://bugs.openjdk.java.net/browse/JDK-8153673
>>
>> Here is the backout webrev URL:
>>
>> http://cr.openjdk.java.net/~dcubed/8153673-webrev/0-jdk9-hs-rt-jdk/
>>
>> Here are the changeset link for JDK-4858370:
>>
>> http://hg.openjdk.java.net/jdk9/hs-rt/jdk/rev/277d7584fa03
>>
>> Jesper and Serguei, thanks, in advance, for the reviews!
>>
>> Gory details below...
>>
>> Dan
>>
>>
>>
>> Here's my jdk repo sanity check note:
>>
>>  Daniel Daugherty added a comment - 1 hour ago
>> Sanity checks for backing out this fix and its test:
>>
>> $ hg log -r 277d7584fa03
>> changeset: 13880:277d7584fa03
>> parent: 13877:645a9be6eddb
>> user: sgehwolf
>> date: Mon Mar 21 11:24:09 2016 +0100
>> summary: 4858370: JDWP: Memory Leak: GlobalRefs never deleted when 
>> processing invokeMethod command
>>
>> $ hg status
>> M src/jdk.jdwp.agent/share/native/libjdwp/invoker.c
>> R test/com/sun/jdi/OomDebugTest.java
>> ? files.list
>>
>> $ hg diff -r 13877 `cat files.list `
>> <empty output>
>>
>> $ hg diff src/jdk.jdwp.agent/share/native/libjdwp/invoker.c
>> diff -r 96b1cfa80016 src/jdk.jdwp.agent/share/native/libjdwp/invoker.c
>> --- a/src/jdk.jdwp.agent/share/native/libjdwp/invoker.c Sat Apr 02 
>> 05:30:48 2016 +0200
>> +++ b/src/jdk.jdwp.agent/share/native/libjdwp/invoker.c Wed Apr 06 
>> 14:57:33 2016 -0700
>> @@ -209,47 +209,6 @@ createGlobalRefs(JNIEnv *env, InvokeRequ
>>      }
>>
>>      return error;
>> -}
>> -
>> -/*
>> - * Delete global references from the request which got put there 
>> before a
>> - * invoke request was carried out. See fillInvokeRequest() and 
>> invoker invoke*()
>> - * impls.
>> - */
>> -static void
>> -deleteGlobalRefs(JNIEnv *env, InvokeRequest *request)
>> -{
>> - void *cursor;
>> - jint argIndex = 0;
>> - jvalue *argument = request->arguments;
>> - jbyte argumentTag = firstArgumentTypeTag(request->methodSignature, 
>> &cursor);
>> -
>> - if (request->clazz != NULL) {
>> - tossGlobalRef(env, &(request->clazz));
>> - }
>> - if (request->instance != NULL) {
>> - tossGlobalRef(env, &(request->instance));
>> - }
>> - /* Delete global argument references */
>> - while (argIndex < request->argumentCount) {
>> - if ((argumentTag == JDWP_TAG(OBJECT)) ||
>> - (argumentTag == JDWP_TAG(ARRAY))) {
>> - if (argument->l != NULL) {
>> - tossGlobalRef(env, &(argument->l));
>> - }
>> - }
>> - argument++;
>> - argIndex++;
>> - argumentTag = nextArgumentTypeTag(&cursor);
>> - }
>> - /* Delete potentially saved return values */
>> - if ((request->invokeType == INVOKE_CONSTRUCTOR) ||
>> - (returnTypeTag(request->methodSignature) == JDWP_TAG(OBJECT)) ||
>> - (returnTypeTag(request->methodSignature) == JDWP_TAG(ARRAY))) {
>> - if (request->returnValue.l != NULL) {
>> - tossGlobalRef(env, &(request->returnValue.l));
>> - }
>> - }
>>  }
>>
>>  static jvmtiError
>> @@ -777,13 +736,6 @@ invoker_completeInvokeRequest(jthread th
>>          (void)outStream_writeObjectRef(env, &out, exc);
>>          outStream_sendReply(&out);
>>      }
>> -
>> - /*
>> - * At this time, there's no need to retain global references on
>> - * arguments since the reply is processed. No one will deal with
>> - * this request ID anymore, so we must call deleteGlobalRefs().
>> - */
>> - deleteGlobalRefs(env, request);
>>  }
>>
>>  jboolean
>>
>> $ hg diff -r 13877 src/jdk.jdwp.agent/share/native/libjdwp/invoker.c
>> <empty output>
>>
>

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