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

[Daniel D. Daugherty]

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>