Dan,
The fixes look good for all 3 HS versions (modulo discussions with
Coleen and Karen).
Great discovery, thank you for doing this!
Thanks,
Serguei
On 2/1/13 11:55 AM, Daniel D. Daugherty wrote:
Greetings,
I have a fix for the following JVM/TI bug:
7182152 Instrumentation hot swap test incorrect monitor count
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7182152
https://jbs.oracle.com/bugs/browse/JDK-7182152
The fix for the bug in the product code is one line:
src/share/vm/oops/klassVtable.cpp:
@@ -992,18 +1020,50 @@
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00200000, ("itable method update: %s(%s)",
new_method->name()->as_C_string(),
new_method->signature()->as_C_string()));
}
- break;
+ // cannot 'break' here; see for-loop comment above.
}
ime++;
}
}
}
and is applicable to JDK7u10/HSX-23.6 and JDK7u14/HSX-24. Coleen
already fixed the bug as part of the Perm Gen Removal (PGR) project
in HSX-25. Yes, we found a 1-line bug fix buried in the monster PGR
changeset. Many thanks to Coleen for her help in this bug hunt!
The rest of the code in the webrevs are:
- additional JVM/TI tracing code backported from Coleen's PGR changeset
- additional JVM/TI tracing code added by me and forward ported to HSX-25
- a new -XX:TraceRedefineClasses=16384 flag value for finding these
elusive old or obsolete methods
- exposure of some printing code to the PRODUCT build so that the new
tracing is available in a PRODUCT build
You might be wondering why the new tracing code is exposed in a PRODUCT
build. Well, it appears that more and more PRODUCT bits deployments are
using JVM/TI RedefineClasses() and/or RetransformClasses() at run-time
to instrument their systems. This bug (7182152) was only intermittently
reproducible in the WLS environment in which it occurred so I made the
tracing available in a PRODUCT build to assist in the hunt.
Raj from the WLS team has also verified that the HSX-23.6 version of
fix resolves the issue in his environment. Thanks Raj!
Here are the URLs for the three webrevs:
http://cr.openjdk.java.net/~dcubed/7182152-webrev/0-hsx23.6/
http://cr.openjdk.java.net/~dcubed/7182152-webrev/0-hsx24/
http://cr.openjdk.java.net/~dcubed/7182152-webrev/0-hsx25/
I have run the following test suites from the JPDA stack on the
JDK7u10/HSX-23.6 version of the fix with -XX:TraceRedefineClasses=16384
specified:
sdk-jdi
sdk-jdi_closed
sdk-jli
vm-heapdump
vm-hprof
vm-jdb
vm-jdi
vm-jdwp
vm-jvmti
vm-sajdi
The tested configs are:
{Solaris-X86, WinXP}
X {Client VM, Server VM}
X {-Xmixed, -Xcomp}
X {product, fastdebug}
With the 1-liner fix in place, the new tracing code does not find any
instances of this failure mode in any of the above test suites. Without
the the 1-liner fix in place, the new tracing code finds one instance
of this failure mode in the above test suites:
test/java/lang/instrument/IsModifiableClassAgent.java
There are two new tests that will be pushed to the JDK repos using
a different bug ID (not yet filed):
test/com/sun/jdi/RedefineAbstractClass.sh
test/java/lang/instrument/RedefineSubclassWithTwoInterfaces.sh
There will be a separate review request for the new tests.
I'm currently running the JPDA stack of tests on the JDK7u14/HSX-24
and JDK8-B75/HSX-25 versions of the fix. That testing will likely
take all weekend to complete.
Thanks, in advance, for any comments and/or suggestions.
Dan
