All I know for certain about the source is that MacPorts pulls the
source tarball from the link http://download.java.net/openjdk/jdk6/promoted/b16/openjdk-6-src-b16-24_apr_2009.tar.gz
. It looks like there is now a b17, but I have no idea whether it
would build on a Mac or if it would work if it did build. Maybe
that's the source of my troubles. I think maybe I'll give that a
try. I was afraid that maybe HSDB hadn't been ported. Thanks for the
info about the debug callable functions. Those might go a long way
towards understanding what's going on. I tried to peek at some of the
data structures, but quickly descended into casting and pointer
dereferencing hell.
On Feb 3, 2010, at 7:32 PM, Tom Rodriguez wrote:
I assume the bits used by MacPorts are coming from http://hg.openjdk.java.net/bsd-port/bsd-port?
That's the only working port of openjdk on the mac as far as I
know. I know there are issues with 16 byte alignment in hotspot but
I assume all of them had been fixed in the bsd-port. If this is
something they missed I'm sure they'd like to know. You might try
their alias at http://mail.openjdk.java.net/mailman/listinfo/bsd-port-dev
. As far as HSDB I don't believe it's been ported to bsd/mac. It
needs either a core file reader, which would be different on the mac
since I assume it's Mach-O, or an API for control a live process
like ptrace, and I don't think either has been written. If you have
a debug build of hotspot there are functions that are callable from
the debugger which can be used to figure some things out, like
findpc which will try to indentify what a piece of generated code is
and ps which will dump a Java stack trace. The full set is in src/
share/vm/utilities/debug.cpp.
tom
On Feb 3, 2010, at 8:06 AM, Daniel D. Daugherty wrote:
Forwarding to hotspot-...@...
Dan
Derek Shinaberry wrote:
I am so far out of my depth here that I am not even sure which
mailing list to start with, but the serviceability-dev seemed as
good a place as any to begin.
First of all, I am NOT well versed in Java, particularly the
minutia and all things VM related. I am well versed in C++, which
led me to believe that I might have half a chance when it comes to
debugging a problem inside the VM.
I'm running Mac OS X 10.5.8 on a 32-bit Core Duo processor, which
doesn't support Java 6. So, I'm attempting to use OpenJDK 6
installed using MacPorts.
After some issues getting the build to work, I figured out what
needed patching and succeeded in building and installing
openjdk6. So far, so good.
The program I'm running that required Java 6, called Marketcetera,
crashes fairly frequently. Using gdb to investigate the crash, I
figured out that it has to do with 16-byte stack alignment
requirements on Mac OS X. I discovered a patch by Landon Fuller
that attempts to address the issues. I fought for a while to get
that patch integrated and building, but it finally built and
installed. Still having the same crash and it is still related to
stack alignment.
I've tracked it down to code that is being generated at runtime,
so gdb isn't much use in discovering exactly what code is the
source of the problem. Enter the Hotspot Debugger. (Finally, he
gets to the point!)
It doesn't appear that HSDB is built by MacPorts on Mac OS X. It
doesn't even look like there is a bsd directory which would
presumably contain that code. Has anyone successfully used HSDB
on Mac OS X? Can anyone point me in the right direction for being
able to understand what is going on inside the VM on Mac OS X?
Any help would be much appreciated.
Cheers,
Derek
