debugging java with dbx, supposed to work?
I have no luck debugging java. When I attach to it it debugs it as a C program.
When trying to force it to interpret it as a java program by suppliing a jar or a class file whe nattacing, dbx crashes. When starting the program from dbx I get
signal SEGV (access to address exceeded protections) in ciEnv::register_method t@9 (l@9) signal SEGV (access to address exceeded protections) in ciEnv::register_method at 0xfea7d2f8
.
I have used both studio 11 and
Sun Dbx Debugger 7.6 SunOS_sparc Build35_2 2006/12/04
[549 byte] By [
willocha] at [2007-11-26 20:53:24]
# 2
% java -version
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot(TM) Server VM (build 1.5.0_06-b05, mixed mode)
% uname -a
SunOS euler 5.10 Generic_118833-24 sun4u sparc SUNW,Sun-Fire
% ./SUNWspro/bin/dbx ~/lib/TRIACQ.jar `pgrep -f java.\*rc.gui`
..........
dbx: internal error: signal SIGSEGV (no mapping at the fault address)
dbx's coredump will appear in /tmp
detaching from process 26761
Abort (core dumped)
% ./SUNWspro/bin/dbx -V
Sun Dbx Debugger 7.6 SunOS_sparc Build40_1 2007/02/08
% stack /tmp/core | c++filt
core '/tmp/core' of 26918:/zfs/Local/./SUNWspro/bin/../prod/bin/sparcv9/dbx /triacq/lib/TRIACQ.j
ffffffff7e5ce520 _lwp_kill (6, 0, ffffffffffffffff, ffffffff7e6e4000, 0, 0) + 8
ffffffff7e548a6c abort (1, 1b8, 0, 19b6a0, 0, 0) + 118
00000001000bea38 ? (b, 100400, 1, 10051628c, 100522df8, 100624000)
ffffffff7e5cd424 __sighndlr (b, ffffffff7fffe750, ffffffff7fffe470, 1000be7c8, 0, a) + c
ffffffff7e5c17d4 call_user_handler (ffffffff7ea02000, ffffffff7ea02000, ffffffff7fffe470, 8, 0, 0) + 3e0
ffffffff7c7b5750 JdbxSurrogateSA::JdbxSurrogateSA #Nvariant 1(Notifier*,unsigned) (10224cf50, 10224cef0, 10, 1adcbc, 10050b730, ffffffff7c90b060) + 50
ffffffff7c7b26cc jvmdiSA::jvmdiSA #Nvariant 1() (10224be30, 10224cef0, 1f8, ffffffff7c90b060, 1589dc, 0) + 4c
ffffffff7c790ae0 jvmdiInterface*JDBContext::jvmdi_sa(JVMProxy*) (100685860, 102248670, 36e55e5, 1000, 101010100000000, 10224be30) + 18
ffffffff7c75776c void JdbxExtension::post_proc_init(Interp*,void*,bool) (100680f30, 102248670, ffffffff7fffeca8, ffffffff7c935cf8, ffffffff7c90b060, ffffffff7ffff09a) + 114
00000001000bece4 ? (100522df8, 1, ffffffff7fffeca8, 10053e648, 10053e000, 10053e)
00000001000c3628 main (3, ffffffff7fffedb8, 100653580, 100516f48, c202, 1000be7c8) + 824
00000001000b579c _start (0, 0, 0, 0, 0, 0) + 17c
# 3
> As for attaching to java app, be sure to read
> "Attaching dbx to a Running Java Application" section
> of dbx manual, since JVM needs to be started with
> special options that enable attaching of the debugger.
Thanks. I manage to use dbx on java now on jar file.
But...
I think information be available in the debugger itself as a help topic.
(help debug, or help java, there is help c++ , help fortran)
Or in the man page.
# 4
The SEGV in dbx happens because you inadvertandly ran into experimental
features of dbx which work with the java servicability agent (http://java.sun.com/j2se/1.5.0/docs/tooldocs/share/jsadebugd.html).
This may happen if your pgrep returns more than one pid or because
using an explicit .class or .jar in an attach scenario confuses dbx. Try
[code]dbx - [i]explicit-pid[/i][/code].
There are helpfiles that provide info on java but you have to get dbx
into java mode to begin with:
[code]
$ dbx75 Frame.class
Will be debugging "Frame"
Reading -
(dbx) help -k java
command summary
jpkgs (Java only command)
jclasses (Java only command)
jon (Java only command)
joff (Java only command)
java (Java only command)
java-debugging (topic)
native (Java only command)
debug (command)
...
[/code]
