Java fatal error, don't know what it means

Question

It happens at the same place in my code (albeit not the first time the method is executed) but I can't make head or tail of what is wrong. (Doubly so as it's code for a robot).

Be most appreciative if someone can give me an idea of what kind of problem it is. I assume it's to do with threading (multi-threaded app) but I don't really know what?!? Worried as deadline for uni project is looming!!!

The message:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0xb70f0ca7, pid=5065, tid=2145643376
#
# JRE version: 6.0_15-b03
# Java VM: Java HotSpot(TM) Server VM (14.1-b02 mixed mode linux-x86 )
# Problematic frame:
# V  [libjvm.so+0x4c9ca7]
#
# An error report file with more information is saved as:
# /home/thomas/workspace/sir13/hs_err_pid5065.log
#
# If you would like to submit a bug report, please visit:
#   http://java.sun.com/webapps/bugreport/crash.jsp
#

The log:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0xb70f0ca7, pid=5065, tid=2145643376
#
# JRE version: 6.0_15-b03
# Java VM: Java HotSpot(TM) Server VM (14.1-b02 mixed mode linux-x86 )
# Problematic frame:
# V  [libjvm.so+0x4c9ca7]
#
# If you would like to submit a bug report, please visit:
#   http://java.sun.com/webapps/bugreport/crash.jsp
#

---------------  T H R E A D  ---------------

Current thread (0x0904ec00):  JavaThread "CompilerThread1" daemon [_thread_in_native, id=5078, stack(0x7fdbe000,0x7fe3f000)]

siginfo:si_signo=SIGSEGV: si_errno=0, si_code=1 (SEGV_MAPERR), si_addr=0x00000004

Registers:
EAX=0x00000000, EBX=0xb733d720, ECX=0x000003b4, EDX=0x00000000
ESP=0x7fe3bf30, EBP=0x7fe3bf78, ESI=0x7fe3c250, EDI=0x7e9a7790
EIP=0xb70f0ca7, CR2=0x00000004, EFLAGS=0x00010283

Top of Stack: (sp=0x7fe3bf30)
0x7fe3bf30:   00020008 7ec8de5c 7fe3c250 00000000
0x7fe3bf40:   7f610451 00001803 7e9a7790 000003f5
0x7fe3bf50:   7e920030 7f239910 7f23b349 7f23b348
0x7fe3bf60:   7f550e35 7fe3c250 0000021b b733d720
0x7fe3bf70:   000003bc 7f23db10 7fe3bfc8 b70f0997
0x7fe3bf80:   7fe3c240 7f23db10 00000000 00000002
0x7fe3bf90:   00000000 7fe3c1b0 00000000 00000000
0x7fe3bfa0:   00004000 00000020 7ec88870 00000002 

Instructions: (pc=0xb70f0ca7)
0xb70f0c97:   7d 08 8b 87 c8 02 00 00 89 c7 8b 45 c4 8b 14 87
0xb70f0ca7:   8b 42 04 8b 00 85 c0 75 22 8b 4e 04 8b 52 1c 39 

Stack: [0x7fdbe000,0x7fe3f000],  sp=0x7fe3bf30,  free space=503k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x4c9ca7]
V  [libjvm.so+0x4c9997]
V  [libjvm.so+0x4c6e23]
V  [libjvm.so+0x25b75f]
V  [libjvm.so+0x2585df]
V  [libjvm.so+0x1f2c2f]
V  [libjvm.so+0x260ceb]
V  [libjvm.so+0x260609]
V  [libjvm.so+0x617286]
V  [libjvm.so+0x6108fe]
V  [libjvm.so+0x531c4e]
C  [libpthread.so.0+0x580e]


Current CompileTask:
C2:133  !   BehaviourLeftUnexplored.action()V (326 bytes)


---------------  P R O C E S S  ---------------

Java Threads: ( => current thread )
  0x08fb5400 JavaThread "DestroyJavaVM" [_thread_blocked, id=5066, stack(0xb6bb0000,0xb6c01000)]
  0x09213c00 JavaThread "Thread-4" [_thread_blocked, id=5085, stack(0x7eeaf000,0x7ef00000)]
  0x09212c00 JavaThread "Thread-3" [_thread_in_Java, id=5084, stack(0x7f863000,0x7f8b4000)]
  0x09206800 JavaThread "AWT-XAWT" daemon [_thread_in_native, id=5083, stack(0x7f8b4000,0x7f905000)]
  0x091b7400 JavaThread "Java2D Disposer" daemon [_thread_blocked, id=5082, stack(0x7f93e000,0x7f98f000)]
  0x09163c00 JavaThread "Thread-0" [_thread_in_native, id=5081, stack(0x7fc87000,0x7fcd8000)]
  0x09050c00 JavaThread "Low Memory Detector" daemon [_thread_blocked, id=5079, stack(0x7fd6d000,0x7fdbe000)]
=>0x0904ec00 JavaThread "CompilerThread1" daemon [_thread_in_native, id=5078, stack(0x7fdbe000,0x7fe3f000)]
  0x0904c000 JavaThread "CompilerThread0" daemon [_thread_blocked, id=5077, stack(0x7fe3f000,0x7fec0000)]
  0x0904a800 JavaThread "Signal Dispatcher" daemon [_thread_blocked, id=5076, stack(0x7fec0000,0x7ff11000)]
  0x09036c00 JavaThread "Finalizer" daemon [_thread_blocked, id=5075, stack(0x7ff57000,0x7ffa8000)]
  0x09035400 JavaThread "Reference Handler" daemon [_thread_blocked, id=5074, stack(0x7ffa8000,0x7fff9000)]

Other Threads:
  0x09031400 VMThread [stack: 0x7fff9000,0x8007a000] [id=5073]
  0x09052800 WatcherThread [stack: 0x7fcec000,0x7fd6d000] [id=5080]

VM state:not at safepoint (normal execution)

VM Mutex/Monitor currently owned by a thread: None

Heap
 PSYoungGen      total 46784K, used 32032K [0xae650000, 0xb3440000, 0xb3a50000)
  eden space 46720K, 68% used [0xae650000,0xb0588f48,0xb13f0000)
  from space 64K, 95% used [0xb3390000,0xb339f428,0xb33a0000)
  to   space 384K, 0% used [0xb33e0000,0xb33e0000,0xb3440000)
 PSOldGen        total 43008K, used 20872K [0x84650000, 0x87050000, 0xae650000)
  object space 43008K, 48% used [0x84650000,0x85ab2308,0x87050000)
 PSPermGen       total 16384K, used 5115K [0x80650000, 0x81650000, 0x84650000)
  object space 16384K, 31% used [0x80650000,0x80b4ec30,0x81650000)

Dynamic libraries:
08048000-08052000 r-xp 00000000 08:05 34708      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/bin/java
08052000-08053000 rwxp 00009000 08:05 34708      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/bin/java
08faf000-09220000 rwxp 00000000 00:00 0          [heap]
7e900000-7e9f9000 rwxp 00000000 00:00 0 
7e9f9000-7ea00000 ---p 00000000 00:00 0 
7ea00000-7ea41000 rwxp 00000000 00:00 0 
7ea41000-7eb00000 ---p 00000000 00:00 0 
7eb00000-7ebfc000 rwxp 00000000 00:00 0 
7ebfc000-7ec00000 ---p 00000000 00:00 0 
7ec00000-7ecf7000 rwxp 00000000 00:00 0 
7ecf7000-7ed00000 ---p 00000000 00:00 0 
7ed00000-7ede7000 rwxp 00000000 00:00 0 
7ede7000-7ee00000 ---p 00000000 00:00 0 
7eeaf000-7eeb2000 ---p 00000000 00:00 0 
7eeb2000-7ef00000 rwxp 00000000 00:00 0 
7ef00000-7eff9000 rwxp 00000000 00:00 0 
7eff9000-7f000000 ---p 00000000 00:00 0 
7f100000-7f1f6000 rwxp 00000000 00:00 0 
7f1f6000-7f200000 ---p 00000000 00:00 0 
7f200000-7f2fc000 rwxp 00000000 00:00 0 
7f2fc000-7f300000 ---p 00000000 00:00 0 
7f300000-7f4fe000 rwxp 00000000 00:00 0 
7f4fe000-7f500000 ---p 00000000 00:00 0 
7f500000-7f5fb000 rwxp 00000000 00:00 0 
7f5fb000-7f600000 ---p 00000000 00:00 0 
7f600000-7f6f9000 rwxp 00000000 00:00 0 
7f6f9000-7f700000 ---p 00000000 00:00 0 
7f700000-7f800000 rwxp 00000000 00:00 0 
7f830000-7f836000 r-xs 00000000 08:05 241611     /var/cache/fontconfig/945677eb7aeaf62f1d50efc3fb3ec7d8-x86.cache-2
7f836000-7f838000 r-xs 00000000 08:05 241612     /var/cache/fontconfig/99e8ed0e538f840c565b6ed5dad60d56-x86.cache-2
7f838000-7f83b000 r-xs 00000000 08:05 241620     /var/cache/fontconfig/e383d7ea5fbe662a33d9b44caf393297-x86.cache-2
7f83b000-7f846000 r-xs 00000000 08:05 241600     /var/cache/fontconfig/0f34bcd4b6ee430af32735b75db7f02b-x86.cache-2
7f863000-7f866000 ---p 00000000 00:00 0 
7f866000-7f8b4000 rwxp 00000000 00:00 0 
7f8b4000-7f8b7000 ---p 00000000 00:00 0 
7f8b7000-7f905000 rwxp 00000000 00:00 0 
7f905000-7f909000 r-xp 00000000 08:05 5012       /usr/lib/libXfixes.so.3.1.0
7f909000-7f90a000 r-xp 00003000 08:05 5012       /usr/lib/libXfixes.so.3.1.0
7f90a000-7f90b000 rwxp 00004000 08:05 5012       /usr/lib/libXfixes.so.3.1.0
7f90b000-7f913000 r-xp 00000000 08:05 5032       /usr/lib/libXrender.so.1.3.0
7f913000-7f914000 r-xp 00007000 08:05 5032       /usr/lib/libXrender.so.1.3.0
7f914000-7f915000 rwxp 00008000 08:05 5032       /usr/lib/libXrender.so.1.3.0
7f915000-7f91e000 r-xp 00000000 08:05 5004       /usr/lib/libXcursor.so.1.0.2
7f91e000-7f91f000 r-xp 00008000 08:05 5004       /usr/lib/libXcursor.so.1.0.2
7f91f000-7f920000 rwxp 00009000 08:05 5004       /usr/lib/libXcursor.so.1.0.2
7f92f000-7f931000 r-xs 00000000 08:05 241622     /var/cache/fontconfig/f24b2111ab8703b4e963115a8cf14259-x86.cache-2
7f931000-7f932000 r-xs 00000000 08:05 241606     /var/cache/fontconfig/4c73fe0c47614734b17d736dbde7580a-x86.cache-2
7f932000-7f936000 r-xs 00000000 08:05 241599     /var/cache/fontconfig/062808c12e6e608270f93bb230aed730-x86.cache-2
7f936000-7f93e000 r-xs 00000000 08:05 241617     /var/cache/fontconfig/d52a8644073d54c13679302ca1180695-x86.cache-2
7f93e000-7f941000 ---p 00000000 00:00 0 
7f941000-7f98f000 rwxp 00000000 00:00 0 
7f98f000-7fa0e000 r-xp 00000000 08:05 34755      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libfontmanager.so
7fa0e000-7fa19000 rwxp 0007e000 08:05 34755      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libfontmanager.so
7fa19000-7fa1d000 rwxp 00000000 00:00 0 
7fa1d000-7fa21000 r-xp 00000000 08:05 5008       /usr/lib/libXdmcp.so.6.0.0
7fa21000-7fa22000 rwxp 00003000 08:05 5008       /usr/lib/libXdmcp.so.6.0.0
7fa22000-7fa3e000 r-xp 00000000 08:05 6029       /usr/lib/libxcb.so.1.1.0
7fa3e000-7fa3f000 r-xp 0001c000 08:05 6029       /usr/lib/libxcb.so.1.1.0
7fa3f000-7fa40000 rwxp 0001d000 08:05 6029       /usr/lib/libxcb.so.1.1.0
7fa40000-7fa42000 r-xp 00000000 08:05 4997       /usr/lib/libXau.so.6.0.0
7fa42000-7fa43000 r-xp 00001000 08:05 4997       /usr/lib/libXau.so.6.0.0
7fa43000-7fa44000 rwxp 00002000 08:05 4997       /usr/lib/libXau.so.6.0.0
7fa44000-7fb6e000 r-xp 00000000 08:05 4991       /usr/lib/libX11.so.6.2.0
7fb6e000-7fb6f000 ---p 0012a000 08:05 4991       /usr/lib/libX11.so.6.2.0
7fb6f000-7fb70000 r-xp 0012a000 08:05 4991       /usr/lib/libX11.so.6.2.0
7fb70000-7fb72000 rwxp 0012b000 08:05 4991       /usr/lib/libX11.so.6.2.0
7fb72000-7fb73000 rwxp 00000000 00:00 0 
7fb73000-7fb81000 r-xp 00000000 08:05 5010       /usr/lib/libXext.so.6.4.0
7fb81000-7fb82000 r-xp 0000d000 08:05 5010       /usr/lib/libXext.so.6.4.0
7fb82000-7fb83000 rwxp 0000e000 08:05 5010       /usr/lib/libXext.so.6.4.0
7fb83000-7fb84000 r-xs 00000000 08:05 241614     /var/cache/fontconfig/c05880de57d1f5e948fdfacc138775d9-x86.cache-2
7fb84000-7fb87000 r-xs 00000000 08:05 241613     /var/cache/fontconfig/a755afe4a08bf5b97852ceb7400b47bc-x86.cache-2
7fb87000-7fb8a000 r-xs 00000000 08:05 241608     /var/cache/fontconfig/6d41288fd70b0be22e8c3a91e032eec0-x86.cache-2
7fb8a000-7fb92000 r-xs 00000000 08:05 219560     /var/cache/fontconfig/e13b20fdb08344e0e664864cc2ede53d-x86.cache-2
7fb92000-7fbd5000 r-xp 00000000 08:05 34752      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/xawt/libmawt.so
7fbd5000-7fbd7000 rwxp 00043000 08:05 34752      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/xawt/libmawt.so
7fbd7000-7fbd8000 rwxp 00000000 00:00 0 
7fbd8000-7fc5c000 r-xp 00000000 08:05 34750      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libawt.so
7fc5c000-7fc63000 rwxp 00084000 08:05 34750      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libawt.so
7fc63000-7fc87000 rwxp 00000000 00:00 0 
7fc87000-7fc8a000 ---p 00000000 00:00 0 
7fc8a000-7fcd8000 rwxp 00000000 00:00 0 
7fcd8000-7fceb000 r-xp 00000000 08:05 34739      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libnet.so
7fceb000-7fcec000 rwxp 00013000 08:05 34739      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libnet.so
7fcec000-7fced000 ---p 00000000 00:00 0 
7fced000-7fd6d000 rwxp 00000000 00:00 0 
7fd6d000-7fd70000 ---p 00000000 00:00 0 
7fd70000-7fdbe000 rwxp 00000000 00:00 0 
7fdbe000-7fdc1000 ---p 00000000 00:00 0 
7fdc1000-7fe3f000 rwxp 00000000 00:00 0 
7fe3f000-7fe42000 ---p 00000000 00:00 0 
7fe42000-7fec0000 rwxp 00000000 00:00 0 
7fec0000-7fec3000 ---p 00000000 00:00 0 
7fec3000-7ff11000 rwxp 00000000 00:00 0 
7ff11000-7ff18000 r-xs 00000000 08:05 134616     /usr/lib/gconv/gconv-modules.cache
7ff18000-7ff57000 r-xp 00000000 08:05 136279     /usr/lib/locale/en_GB.utf8/LC_CTYPE
7ff57000-7ff5a000 ---p 00000000 00:00 0 
7ff5a000-7ffa8000 rwxp 00000000 00:00 0 
7ffa8000-7ffab000 ---p 00000000 00:00 0 
7ffab000-7fff9000 rwxp 00000000 00:00 0 
7fff9000-7fffa000 ---p 00000000 00:00 0 
7fffa000-800ad000 rwxp 00000000 00:00 0 
800ad000-80243000 r-xs 02fb3000 08:05 34883      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/rt.jar
80243000-80244000 ---p 00000000 00:00 0 
80244000-802c4000 rwxp 00000000 00:00 0 
802c4000-802c5000 ---p 00000000 00:00 0 
802c5000-8034d000 rwxp 00000000 00:00 0 
8034d000-80365000 rwxp 00000000 00:00 0 
80365000-8037a000 rwxp 00000000 00:00 0 
8037a000-804b5000 rwxp 00000000 00:00 0 
804b5000-804bd000 rwxp 00000000 00:00 0 
804bd000-804d5000 rwxp 00000000 00:00 0 
804d5000-804ea000 rwxp 00000000 00:00 0 
804ea000-80625000 rwxp 00000000 00:00 0 
80625000-8064c000 rwxp 00000000 00:00 0 
8064c000-8064f000 rwxp 00000000 00:00 0 
8064f000-81650000 rwxp 00000000 00:00 0 
81650000-84650000 rwxp 00000000 00:00 0 
84650000-87050000 rwxp 00000000 00:00 0 
87050000-ae650000 rwxp 00000000 00:00 0 
ae650000-b3440000 rwxp 00000000 00:00 0 
b3440000-b3a50000 rwxp 00000000 00:00 0 
b3a50000-b3a52000 r-xs 00000000 08:05 241602     /var/cache/fontconfig/2c5ba8142dffc8bf0377700342b8ca1a-x86.cache-2
b3a52000-b3a5b000 r-xp 00000000 08:05 5018       /usr/lib/libXi.so.6.0.0
b3a5b000-b3a5c000 r-xp 00008000 08:05 5018       /usr/lib/libXi.so.6.0.0
b3a5c000-b3a5d000 rwxp 00009000 08:05 5018       /usr/lib/libXi.so.6.0.0
b3a5d000-b3a66000 rwxp 00000000 00:00 0 
b3a66000-b3b1d000 rwxp 00000000 00:00 0 
b3b1d000-b3d5d000 rwxp 00000000 00:00 0 
b3d5d000-b6b1d000 rwxp 00000000 00:00 0 
b6b1d000-b6b2c000 r-xp 00000000 08:05 34735      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libzip.so
b6b2c000-b6b2e000 rwxp 0000e000 08:05 34735      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libzip.so
b6b2e000-b6b38000 r-xp 00000000 08:05 1042       /lib/tls/i686/cmov/libnss_files-2.10.1.so
b6b38000-b6b39000 r-xp 00009000 08:05 1042       /lib/tls/i686/cmov/libnss_files-2.10.1.so
b6b39000-b6b3a000 rwxp 0000a000 08:05 1042       /lib/tls/i686/cmov/libnss_files-2.10.1.so
b6b3a000-b6b43000 r-xp 00000000 08:05 1055       /lib/tls/i686/cmov/libnss_nis-2.10.1.so
b6b43000-b6b44000 r-xp 00008000 08:05 1055       /lib/tls/i686/cmov/libnss_nis-2.10.1.so
b6b44000-b6b45000 rwxp 00009000 08:05 1055       /lib/tls/i686/cmov/libnss_nis-2.10.1.so
b6b45000-b6b4b000 r-xp 00000000 08:05 1028       /lib/tls/i686/cmov/libnss_compat-2.10.1.so
b6b4b000-b6b4c000 r-xp 00005000 08:05 1028       /lib/tls/i686/cmov/libnss_compat-2.10.1.so
b6b4c000-b6b4d000 rwxp 00006000 08:05 1028       /lib/tls/i686/cmov/libnss_compat-2.10.1.so
b6b4d000-b6b54000 r-xs 00035000 08:05 304369     /home/thomas/workspace/sir13/javaclient/jars/javaclient.jar
b6b54000-b6b5c000 rwxs 00000000 08:05 393570     /tmp/hsperfdata_thomas/5065
b6b5c000-b6b6f000 r-xp 00000000 08:05 1020       /lib/tls/i686/cmov/libnsl-2.10.1.so
b6b6f000-b6b70000 r-xp 00012000 08:05 1020       /lib/tls/i686/cmov/libnsl-2.10.1.so
b6b70000-b6b71000 rwxp 00013000 08:05 1020       /lib/tls/i686/cmov/libnsl-2.10.1.so
b6b71000-b6b73000 rwxp 00000000 00:00 0 
b6b73000-b6b77000 r-xp 00000000 08:05 5038       /usr/lib/libXtst.so.6.1.0
b6b77000-b6b78000 r-xp 00004000 08:05 5038       /usr/lib/libXtst.so.6.1.0
b6b78000-b6b79000 rwxp 00005000 08:05 5038       /usr/lib/libXtst.so.6.1.0
b6b79000-b6b7f000 r-xp 00000000 08:05 34723      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/native_threads/libhpi.so
b6b7f000-b6b80000 rwxp 00006000 08:05 34723      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/native_threads/libhpi.so
b6b80000-b6b81000 rwxp 00000000 00:00 0 
b6b81000-b6b82000 r-xp 00000000 00:00 0 
b6b82000-b6ba5000 r-xp 00000000 08:05 34733      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libjava.so
b6ba5000-b6ba7000 rwxp 00023000 08:05 34733      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libjava.so
b6ba7000-b6bae000 r-xp 00000000 08:05 1733       /lib/tls/i686/cmov/librt-2.10.1.so
b6bae000-b6baf000 r-xp 00006000 08:05 1733       /lib/tls/i686/cmov/librt-2.10.1.so
b6baf000-b6bb0000 rwxp 00007000 08:05 1733       /lib/tls/i686/cmov/librt-2.10.1.so
b6bb0000-b6bb3000 ---p 00000000 00:00 0 
b6bb3000-b6c01000 rwxp 00000000 00:00 0 
b6c01000-b6c25000 r-xp 00000000 08:05 1016       /lib/tls/i686/cmov/libm-2.10.1.so
b6c25000-b6c26000 r-xp 00023000 08:05 1016       /lib/tls/i686/cmov/libm-2.10.1.so
b6c26000-b6c27000 rwxp 00024000 08:05 1016       /lib/tls/i686/cmov/libm-2.10.1.so
b6c27000-b72f4000 r-xp 00000000 08:05 34724      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/server/libjvm.so
b72f4000-b7341000 rwxp 006cc000 08:05 34724      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/server/libjvm.so
b7341000-b7765000 rwxp 00000000 00:00 0 
b7765000-b78a3000 r-xp 00000000 08:05 967        /lib/tls/i686/cmov/libc-2.10.1.so
b78a3000-b78a4000 ---p 0013e000 08:05 967        /lib/tls/i686/cmov/libc-2.10.1.so
b78a4000-b78a6000 r-xp 0013e000 08:05 967        /lib/tls/i686/cmov/libc-2.10.1.so
b78a6000-b78a7000 rwxp 00140000 08:05 967        /lib/tls/i686/cmov/libc-2.10.1.so
b78a7000-b78aa000 rwxp 00000000 00:00 0 
b78aa000-b78ac000 r-xp 00000000 08:05 1014       /lib/tls/i686/cmov/libdl-2.10.1.so
b78ac000-b78ad000 r-xp 00001000 08:05 1014       /lib/tls/i686/cmov/libdl-2.10.1.so
b78ad000-b78ae000 rwxp 00002000 08:05 1014       /lib/tls/i686/cmov/libdl-2.10.1.so
b78ae000-b78b5000 r-xp 00000000 08:05 34734      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/jli/libjli.so
b78b5000-b78b7000 rwxp 00006000 08:05 34734      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/jli/libjli.so
b78b7000-b78b8000 rwxp 00000000 00:00 0 
b78b8000-b78cd000 r-xp 00000000 08:05 1081       /lib/tls/i686/cmov/libpthread-2.10.1.so
b78cd000-b78ce000 r-xp 00014000 08:05 1081       /lib/tls/i686/cmov/libpthread-2.10.1.so
b78ce000-b78cf000 rwxp 00015000 08:05 1081       /lib/tls/i686/cmov/libpthread-2.10.1.so
b78cf000-b78d1000 rwxp 00000000 00:00 0 
b78d1000-b78d2000 r-xs 00000000 08:05 161622     /var/cache/fontconfig/4794a0821666d79190d59a36cb4f44b5-x86.cache-2
b78d2000-b78d4000 r-xs 00000000 08:05 241610     /var/cache/fontconfig/7ef2298fde41cc6eeb7af42e48b7d293-x86.cache-2
b78d4000-b78df000 r-xp 00000000 08:05 34732      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libverify.so
b78df000-b78e0000 rwxp 0000b000 08:05 34732      /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/libverify.so
b78e0000-b78e2000 rwxp 00000000 00:00 0 
b78e2000-b78e3000 r-xp 00000000 00:00 0          [vdso]
b78e3000-b78fe000 r-xp 00000000 08:05 64         /lib/ld-2.10.1.so
b78fe000-b78ff000 r-xp 0001a000 08:05 64         /lib/ld-2.10.1.so
b78ff000-b7900000 rwxp 0001b000 08:05 64         /lib/ld-2.10.1.so
bfc33000-bfc48000 rwxp 00000000 00:00 0          [stack]

VM Arguments:
jvm_args: -Dfile.encoding=UTF-8 
java_command: Main
Launcher Type: SUN_STANDARD

Environment Variables:
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
USERNAME=thomas
LD_LIBRARY_PATH=/usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/server:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/../lib/i386:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/client:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386:/usr/lib/xulrunner-addons:/usr/lib/xulrunner-addons
SHELL=/bin/bash
DISPLAY=:0.0

Signal Handlers:
SIGSEGV: [libjvm.so+0x650690], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGBUS: [libjvm.so+0x650690], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGFPE: [libjvm.so+0x52f580], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGPIPE: [libjvm.so+0x52f580], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGXFSZ: [libjvm.so+0x52f580], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGILL: [libjvm.so+0x52f580], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGUSR1: SIG_DFL, sa_mask[0]=0x00000000, sa_flags=0x00000000
SIGUSR2: [libjvm.so+0x532170], sa_mask[0]=0x00000004, sa_flags=0x10000004
SIGHUP: [libjvm.so+0x531ea0], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGINT: [libjvm.so+0x531ea0], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGTERM: [libjvm.so+0x531ea0], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGQUIT: [libjvm.so+0x531ea0], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004


---------------  S Y S T E M  ---------------

OS:squeeze/sid

uname:Linux 2.6.31-20-generic #57-Ubuntu SMP Mon Feb 8 09:05:19 UTC 2010 i686
libc:glibc 2.10.1 NPTL 2.10.1 
rlimit: STACK 8192k, CORE 0k, NPROC infinity, NOFILE 1024, AS infinity
load average:1.07 0.55 0.23

CPU:total 2 (2 cores per cpu, 1 threads per core) family 6 model 15 stepping 13, cmov, cx8, fxsr, mmx, sse, sse2, sse3, ssse3

Memory: 4k page, physical 3095836k(1519972k free), swap 1261060k(1261060k free)

vm_info: Java HotSpot(TM) Server VM (14.1-b02) for linux-x86 JRE (1.6.0_15-b03), built on Jul  2 2009 15:49:13 by "java_re" with gcc 3.2.1-7a (J2SE release)

time: Mon Mar 22 12:08:40 2010
elapsed time: 21 seconds

Answer 1

The following error:

SIGSEGV (0xb) at pc=0xb70f0ca7, pid=5065, tid=2145643376

Shows that somewhere, you're accessing an invalid memory adress or NULL from process ID (5065) (not relevant at this moment).

So, if you're programming a robot, it means that you're either:

• Using a library (DLL) that can communicate to a serial port to access that robot, your code to talk to the library is probably passing a NULL which in turn, crashes in the DLL.
• Writing your own native library which then is accessing a NULL or invalid memory address.

The JVM then crashes. I can't help you further that this because I don't know how your programmed (in Java) to communicate to your robot so this is just an investigation.

Learn about SIGSEGV.

Answer 2

You are running Java 1.6.0 patch 15. The latest patch release (Java 1.6.0 patch 18) has fixes for a number of JVM crashing bugs according to the release notes. So it would be worth trying an upgrade.

However, the theory that your problems are caused by flakey JNI code is also plausible.

Here is some Sun documentation on Troubleshooting System Crashes for Java 6.