Java run time crash with fatal error

Question

Hi I am running java application/ in fact it is a test on embedded Linux box. After a while the test fails with the crash

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (os_linux_zero.cpp:270), pid=2951, tid=1328632944
#  fatal error: caught unhandled signal 11
#
# JRE version: 6.0_24-b24
# Java VM: OpenJDK Zero VM (20.0-b12 mixed mode linux-arm )
# Derivative: IcedTea6 1.12pre
# Distribution: Built for 
# If you would like to submit a bug report, please include
# instructions how to reproduce the bug and visit:
#   http://icedtea.classpath.org/bugzilla
#

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

Current thread (0x00073a40):  VMThread [stack: 0x4f297000,0x4f316000] [id=2953]

Stack: [0x4f297000,0x4f316000],  sp=0x4f314454,  free space=501k
VM_Operation (0x40ffb484): GenCollectForAllocation, mode: safepoint, requested by thread 0x0001db38


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

Java Threads: ( => current thread )
  0x000418c0 JavaThread "Thread-1" daemon [_thread_in_native, id=2990, stack(0x51a36000,0x51bb6000)]
  0x000e6150 JavaThread "Thread-0" daemon [_thread_in_native, id=2989, stack(0x518b6000,0x51a36000)]
  0x0008c290 JavaThread "Low Memory Detector" daemon [_thread_blocked, id=2960, stack(0x4f796000,0x4f916000)]
  0x00089988 JavaThread "Signal Dispatcher" daemon [_thread_blocked, id=2959, stack(0x4f616000,0x4f796000)]
  0x0007c288 JavaThread "Finalizer" daemon [_thread_blocked, id=2958, stack(0x4f496000,0x4f616000)]
  0x00077868 JavaThread "Reference Handler" daemon [_thread_blocked, id=2957, stack(0x4f316000,0x4f496000)]
  0x0001db38 JavaThread "main" [_thread_blocked, id=2952, stack(0x40f3a000,0x410b9000)]

Other Threads:
=>0x00073a40 VMThread [stack: 0x4f297000,0x4f316000] [id=2953]
  0x0008df80 WatcherThread [stack: 0x4f917000,0x4f996000] [id=2961]

VM state:at safepoint (normal execution)

VM Mutex/Monitor currently owned by a thread:  ([mutex/lock_event])
[0x0001cfb0] Threads_lock - owner thread: 0x00073a40
[0x0001d3c0] Heap_lock - owner thread: 0x0001db38

Heap
 def new generation   total 4480K, used 4181K [0x43200000, 0x436c0000, 0x45c00000)
  eden space 4096K,  99% used [0x43200000, 0x435fffd0, 0x43600000)
  from space 384K,  22% used [0x43660000, 0x436755f8, 0x436c0000)
  to   space 384K, 100% used [0x43600000, 0x43660000, 0x43660000)
 tenured generation   total 9572K, used 5980K [0x45c00000, 0x46559000, 0x4b000000)
   the space 9572K,  62% used [0x45c00000, 0x461d70e8, 0x461d7200, 0x46559000)
 compacting perm gen  total 4352K, used 4258K [0x4b000000, 0x4b440000, 0x4f000000)
   the space 4352K,  97% used [0x4b000000, 0x4b4289c8, 0x4b428a00, 0x4b440000)
No shared spaces configured.

Code Cache  [0x4117b000, 0x411a3000, 0x4317b000)
 total_blobs=80 nmethods=0 adapters=66 free_code_cache=33482752 largest_free_block=0

Dynamic libraries:
00008000-00011000 r-xp 00000000 1f:0b 4430       /usr/local/jvm/icedtea-openjdk-oe-core-jre/bin/java
00018000-00019000 rwxp 00008000 1f:0b 4430       /usr/local/jvm/icedtea-openjdk-oe-core-jre/bin/java
00019000-00898000 rwxp 00000000 00:00 0          [heap]
40000000-4001f000 r-xp 00000000 1f:0b 532        /lib/ld-2.11.1.so
4001f000-40022000 rwxp 00000000 00:00 0 
40022000-40023000 ---p 00000000 00:00 0 
40023000-40024000 rwxp 00000000 00:00 0 
40024000-40026000 r-xs 00013000 1f:0b 4451       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/jce.jar
40026000-40027000 r-xp 0001e000 1f:0b 532        /lib/ld-2.11.1.so
40027000-40028000 rwxp 0001f000 1f:0b 532        /lib/ld-2.11.1.so
40028000-4003d000 r-xp 00000000 1f:0b 566        /lib/libpthread-2.11.1.so
4003d000-40044000 ---p 00015000 1f:0b 566        /lib/libpthread-2.11.1.so
40044000-40045000 r-xp 00014000 1f:0b 566        /lib/libpthread-2.11.1.so
40045000-40046000 rwxp 00015000 1f:0b 566        /lib/libpthread-2.11.1.so
40046000-40048000 rwxp 00000000 00:00 0 
40048000-4004b000 r-xp 00000000 1f:0b 4502       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/jli/libjli.so
4004b000-40052000 ---p 00003000 1f:0b 4502       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/jli/libjli.so
40052000-40053000 rwxp 00002000 1f:0b 4502       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/jli/libjli.so
40053000-40057000 r-xp 00000000 1f:0b 544        /lib/libdl-2.11.1.so
40057000-4005e000 ---p 00004000 1f:0b 544        /lib/libdl-2.11.1.so
4005e000-4005f000 r-xp 00003000 1f:0b 544        /lib/libdl-2.11.1.so
4005f000-40060000 rwxp 00004000 1f:0b 544        /lib/libdl-2.11.1.so
40060000-4019b000 r-xp 00000000 1f:0b 538        /lib/libc-2.11.1.so
4019b000-401a2000 ---p 0013b000 1f:0b 538        /lib/libc-2.11.1.so
401a2000-401a4000 r-xp 0013a000 1f:0b 538        /lib/libc-2.11.1.so
401a4000-401a5000 rwxp 0013c000 1f:0b 538        /lib/libc-2.11.1.so
401a5000-401a8000 rwxp 00000000 00:00 0 
401a8000-401c7000 r-xp 00000000 1f:0b 3153       /usr/lib/libz.so.1.2.3
401c7000-401ce000 ---p 0001f000 1f:0b 3153       /usr/lib/libz.so.1.2.3
401ce000-401cf000 rwxp 0001e000 1f:0b 3153       /usr/lib/libz.so.1.2.3
401cf000-401da000 r-xp 00000000 1f:0b 547        /lib/libgcc_s.so.1
401da000-401e1000 ---p 0000b000 1f:0b 547        /lib/libgcc_s.so.1
401e1000-401e2000 rwxp 0000a000 1f:0b 547        /lib/libgcc_s.so.1
401e2000-40555000 r-xp 00000000 1f:0b 4504       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/server/libjvm.so
40555000-4055d000 ---p 00373000 1f:0b 4504       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/server/libjvm.so
4055d000-4057a000 rwxp 00373000 1f:0b 4504       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/server/libjvm.so
4057a000-405d4000 rwxp 00000000 00:00 0 
405d4000-4069b000 r-xp 00000000 1f:0b 575        /lib/libstdc++.so.6.0.12
4069b000-406a3000 ---p 000c7000 1f:0b 575        /lib/libstdc++.so.6.0.12
406a3000-406a6000 r-xp 000c7000 1f:0b 575        /lib/libstdc++.so.6.0.12
406a6000-406a8000 rwxp 000ca000 1f:0b 575        /lib/libstdc++.so.6.0.12
406a8000-406ae000 rwxp 00000000 00:00 0 
406ae000-40722000 r-xp 00000000 1f:0b 548        /lib/libm-2.11.1.so
40722000-40729000 ---p 00074000 1f:0b 548        /lib/libm-2.11.1.so
40729000-4072a000 r-xp 00073000 1f:0b 548        /lib/libm-2.11.1.so
4072a000-4072b000 rwxp 00074000 1f:0b 548        /lib/libm-2.11.1.so
4072b000-40730000 r-xp 00000000 1f:0b 3056       /usr/lib/libffi.so.5
40730000-40738000 ---p 00005000 1f:0b 3056       /usr/lib/libffi.so.5
40738000-40739000 rwxp 00005000 1f:0b 3056       /usr/lib/libffi.so.5
40739000-40f39000 rwxp 00000000 00:00 0 
40f39000-40f3d000 ---p 00000000 00:00 0 
40f3d000-410b9000 rwxp 00000000 00:00 0 
410b9000-410c0000 r-xp 00000000 1f:0b 572        /lib/librt-2.11.1.so
410c0000-410c7000 ---p 00007000 1f:0b 572        /lib/librt-2.11.1.so
410c7000-410c8000 r-xp 00006000 1f:0b 572        /lib/librt-2.11.1.so
410c8000-410c9000 rwxp 00007000 1f:0b 572        /lib/librt-2.11.1.so
410c9000-410d2000 r-xp 00000000 1f:0b 4496       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libverify.so
410d2000-410da000 ---p 00009000 1f:0b 4496       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libverify.so
410da000-410db000 rwxp 00009000 1f:0b 4496       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libverify.so
410db000-41101000 r-xp 00000000 1f:0b 4481       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libjava.so
41101000-41109000 ---p 00026000 1f:0b 4481       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libjava.so
41109000-4110b000 rwxp 00026000 1f:0b 4481       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libjava.so
4110b000-41113000 r-xp 00000000 1f:0b 553        /lib/libnss_compat-2.11.1.so
41113000-4111a000 ---p 00008000 1f:0b 553        /lib/libnss_compat-2.11.1.so
4111a000-4111b000 r-xp 00007000 1f:0b 553        /lib/libnss_compat-2.11.1.so
4111b000-4111c000 rwxp 00008000 1f:0b 553        /lib/libnss_compat-2.11.1.so
4111c000-41131000 r-xp 00000000 1f:0b 551        /lib/libnsl-2.11.1.so
41131000-41138000 ---p 00015000 1f:0b 551        /lib/libnsl-2.11.1.so
41138000-41139000 r-xp 00014000 1f:0b 551        /lib/libnsl-2.11.1.so
41139000-4113a000 rwxp 00015000 1f:0b 551        /lib/libnsl-2.11.1.so
4113a000-4113c000 rwxp 00000000 00:00 0 
4113c000-41147000 r-xp 00000000 1f:0b 561        /lib/libnss_nis-2.11.1.so
41147000-4114e000 ---p 0000b000 1f:0b 561        /lib/libnss_nis-2.11.1.so
4114e000-4114f000 r-xp 0000a000 1f:0b 561        /lib/libnss_nis-2.11.1.so
4114f000-41150000 rwxp 0000b000 1f:0b 561        /lib/libnss_nis-2.11.1.so
41150000-4115c000 r-xp 00000000 1f:0b 557        /lib/libnss_files-2.11.1.so
4115c000-41163000 ---p 0000c000 1f:0b 557        /lib/libnss_files-2.11.1.so
41163000-41164000 r-xp 0000b000 1f:0b 557        /lib/libnss_files-2.11.1.so
41164000-41165000 rwxp 0000c000 1f:0b 557        /lib/libnss_files-2.11.1.so
41165000-4116d000 rwxs 00000000 00:11 6173       /tmp/hsperfdata_root/2951
4116d000-41173000 r-xp 00000000 1f:0b 4497       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libzip.so
41173000-4117a000 ---p 00006000 1f:0b 4497       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libzip.so
4117a000-4117b000 rwxp 00005000 1f:0b 4497       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/libzip.so
4117b000-411a3000 rwxp 00000000 00:00 0 
411a3000-4317b000 rwxp 00000000 00:00 0 
4317b000-4317c000 rwxp 00000000 00:00 0 
4317c000-431fb000 rwxp 00000000 00:00 0 
431fb000-431fe000 r-xs 0007d000 1f:0b 4453       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/jsse.jar
431fe000-43200000 r-xs 0009a000 1f:0d 2388       /mnt/platform/javaTest.jar
43200000-436c0000 rwxp 00000000 00:00 0 
436c0000-45c00000 rwxp 00000000 00:00 0 
45c00000-46559000 rwxp 00000000 00:00 0 
46559000-4b000000 rwxp 00000000 00:00 0 
4b000000-4b440000 rwxp 00000000 00:00 0 
4b440000-4f000000 rwxp 00000000 00:00 0 
4f000000-4f003000 rwxp 00000000 00:00 0 
4f003000-4f015000 rwxp 00000000 00:00 0 
4f015000-4f01a000 rwxp 00000000 00:00 0 
4f01a000-4f03f000 rwxp 00000000 00:00 0 
4f03f000-4f042000 rwxp 00000000 00:00 0 
4f042000-4f05f000 rwxp 00000000 00:00 0 
4f05f000-4f065000 rwxp 00000000 00:00 0 
4f065000-4f08b000 rwxp 00000000 00:00 0 
4f08b000-4f08e000 rwxp 00000000 00:00 0 
4f08e000-4f0ac000 rwxp 00000000 00:00 0 
4f0ac000-4f0b3000 r-xs 000fb000 1f:0b 4462       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/resources.jar
4f0b3000-4f253000 r-xs 019cd000 1f:0b 4463       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/rt.jar
4f253000-4f288000 rwxp 00000000 00:00 0 
4f288000-4f296000 r-xs 00351000 1f:0b 4434       /usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/charsets.jar
4f296000-4f297000 ---p 00000000 00:00 0 
4f297000-4f316000 rwxp 00000000 00:00 0          [threadstack:0007dfa8]
4f316000-4f319000 ---p 00000000 00:00 0 
4f319000-4f496000 rwxp 00000000 00:00 0 
4f496000-4f499000 ---p 00000000 00:00 0 
4f499000-4f616000 rwxp 00000000 00:00 0 
4f616000-4f619000 ---p 00000000 00:00 0 
4f619000-4f796000 rwxp 00000000 00:00 0 
4f796000-4f799000 ---p 00000000 00:00 0 
4f799000-4f916000 rwxp 00000000 00:00 0 
4f916000-4f917000 ---p 00000000 00:00 0 
4f917000-4f996000 rwxp 00000000 00:00 0 
4f996000-4f998000 r-xs 0009a000 1f:0d 2388       /mnt/platform/javaTest.jar
4f998000-4f99f000 r-xs 0007d000 1f:0d 2389       /mnt/platform/lib/Symbol.RFID.API3.jar
4f99f000-4f9b4000 r-xp 00000000 1f:0d 1692       /mnt/platform/lib/librfidapi32jni.so
4f9b4000-4f9bc000 ---p 00015000 1f:0d 1692       /mnt/platform/lib/librfidapi32jni.so
4f9bc000-4f9bd000 rwxp 00015000 1f:0d 1692       /mnt/platform/lib/librfidapi32jni.so
4f9bd000-4fa54000 r-xp 00000000 1f:0d 1693       /mnt/platform/lib/librfidapi32.so
4fa54000-4fa5c000 ---p 00097000 1f:0d 1693       /mnt/platform/lib/librfidapi32.so
4fa5c000-4fa5f000 rwxp 00097000 1f:0d 1693       /mnt/platform/lib/librfidapi32.so
4fa5f000-4fa60000 rwxp 00000000 00:00 0 
4fa60000-4fb84000 r-xp 00000000 1f:0b 3149       /usr/lib/libxml2.so.2.7.8
4fb84000-4fb8c000 ---p 00124000 1f:0b 3149       /usr/lib/libxml2.so.2.7.8
4fb8c000-4fb91000 rwxp 00124000 1f:0b 3149       /usr/lib/libxml2.so.2.7.8
4fb91000-4fb92000 rwxp 00000000 00:00 0 
4fb92000-4fca0000 r-xp 00000000 1f:0d 1685       /mnt/platform/lib/libltk.so
4fca0000-4fca8000 ---p 0010e000 1f:0d 1685       /mnt/platform/lib/libltk.so
4fca8000-4fcb4000 rwxp 0010e000 1f:0d 1685       /mnt/platform/lib/libltk.so
4fcb4000-4fcd6000 r-xp 00000000 1f:0b 3128       /usr/lib/libssh2.so.1.0.1
4fcd6000-4fcde000 ---p 00022000 1f:0b 3128       /usr/lib/libssh2.so.1.0.1
4fcde000-4fcdf000 rwxp 00022000 1f:0b 3128       /usr/lib/libssh2.so.1.0.1
4fcdf000-4fd32000 r-xp 00000000 1f:0b 3132       /usr/lib/libssl.so.1.0.0
4fd32000-4fd3a000 ---p 00053000 1f:0b 3132       /usr/lib/libssl.so.1.0.0
4fd3a000-4fd3f000 rwxp 00053000 1f:0b 3132       /usr/lib/libssl.so.1.0.0
4fd3f000-4fd93000 r-xp 00000000 1f:0b 3048       /usr/lib/libcurl.so.4.3.0
4fd93000-4fd9b000 ---p 00054000 1f:0b 3048       /usr/lib/libcurl.so.4.3.0
4fd9b000-4fd9d000 rwxp 00054000 1f:0b 3048       /usr/lib/libcurl.so.4.3.0
4fd9d000-4ff94000 r-xp 00000000 1f:0b 3044       /usr/lib/libcrypto.so.1.0.0
4ff94000-4ff9b000 ---p 001f7000 1f:0b 3044       /usr/lib/libcrypto.so.1.0.0
4ff9b000-4ffb1000 rwxp 001f6000 1f:0b 3044       /usr/lib/libcrypto.so.1.0.0
4ffb1000-500b6000 rwxp 00000000 00:00 0 
500b6000-500b7000 ---p 00000000 00:00 0 
500b7000-508b6000 rwxp 00000000 00:00 0 
508b6000-508b7000 ---p 00000000 00:00 0 
508b7000-510b6000 rwxp 00000000 00:00 0 
510b6000-510b7000 ---p 00000000 00:00 0 
510b7000-518b6000 rwxp 00000000 00:00 0 
518b6000-518b9000 ---p 00000000 00:00 0 
518b9000-51a36000 rwxp 00000000 00:00 0 
51a36000-51a39000 ---p 00000000 00:00 0 
51a39000-51bb6000 rwxp 00000000 00:00 0 
51c00000-51d21000 rwxp 00000000 00:00 0 
51d21000-51e00000 ---p 00000000 00:00 0 
beede000-bef11000 rw-p 00000000 00:00 0          [stack]

VM Arguments:
java_command: javaTest.jar
Launcher Type: SUN_STANDARD

Environment Variables:
JAVA_HOME=/usr/local/jvm/icedtea-openjdk-oe-core-jre
CLASSPATH=/platform/lib/Symbol.RFID.API3.jar
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/usr/local/jvm/icedtea-openjdk-oe-core-jre/bin
LD_LIBRARY_PATH=/usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm/server:/usr/local/jvm/icedtea-openjdk-oe-core-jre/lib/arm:/usr/local/jvm/icedtea-openjdk-oe-core-jre/../lib/arm:/platform/lib/
SHELL=/bin/bash

Signal Handlers:
SIGSEGV: [libjvm.so+0x31ecfc], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGBUS: [libjvm.so+0x31ecfc], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGFPE: [libjvm.so+0x2718c8], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGPIPE: [libjvm.so+0x2718c8], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGXFSZ: [libjvm.so+0x2718c8], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGILL: [libjvm.so+0x2718c8], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGUSR1: SIG_DFL, sa_mask[0]=0x00000000, sa_flags=0x00000000
SIGUSR2: [libjvm.so+0x271a78], sa_mask[0]=0x00000000, sa_flags=0x10000004
SIGHUP: [libjvm.so+0x274094], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGINT: [libjvm.so+0x274094], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGTERM: [libjvm.so+0x274094], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGQUIT: [libjvm.so+0x274094], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004


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

OS:Linux
uname:Linux 2.6.32.8 #160 PREEMPT Wed Nov 20 09:35:38 EST 2013 armv7l
libc:glibc 2.11.1 NPTL 2.11.1 
rlimit: STACK 8192k, CORE 2048k, NPROC 1991, NOFILE 1024, AS infinity
load average:4.10 3.66 3.59

/proc/meminfo:
MemTotal:         255080 kB
MemFree:          101392 kB
Buffers:               0 kB
Cached:            73876 kB
SwapCached:            0 kB
Active:            96644 kB
Inactive:          42048 kB
Active(anon):      67736 kB
Inactive(anon):        0 kB
Active(file):      28908 kB
Inactive(file):    42048 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:         64836 kB
Mapped:            20092 kB
Shmem:              2920 kB
Slab:               9524 kB
SReclaimable:       2328 kB
SUnreclaim:         7196 kB
KernelStack:        1496 kB
PageTables:         1312 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:      127540 kB
Committed_AS:    1096640 kB
VmallocTotal:     647168 kB
VmallocUsed:         628 kB
VmallocChunk:     645884 kB


CPU:total 1 

Memory: 4k page, physical 255080k(101392k free), swap 0k(0k free)

vm_info: OpenJDK Zero VM (20.0-b12) for linux-arm JRE (1.6.0_24-b24), built on Jul 24 2012 19:26:05 by "mvdev" with gcc 4.7.2 20120706 (prerelease)

time: Wed Nov 20 17:51:51 2013
elapsed time: 11574 seconds

How do I find out the root cause of the issue? I see a "core-java-2951-1384969911" file created which is around 2MB core dump. Do I really need to debug the core dump? if yes, how do I do it?

Answer 1

Since the core dump is just a raw dump of the running process's data, one thing I do is convert it to a heap dump. To do this, you can use jmap:

jmap -heap:format=b <java-executable> <core-file>

Depending on the size of your core file, now may be a good time to get a beverage, go to lunch, or perhaps even catch up on your movies. (I've seen this command anywhere from 20 minutes to an hour and a half.) Make sure the argument points to the java executable file that actually created the core dump. It is probably also safest to make sure you are running the jmap command from that same version of java. (jmap is fairly old, and ships with the jdk as early as java 1.4.2.)

Once this command completes, you should have a heap.bin file that can be browsed with the jhat tool. (They should be viewable with the newer JVisualVM tool, but for some reason, that tool seems to fail when loading these files.) This tool is not as old as jmap (jhat started shipping with JDK's around version 1.6), but since we now have a heap file rather than a raw core dump, we can use the jhat that is distributed with a newer JDK. Since you are on Java 6 anyway, you will be fine:

jhat -J-Xmx1024M heap.bin

Again, depending on the size of the heap file, this command may take a LOT of time and memory. You may have to bump up the "1024" argument. You may even have to run it on a server (rather than your local machine) in order to get around the 2 GB heap limit Java imposes on Windows. Sometimes the heap files generated from core cause jhat to generate a ton of errors, so you may want to redirect standard output to a file. Eventually, the jhat process will finish reading the file and begin listening on port 7000. You may then point your Web browser to the machine jhat is running on (don't forget to add ":7000" to the host name) and begin browsing objects that were on the heap at the time of the JVM crash.

UPDATE: maybe the arguments have changed since I've last run the JMap tool. I just tried running it again, and it seems as though I had to use:

jmap -dump:live,format=b,file=heap.bin <java-executable> <core-file>

If one command doesn't work for you, you may want to try the other.