Java process run on JRE 7 Update 5 is hung eventually.

The process used
Java SE 1.7.0_05-b06 (23.1-b03)

Operating system:
64-bit Oracle Solaris 10 x86
Oracle Solaris 10 8/11 s10x_u10wos_17b X86

1. Symptoms
-----------
1.1 gcore
---------
The core file was generated by gcore, while the process was hung.

The process used the following command line:

% more pargs.26552.out
core 'core_ngprodjms01_java_500004_700_1366111220_26552' of 26552: /usr/java/bin/java -server -cp /usr/bin/../../usr/share/lib/imq/imqbroker.jar:/
argv[0]: /usr/java/bin/java
argv[1]: -server
argv[2]: -cp
argv[3]: /usr/bin/../../usr/share/lib/imq/imqbroker.jar:/usr/bin/../../usr/share/lib/imq/imqutil.jar:/usr/bin/../../usr/share/lib/imq/jsse.jar:/usr/bin/../../usr/share/lib/imq/jnet.jar:/usr/bin/../../usr/share/lib/imq/jcert.jar:/usr/lib/audit/Audit.jar:/opt/SUNWjdmk/5.1/lib/jdmkrt.jar:/opt/SUNWmfwk/lib/mfwk_instrum_tk.jar:/opt/SUNWhadb/4/lib/hadbjdbc4.jar:/opt/SUNWjavadb/derby.jar:/usr/bin/../../usr/share/lib/imq/ext:/usr/bin/../../usr/share/lib/ext
argv[4]: -Xms32m
argv[5]: -Xmx192m
argv[6]: -Xss128k
argv[7]: -XX:+UseConcMarkSweepGC
argv[8]: -XX:MaxGCPauseMillis=500
argv[9]: -XX:+PrintGCTimeStamps
argv[10]: -XX:+PrintGCDetails
argv[11]: -verbose:gc
argv[12]: -Xloggc:/pegs/s1mq/var//instances/RVNGBroker/log/gc.log
argv[13]: -Xmx2048m
argv[14]: -Xms256m
argv[15]: -Xss128k
argv[16]: -Dimq.home=/usr/bin/../..
argv[17]: -Dimq.varhome=/pegs/s1mq/var/
argv[18]: -Dimq.etchome=/usr/bin/../../etc/imq
argv[19]: -Dimq.libhome=/usr/bin/../../usr/share/lib/imq
argv[20]: com.sun.messaging.jmq.jmsserver.Broker
argv[21]: -Dimq.hostname=ngprodjms01.pegs.com
argv[22]: -Dimq.brokerid=ngprodjms01
argv[23]: -bgnd
argv[24]: -name
argv[25]: RVNGBroker
%

1.2 number of threads
---------------------
 The process executed 3154 threads:
% wc threads.26552.out
    3154 22079 244948 threads.26552.out

1.3 no Java level deadlock was found
------------------------------------
Attaching to core core_ngprodjms01_java_500004_700_1366111220_26552 from executable /1.7.0_05/bin/java, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 23.1-b03

Deadlock Detection:

No deadlocks found.
[...]

1.4 Threads in SafePointing
---------------------------
 1497 threads are trying to SafePoint the application:
% grep 'Monitor::lock_without_safepoint_check' jstack.26552.out | wc
    1497 7485 95808

 All these 1497 threads look like follows:
----------------- t@10 -----------------
0xfee9c545 ___lwp_cond_wait + 0x15
0xfe882bdd void os::PlatformEvent::park() + 0xbd
0xfe84a0d0 void Monitor::lock_without_safepoint_check() + 0x588
0xfdfa387f void SafepointSynchronize::block(JavaThread*) + 0x1c3
0xfe123aca int os::signal_wait() + 0x2aa
0xfe121e77 void signal_thread_entry(JavaThread*,Thread*) + 0x37
0xfe053784 void JavaThread::run() + 0x420
0xfe877cf2 java_start + 0xada
0xfee98aab _thr_setup + 0x4e
0xfee98db0 _lwp_start

1.5 Thread #1 is in ContinueInNewThread()
----------------- t@1 -----------------
0xfee9c455 __lwp_wait + 0x15
0xfee95d36 _thrp_join + 0x5a
0xfee95e78 thr_join + 0x20
0xfef55d59 ContinueInNewThread0 + 0x55
0xfef48ed2 ContinueInNewThread + 0xa2
0xfef55da8 JVMInit + 0x38
0xfef423e6 JLI_Launch + 0xf0a
0x0805083c main + 0x70
0x0805073d _start + 0x7d