Freeze in GC_suspend_handler

[Daniel Bonniot]

Hi,

I have been trying to use various versions of gcj on my compiler 
(http://nice.sf.net). There is progress: first versions of gcj crashed 
at compile time. After summiting bugs, version 3.1 now compiles fine. 
The generated program now runs, but unfortunately freezes (works fine 
with a java interpreter). I haven't submited a bug report yet, as the 
program is bug, and I have no clue on how to isolate the problem. Here 
are the symptoms, running the program with gdb. After it stops running 
(no CPU used for some time), I pressed Control-C:

(gdb) info threads
* 3 Thread 1026 (LWP 5491)  0x4068887e in sigsuspend () from /lib/libc.so.6
  2 Thread 2049 (LWP 5490)  0x40727b90 in poll () from /lib/libc.so.6
  1 Thread 1024 (LWP 5489)  0x406ffdc1 in nanosleep () from /lib/libc.so.6
(gdb) where
#0  0x4068887e in sigsuspend () from /lib/libc.so.6
#1  0x403a3c84 in GC_suspend_handler () from /usr/lib/libgcj.so.3
#2  0x40641f54 in pthread_sighandler () from /lib/libpthread.so.0
#3  0x406886b8 in sigaction () from /lib/libc.so.6
#4  0x40641879 in __pthread_wait_for_restart_signal ()
   from /lib/libpthread.so.0
#5  0x4063e102 in pthread_cond_wait () from /lib/libpthread.so.0
#6  0x4039dbac in _Jv_CondWait(_Jv_ConditionVariable_t*, _Jv_Mutex_t*, 
long long, int) () from /usr/lib/libgcj.so.3
#7  0x4024e174 in java::lang::Object::wait(long long, int) ()
   from /usr/lib/libgcj.so.3
#8  0x402599db in java::lang::Object::wait() () from /usr/lib/libgcj.so.3
#9  0x402bcc75 in gnu::gcj::runtime::FinalizerThread::run() ()
   from /usr/lib/libgcj.so.3
#10 0x402523de in _Jv_ThreadRun(java::lang::Thread*) ()
   from /usr/lib/libgcj.so.3
#11 0x4039e004 in _Jv_ThreadUnRegister() () from /usr/lib/libgcj.so.3
#12 0x403a4926 in GC_start_routine () from /usr/lib/libgcj.so.3
#13 0x4063f0ba in pthread_start_thread () from /lib/libpthread.so.0
#14 0x4063f101 in pthread_start_thread_event () from /lib/libpthread.so.0

Do you have any idea about what is going on? What direction to follow to 
isolate the problem? Should I send the program (1MB self-contained jar) 
+ compilation instructions as a bug report / to the list / to somebody 
interested to investigate?

Daniel Bonniot

PS: please CC-me answers.
System: Debian 3.0, Kernel 2.4-18-bf2.4