[Vm-dev] Re: Cog on Linux

[Paul DeBruicker]

Hi Eliot,


On 07/22/2010 05:02 PM, vm-dev-request at lists.squeakfoundation.org wrote:
> handle SIGUSR2 nostop noprint noignore
>    
If I include the above line in my .gdbinit then gdb complains:

Cannot find user-level thread for LWP XXXXX

where XXXXX is the process number for the VM.  Sometimes the VM window 
stays open and freezes at that point and sometimes it closes. Gdb then 
states that the "Target is running" when I type in the commands you 
listed.  If I comment the "handle SIGUSR2 ..." line out then I get this 
from those commands:

  (gdb) where
#0  0xf7fdf430 in __kernel_vsyscall ()
#1  0xf7fabb16 in nanosleep () from /lib32/libpthread.so.0
#2  0x0805fa38 in tickerSleepCycle (ignored=0x0)
     at /home/paul/src/squeakvm/platforms/unix/vm/sqUnixHeartbeat.c:375
#3  0xf7fa396e in start_thread () from /lib32/libpthread.so.0
#4  0xf7ed6b5e in clone () from /lib32/libc.so.6

(gdb) info registers
eax            0xfffffdfc       -516
ecx            0x0      0
edx            0xb7adb388       -1213353080
ebx            0xb7adb388       -1213353080
esp            0xb7adb358       0xb7adb358
ebp            0xb7adb398       0xb7adb398
esi            0xb7adbb70       -1213351056
edi            0x3d0f00 4001536
eip            0xf7fdf430       0xf7fdf430 <__kernel_vsyscall+16>
eflags         0x296    [ PF AF SF IF ]
cs             0x23     35
ss             0x2b     43
ds             0x2b     43
es             0x2b     43
fs             0x0      0
gs             0x63     99

(gdb) x/5i $eip
=> 0xf7fdf430 <__kernel_vsyscall+16>:   pop    %ebp
    0xf7fdf431 <__kernel_vsyscall+17>:   pop    %edx
    0xf7fdf432 <__kernel_vsyscall+18>:   pop    %ecx
    0xf7fdf433 <__kernel_vsyscall+19>:   ret
    0xf7fdf434:  add    %ch,(%esi)

(gdb) info threads
* 2 Thread 0xb7adbb70 (LWP 27239)  0xf7fdf430 in __kernel_vsyscall ()
   1 Thread 0xf7e056c0 (LWP 27236)  heartbeat_handler (sig=14,
     sig_info=0x63, context=0x0)
     at /home/paul/src/squeakvm/platforms/unix/vm/sqUnixHeartbeat.c:461

(gdb) thread 1
[Switching to thread 1 (Thread 0xf7e056c0 (LWP 27236))]#0  heartbeat_handler
     (sig=14, sig_info=0x63, context=0x0)
     at /home/paul/src/squeakvm/platforms/unix/vm/sqUnixHeartbeat.c:461
461     {

(gdb) bt
#0  heartbeat_handler (sig=14, sig_info=0x63, context=0x0)
     at /home/paul/src/squeakvm/platforms/unix/vm/sqUnixHeartbeat.c:461
#1 <signal handler called>
#2  0xf7feefe0 in _dl_debug_state () from /lib/ld-linux.so.2
#3  0xf7ff272c in ?? () from /lib/ld-linux.so.2
#4  0xf7fee2f6 in ?? () from /lib/ld-linux.so.2
#5  0xf7ff2106 in ?? () from /lib/ld-linux.so.2
#6  0xf7fb7c0b in ?? () from /lib32/libdl.so.2
#7  0xf7fee2f6 in ?? () from /lib/ld-linux.so.2
#8  0xf7fb809c in ?? () from /lib32/libdl.so.2
#9  0xf7fb7b41 in dlopen () from /lib32/libdl.so.2
#10 0xf7c01b27 in ?? () from /usr/lib32/libX11.so.6
#11 0xf7c01fe7 in _XNoticeCreateBitmap () from /usr/lib32/libX11.so.6
#12 0xf7c0220d in XCreatePixmap () from /usr/lib32/libX11.so.6
#13 0xf7c010e2 in XCreateBitmapFromData () from /usr/lib32/libX11.so.6
#14 0xf7db70bb in display_ioSetCursorWithMask (cursorBitsIndex=-1210764836,
     cursorMaskIndex=<value optimized out>, offsetX=-1, offsetY=-1)
     at 
/home/paul/src/squeakvm/platforms/unix/vm-display-X11/sqUnixX11.c:3855
#15 0x08071422 in primitiveBeCursor ()
     at /home/paul/src/squeakvm/src/vm/gcc3x-cointerp.c:23540
#16 0x0807f443 in interpret ()
     at /home/paul/src/squeakvm/src/vm/gcc3x-cointerp.c:4872
#17 0x0807eeec in enterSmalltalkExecutiveImplementation ()
     at /home/paul/src/squeakvm/src/vm/gcc3x-cointerp.c:14771
#18 0x0807f118 in initStackPagesAndInterpret ()
     at /home/paul/src/squeakvm/src/vm/gcc3x-cointerp.c:18367
#19 0x0805eed3 in main (argc=2, argv=0xffffcda4, envp=0xffffcdb0)
     at /home/paul/src/squeakvm/platforms/unix/vm/sqUnixMain.c:1627

(gdb) thread 2
[Switching to thread 2 (Thread 0xb7adbb70 (LWP 27239))]#0  0xf7fdf430 in 
__kernel_vsyscall ()

(gdb) bt
#0  0xf7fdf430 in __kernel_vsyscall ()
#1  0xf7fabb16 in nanosleep () from /lib32/libpthread.so.0
#2  0x0805fa38 in tickerSleepCycle (ignored=0x0)
     at /home/paul/src/squeakvm/platforms/unix/vm/sqUnixHeartbeat.c:375
#3  0xf7fa396e in start_thread () from /lib32/libpthread.so.0
#4  0xf7ed6b5e in clone () from /lib32/libc.so.6