[Vm-dev] Re: Cog on Linux

[Eliot Miranda]

Hi Paul,

On Thu, Jul 22, 2010 at 2:14 PM, Paul DeBruicker <pdebruic at gmail.com> wrote:

>
> 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:
>

just looks like the OS/run-time is not letting the program set a handler for
SIGUSR2 and/or not allowing it to be caught.  This is a deal breaker.  Why
it's happening I don't know, but currently Cog's heartbeat on linux depends
on being able to catch SIGUSR2.

HTH
Eliot


>  (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
>
>
>
>
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