Threading crash

[waywardmonkeys]

When using the current master and running Koala, after serving a request, you get a crash due to NLX stuff.

Using the nlx trace logging:

[nlx] BUG: unwind reached top
[nlx] BUG: previous uwp is null
[nlx] step: unwinding to 0x0
[nlx] BUG: previous uwp is null

And the stack in gdb:

0x00135849 in nlx_step (ultimate_destination=0xb8fb80) at /Users/bruce/Development/opendylan/sources/dfmc/c-run-time/run-time.c:4112
4112        teb->uwp_frame->ultimate_destination = ultimate_destination;
(gdb) bt
#0  0x00135849 in nlx_step (ultimate_destination=0xb8fb80) at /Users/bruce/Development/opendylan/sources/dfmc/c-run-time/run-time.c:4112
#1  0x00135959 in CONTINUE_UNWIND () at /Users/bruce/Development/opendylan/sources/dfmc/c-run-time/run-time.c:4153
#2  0x0002795a in Krespond_top_levelYhttpiVkoalaI (client_=0xc34c48) at server.c:8026
#3  0x0002724a in Kdo_respondF226I () at server.c:7842
#4  0x00203bb4 in Kanonymous_of_trampoline_functionF66I () at /Users/bruce/Development/dylan/http/_build/build/koala/../base64/../common-dylan/../dylan/thread.c:1478
#5  0x00247fff in trampoline (arg=0xc4f4e0) at posix-threads.c:376
#6  0x0097b657 in GC_inner_start_routine ()
#7  0x00975a7e in GC_call_with_stack_base ()
#8  0x0097b6a2 in GC_start_routine ()
#9  0x93fdd259 in _pthread_start ()
#10 0x93fdd0de in thread_start ()

and:

(gdb) print teb
$1 = (TEB *) 0xc13000
(gdb) print teb->uwp_frame 
$2 = (Unwind_protect_frame *) 0x0

The code involved here has a lot of stuff going on with exit frames and dynamic unwinds.

Thoughts, @promovicz, @housel, @hannesm ?

[waywardmonkeys]

@cgay too ...

[hannesm]

we're getting smaller: http://paste.lisp.org/display/130273

[hannesm]

but slightly different:
[nlx] step: unwinding to 0xb00809d0
[nlx] unwinding uwp 0xb00809d0 towards bef 0x6da2e0
[nlx] step: reached uwp 0xb00809d0
[nlx] fall-through from uwp 0xb00809d0
Segmentation fault

primitive_write_thread_variable (h=0xdb3e000, nv=0xc04b8) at posix-threads.c:1429
1429 tlv_vector[offset] = nv;
(gdb) bt
#0 primitive_write_thread_variable (h=0xdb3e000, nv=0xc04b8) at posix-threads.c:1429
#1 0x00005c97 in Krespond_top_levelYhttpiVkoalaI () at server.c:952
#2 0x00088889 in Kanonymous_of_trampoline_functionF66I () at thread.c:1478
#3 0x000bd498 in trampoline (arg=0x5a4e20) at posix-threads.c:376
#4 0x004c7b73 in GC_inner_start_routine ()
#5 0x004c27f1 in GC_call_with_stack_base ()
#6 0x004c8aea in GC_start_routine ()
#7 0x976b9ed9 in _pthread_start ()
#8 0x976bd6de in thread_start ()

[hannesm]

this is fixed now... thanks @promovicz