Re: co-arrays and libgfortran

[Steve Kargl <sgk@troutmask.apl.washington.edu>]

On Tue, Dec 22, 2020 at 02:08:47PM -0800, Steve Kargl wrote:
> More monologuing.
> 
> I copied gcc/testsuite/gfortran.dg/caf-shared/dummy_1.f90 to tmp/dummy_1.f90.
> 
> % gfccas -o z dummy_1.f90 
> % ./z
> ERROR: Image 2(0x1748) failed
> % ps | grep z
>  5958  1  I    0:00.00 ./z
>  5959  1  I    0:00.00 ./z
>  5963  1  S+   0:00.01 grep z
> % kill 5959
> ERROR: Image 2(0x1747) failed
> 

Recompiled with -g and the image dropped core.

% gdb ./z z.core

Core was generated by `./z'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  scan_inside_lookahead (id=134523584, expected_off=<optimized out>, 
    hm=0x281c2198) at ../../../cas/libgfortran/caf_shared/hashmap.c:157
157       lookahead = data[expected_off].max_lookahead;
(gdb) bt
#0  scan_inside_lookahead (id=134523584, expected_off=<optimized out>, 
    hm=0x281c2198) at ../../../cas/libgfortran/caf_shared/hashmap.c:157
#1  hashmap_get (hm=0x281c2198, id=134523584)
    at ../../../cas/libgfortran/caf_shared/hashmap.c:196
#2  0x2808d002 in get_memory_by_id_internal (iface=0x281c2188, size=8, 
    id=134523584, zero_mem=false)
    at ../../../cas/libgfortran/caf_shared/alloc.c:55
#3  0x2808ed9f in _gfortran_cas_coarray_alloc (desc=0x804aac0 <b>, 
    elem_size=4, corank=1, alloc_type=1)
    at ../../../cas/libgfortran/caf_shared/wrapper.c:154
#4  0x08048dbe in MAIN__ () at dummy_1.f90:30
(gdb) up 1
#1  hashmap_get (hm=0x281c2198, id=134523584)
    at ../../../cas/libgfortran/caf_shared/hashmap.c:196
196       res = scan_inside_lookahead (hm, expected_offset, id);
(gdb) p *hm
$1 = {s = 0x281ef0bc, sm = 0x281c2184, a = 0x281c2190}
(gdb) p *hm->s
$2 = {data = {offset = 208}, size = 32, bitnum = 5}
(gdb) p *hm->sm
$3 = (shared_memory) 0x2808a020
(gdb) p **hm->sm
$4 = {meta = 0x281ef000, header = 0x0, last_seen_size = 4096, 
  num_local_allocs = 1, allocs = 0x2808a030}
(gdb) p *hm->a
$5 = {s = 0x281ef03c, shm = 0x281c2184}
(gdb) p *hm->a->s
$6 = {free_bucket_head = {{offset = -1} <repeats 32 times>}}
(gdb) p *hm->a->shm
$7 = (shared_memory) 0x2808a020
(gdb) p **hm->a->shm
$8 = {meta = 0x281ef000, header = 0x0, last_seen_size = 4096, 
  num_local_allocs = 1, allocs = 0x2808a030}

Any of this look familiar?

-- 
Steve