[Bug target/36806] [4.4 Regression] I/Os hang at rev. 137631 on darwin9

[dominiq at lps dot ens dot fr]

------- Comment #11 from dominiq at lps dot ens dot fr  2008-07-13 16:19 -------
I confirm that the problem appears at revision 137631 (137630 works fine).

Using gdb, the hanging depends on the code: for the comment #10 I get the
following backtrace

#0  0x93b424ee in semaphore_wait_signal_trap ()
#1  0x93b49fc5 in pthread_mutex_lock ()
#2  0x0019c172 in *__gfortrani_close_units () at ../gcc/gthr-posix.h:695
#3  0x000fc291 in cleanup () at
../../../gcc-4.4-work/libgfortran/runtime/main.c:175
#4  0x8fe12fc3 in
__dyld__ZN16ImageLoaderMachO13doTerminationERKN11ImageLoader11LinkContextE ()
#5  0x8fe04f7b in __dyld__ZN4dyld14runTerminatorsEPv ()
#6  0x93b6afdc in __cxa_finalize ()
#7  0x93b6aed0 in exit ()
#8  0x00001eef in start ()

If I add 

print *, 'open'
close(11)

before the 'end', I get

#0  0x93b424ee in semaphore_wait_signal_trap ()
#1  0x93b49fc5 in pthread_mutex_lock ()
#2  0x0019c1e5 in get_external_unit (n=6, do_create=1) at
../../../gcc-4.4-work/libgfortran/io/unit.c:288
#3  0x0019a501 in data_transfer_init (dtp=0xbfffd9d8, read_flag=0) at
../../../gcc-4.4-work/libgfortran/io/transfer.c:1828
#4  0x00001efd in MAIN__ ()
#5  0x00001f98 in main (argc=1, argv=0xbfffdb84) at
../../../gcc-4.4-work/libgfortran/fmain.c:21

In all cases I have looked at the hanging occurs after:

...
(gdb) stepi
0x93b42cf7 in _sysenter_trap ()
(gdb) stepi
^C  
Program received signal SIGINT, Interrupt.
0x93b424ee in semaphore_wait_signal_trap ()
(gdb) disassemble 0x93b42cf0 0x93b42d00
Dump of assembler code from 0x93b42cf0 to 0x93b42d00:
0x93b42cf0 <cerror+56>: inc    %ebx
0x93b42cf2 <cerror+58>: xchg   %ax,%ax
0x93b42cf4 <_sysenter_trap+0>:  pop    %edx
0x93b42cf5 <_sysenter_trap+1>:  mov    %esp,%ecx
0x93b42cf7 <_sysenter_trap+3>:  sysenter 
0x93b42cf9 <_sysenter_trap+5>:  nopl   (%eax)
0x93b42cfc <i386_get_ldt+0>:    mov    $0x6,%eax
End of assembler dump.


-- 

dominiq at lps dot ens dot fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.4 Regression] Broken IOs |[4.4 Regression] I/Os hang
                   |at rev. 137644 on i686-     |at rev. 137631 on darwin9
                   |apple-darwin9               |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36806