Mykola Dzham wrote:
> Yar Tikhiy (y
...@comp.chem.msu.su):
>>Правило 3
>>Существует ровно один тип статических данных, sig_atomic_t, переменную
>>которого обработчик сигнала может установить. Поведение приложения
>>неопределено, если обработчик сигнала обращается к статическим
>>данным любым другим способом.
> А вот если делать обработчик сигнала например в перловом скрипте,
> то как там с подобным ограничением поступать?
Plug and pray...
Хорошо, что Perl не работает на моем тостере.
=== pl source code ===
$SIG{'ALRM'} = \&handler;
$\="\n";
alarm(1);
sleep(2);
alarm(1);
sleep(2);
print 'exit';
sub handler() {
print 'alarm';
}
=== pl source code ===
=== ktrace perl pl ===
2694 perl CALL nanosleep(0xbfbff668,0xbfbff660)
2694 perl PSIG SIGALRM caught handler=0x280be470 mask=0x0 code=0x0
2694 perl RET nanosleep -1 errno 4 Interrupted system call
2694 perl CALL fstat(0x1,0xbfbff1a4)
2694 perl RET fstat 0
2694 perl CALL ioctl(0x1,TIOCGETA,0xbfbff1d8)
2694 perl RET ioctl 0
2694 perl CALL write(0x1,0x805c000,0x6)
2694 perl GIO fd 1 wrote 6 bytes
"alarm
"
2694 perl RET write 6
2694 perl CALL sigreturn(0xbfbff4b0)
2694 perl RET sigreturn JUSTRETURN
2694 perl CALL gettimeofday(0xbfbff668,0)
2694 perl RET gettimeofday 0
2694 perl CALL setitimer(0,0xbfbff670,0xbfbff660)
2694 perl RET setitimer 0
2694 perl CALL gettimeofday(0xbfbff668,0)
2694 perl RET gettimeofday 0
2694 perl CALL nanosleep(0xbfbff668,0xbfbff660)
2694 perl PSIG SIGALRM caught handler=0x280be470 mask=0x0 code=0x0
2694 perl RET nanosleep -1 errno 4 Interrupted system call
2694 perl CALL write(0x1,0x805c000,0x6)
2694 perl GIO fd 1 wrote 6 bytes
"alarm
"
2694 perl RET write 6
2694 perl CALL sigreturn(0xbfbff4b0)
2694 perl RET sigreturn JUSTRETURN
2694 perl CALL gettimeofday(0xbfbff668,0)
2694 perl RET gettimeofday 0
2694 perl CALL write(0x1,0x805c000,0x5)
2694 perl GIO fd 1 wrote 5 bytes
"exit
"
=== kdump ===
=== gdb'ing perl ===
[vlm@spelio:~]>gdb perl
GNU gdb 4.18 (FreeBSD)
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-unknown-freebsd"...(no debugging symbols
found)...
(gdb) br 0x280be470
Function "0x280be470" not defined.
(gdb) br main
Breakpoint 1 at 0x8048dfb
(gdb) run pl
Starting program: /usr/bin/perl pl
(no debugging symbols found)...(no debugging symbols found)...(no debugging
symbols found)...(no debugging symbols found)...
(no debugging symbols found)...(no debugging symbols found)...(no debugging
symbols found)...
Breakpoint 1, 0x8048dfb in main ()
(gdb) br *(0x280be470)
Breakpoint 2 at 0x280be470
(gdb) cont
Continuing.
Breakpoint 2, 0x280be470 in Perl_sighandler () from /usr/lib/libperl.so.3
(gdb)
=== end of gdb'ing perl ===
=== Perl_sighandler from Perl's sources ===
PUSHSTACKi(PERLSI_SIGNAL);
PUSHMARK(SP);
PUSHs(sv);
PUTBACK;
call_sv((SV*)cv, G_DISCARD);
POPSTACK;
cleanup:
if (flags & 1)
PL_savestack_ix -= 8; /* Unprotect save in progress. */
if (flags & 4)
PL_markstack_ptr--;
if (flags & 8)
PL_retstack_ix--;
if (flags & 16)
PL_scopestack_ix -= 1;
if (flags & 64)
SvREFCNT_dec(sv);
PL_op = myop; /* Apparently not needed... */
=== end of Perl sources ===
--
Lev Walkin
v...@netli.com
