need help with sigaction and siginfo_t

[Tijl Coosemans]

On Saturday 17 November 2007 17:03:51 nikita kozlov wrote:
> I'm a student and we are working on FreeBSD.
> My problem is i don't understand how to use SA_SIGINFO and siginfo_t.
> The following code caught my SIGUSR1 with a "kill -30 my_server_pid"
> from my shell.
> but siginfo_t is empty when i'm debugging my program with gdb.
> my output is :
> > pid 0
> and in gdb i have :
> {
> si_signo = 30,
> si_errno = 0,
> si_code = 0,
> si_pid = 0,
> si_uid = 0,
> si_status = 0,
> si_addr = 0x2,
> si_value = {sigval_int = 0,sigval_ptr = 0x0},
> si_band = 0,
> __spare__ = {0, 0, 0, 0, 0, 0, 0}
> }
> 
> anyone have an idea why my siginfo_t is empty please ?

Well, it isn't empty. It's just that the si_pid field usually isn't
set. It probably should be, but either way, your code should work if
you send signals with sigqueue(2) instead of kill(2).