SungHawk Kim wrote:
> Is there any way to implement signal-safe code using not pselect() but
> select()?
Yes. In Linux longjmp and siglongjmp can reliably jump out of a signal
handler. See below.
> I have two cases in that select() should returns,
> . when any of the descriptors are ready
> . when a specific signal(ie, SIGUSR1) is pending
>
> What I want to do is like this:
>
> unblock SIGUSR1
> select();
> block SIGUSR1
>
> This code seems good, but has a problem.
> If a SIGUSR1 signal arrives between unblock and select(), the signal is
> lost. so, select() can sleep forerver.
Solution is:
jmp_buf * save_jb;
volatile sigatomic_t save_jb_flag = 0;
jmp_buf jb;
if (!setjmp (&jb)) {
save_jb = &jb;
save_jb_flag = 1;
unblock SIGUSR1
select();
save_jb_flag = 0;
save_jb = 0;
}
block SIGUSR1
With SIGUSR1 handler:
if (save_jb_flag)
longjmp (save_jb, 1);
The appropriate settings for sigaction are left as an exercise...
enjoy,
-- Jamie
-
To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to [EMAIL PROTECTED]
