First, the code you wrote here doesn't use os/signal, so you can't really
fault Ian for giving that advice. Here's my understanding:
In general, there are two kinds of signals: synchronous ones, raised e.g.
by dereferencing invalid memory. They produce a runtime panic at the site
that produced them in the corresponding goroutine. And asynchronous ones,
raised e.g. by using the kill command or os.Kill. They do not produce a
runtime panic but instead need to be handled via os/signal.
Now, to "catch" asynchronous panic's, you need to use os/signal and if you
need them to produce a runtime-panic on the goroutine running main, you
need to read from that channel in main and produce a panic whenever you
read a value. You could, for example, do this:
func main() {
ch := make(chan os.Signal)
signal.Notify(ch, mySignals)
errs := make(chan interface{})
go func() {
defer func() {
errs <- recover()
}()
for {
C.do_something()
}
}()
for {
select {
case s := <-ch:
panic(fmt.Sprintf("received signal: %v", s))
case v := <-errs:
panic(fmt.Sprintf("recovered runtime panic in C-code: %v", v))
}
}
}
this will get asynchronous signals via os/signal and synchronous signals in
the C-code raising runtime-panics via recover.
Now, what is *not* possible, is to somehow recover from runtime panics
caused by synchronous signals in *other* goroutines. The spec is pretty clear
about that <https://golang.org/ref/spec#Handling_panics>; a panic that
isn't recovered will cause the program to crash.
Hope this helps.
On Wed, Feb 15, 2017 at 6:44 PM, Yucong Sun <[email protected]> wrote:
> hi,
>
> Maybe I wasn't clear, I am indeed using os.signal package. But it doesn't
> do what I want! I want to trigger a panic in main function , seems there
> is no way to do it by using a signal channel .
>
> Thanks
>
> --
> You received this message because you are subscribed to the Google Groups
> "golang-nuts" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
