Re^8: IO::Socket::SSL sometimes says 'SSL wants a read first'

You have some point that easy things should be easy. But, different users have a different understanding of what is easy and how they expect programs to behave. IO::Socket::SSL is not specifically designed to make it harder. Regarding EINTR it just behaves like all the other IO::Socket modules and it would in my opinion against the expectations if it would behave differently. Just try the following code and you'll see that IO::Socket::INET behaves the same regarding EINTR, i.e. breaks the connect if SIGCHLD is triggered before the connect is done:

$SIG{CHLD} = sub { warn "child returned" };
if (!fork()) {
    sleep(1);
    exit(0);
}
# parent: fails with EINTR if child returns before connect succeeds
my $cl = IO::Socket::INET->new('some_host:dropped_port') or die $!;
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Re^9: IO::Socket::SSL sometimes says 'SSL wants a read first' by salva (Canon) on Apr 21, 2017 at 09:34 UTC
you'll see that IO::Socket::INET behaves the same regarding EINTR Right, but those are two completely different beasts: `IO::Socket::INET` is just a thin wrapper around the networking support provided by the kernel. On the other hand, `IO::Socket::SSL` implements a full and complex protocol on top of that. It even allows you to pass callbacks for customizing the `connect` behavior. Restarting a TCP socket is cheap and doesn't have visible consecuences for the user while restarting a TLS connection may require some repeated interaction with the user, as for instance, accepting certificates. Besides that, signals showing up while inside `IO::Socket::SSL` will turn into `EINTR` errors only when they catch the module inside a blocking syscall which, as TLS has a significant computational cost, may be quite less often than in the `IO::Socket::INET` case. So, depending on `EINTR` may be quite unreliable anyway and so useless.	[reply] [d/l] [select]

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Re^9: IO::Socket::SSL sometimes says 'SSL wants a read first'
by salva (Canon) on Apr 21, 2017 at 09:34 UTC

you'll see that IO::Socket::INET behaves the same regarding EINTR

Right, but those are two completely different beasts: IO::Socket::INET is just a thin wrapper around the networking support provided by the kernel. On the other hand, IO::Socket::SSL implements a full and complex protocol on top of that. It even allows you to pass callbacks for customizing the connect behavior. Restarting a TCP socket is cheap and doesn't have visible consecuences for the user while restarting a TLS connection may require some repeated interaction with the user, as for instance, accepting certificates.

Besides that, signals showing up while inside IO::Socket::SSL will turn into EINTR errors only when they catch the module inside a blocking syscall which, as TLS has a significant computational cost, may be quite less often than in the IO::Socket::INET case. So, depending on EINTR may be quite unreliable anyway and so useless.

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