不使用 TLS 时，localhost 的 AnyEvent tcp 服务器-客户端示例挂起
AnyEvent tcp server-client example for localhost hangs when not using TLS
调试 AnyEvent on Windows, I created the following script based on test 80_ssltest.t 的失败测试时：
use feature qw(say);
use strict;
use warnings;
use AnyEvent::Socket;
use AnyEvent::Handle;
use AnyEvent::TLS;
my $ctx = AnyEvent::TLS->new( cert_file => [=10=] );
my $server_done = AnyEvent->condvar;
my $client_done = AnyEvent->condvar;
my $server_port = AnyEvent->condvar;
my $host = "127.0.0.1";
my $server = tcp_server(
$host,
undef, # service: must be either a service name or a numeric port number
# (or 0 or undef, in which case an ephemeral port will be used).
#
sub { # This is the accept callback..
my ($fh, $host, $port) = @_;
say "server_accept";
my $hd; $hd = AnyEvent::Handle->new(
#tls => "accept",
#tls_ctx => $ctx,
fh => $fh,
timeout => 8,
on_error => sub {
say "server_error <$_[2]>";
$server_done->send; undef $hd;
},
on_eof => sub {
say "server_eof";
$server_done->send; undef $hd;
}
);
$hd->push_read (
line => sub {
say "server got line <$_[1]>";
}
);
}, # end of accept callback..
sub { # This is the prepare callback
say "server_listen";
$server_port->send ($_[2]);
}
);
my $port = $server_port->recv; # At this point the server should be listening...
my $hd; $hd = AnyEvent::Handle->new(
connect => [$host, $port],
#tls => "connect",
#tls_ctx => $ctx,
timeout => 8,
on_connect => sub {
say "client_connect";
},
on_error => sub {
say "client_error <$_[2]>";
$client_done->send; undef $hd;
},
on_eof => sub {
say "client_eof";
$client_done->send; undef $hd;
}
);
$hd->push_write ("1\n");
say "Sleeping..";
sleep 1;
$hd->on_drain (sub {
say "client_drain";
$client_done->send;
undef $hd; # For some reason this does not send EOF to the server
});
say "Waiting for client done..";
$client_done->recv;
say "Waiting for server done..";
$server_done->recv;
__END__
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
-----
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
此脚本挂起（Ubuntu 20.04，perl 版本 5.30），但如果我使用 TLS 握手（取消注释代码中带有 tls 和 tls_ctx 的行）它工作正常.
没有 TLS 的输出是：
server_listen
Sleeping..
Waiting for client done..
client_drain
server_accept
Waiting for server done..
server got line <1>
server_error <Connection timed out>
使用 TLS 的输出（在取消注释以 tls 和 tls_ctx 开头的 4 行之后）是：
server_listen
Sleeping..
Waiting for client done..
client_connect
server_accept
client_drain
Waiting for server done..
server got line <1>
server_eof
- 请注意，不使用 TLS 时，不会调用
on_connect（输出中缺少 client_connect），
- 不使用TLS时即使客户端不连接，服务端也收到数据并打印
server got line <1>...很奇怪
知道不使用 TLS 时会出现什么问题吗？
从表面上看，您不是在阅读 socket/handle。如果不从套接字读取，就无法检测到 EOF 条件。
使用 TLS 时出现不同行为的原因是 TLS 不模拟套接字语义并且 AnyEvent::Handle 基本上必须始终读取，即使您没有明确的读取请求，因此它会检测到 EOF瞬间状态。
您可以通过添加 on_read 处理程序来检查这一点，例如服务器中 push_read 之后或之前：
$hd->push_read (sub { });
有了这个礼物，不管有没有 TLS，它的行为应该或多或少是一样的。
根据 documentation:
Note that, unlike requests in the read queue, an on_read callback
doesn't mean you require some data: if there is an EOF and there are
outstanding read requests then an error will be flagged. With an
on_read callback, the on_eof callback will be invoked.
这表明我需要 on_read 回调才能调用 on_eof 回调。我试图将服务器更改为：
my $server = tcp_server(
$host,
undef, # service: must be either a service name or a numeric port number
# (or 0 or undef, in which case an ephemeral port will be used).
#
sub { # This is the accept callback..
my ($fh, $host, $port) = @_;
say "server_accept";
my $hd; $hd = AnyEvent::Handle->new(
fh => $fh,
timeout => 5,
on_error => sub {
say "server_error <$_[2]>";
$server_done->send; undef $hd;
},
on_eof => sub {
say "server_eof";
$server_done->send; undef $hd;
}
);
$hd->on_read(sub{ say "server on_read() callback"});
$hd->push_read (
line => sub {
say "server got line <$_[1]>";
}
);
}, # end of accept callback..
sub { # This is the prepare callback
say "server_listen";
$server_port->send ($_[2]);
}
);
现在的输出是：
server_listen
Sleeping..
Waiting for client done..
client_drain
server_accept
Waiting for server done..
server got line <1>
server_eof
所以它有效！ （我仍然想知道为什么客户端 on_connect 不是 运行，即“客户端连接”不显示）。另请注意，on_read 回调不是 运行，因为“服务器 on_read() 回调”行未输出。
另见 Why isn't on_eof called in this AnyEvent::Handle example?
调试 AnyEvent on Windows, I created the following script based on test 80_ssltest.t 的失败测试时：
use feature qw(say);
use strict;
use warnings;
use AnyEvent::Socket;
use AnyEvent::Handle;
use AnyEvent::TLS;
my $ctx = AnyEvent::TLS->new( cert_file => [=10=] );
my $server_done = AnyEvent->condvar;
my $client_done = AnyEvent->condvar;
my $server_port = AnyEvent->condvar;
my $host = "127.0.0.1";
my $server = tcp_server(
$host,
undef, # service: must be either a service name or a numeric port number
# (or 0 or undef, in which case an ephemeral port will be used).
#
sub { # This is the accept callback..
my ($fh, $host, $port) = @_;
say "server_accept";
my $hd; $hd = AnyEvent::Handle->new(
#tls => "accept",
#tls_ctx => $ctx,
fh => $fh,
timeout => 8,
on_error => sub {
say "server_error <$_[2]>";
$server_done->send; undef $hd;
},
on_eof => sub {
say "server_eof";
$server_done->send; undef $hd;
}
);
$hd->push_read (
line => sub {
say "server got line <$_[1]>";
}
);
}, # end of accept callback..
sub { # This is the prepare callback
say "server_listen";
$server_port->send ($_[2]);
}
);
my $port = $server_port->recv; # At this point the server should be listening...
my $hd; $hd = AnyEvent::Handle->new(
connect => [$host, $port],
#tls => "connect",
#tls_ctx => $ctx,
timeout => 8,
on_connect => sub {
say "client_connect";
},
on_error => sub {
say "client_error <$_[2]>";
$client_done->send; undef $hd;
},
on_eof => sub {
say "client_eof";
$client_done->send; undef $hd;
}
);
$hd->push_write ("1\n");
say "Sleeping..";
sleep 1;
$hd->on_drain (sub {
say "client_drain";
$client_done->send;
undef $hd; # For some reason this does not send EOF to the server
});
say "Waiting for client done..";
$client_done->recv;
say "Waiting for server done..";
$server_done->recv;
__END__
-----BEGIN RSA PRIVATE KEY-----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Hpkl+ZlBAoGBAOyfjVLD0OznJKSFksoCZKS4dlPHgXUb47Qb/XchIySQ/DNO6ff9
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s3CIM20TuzLndFPrEGFgOrt+i5qKisti2OOZhjsDwfd48vsBm9U20lUpAoGBAOS1
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W4pc59Ql5KDLzu/Sne8oC3pxhaWeIPhc2d3cd/8UyGtQLtN2QnilwkjHgi3x1JGb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-----END RSA PRIVATE KEY-----
-----
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
此脚本挂起（Ubuntu 20.04，perl 版本 5.30），但如果我使用 TLS 握手（取消注释代码中带有 tls 和 tls_ctx 的行）它工作正常.
没有 TLS 的输出是：
server_listen
Sleeping..
Waiting for client done..
client_drain
server_accept
Waiting for server done..
server got line <1>
server_error <Connection timed out>
使用 TLS 的输出（在取消注释以 tls 和 tls_ctx 开头的 4 行之后）是：
server_listen
Sleeping..
Waiting for client done..
client_connect
server_accept
client_drain
Waiting for server done..
server got line <1>
server_eof
- 请注意，不使用 TLS 时，不会调用
on_connect（输出中缺少client_connect）， - 不使用TLS时即使客户端不连接，服务端也收到数据并打印
server got line <1>...很奇怪
知道不使用 TLS 时会出现什么问题吗？
从表面上看，您不是在阅读 socket/handle。如果不从套接字读取，就无法检测到 EOF 条件。
使用 TLS 时出现不同行为的原因是 TLS 不模拟套接字语义并且 AnyEvent::Handle 基本上必须始终读取，即使您没有明确的读取请求，因此它会检测到 EOF瞬间状态。
您可以通过添加 on_read 处理程序来检查这一点，例如服务器中 push_read 之后或之前：
$hd->push_read (sub { });
有了这个礼物，不管有没有 TLS，它的行为应该或多或少是一样的。
根据 documentation:
Note that, unlike requests in the read queue, an
on_readcallback doesn't mean you require some data: if there is an EOF and there are outstanding read requests then an error will be flagged. With anon_readcallback, theon_eofcallback will be invoked.
这表明我需要 on_read 回调才能调用 on_eof 回调。我试图将服务器更改为：
my $server = tcp_server(
$host,
undef, # service: must be either a service name or a numeric port number
# (or 0 or undef, in which case an ephemeral port will be used).
#
sub { # This is the accept callback..
my ($fh, $host, $port) = @_;
say "server_accept";
my $hd; $hd = AnyEvent::Handle->new(
fh => $fh,
timeout => 5,
on_error => sub {
say "server_error <$_[2]>";
$server_done->send; undef $hd;
},
on_eof => sub {
say "server_eof";
$server_done->send; undef $hd;
}
);
$hd->on_read(sub{ say "server on_read() callback"});
$hd->push_read (
line => sub {
say "server got line <$_[1]>";
}
);
}, # end of accept callback..
sub { # This is the prepare callback
say "server_listen";
$server_port->send ($_[2]);
}
);
现在的输出是：
server_listen
Sleeping..
Waiting for client done..
client_drain
server_accept
Waiting for server done..
server got line <1>
server_eof
所以它有效！ （我仍然想知道为什么客户端 on_connect 不是 运行，即“客户端连接”不显示）。另请注意，on_read 回调不是 运行，因为“服务器 on_read() 回调”行未输出。
另见 Why isn't on_eof called in this AnyEvent::Handle example?