[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent/Handle.pm

Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.211 by root, Fri Dec 31 04:47:41 2010 UTC vs.
Revision 1.222 by root, Thu Aug 25 03:08:48 2011 UTC

    my $hdl; $hdl = new AnyEvent::Handle
       fh => \*STDIN,
       on_error => sub {
          my ($hdl, $fatal, $msg) = @_;
-         warn "got error $msg\n";
+         AE::log warn => "got error $msg\n";
          $hdl->destroy;
          $cv->send;
       };
    # send some request line
    $hdl->push_write ("getinfo\015\012");
    # read the response line
    $hdl->push_read (line => sub {
       my ($hdl, $line) = @_;
-      warn "got line <$line>\n";
+      AE::log warn => "got line <$line>\n";
       $cv->send;
    });
    $cv->recv;
 many seconds pass without a successful read or write on the underlying
 file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
 will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
 error will be raised).
-There are three variants of the timeouts that work independently
+There are three variants of the timeouts that work independently of each
-of each other, for both read and write, just read, and just write:
+other, for both read and write (triggered when nothing was read I<OR>
+written), just read (triggered when nothing was read), and just write:
 C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
 C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
 C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
-Note that timeout processing is active even when you do not have
+Note that timeout processing is active even when you do not have any
-any outstanding read or write requests: If you plan to keep the connection
+outstanding read or write requests: If you plan to keep the connection
-idle then you should disable the timeout temporarily or ignore the timeout
+idle then you should disable the timeout temporarily or ignore the
-in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
+timeout in the corresponding C<on_timeout> callback, in which case
-restart the timeout.
+AnyEvent::Handle will simply restart the timeout.
-Zero (the default) disables this timeout.
+Zero (the default) disables the corresponding timeout.
 =item on_timeout => $cb->($handle)
+=item on_rtimeout => $cb->($handle)
+=item on_wtimeout => $cb->($handle)
 Called whenever the inactivity timeout passes. If you return from this
 callback, then the timeout will be reset as if some activity had happened,
 so this condition is not fatal in any way.
 already have occured on BSD systems), but at least it will protect you
 from most attacks.
 =item read_size => <bytes>
-The initial read block size, the number of bytes this module will try to
+The initial read block size, the number of bytes this module will try
-read during each loop iteration. Each handle object will consume at least
+to read during each loop iteration. Each handle object will consume
-this amount of memory for the read buffer as well, so when handling many
+at least this amount of memory for the read buffer as well, so when
-connections requirements). See also C<max_read_size>. Default: C<2048>.
+handling many connections watch out for memory requirements). See also
+C<max_read_size>. Default: C<2048>.
 =item max_read_size => <bytes>
 The maximum read buffer size used by the dynamic adjustment
 algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
                             });
                   } else {
                      if ($self->{on_connect_error}) {
                         $self->{on_connect_error}($self, "$!");
-                        $self->destroy;
+                        $self->destroy if $self;
                      } else {
                         $self->_error ($!, 1);
                      }
                   }
                },
 sub rbuf_max {
    $_[0]{rbuf_max} = $_[1];
 }
-sub rbuf_max {
+sub wbuf_max {
    $_[0]{wbuf_max} = $_[1];
 }
 #############################################################################
 =item $handle->rtimeout ($seconds)
 =item $handle->wtimeout ($seconds)
 Configures (or disables) the inactivity timeout.
+The timeout will be checked instantly, so this method might destroy the
+handle before it returns.
 =item $handle->timeout_reset
 =item $handle->rtimeout_reset
 before it was actually written. One way to do that is to replace your
 C<on_drain> handler by a callback that shuts down the socket (and set
 C<low_water_mark> to C<0>). This method is a shorthand for just that, and
 replaces the C<on_drain> callback with:
-   sub { shutdown $_[0]{fh}, 1 }    # for push_shutdown
+   sub { shutdown $_[0]{fh}, 1 }
 This simply shuts down the write side and signals an EOF condition to the
 the peer.
 You can rely on the normal read queue and C<on_eof> handling
 data.
 Example: read 2 bytes.
    $handle->push_read (chunk => 2, sub {
-      warn "yay ", unpack "H*", $_[1];
+      AE::log debug => "yay " . unpack "H*", $_[1];
    });
 =cut
 register_read_type chunk => sub {
    sub {
       # accept
       if ($$rbuf =~ $accept) {
          $data .= substr $$rbuf, 0, $+[0], "";
-         $cb->($self, $data);
+         $cb->($_[0], $data);
          return 1;
       }
       # reject
       if ($reject && $$rbuf =~ $reject) {
-         $self->_error (Errno::EBADMSG);
+         $_[0]->_error (Errno::EBADMSG);
       }
       # skip
       if ($skip && $$rbuf =~ $skip) {
          $data .= substr $$rbuf, 0, $+[0], "";
    my ($self, $cb) = @_;
    sub {
       unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
          if ($_[0]{rbuf} =~ /[^0-9]/) {
-            $self->_error (Errno::EBADMSG);
+            $_[0]->_error (Errno::EBADMSG);
          }
          return;
       }
       my $len = $1;
-      $self->unshift_read (chunk => $len, sub {
+      $_[0]->unshift_read (chunk => $len, sub {
          my $string = $_[1];
          $_[0]->unshift_read (chunk => 1, sub {
             if ($_[1] eq ",") {
                $cb->($_[0], $string);
             } else {
-               $self->_error (Errno::EBADMSG);
+               $_[0]->_error (Errno::EBADMSG);
             }
          });
       });
       1
    sub {
       # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
       defined (my $len = eval { unpack $format, $_[0]{rbuf} })
          or return;
-      warn "len $len\n";#d#
       $format = length pack $format, $len;
-      warn "len2 $format\n";#d#
       # bypass unshift if we already have the remaining chunk
       if ($format + $len <= length $_[0]{rbuf}) {
          my $data = substr $_[0]{rbuf}, $format, $len;
          substr $_[0]{rbuf}, 0, $format + $len, "";
    my $data;
    my $rbuf = \$self->{rbuf};
    sub {
-      my $ref = eval { $json->incr_parse ($self->{rbuf}) };
+      my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
       if ($ref) {
-         $self->{rbuf} = $json->incr_text;
+         $_[0]{rbuf} = $json->incr_text;
          $json->incr_text = "";
-         $cb->($self, $ref);
+         $cb->($_[0], $ref);
          1
       } elsif ($@) {
          # error case
          $json->incr_skip;
-         $self->{rbuf} = $json->incr_text;
+         $_[0]{rbuf} = $json->incr_text;
          $json->incr_text = "";
-         $self->_error (Errno::EBADMSG);
+         $_[0]->_error (Errno::EBADMSG);
          ()
       } else {
-         $self->{rbuf} = "";
+         $_[0]{rbuf} = "";
          ()
       }
    }
 };
          # read remaining chunk
          $_[0]->unshift_read (chunk => $len, sub {
             if (my $ref = eval { Storable::thaw ($_[1]) }) {
                $cb->($_[0], $ref);
             } else {
-               $self->_error (Errno::EBADMSG);
+               $_[0]->_error (Errno::EBADMSG);
             }
          });
       }
       1
 Note that AnyEvent::Handle will automatically C<start_read> for you when
 you change the C<on_read> callback or push/unshift a read callback, and it
 will automatically C<stop_read> for you when neither C<on_read> is set nor
 there are any read requests in the queue.
-These methods will have no effect when in TLS mode (as TLS doesn't support
+In older versions of this module (<= 5.3), these methods had no effect,
-half-duplex connections).
+as TLS does not support half-duplex connections. In current versions they
+work as expected, as this behaviour is required to avoid certain resource
+attacks, where the program would be forced to read (and buffer) arbitrary
+amounts of data before being able to send some data. The drawback is that
+some readings of the the SSL/TLS specifications basically require this
+attack to be working, as SSL/TLS implementations might stall sending data
+during a rehandshake.
+As a guideline, during the initial handshake, you should not stop reading,
+and as a client, it might cause problems, depending on your applciation.
 =cut
 sub stop_read {
    my ($self) = @_;
-   delete $self->{_rw} unless $self->{tls};
+   delete $self->{_rw};
 }
 sub start_read {
    my ($self) = @_;
    Net::SSLeay::CTX_set_mode ($tls, 1|2);
    $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
    $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
-   Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
+   Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
+   $self->{rbuf} = "";
    Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
    $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
       if $self->{on_starttls};
    $self->{tls_ctx}->_put_session (delete $self->{tls})
       if $self->{tls} > 0;
    delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
 }
+=item $handle->resettls
+This rarely-used method simply resets and TLS state on the handle, usually
+causing data loss.
+One case where it may be useful is when you want to skip over the data in
+the stream but you are not interested in interpreting it, so data loss is
+no concern.
+=cut
+*resettls = \&_freetls;
 sub DESTROY {
    my ($self) = @_;
    &_freetls;
    $handle->on_eof (undef);
    $handle->on_error (sub {
       my $data = delete $_[0]{rbuf};
    });
+Note that this example removes the C<rbuf> member from the handle object,
+which is not normally allowed by the API. It is expressly permitted in
+this case only, as the handle object needs to be destroyed afterwards.
 The reason to use C<on_error> is that TCP connections, due to latencies
 and packets loss, might get closed quite violently with an error, when in
 fact all data has been received.
 It is usually better to use acknowledgements when transferring data,
 C<low_water_mark> this will be called precisely when all data has been
 written to the socket:
    $handle->push_write (...);
    $handle->on_drain (sub {
-      warn "all data submitted to the kernel\n";
+      AE::log debug => "all data submitted to the kernel\n";
       undef $handle;
    });
 If you just want to queue some data and then signal EOF to the other side,
 consider using C<< ->push_shutdown >> instead.

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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents): Revision 1.211 by root, Fri Dec 31 04:47:41 2010 UTC vs. Revision 1.222 by root, Thu Aug 25 03:08:48 2011 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.211 by root, Fri Dec 31 04:47:41 2010 UTC vs.
Revision 1.222 by root, Thu Aug 25 03:08:48 2011 UTC