From eb7b8a413a99b2e43e8feee410f2b860e99e7056 Mon Sep 17 00:00:00 2001 From: Martin Sustrik Date: Sat, 7 Aug 2010 11:24:07 +0200 Subject: REP socket layered on top of XREP socket --- src/rep.cpp | 263 +++++++++--------------------------------------------------- 1 file changed, 38 insertions(+), 225 deletions(-) (limited to 'src/rep.cpp') diff --git a/src/rep.cpp b/src/rep.cpp index 7636d13..b2ada66 100644 --- a/src/rep.cpp +++ b/src/rep.cpp @@ -21,175 +21,36 @@ #include "rep.hpp" #include "err.hpp" -#include "pipe.hpp" zmq::rep_t::rep_t (class ctx_t *parent_, uint32_t slot_) : - socket_base_t (parent_, slot_), - active (0), - current (0), + xrep_t (parent_, slot_), sending_reply (false), - more (false), - reply_pipe (NULL) + request_begins (true) { - options.requires_in = true; - options.requires_out = true; - - // We don't need immediate connect. We'll be able to send messages - // (replies) only when connection is established and thus requests - // can arrive anyway. - options.immediate_connect = false; } zmq::rep_t::~rep_t () { - zmq_assert (in_pipes.empty ()); - zmq_assert (out_pipes.empty ()); -} - -void zmq::rep_t::xattach_pipes (class reader_t *inpipe_, - class writer_t *outpipe_, const blob_t &peer_identity_) -{ - zmq_assert (inpipe_ && outpipe_); - zmq_assert (in_pipes.size () == out_pipes.size ()); - - inpipe_->set_event_sink (this); - in_pipes.push_back (inpipe_); - in_pipes.swap (active, in_pipes.size () - 1); - - outpipe_->set_event_sink (this); - out_pipes.push_back (outpipe_); - out_pipes.swap (active, out_pipes.size () - 1); - - active++; -} - -void zmq::rep_t::xterm_pipes () -{ - for (in_pipes_t::size_type i = 0; i != in_pipes.size (); i++) - in_pipes [i]->terminate (); - for (out_pipes_t::size_type i = 0; i != out_pipes.size (); i++) - out_pipes [i]->terminate (); -} - -void zmq::rep_t::terminated (reader_t *pipe_) -{ - // ??? - zmq_assert (sending_reply || !more || in_pipes [current] != pipe_); - - zmq_assert (pipe_); - zmq_assert (in_pipes.size () == out_pipes.size ()); - - in_pipes_t::size_type index = in_pipes.index (pipe_); - - if (index < active) { - active--; - if (current == active) - current = 0; - } - in_pipes.erase (index); - - // ??? - if (!zombie) { - if (out_pipes [index]) - out_pipes [index]->terminate (); - out_pipes.erase (index); - } -} - -void zmq::rep_t::terminated (writer_t *pipe_) -{ - zmq_assert (pipe_); - zmq_assert (in_pipes.size () == out_pipes.size ()); - - out_pipes_t::size_type index = out_pipes.index (pipe_); - - // If the connection we've got the request from disconnects, - // there's nowhere to send the reply. Forget about the reply pipe. - // Once the reply is sent it will be dropped. - if (sending_reply && pipe_ == reply_pipe) - reply_pipe = NULL; - - if (out_pipes.index (pipe_) < active) { - active--; - if (current == active) - current = 0; - } - - out_pipes.erase (index); - - // ??? - if (!zombie) { - if (in_pipes [index]) - in_pipes [index]->terminate (); - in_pipes.erase (index); - } -} - -bool zmq::rep_t::xhas_pipes () -{ - return !in_pipes.empty () || !out_pipes.empty (); -} - -void zmq::rep_t::activated (reader_t *pipe_) -{ - // Move the pipe to the list of active pipes. - in_pipes_t::size_type index = in_pipes.index (pipe_); - in_pipes.swap (index, active); - out_pipes.swap (index, active); - active++; -} - -void zmq::rep_t::activated (writer_t *pipe_) -{ - // TODO: What here? - zmq_assert (false); } int zmq::rep_t::xsend (zmq_msg_t *msg_, int flags_) { + // If we are in the middle of receiving a request, we cannot send reply. if (!sending_reply) { errno = EFSM; return -1; } - if (reply_pipe) { - - // Push message to the reply pipe. - bool written = reply_pipe->write (msg_); - zmq_assert (!more || written); + bool more = (msg_->flags & ZMQ_MSG_MORE); - // The pipe is full... - // When this happens, we simply return an error. - // This makes REP sockets vulnerable to DoS attack when - // misbehaving requesters stop collecting replies. - // TODO: Tear down the underlying connection (?) - if (!written) { + // Push message to the reply pipe. + int rc = xrep_t::xsend (msg_, flags_); + if (rc != 0) + return rc; - // TODO: The reply socket becomes deactivated here... - errno = EAGAIN; - return -1; - } - - more = msg_->flags & ZMQ_MSG_MORE; - } - else { - - // If the requester have disconnected in the meantime, drop the reply. - more = msg_->flags & ZMQ_MSG_MORE; - zmq_msg_close (msg_); - } - - // Flush the reply to the requester. - if (!more) { - if (reply_pipe) - reply_pipe->flush (); + // If the reply is complete flip the FSM back to request receiving state. + if (!more) sending_reply = false; - reply_pipe = NULL; - } - - // Detach the message from the data buffer. - int rc = zmq_msg_init (msg_); - zmq_assert (rc == 0); return 0; } @@ -202,70 +63,44 @@ int zmq::rep_t::xrecv (zmq_msg_t *msg_, int flags_) return -1; } - // Deallocate old content of the message. - zmq_msg_close (msg_); + if (request_begins) { - // We haven't started reading a request yet... - if (!more) { + // Copy the backtrace stack to the reply pipe. + bool bottom = false; + while (!bottom) { - // Round-robin over the pipes to get next message. - int count; - for (count = active; count != 0; count--) { - if (in_pipes [current]->read (msg_)) - break; + // TODO: What if request can be read but reply pipe is not + // ready for writing? - // Move the pipe to the list of inactive pipes. - active--; - in_pipes.swap (current, active); - out_pipes.swap (current, active); + // Get next part of the backtrace stack. + int rc = xrep_t::xrecv (msg_, flags_); + if (rc != 0) + return rc; + zmq_assert (msg_->flags & ZMQ_MSG_MORE); - // Move to next pipe. - current++; - if (current >= active) - current = 0; - } + // Empty message part delimits the traceback stack. + bottom = (zmq_msg_size (msg_) == 0); - // No message is available. Initialise the output parameter - // to be a 0-byte message. - if (count == 0) { - zmq_msg_init (msg_); - errno = EAGAIN; - return -1; + // Push it to the reply pipe. + rc = xrep_t::xsend (msg_, flags_); + zmq_assert (rc == 0); } - // We are aware of a new message now. Setup the reply pipe. - reply_pipe = out_pipes [current]; - - // Copy the routing info to the reply pipe. - while (true) { - - // Push message to the reply pipe. - // TODO: What if the pipe is full? - // Tear down the underlying connection? - bool written = reply_pipe->write (msg_); - zmq_assert (written); - - // Message part of zero size delimits the traceback stack. - if (zmq_msg_size (msg_) == 0) - break; - - // Get next part of the message. - bool fetched = in_pipes [current]->read (msg_); - zmq_assert (fetched); - } + request_begins = false; } - // Now the routing info is processed. Get the first part + // Now the routing info is safely stored. Get the first part // of the message payload and exit. - bool fetched = in_pipes [current]->read (msg_); - zmq_assert (fetched); - more = msg_->flags & ZMQ_MSG_MORE; - if (!more) { - current++; - if (current >= active) - current = 0; + int rc = xrep_t::xrecv (msg_, flags_); + if (rc != 0) + return rc; + + // If whole request is read, flip the FSM to reply-sending state. + if (!(msg_->flags & ZMQ_MSG_MORE)) { sending_reply = true; + request_begins = true; } + return 0; } @@ -274,25 +109,7 @@ bool zmq::rep_t::xhas_in () if (sending_reply) return false; - if (more) - return true; - - for (int count = active; count != 0; count--) { - if (in_pipes [current]->check_read ()) - return !sending_reply; - - // Move the pipe to the list of inactive pipes. - active--; - in_pipes.swap (current, active); - out_pipes.swap (current, active); - - // Move to the next pipe. - current++; - if (current >= active) - current = 0; - } - - return false; + return xrep_t::xhas_in (); } bool zmq::rep_t::xhas_out () @@ -300,10 +117,6 @@ bool zmq::rep_t::xhas_out () if (!sending_reply) return false; - if (more) - return true; - - // TODO: No check for write here... - return sending_reply; + return xrep_t::xhas_out (); } -- cgit v1.2.3