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131 lines
3.5 KiB
C++
131 lines
3.5 KiB
C++
/*
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Copyright (c) 2007-2010 iMatix Corporation
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This file is part of 0MQ.
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0MQ is free software; you can redistribute it and/or modify it under
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the terms of the Lesser GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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0MQ is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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Lesser GNU General Public License for more details.
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You should have received a copy of the Lesser GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "../include/zmq.h"
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#include "fq.hpp"
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#include "pipe.hpp"
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#include "err.hpp"
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zmq::fq_t::fq_t () :
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active (0),
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current (0),
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more (false)
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{
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}
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zmq::fq_t::~fq_t ()
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{
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for (pipes_t::size_type i = 0; i != pipes.size (); i++)
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pipes [i]->term ();
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}
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void zmq::fq_t::attach (reader_t *pipe_)
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{
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pipes.push_back (pipe_);
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pipes.swap (active, pipes.size () - 1);
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active++;
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}
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void zmq::fq_t::detach (reader_t *pipe_)
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{
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zmq_assert (!more || pipes [current] != pipe_);
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// Remove the pipe from the list; adjust number of active pipes
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// accordingly.
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if (pipes.index (pipe_) < active) {
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active--;
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if (current == active)
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current = 0;
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}
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pipes.erase (pipe_);
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}
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void zmq::fq_t::kill (reader_t *pipe_)
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{
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// Move the pipe to the list of inactive pipes.
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active--;
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if (current == active)
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current = 0;
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pipes.swap (pipes.index (pipe_), active);
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}
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void zmq::fq_t::revive (reader_t *pipe_)
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{
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// Move the pipe to the list of active pipes.
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pipes.swap (pipes.index (pipe_), active);
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active++;
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}
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int zmq::fq_t::recv (zmq_msg_t *msg_, int flags_)
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{
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// Deallocate old content of the message.
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zmq_msg_close (msg_);
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// Round-robin over the pipes to get the next message.
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for (int count = active; count != 0; count--) {
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// Try to fetch new message. If we've already read part of the message
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// subsequent part should be immediately available.
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bool fetched = pipes [current]->read (msg_);
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zmq_assert (!(more && !fetched));
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// Note that when message is not fetched, current pipe is killed and
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// replaced by another active pipe. Thus we don't have to increase
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// the 'current' pointer.
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if (fetched) {
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more = msg_->flags & ZMQ_MSG_MORE;
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if (!more) {
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current++;
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if (current >= active)
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current = 0;
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}
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return 0;
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}
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}
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// No message is available. Initialise the output parameter
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// to be a 0-byte message.
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zmq_msg_init (msg_);
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errno = EAGAIN;
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return -1;
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}
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bool zmq::fq_t::has_in ()
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{
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// There are subsequent parts of the partly-read message available.
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if (more)
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return true;
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// Note that messing with current doesn't break the fairness of fair
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// queueing algorithm. If there are no messages available current will
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// get back to its original value. Otherwise it'll point to the first
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// pipe holding messages, skipping only pipes with no messages available.
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for (int count = active; count != 0; count--) {
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if (pipes [current]->check_read ())
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return true;
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current++;
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if (current >= active)
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current = 0;
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}
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return false;
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}
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