Line data    Source code

       1             : /*
       2             :     Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
       3             : 
       4             :     This file is part of libzmq, the ZeroMQ core engine in C++.
       5             : 
       6             :     libzmq is free software; you can redistribute it and/or modify it under
       7             :     the terms of the GNU Lesser General Public License (LGPL) as published
       8             :     by the Free Software Foundation; either version 3 of the License, or
       9             :     (at your option) any later version.
      10             : 
      11             :     As a special exception, the Contributors give you permission to link
      12             :     this library with independent modules to produce an executable,
      13             :     regardless of the license terms of these independent modules, and to
      14             :     copy and distribute the resulting executable under terms of your choice,
      15             :     provided that you also meet, for each linked independent module, the
      16             :     terms and conditions of the license of that module. An independent
      17             :     module is a module which is not derived from or based on this library.
      18             :     If you modify this library, you must extend this exception to your
      19             :     version of the library.
      20             : 
      21             :     libzmq is distributed in the hope that it will be useful, but WITHOUT
      22             :     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
      23             :     FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
      24             :     License for more details.
      25             : 
      26             :     You should have received a copy of the GNU Lesser General Public License
      27             :     along with this program.  If not, see <http://www.gnu.org/licenses/>.
      28             : */
      29             : 
      30             : #include "precompiled.hpp"
      31             : #include "mailbox_safe.hpp"
      32             : #include "clock.hpp"
      33             : #include "err.hpp"
      34             : 
      35          51 : zmq::mailbox_safe_t::mailbox_safe_t (mutex_t* sync_) :
      36         102 :     sync (sync_)
      37             : {
      38             :     //  Get the pipe into passive state. That way, if the users starts by
      39             :     //  polling on the associated file descriptor it will get woken up when
      40             :     //  new command is posted.
      41          51 :     const bool ok = cpipe.read (NULL);
      42          51 :     zmq_assert (!ok);
      43          51 : }
      44             : 
      45         255 : zmq::mailbox_safe_t::~mailbox_safe_t ()
      46             : {
      47             :     //  TODO: Retrieve and deallocate commands inside the cpipe.
      48             : 
      49             :     // Work around problem that other threads might still be in our
      50             :     // send() method, by waiting on the mutex before disappearing.
      51          51 :     sync->lock ();
      52          51 :     sync->unlock ();
      53         102 : }
      54             : 
      55          54 : void zmq::mailbox_safe_t::add_signaler (signaler_t* signaler)
      56             : {
      57          54 :     signalers.push_back(signaler);
      58          54 : }
      59             : 
      60           0 : void zmq::mailbox_safe_t::remove_signaler (signaler_t* signaler)
      61             : {
      62           0 :     std::vector<signaler_t*>::iterator it = signalers.begin();
      63             : 
      64             :     // TODO: make a copy of array and signal outside the lock
      65           0 :     for (; it != signalers.end(); ++it){
      66           0 :         if (*it == signaler)
      67             :            break;
      68             :     }
      69             : 
      70           0 :     if (it != signalers.end())
      71           0 :         signalers.erase(it);
      72           0 : }
      73             : 
      74          51 : void zmq::mailbox_safe_t::clear_signalers ()
      75             : {
      76          51 :     signalers.clear ();
      77          51 : }
      78             : 
      79        1571 : void zmq::mailbox_safe_t::send (const command_t &cmd_)
      80             : {
      81        1571 :     sync->lock ();
      82        1571 :     cpipe.write (cmd_, false);
      83        1571 :     const bool ok = cpipe.flush ();
      84             : 
      85        1571 :     if (!ok) {
      86        1485 :         cond_var.broadcast ();
      87        7671 :         for (std::vector<signaler_t*>::iterator it = signalers.begin(); it != signalers.end(); ++it){
      88          82 :             (*it)->send();
      89             :         }
      90             :     }
      91             : 
      92        1571 :     sync->unlock ();
      93        1571 : }
      94             : 
      95        9598 : int zmq::mailbox_safe_t::recv (command_t *cmd_, int timeout_)
      96             : {
      97             :     //  Try to get the command straight away.
      98        9598 :     if (cpipe.read (cmd_))
      99             :         return 0;
     100             : 
     101             :     //  Wait for signal from the command sender.
     102        8984 :     int rc = cond_var.wait (sync, timeout_);
     103        8984 :     if (rc == -1) {
     104        7507 :         errno_assert (errno == EAGAIN || errno == EINTR);
     105             :         return -1;
     106             :     }
     107             : 
     108             :     //  Another thread may already fetch the command
     109        1477 :     const bool ok = cpipe.read (cmd_);
     110             : 
     111        1477 :     if (!ok) {
     112         520 :         errno = EAGAIN;
     113         520 :         return -1;
     114             :     }
     115             : 
     116             :     return 0;
     117             : }