Merge commit 'e988fee1679536137b87d10e939eff5c1f27c8ab' as 'libs/libzmq'

libs/libzmq/src/select.hpp

@@ -0,0 +1,171 @@
+/*
+    Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
+
+    This file is part of libzmq, the ZeroMQ core engine in C++.
+
+    libzmq is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    As a special exception, the Contributors give you permission to link
+    this library with independent modules to produce an executable,
+    regardless of the license terms of these independent modules, and to
+    copy and distribute the resulting executable under terms of your choice,
+    provided that you also meet, for each linked independent module, the
+    terms and conditions of the license of that module. An independent
+    module is a module which is not derived from or based on this library.
+    If you modify this library, you must extend this exception to your
+    version of the library.
+
+    libzmq is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_SELECT_HPP_INCLUDED__
+#define __ZMQ_SELECT_HPP_INCLUDED__
+
+//  poller.hpp decides which polling mechanism to use.
+#include "poller.hpp"
+#if defined ZMQ_IOTHREAD_POLLER_USE_SELECT
+
+#include <stddef.h>
+#include <vector>
+#include <map>
+
+#if defined ZMQ_HAVE_WINDOWS
+#elif defined ZMQ_HAVE_OPENVMS
+#include <sys/types.h>
+#include <sys/time.h>
+#else
+#include <sys/select.h>
+#endif
+
+#include "ctx.hpp"
+#include "fd.hpp"
+#include "poller_base.hpp"
+
+namespace zmq
+{
+struct i_poll_events;
+
+//  Implements socket polling mechanism using POSIX.1-2001 select()
+//  function.
+
+class select_t ZMQ_FINAL : public worker_poller_base_t
+{
+  public:
+    typedef fd_t handle_t;
+
+    select_t (const thread_ctx_t &ctx_);
+    ~select_t () ZMQ_FINAL;
+
+    //  "poller" concept.
+    handle_t add_fd (fd_t fd_, zmq::i_poll_events *events_);
+    void rm_fd (handle_t handle_);
+    void set_pollin (handle_t handle_);
+    void reset_pollin (handle_t handle_);
+    void set_pollout (handle_t handle_);
+    void reset_pollout (handle_t handle_);
+    void stop ();
+
+    static int max_fds ();
+
+  private:
+    //  Main event loop.
+    void loop () ZMQ_FINAL;
+
+    //  Internal state.
+    struct fds_set_t
+    {
+        fds_set_t ();
+        fds_set_t (const fds_set_t &other_);
+        fds_set_t &operator= (const fds_set_t &other_);
+        //  Convenience method to descriptor from all sets.
+        void remove_fd (const fd_t &fd_);
+
+        fd_set read;
+        fd_set write;
+        fd_set error;
+    };
+
+    struct fd_entry_t
+    {
+        fd_t fd;
+        zmq::i_poll_events *events;
+    };
+    typedef std::vector<fd_entry_t> fd_entries_t;
+
+    void trigger_events (const fd_entries_t &fd_entries_,
+                         const fds_set_t &local_fds_set_,
+                         int event_count_);
+
+    struct family_entry_t
+    {
+        family_entry_t ();
+
+        fd_entries_t fd_entries;
+        fds_set_t fds_set;
+        bool has_retired;
+    };
+
+    void select_family_entry (family_entry_t &family_entry_,
+                              int max_fd_,
+                              bool use_timeout_,
+                              struct timeval &tv_);
+
+#if defined ZMQ_HAVE_WINDOWS
+    typedef std::map<u_short, family_entry_t> family_entries_t;
+
+    struct wsa_events_t
+    {
+        wsa_events_t ();
+        ~wsa_events_t ();
+
+        //  read, write, error and readwrite
+        WSAEVENT events[4];
+    };
+
+    family_entries_t _family_entries;
+    // See loop for details.
+    family_entries_t::iterator _current_family_entry_it;
+
+    int try_retire_fd_entry (family_entries_t::iterator family_entry_it_,
+                             zmq::fd_t &handle_);
+
+    static const size_t fd_family_cache_size = 8;
+    std::pair<fd_t, u_short> _fd_family_cache[fd_family_cache_size];
+
+    u_short get_fd_family (fd_t fd_);
+
+    //  Socket's family or AF_UNSPEC on error.
+    static u_short determine_fd_family (fd_t fd_);
+#else
+    //  on non-Windows, we can treat all fds as one family
+    family_entry_t _family_entry;
+    fd_t _max_fd;
+#endif
+
+    void cleanup_retired ();
+    bool cleanup_retired (family_entry_t &family_entry_);
+
+    //  Checks if an fd_entry_t is retired.
+    static bool is_retired_fd (const fd_entry_t &entry_);
+
+    static fd_entries_t::iterator
+    find_fd_entry_by_handle (fd_entries_t &fd_entries_, handle_t handle_);
+
+    ZMQ_NON_COPYABLE_NOR_MOVABLE (select_t)
+};
+
+typedef select_t poller_t;
+}
+
+#endif
+
+#endif