Merge pull request zeromq#599 from somdoron/master

problem: Polling once with NetMQPoller is complicated

src/NetMQ/NetMQPoller.cs

@@ -31,10 +31,10 @@ public sealed class NetMQPoller :
         private readonly List<NetMQTimer> m_timers = new List<NetMQTimer>();
         private readonly Dictionary<Socket, Action<Socket>> m_pollinSockets = new Dictionary<Socket, Action<Socket>>();
         private readonly Switch m_switch = new Switch(false);
-        private readonly Selector m_selector = new Selector();
+        private readonly NetMQSelector m_netMqSelector = new NetMQSelector();
         private readonly StopSignaler m_stopSignaler = new StopSignaler();
 
-        private SelectItem[] m_pollSet;
+        private NetMQSelector.Item[] m_pollSet;
         private NetMQSocket[] m_pollact;
 
         private volatile bool m_isPollSetDirty = true;
@@ -340,7 +340,7 @@ public void Run()
 
                     if (m_pollSet.Length != 0)
                     {
-                        isItemAvailable = m_selector.Select(m_pollSet, m_pollSet.Length, timeout);
+                        isItemAvailable = m_netMqSelector.Select(m_pollSet, m_pollSet.Length, timeout);
                     }
                     else if (timeout > 0)
                     {
@@ -372,7 +372,7 @@ public void Run()
 
                     for (var i = 0; i < m_pollSet.Length; i++)
                     {
-                        SelectItem item = m_pollSet[i];
+                        NetMQSelector.Item item = m_pollSet[i];
 
                         if (item.Socket != null)
                         {
@@ -473,7 +473,7 @@ private void RebuildPollset()
 #endif
 
             // Recreate the m_pollSet and m_pollact arrays.
-            m_pollSet = new SelectItem[m_sockets.Count + m_pollinSockets.Count];
+            m_pollSet = new NetMQSelector.Item[m_sockets.Count + m_pollinSockets.Count];
             m_pollact = new NetMQSocket[m_sockets.Count];
 
             // For each socket in m_sockets,
@@ -482,14 +482,14 @@ private void RebuildPollset()
 
             foreach (var socket in m_sockets)
             {
-                m_pollSet[index] = new SelectItem(socket.SocketHandle, socket.GetPollEvents());
+                m_pollSet[index] = new NetMQSelector.Item(socket, socket.GetPollEvents());
                 m_pollact[index] = socket;
                 index++;
             }
 
             foreach (var socket in m_pollinSockets.Keys)
             {
-                m_pollSet[index] = new SelectItem(socket, PollEvents.PollError | PollEvents.PollIn);
+                m_pollSet[index] = new NetMQSelector.Item(socket, PollEvents.PollError | PollEvents.PollIn);
                 index++;
             }
 

src/NetMQ/Core/Utils/Selector.cs → src/NetMQ/NetMQSelector.cs

@@ -3,55 +3,58 @@
 using System.Diagnostics;
 using System.Net.Sockets;
 using JetBrains.Annotations;
+using NetMQ.Core;
+using NetMQ.Core.Utils;
 
-namespace NetMQ.Core.Utils
-{
+namespace NetMQ
+{   
     /// <summary>
-    /// A SelectItem is a pairing of a (Socket or SocketBase) and a PollEvents value.
+    /// For selecting on NetMQSocket or regualr .net Socket.
+    /// This is for advanced usages, for most cases NetMQPoller is the suggested alternative.
     /// </summary>
-    internal sealed class SelectItem
+    public sealed class NetMQSelector
     {
-        public SelectItem(SocketBase socket, PollEvents @event)
-        {
-            Socket = socket;
-            Event = @event;
-        }
+        private readonly List<Socket> m_checkRead = new List<Socket>();
+        private readonly List<Socket> m_checkWrite = new List<Socket>();
+        private readonly List<Socket> m_checkError = new List<Socket>();
 
-        public SelectItem(Socket fileDescriptor, PollEvents @event)
+        /// <summary>
+        /// Selector Item used to hold the NetMQSocket/Socket and PollEvents
+        /// </summary>
+        public sealed class Item
         {
-            FileDescriptor = fileDescriptor;
-            Event = @event;
-        }
+            public Item(NetMQSocket socket, PollEvents @event)
+            {
+                Socket = socket;
+                Event = @event;
+            }
 
-        public Socket FileDescriptor { get; }
+            public Item(Socket fileDescriptor, PollEvents @event)
+            {
+                FileDescriptor = fileDescriptor;
+                Event = @event;
+            }
 
-        public SocketBase Socket { get; }
+            public Socket FileDescriptor { get; }
 
-        public PollEvents Event { get; }
+            public NetMQSocket Socket { get; }
 
-        public PollEvents ResultEvent { get; set; }
-    }
+            public PollEvents Event { get; }
 
-    /// <summary>
-    /// A Selector holds three lists of Sockets - for read, write, and error,
-    /// and provides a Select method.
-    /// </summary>
-    internal sealed class Selector
-    {
-        private readonly List<Socket> m_checkRead = new List<Socket>();
-        private readonly List<Socket> m_checkWrite = new List<Socket>();
-        private readonly List<Socket> m_checkError = new List<Socket>();
+            public PollEvents ResultEvent { get; set; }
+        }
 
         /// <summary>
+        /// Select on NetMQSocket or Socket, similar behavior to Socket.Select.
         /// </summary>
-        /// <param name="items">  (must not be null)</param>
-        /// <param name="itemsCount"></param>
+        /// <param name="items">Items to select on (must not be null)</param>
+        /// <param name="itemsCount">Number of items in the array to select on</param>
         /// <param name="timeout">a time-out period, in milliseconds</param>
         /// <returns></returns>
         /// <exception cref="FaultException">The internal select operation failed.</exception>
         /// <exception cref="ArgumentNullException"><paramref name="items"/> is <c>null</c>.</exception>
         /// <exception cref="TerminatingException">The socket has been stopped.</exception>
-        public bool Select([NotNull] SelectItem[] items, int itemsCount, long timeout)
+        public bool Select([NotNull] Item[] items, int itemsCount, long timeout)
         {
             if (items == null)
                 throw new ArgumentNullException(nameof(items));
@@ -103,8 +106,8 @@ public bool Select([NotNull] SelectItem[] items, int itemsCount, long timeout)
 
                     if (pollItem.Socket != null)
                     {
-                        if (pollItem.Event != PollEvents.None && pollItem.Socket.Handle.Connected)
-                            m_checkRead.Add(pollItem.Socket.Handle);
+                        if (pollItem.Event != PollEvents.None && pollItem.Socket.SocketHandle.Handle.Connected)
+                            m_checkRead.Add(pollItem.Socket.SocketHandle.Handle);
                     }
                     else
                     {

src/NetMQ/NetMQSocket.cs

@@ -16,7 +16,7 @@ public abstract class NetMQSocket : IOutgoingSocket, IReceivingSocket, ISocketPo
     {
         private readonly SocketBase m_socketHandle;
         private readonly NetMQSocketEventArgs m_socketEventArgs;
-        private readonly Selector m_selector;
+        private readonly NetMQSelector m_netMqSelector;
 
         private EventHandler<NetMQSocketEventArgs> m_receiveReady;
         private EventHandler<NetMQSocketEventArgs> m_sendReady;
@@ -37,7 +37,7 @@ internal enum DefaultAction
         internal NetMQSocket(ZmqSocketType socketType, string connectionString, DefaultAction defaultAction)
         {
             m_socketHandle = NetMQConfig.Context.CreateSocket(socketType);
-            m_selector = new Selector();
+            m_netMqSelector = new NetMQSelector();
             Options = new SocketOptions(this);
             m_socketEventArgs = new NetMQSocketEventArgs(this);
 
@@ -77,7 +77,7 @@ internal NetMQSocket(ZmqSocketType socketType, string connectionString, DefaultA
         /// <param name="socketHandle">a SocketBase object to assign to the new socket</param>
         internal NetMQSocket([NotNull] SocketBase socketHandle)
         {
-            m_selector = new Selector();
+            m_netMqSelector = new NetMQSelector();
             m_socketHandle = socketHandle;
             Options = new SocketOptions(this);
             m_socketEventArgs = new NetMQSocketEventArgs(this);
@@ -296,9 +296,9 @@ public bool Poll(TimeSpan timeout)
         /// <exception cref="TerminatingException">The socket has been stopped.</exception>
         public PollEvents Poll(PollEvents pollEvents, TimeSpan timeout)
         {
-            SelectItem[] items = { new SelectItem(SocketHandle, pollEvents) };
+            NetMQSelector.Item[] items = { new NetMQSelector.Item(this, pollEvents) };
 
-            m_selector.Select(items, 1, (long)timeout.TotalMilliseconds);
+            m_netMqSelector.Select(items, 1, (long)timeout.TotalMilliseconds);
             return items[0].ResultEvent;
         }