zmq_poll implemented on Win32 platform

bindings/c/zmq.h

@@ -26,6 +26,9 @@ extern "C" {
 
 #include <errno.h>
 #include <stddef.h>
+#if defined _WIN32
+#include "winsock2.h"
+#endif
 
 //  Microsoft Visual Studio uses non-standard way to export/import symbols.
 #if defined ZMQ_BUILDING_LIBZMQ_WITH_MSVC
@@ -185,7 +188,11 @@ ZMQ_EXPORT int zmq_recv (void *s, zmq_msg_t *msg, int flags);
 typedef struct
 {
     void *socket;
+#if defined _WIN32
+    SOCKET fd;
+#else
     int fd;
+#endif
     short events;
     short revents;
 } zmq_pollitem_t;

src/zmq.cpp

@@ -31,6 +31,7 @@
 #include "platform.hpp"
 #include "stdint.hpp"
 #include "err.hpp"
+#include "fd.hpp"
 
 #if defined ZMQ_HAVE_LINUX
 #include <poll.h>
@@ -263,12 +264,10 @@ int zmq_recv (void *s_, zmq_msg_t *msg_, int flags_)
 
 int zmq_poll (zmq_pollitem_t *items_, int nitems_)
 {
-    //  TODO: Replace the polling mechanism by the virtualised framework
-    //  used in 0MQ I/O threads. That'll make the thing work on all platforms.
-#if !defined ZMQ_HAVE_LINUX
-    errno = ENOTSUP;
-    return -1;
-#else
+#if defined ZMQ_HAVE_LINUX || defined ZMQ_HAVE_FREEBSD ||\
+    defined ZMQ_HAVE_OPENBSD || defined ZMQ_HAVE_SOLARIS ||\
+    defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_QNXNTO ||\
+    defined ZMQ_HAVE_HPUX || defined ZMQ_HAVE_AIX
 
     pollfd *pollfds = (pollfd*) malloc (nitems_ * sizeof (pollfd));
     zmq_assert (pollfds);
@@ -368,6 +367,119 @@ int zmq_poll (zmq_pollitem_t *items_, int nitems_)
     free (pollfds);
     return nevents;
 
+#elif defined ZMQ_HAVE_WINDOWS || defined ZMQ_HAVE_OPENVMS
+
+    fd_set pollset_in;
+    FD_ZERO (&pollset_in);
+    fd_set pollset_out;
+    FD_ZERO (&pollset_out);
+    fd_set pollset_err;
+    FD_ZERO (&pollset_err);
+
+    zmq::app_thread_t *app_thread = NULL;
+    int nsockets = 0;
+    zmq::fd_t maxfd = zmq::retired_fd;
+    zmq::fd_t notify_fd = zmq::retired_fd;
+
+    for (int i = 0; i != nitems_; i++) {
+
+        //  0MQ sockets.
+        if (items_ [i].socket) {
+
+            //  Get the app_thread the socket is living in. If there are two
+            //  sockets in the same pollset with different app threads, fail.
+            zmq::socket_base_t *s = (zmq::socket_base_t*) items_ [i].socket;
+            if (app_thread) {
+                if (app_thread != s->get_thread ()) {
+                    errno = EFAULT;
+                    return -1;
+                }
+            }
+            else
+                app_thread = s->get_thread ();
+
+            nsockets++;
+            continue;
+        }
+
+        //  Raw file descriptors.
+        if (items_ [i].events & ZMQ_POLLIN)
+            FD_SET (items_ [i].fd, &pollset_in);
+        if (items_ [i].events & ZMQ_POLLOUT)
+            FD_SET (items_ [i].fd, &pollset_out);
+        if (maxfd == zmq::retired_fd || maxfd < items_ [i].fd)
+            maxfd = items_ [i].fd;
+    }
+
+    //  If there's at least one 0MQ socket in the pollset we have to poll
+    //  for 0MQ commands. If ZMQ_POLL was not set, fail.
+    if (nsockets) {
+        notify_fd = app_thread->get_signaler ()->get_fd ();
+        if (notify_fd == zmq::retired_fd) {
+            errno = ENOTSUP;
+            return -1;
+        }
+        FD_SET (notify_fd, &pollset_in);
+        if (maxfd == zmq::retired_fd || maxfd < notify_fd)
+            maxfd = notify_fd;
+    }
+
+    int nevents = 0;
+    bool initial = true;
+    while (!nevents) {
+
+        //  Wait for activity. In the first iteration just check for events,
+        //  don't wait. Waiting would prevent exiting on any events that may
+        //  already be signaled on 0MQ sockets.
+        timeval timeout = {0, 0};
+        int rc = select (maxfd, &pollset_in, &pollset_out, &pollset_err,
+            initial ? &timeout : NULL);
+#if defined ZMQ_HAVE_WINDOWS
+        wsa_assert (rc != SOCKET_ERROR);
+#else
+        if (rc == -1 && errno == EINTR)
+            continue;
+#endif
+
+        errno_assert (rc >= 0);
+        initial = false;
+
+        //  Process 0MQ commands if needed.
+        if (nsockets && FD_ISSET (notify_fd, &pollset_in))
+            app_thread->process_commands (false, false);
+
+        //  Check for the events.
+        int pollfd_pos = 0;
+        for (int i = 0; i != nitems_; i++) {
+
+            //  If the poll item is a raw file descriptor, simply convert
+            //  the events to zmq_pollitem_t-style format.
+            if (!items_ [i].socket) {
+                items_ [i].revents =
+                    (FD_ISSET (items_ [i].fd, &pollset_in) ? ZMQ_POLLIN : 0) |
+                    (FD_ISSET (items_ [i].fd, &pollset_out) ? ZMQ_POLLOUT : 0);
+                if (items_ [i].revents)
+                    nevents++;
+                continue;
+            }
+
+            //  The poll item is a 0MQ socket.
+            zmq::socket_base_t *s = (zmq::socket_base_t*) items_ [i].socket;
+            items_ [i].revents = 0;
+            if ((items_ [i].events & ZMQ_POLLOUT) && s->has_out ())
+                items_ [i].revents |= ZMQ_POLLOUT;
+            if ((items_ [i].events & ZMQ_POLLIN) && s->has_in ())
+                items_ [i].revents |= ZMQ_POLLIN;
+            if (items_ [i].revents)
+                nevents++;
+        }
+    }
+
+    return nevents;
+
+#else
+    errno = ENOTSUP;
+    return -1;
 #endif
 }
 
@@ -428,4 +540,3 @@ unsigned long zmq_stopwatch_stop (void *watch_)
     free (watch_);
     return (unsigned long) (end - start);
 }
-