Problem: zmq_poller only signals one event

Solution: zmq_poller_wait_all signals all events

allows signaling multiple events with one call to zmq_poller_wait_all
rather than emitting only one event.

this prepares for zmq_poll being based on zmq_poller,
which requires events for all sockets rather than just one.

include/zmq.h

@@ -577,6 +577,7 @@ ZMQ_EXPORT int  zmq_poller_add (void *poller, void *socket, void *user_data, sho
 ZMQ_EXPORT int  zmq_poller_modify (void *poller, void *socket, short events);
 ZMQ_EXPORT int  zmq_poller_remove (void *poller, void *socket);
 ZMQ_EXPORT int  zmq_poller_wait (void *poller, zmq_poller_event_t *event, long timeout);
+ZMQ_EXPORT int  zmq_poller_wait_all (void *poller, zmq_poller_event_t *events, long timeout);
 
 #if defined _WIN32
 ZMQ_EXPORT int zmq_poller_add_fd (void *poller, SOCKET fd, void *user_data, short events);

src/socket_poller.cpp

@@ -380,7 +380,7 @@ int zmq::socket_poller_t::rebuild ()
     return 0;
 }
 
-int zmq::socket_poller_t::wait (zmq::socket_poller_t::event_t *event_, long timeout_)
+int zmq::socket_poller_t::wait (zmq::socket_poller_t::event_t *events_, long timeout_)
 {
     if (need_rebuild)
         if (rebuild () == -1)
@@ -412,6 +412,7 @@ int zmq::socket_poller_t::wait (zmq::socket_poller_t::event_t *event_, long time
     uint64_t end = 0;
 
     bool first_pass = true;
+    bool found = false;
 
     while (true) {
         //  Compute the timeout for the subsequent poll.
@@ -439,7 +440,13 @@ int zmq::socket_poller_t::wait (zmq::socket_poller_t::event_t *event_, long time
             signaler.recv ();
 
         //  Check for the events.
-        for (items_t::iterator it = items.begin (); it != items.end (); ++it) {
+        int i=0;
+        for (items_t::iterator it = items.begin (); it != items.end (); ++i, ++it) {
+
+            events_[i].socket = NULL;
+            events_[i].fd = 0;
+            events_[i].user_data = NULL;
+            events_[i].events = 0;
 
             //  The poll item is a 0MQ socket. Retrieve pending events
             //  using the ZMQ_EVENTS socket option.
@@ -451,12 +458,10 @@ int zmq::socket_poller_t::wait (zmq::socket_poller_t::event_t *event_, long time
                 }
 
                 if (it->events & events) {
-                    event_->socket = it->socket;
-                    event_->user_data = it->user_data;
-                    event_->events = it->events & events;
-
-                    //  If there is event to return, we can exit immediately.
-                    return 0;
+                    events_[i].socket = it->socket;
+                    events_[i].user_data = it->user_data;
+                    events_[i].events = it->events & events;
+                    found = true;
                 }
             }
             //  Else, the poll item is a raw file descriptor, simply convert
@@ -475,16 +480,17 @@ int zmq::socket_poller_t::wait (zmq::socket_poller_t::event_t *event_, long time
                     events |= ZMQ_POLLERR;
 
                 if (events) {
-                    event_->socket = NULL;
-                    event_->user_data = it->user_data;
-                    event_->fd = it->fd;
-                    event_->events = events;
-
-                    //  If there is event to return, we can exit immediately.
-                    return 0;
+                    events_[i].socket = NULL;
+                    events_[i].user_data = it->user_data;
+                    events_[i].fd = it->fd;
+                    events_[i].events = events;
+                    found = true;
                 }
             }
         }
+        if (found) {
+            return 0;
+        }
 
         //  If timeout is zero, exit immediately whether there are events or not.
         if (timeout_ == 0)
@@ -516,7 +522,6 @@ int zmq::socket_poller_t::wait (zmq::socket_poller_t::event_t *event_, long time
         if (now >= end)
             break;
     }
-
     errno = ETIMEDOUT;
     return -1;
 

src/socket_poller.hpp

@@ -75,6 +75,8 @@ namespace zmq
 
         int wait (event_t *event, long timeout);
 
+        inline int size (void) { return items.size (); };
+
         //  Return false if object is not a socket.
         bool check_tag ();
 

src/zmq.cpp

@@ -1222,15 +1222,46 @@ int zmq_poller_wait (void *poller_, zmq_poller_event_t *event, long timeout_)
 
     zmq_assert (event != NULL);
 
-    zmq::socket_poller_t::event_t e;
-    memset (&e, 0, sizeof (e));
+    int n_items = ((zmq::socket_poller_t*)poller_)->size ();
+    zmq_poller_event_t *events;
+    events = new zmq_poller_event_t[n_items];
+    alloc_assert(events);
 
-    int rc = ((zmq::socket_poller_t*)poller_)->wait (&e, timeout_);
+    int rc = zmq_poller_wait_all(poller_, events, timeout_);
 
-    event->socket = e.socket;
-    event->fd = e.fd;
-    event->user_data = e.user_data;
-    event->events = e.events;
+    if (rc >= 0) {
+        *event = events[0];
+    } else {
+        memset (event, 0, sizeof(zmq_poller_event_t));
+    }
+    delete [] events;
+
+    return rc;
+}
+
+int zmq_poller_wait_all (void *poller_, zmq_poller_event_t *events, long timeout_)
+{
+    if (!poller_ || !((zmq::socket_poller_t*)poller_)->check_tag ()) {
+        errno = EFAULT;
+        return -1;
+    }
+
+    zmq_assert (events != NULL);
+
+    int n_items = ((zmq::socket_poller_t*)poller_)->size ();
+    zmq::socket_poller_t::event_t *evts;
+    evts = new zmq::socket_poller_t::event_t[n_items];
+    alloc_assert(evts);
+
+    int rc = ((zmq::socket_poller_t*)poller_)->wait (evts, timeout_);
+
+    for(int i = 0; i < n_items; ++i) {
+        events[i].socket = evts[i].socket;
+        events[i].fd = evts[i].fd;
+        events[i].user_data = evts[i].user_data;
+        events[i].events = evts[i].events;
+    }
+    delete [] evts;
 
     return rc;
 }

src/zmq_draft.h

@@ -80,6 +80,7 @@ int  zmq_poller_add (void *poller, void *socket, void *user_data, short events);
 int  zmq_poller_modify (void *poller, void *socket, short events);
 int  zmq_poller_remove (void *poller, void *socket);
 int  zmq_poller_wait (void *poller, zmq_poller_event_t *event, long timeout);
+int  zmq_poller_wait_all (void *poller, zmq_poller_event_t *events, long timeout);
 
 #if defined _WIN32
 int zmq_poller_add_fd (void *poller, SOCKET fd, void *user_data, short events);