Problem: code duplication and unnecessary nesting around ZMQ_THREAD_SAFE

querying

Solution: remove code duplication and rearrange conditions

src/socket_poller.cpp

@@ -31,6 +31,17 @@
 #include "socket_poller.hpp"
 #include "err.hpp"
 
+static bool is_thread_safe (zmq::socket_base_t &socket)
+{
+    int thread_safe;
+    size_t thread_safe_size = sizeof (int);
+
+    int rc =
+      socket.getsockopt (ZMQ_THREAD_SAFE, &thread_safe, &thread_safe_size);
+    zmq_assert (rc == 0);
+    return thread_safe;
+}
+
 zmq::socket_poller_t::socket_poller_t () :
     tag (0xCAFEBABE),
     signaler (NULL),
@@ -67,15 +78,10 @@ zmq::socket_poller_t::~socket_poller_t ()
     tag = 0xdeadbeef;
 
     for (items_t::iterator it = items.begin (); it != items.end (); ++it) {
-        if (it->socket && it->socket->check_tag ()) {
-            int thread_safe;
-            size_t thread_safe_size = sizeof (int);
-
-            if (it->socket->getsockopt (ZMQ_THREAD_SAFE, &thread_safe,
-                                        &thread_safe_size)
-                  == 0
-                && thread_safe)
-                it->socket->remove_signaler (signaler);
+        // TODO shouldn't this zmq_assert (it->socket->check_tag ()) instead?
+        if (it->socket && it->socket->check_tag ()
+            && is_thread_safe (*it->socket)) {
+            it->socket->remove_signaler (signaler);
         }
     }
 
@@ -108,14 +114,7 @@ int zmq::socket_poller_t::add (socket_base_t *socket_,
         }
     }
 
-    int thread_safe;
-    size_t thread_safe_size = sizeof (int);
-
-    int rc =
-      socket_->getsockopt (ZMQ_THREAD_SAFE, &thread_safe, &thread_safe_size);
-    zmq_assert (rc == 0);
-
-    if (thread_safe) {
+    if (is_thread_safe (*socket_)) {
         if (signaler == NULL) {
             signaler = new (std::nothrow) signaler_t ();
             if (!signaler) {
@@ -233,13 +232,9 @@ int zmq::socket_poller_t::remove (socket_base_t *socket_)
     items.erase (it);
     need_rebuild = true;
 
-    int thread_safe;
-    size_t thread_safe_size = sizeof (int);
-
-    if (socket_->getsockopt (ZMQ_THREAD_SAFE, &thread_safe, &thread_safe_size)
-          == 0
-        && thread_safe)
+    if (is_thread_safe (*socket_)) {
         socket_->remove_signaler (signaler);
+    }
 
     return 0;
 }
@@ -279,21 +274,11 @@ void zmq::socket_poller_t::rebuild ()
 
     for (items_t::iterator it = items.begin (); it != items.end (); ++it) {
         if (it->events) {
-            if (it->socket) {
-                int thread_safe;
-                size_t thread_safe_size = sizeof (int);
-
-                int rc = it->socket->getsockopt (ZMQ_THREAD_SAFE, &thread_safe,
-                                                 &thread_safe_size);
-                zmq_assert (rc == 0);
-
-                if (thread_safe) {
-                    if (!use_signaler) {
-                        use_signaler = true;
-                        poll_size++;
-                    }
-                } else
+            if (it->socket && is_thread_safe (*it->socket)) {
+                if (!use_signaler) {
+                    use_signaler = true;
                     poll_size++;
+                }
             } else
                 poll_size++;
         }
@@ -316,17 +301,10 @@ void zmq::socket_poller_t::rebuild ()
     for (items_t::iterator it = items.begin (); it != items.end (); ++it) {
         if (it->events) {
             if (it->socket) {
-                int thread_safe;
-                size_t thread_safe_size = sizeof (int);
-
-                int rc = it->socket->getsockopt (ZMQ_THREAD_SAFE, &thread_safe,
-                                                 &thread_safe_size);
-                zmq_assert (rc == 0);
-
-                if (!thread_safe) {
+                if (!is_thread_safe (*it->socket)) {
                     size_t fd_size = sizeof (zmq::fd_t);
-                    rc = it->socket->getsockopt (ZMQ_FD, &pollfds[item_nbr].fd,
-                                                 &fd_size);
+                    int rc = it->socket->getsockopt (
+                      ZMQ_FD, &pollfds[item_nbr].fd, &fd_size);
                     zmq_assert (rc == 0);
 
                     pollfds[item_nbr].events = POLLIN;
@@ -359,20 +337,11 @@ void zmq::socket_poller_t::rebuild ()
     use_signaler = false;
 
     for (items_t::iterator it = items.begin (); it != items.end (); ++it) {
-        if (it->socket) {
-            int thread_safe;
-            size_t thread_safe_size = sizeof (int);
-
-            int rc = it->socket->getsockopt (ZMQ_THREAD_SAFE, &thread_safe,
-                                             &thread_safe_size);
-            zmq_assert (rc == 0);
-
-            if (thread_safe && it->events) {
-                use_signaler = true;
-                FD_SET (signaler->get_fd (), &pollset_in);
-                poll_size = 1;
-                break;
-            }
+        if (it->socket && is_thread_safe (*it->socket) && it->events) {
+            use_signaler = true;
+            FD_SET (signaler->get_fd (), &pollset_in);
+            poll_size = 1;
+            break;
         }
     }
 
@@ -384,17 +353,11 @@ void zmq::socket_poller_t::rebuild ()
             //  If the poll item is a 0MQ socket we are interested in input on the
             //  notification file descriptor retrieved by the ZMQ_FD socket option.
             if (it->socket) {
-                int thread_safe;
-                size_t thread_safe_size = sizeof (int);
-
-                int rc = it->socket->getsockopt (ZMQ_THREAD_SAFE, &thread_safe,
-                                                 &thread_safe_size);
-                zmq_assert (rc == 0);
-
-                if (!thread_safe) {
+                if (!is_thread_safe (*it->socket)) {
                     zmq::fd_t notify_fd;
                     size_t fd_size = sizeof (zmq::fd_t);
-                    rc = it->socket->getsockopt (ZMQ_FD, &notify_fd, &fd_size);
+                    int rc =
+                      it->socket->getsockopt (ZMQ_FD, &notify_fd, &fd_size);
                     zmq_assert (rc == 0);
 
                     FD_SET (notify_fd, &pollset_in);