C++ binding uses exceptions to signal failure

include/zmq.hpp

@@ -23,6 +23,8 @@
 #include "zmq.h"
 
 #include <assert.h>
+#include <errno.h>
+#include <exception>
 
 namespace zmq
 {
@@ -36,6 +38,38 @@ namespace zmq
         message_delimiter = 1 << ZMQ_DELIMITER
     };
 
+    class no_memory : public exception
+    {
+        virtual const char *what ()
+        {
+            return "Out of memory";
+        }
+    };
+
+    class invalid_argument : public exception
+    {
+        virtual const char *what ()
+        {
+            return "Invalid argument";
+        }
+    };
+
+    class too_many_threads : public exception
+    {
+        virtual const char *what ()
+        {
+            return "Too many threads";
+        }
+    };
+
+    class address_in_use : public exception
+    {
+        virtual const char *what ()
+        {
+            return "Address in use";
+        }
+    };
+
     //  A message. Caution: Don't change the body of the message once you've
     //  copied it - the behaviour is undefined. Don't change the body of the
     //  received message either - other threads may be accessing it in parallel.
@@ -50,7 +84,10 @@ namespace zmq
         inline message_t (size_t size_ = 0)
         {
             int rc = zmq_msg_init_size (this, size_);
-            assert (rc == 0);
+            if (rc == -1) {
+                assert (errno == ENOMEM);
+                throw no_memory ();
+            }
         }
 
         //  Creates message from the supplied buffer. 0MQ takes care of
@@ -79,7 +116,10 @@ namespace zmq
             int rc = zmq_msg_close (this);
             assert (rc == 0);
             rc = zmq_msg_init_size (this, size_);
-            assert (rc == 0);
+            if (rc == -1) {
+                assert (errno == ENOMEM);
+                throw no_memory ();
+            }
         }
 
         //  Same as above, however, the message is rebuilt from the supplied
@@ -147,7 +187,10 @@ namespace zmq
         inline context_t (int app_threads_, int io_threads_)
         {
             ptr = zmq_init (app_threads_, io_threads_);
-            assert (ptr);
+            if (ptr == NULL) {
+                assert (errno == EINVAL);
+                throw invalid_argument ();
+            }
         }
 
         inline ~context_t ()
@@ -172,7 +215,13 @@ namespace zmq
         inline socket_t (context_t &context_, int type_ = 0)
         {
             ptr = zmq_socket (context_.ptr, type_);
-            assert (ptr);
+            if (ptr == NULL) {
+                assert (errno == EMFILE || errno == EINVAL);
+                if (errno == EMFILE)
+                    throw too_many_threads ();
+                else
+                    throw invalid_argument ();
+            }
         }
 
         inline ~socket_t ()
@@ -184,13 +233,25 @@ namespace zmq
         inline void bind (const char *addr_, zmq_opts *opts_ = NULL)
         {
             int rc = zmq_bind (ptr, addr_, opts_);
-            assert (rc == 0);
+            if (rc == -1) {
+                assert (errno == EINVAL || errno == EADDRINUSE);
+                if (errno == EINVAL)
+                    throw invalid_argument ();
+                else
+                    throw address_in_use ();
+            }
         }
 
         inline void connect (const char *addr_, zmq_opts *opts_ = NULL)
         {
             int rc = zmq_connect (ptr, addr_, opts_);
-            assert (rc == 0);
+            if (rc == -1) {
+                assert (errno == EINVAL || errno == EADDRINUSE);
+                if (errno == EINVAL)
+                    throw invalid_argument ();
+                else
+                    throw address_in_use ();
+            }
         }
 
         inline void subscribe (const char *criteria_)
@@ -199,10 +260,11 @@ namespace zmq
             assert (rc == 0);
         }
 
-        inline void send (message_t &msg_, int flags_ = 0)
+        inline int send (message_t &msg_, int flags_ = 0)
         {
             int rc = zmq_send (ptr, &msg_, flags_);
-            assert (rc == 0);
+            assert (rc == 0 || (rc == -1 && errno == EAGAIN));
+            return rc;
         }
 
         inline void flush ()
@@ -211,10 +273,11 @@ namespace zmq
             assert (rc == 0);
         }
 
-        inline void recv (message_t *msg_, int flags_ = 0)
+        inline int recv (message_t *msg_, int flags_ = 0)
         {
             int rc = zmq_recv (ptr, msg_, flags_);
-            assert (rc == 0);
+            assert (rc == 0 || (rc == -1 && errno == EAGAIN));
+            return rc;
         }
 
     private: