Problem: ZMQ_TCP_RETRANSMIT_TIMEOUT is a clumsy name

Solution: rename to ZMQ_MAXRT

This is the option name used on Windows, so easier to use and
remember.

doc/zmq_getsockopt.txt

@@ -700,14 +700,13 @@ Default value:: -1 (leave to OS default)
 Applicable socket types:: all, when using TCP transports.
 
 
-ZMQ_TCP_RETRANSMIT_TIMEOUT: Retrieve TCP Retransmit Timeout
+ZMQ_TCP_MAXRT: Retrieve Max TCP Retransmit Timeout
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 On OSes where it is supported, retrieves how long before an unacknowledged TCP
-retransmit times out.
+retransmit times out. The system normally attempts many TCP retransmits
-The system normally attempts many TCP retransmits following an exponential
+following an exponential backoff strategy. This means that after a network
-backoff strategy. This means that after a network outage, it may take a long
+outage, it may take a long time before the session can be re-established.
-time before the session can be re-established. Setting this option allows
+Setting this option allows the timeout to happen at a shorter interval.
-the timeout to happen at a shorter interval.
 
 [horizontal]
 Option value type:: int

doc/zmq_setsockopt.txt

@@ -870,14 +870,13 @@ Default value:: -1 (leave to OS default)
 Applicable socket types:: all, when using TCP transports.
 
 
-ZMQ_TCP_RETRANSMIT_TIMEOUT: Set TCP Retransmit Timeout
+ZMQ_TCP_MAXRT: Set TCP Maximum Retransmit Timeout
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 On OSes where it is supported, sets how long before an unacknowledged TCP
-retransmit times out.
+retransmit times out. The system normally attempts many TCP retransmits
-The system normally attempts many TCP retransmits following an exponential
+following an exponential backoff strategy. This means that after a network
-backoff strategy. This means that after a network outage, it may take a long
+outage, it may take a long time before the session can be re-established.
-time before the session can be re-established. Setting this option allows
+Setting this option allows the timeout to happen at a shorter interval.
-the timeout to happen at a shorter interval.
 
 [horizontal]
 Option value type:: int

include/zmq.h

@@ -325,6 +325,8 @@ ZMQ_EXPORT const char *zmq_msg_group (zmq_msg_t *msg);
 #define ZMQ_HANDSHAKE_IVL 66
 #define ZMQ_SOCKS_PROXY 68
 #define ZMQ_XPUB_NODROP 69
+//  All options after this is for version 4.2 and still *draft*
+//  Subject to arbitrary change without notice
 #define ZMQ_BLOCKY 70
 #define ZMQ_XPUB_MANUAL 71
 #define ZMQ_XPUB_WELCOME_MSG 72
@@ -335,7 +337,7 @@ ZMQ_EXPORT const char *zmq_msg_group (zmq_msg_t *msg);
 #define ZMQ_HEARTBEAT_TIMEOUT 77
 #define ZMQ_XPUB_VERBOSE_UNSUBSCRIBE 78
 #define ZMQ_CONNECT_TIMEOUT 79
-#define ZMQ_TCP_RETRANSMIT_TIMEOUT 80
+#define ZMQ_TCP_MAXRT 80
 #define ZMQ_THREAD_SAFE 81
 #define ZMQ_TCP_RECV_BUFFER 82
 #define ZMQ_TCP_SEND_BUFFER 83

src/options.cpp

@@ -48,7 +48,7 @@ zmq::options_t::options_t () :
     type (-1),
     linger (-1),
     connect_timeout (0),
-    tcp_retransmit_timeout (0),
+    tcp_maxrt (0),
     reconnect_ivl (100),
     reconnect_ivl_max (0),
     backlog (100),
@@ -178,9 +178,9 @@ int zmq::options_t::setsockopt (int option_, const void *optval_,
             }
             break;
 
-        case ZMQ_TCP_RETRANSMIT_TIMEOUT:
+        case ZMQ_TCP_MAXRT:
             if (is_int && value >= 0) {
-                tcp_retransmit_timeout = value;
+                tcp_maxrt = value;
                 return 0;
             }
             break;
@@ -745,9 +745,9 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
             }
             break;
 
-        case ZMQ_TCP_RETRANSMIT_TIMEOUT:
+        case ZMQ_TCP_MAXRT:
             if (is_int) {
-                *value = tcp_retransmit_timeout;
+                *value = tcp_maxrt;
                 return 0;
             }
             break;

src/options.hpp

@@ -104,7 +104,7 @@ namespace zmq
         //  Maximum interval in milliseconds beyond which TCP will timeout
         //  retransmitted packets.
         //  Default 0 (unused)
-        int tcp_retransmit_timeout;
+        int tcp_maxrt;
 
         //  Minimum interval between attempts to reconnect, in milliseconds.
         //  Default 100ms

src/tcp.cpp

@@ -153,7 +153,7 @@ void zmq::tune_tcp_keepalives (fd_t s_, int keepalive_, int keepalive_cnt_, int
 #endif // ZMQ_HAVE_WINDOWS
 }
 
-void zmq::tune_tcp_retransmit_timeout (fd_t sockfd_, int timeout_)
+void zmq::tune_tcp_maxrt (fd_t sockfd_, int timeout_)
 {
     if (timeout_ <= 0)
         return;

src/tcp.hpp

@@ -47,8 +47,8 @@ namespace zmq
     //  Tunes TCP keep-alives
     void tune_tcp_keepalives (fd_t s_, int keepalive_, int keepalive_cnt_, int keepalive_idle_, int keepalive_intvl_);
 
-    //  Tunes TCP retransmit timeout
+    //  Tunes TCP max retransmit timeout
-    void tune_tcp_retransmit_timeout (fd_t sockfd_, int timeout_);
+    void tune_tcp_maxrt (fd_t sockfd_, int timeout_);
 
     //  Writes data to the socket. Returns the number of bytes actually
     //  written (even zero is to be considered to be a success). In case

src/tcp_connecter.cpp

@@ -146,7 +146,7 @@ void zmq::tcp_connecter_t::out_event ()
 
     tune_tcp_socket (fd);
     tune_tcp_keepalives (fd, options.tcp_keepalive, options.tcp_keepalive_cnt, options.tcp_keepalive_idle, options.tcp_keepalive_intvl);
-    tune_tcp_retransmit_timeout (fd, options.tcp_retransmit_timeout);
+    tune_tcp_maxrt (fd, options.tcp_maxrt);
 
     // remember our fd for ZMQ_SRCFD in messages
     socket->set_fd (fd);

src/tcp_listener.cpp

@@ -100,7 +100,7 @@ void zmq::tcp_listener_t::in_event ()
 
     tune_tcp_socket (fd);
     tune_tcp_keepalives (fd, options.tcp_keepalive, options.tcp_keepalive_cnt, options.tcp_keepalive_idle, options.tcp_keepalive_intvl);
-    tune_tcp_retransmit_timeout (fd, options.tcp_retransmit_timeout);
+    tune_tcp_maxrt (fd, options.tcp_maxrt);
 
     // remember our fd for ZMQ_SRCFD in messages
     socket->set_fd(fd);