Problem: no permission to relicense ZMQ_RECONNECT_IVL_MAX

Solution: remove the implementation. Thijs Terlouw <thijsterlouw@gmail.com>,
the author, did not respond to requests to allow relicensing to MPL2,
so we have to remove his copyrighted work.
Remove the implementation and make get/set return -EOPNOTSUPP.

doc/zmq_getsockopt.txt

@@ -619,23 +619,11 @@ Default value:: 100
 Applicable socket types:: all, only for connection-oriented transports
 
 
-ZMQ_RECONNECT_IVL_MAX: Retrieve maximum reconnection interval
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The 'ZMQ_RECONNECT_IVL_MAX' option shall retrieve the maximum reconnection
-interval for the specified 'socket'.  This is the maximum period 0MQ shall wait
-between attempts to reconnect. On each reconnect attempt, the previous interval
-shall be doubled until ZMQ_RECONNECT_IVL_MAX is reached. This allows for
-exponential backoff strategy. Default value means no exponential backoff is
-performed and reconnect interval calculations are only based on
-ZMQ_RECONNECT_IVL.
-
-NOTE:  Values less than ZMQ_RECONNECT_IVL will be ignored.
-
-[horizontal]
-Option value type:: int
-Option value unit:: milliseconds
-Default value:: 0 (only use ZMQ_RECONNECT_IVL)
-Applicable socket types:: all, only for connection-oriented transport
+ZMQ_RECONNECT_IVL_MAX: DEPRECATED
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The 'ZMQ_RECONNECT_IVL_MAX option is an empty stub that only returns an
+*EOPNOTSUPP* error, as the author did not provide a relicense agreement for
+the Mozilla Public License v2 relicense of libzmq.
 
 
 ZMQ_RECONNECT_STOP: Retrieve condition where reconnection will stop
@@ -985,8 +973,8 @@ Applicable socket types:: All, when using TCP, IPC, PGM or NORM transport.
 
 ZMQ_TOPICS_COUNT: Number of topic subscriptions received
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Gets the number of topic (prefix) subscriptions either 
-* received on a (X)PUB socket from all the connected (X)SUB sockets or 
+Gets the number of topic (prefix) subscriptions either
+* received on a (X)PUB socket from all the connected (X)SUB sockets or
 * acknowledged on an (X)SUB socket from all the connected (X)PUB sockets
 
 NOTE: in DRAFT state, not yet available in stable releases.

doc/zmq_setsockopt.txt

@@ -750,22 +750,11 @@ Default value:: 100
 Applicable socket types:: all, only for connection-oriented transports
 
 
-ZMQ_RECONNECT_IVL_MAX: Set maximum reconnection interval
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The 'ZMQ_RECONNECT_IVL_MAX' option shall set the maximum reconnection interval
-for the specified 'socket'.  This is the maximum period 0MQ shall wait between
-attempts to reconnect. On each reconnect attempt, the previous interval shall be
-doubled until ZMQ_RECONNECT_IVL_MAX is reached. This allows for exponential
-backoff strategy. Default value means no exponential backoff is performed and
-reconnect interval calculations are only based on ZMQ_RECONNECT_IVL.
-
-NOTE:  Values less than ZMQ_RECONNECT_IVL will be ignored.
-
-[horizontal]
-Option value type:: int
-Option value unit:: milliseconds
-Default value:: 0 (only use ZMQ_RECONNECT_IVL)
-Applicable socket types:: all, only for connection-oriented transports
+ZMQ_RECONNECT_IVL_MAX: DEPRECATED
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The 'ZMQ_RECONNECT_IVL_MAX option is an empty stub that only returns an
+*EOPNOTSUPP* error, as the author did not provide a relicense agreement for
+the Mozilla Public License v2 relicense of libzmq.
 
 
 ZMQ_RECONNECT_STOP: Set condition where reconnection will stop
@@ -784,7 +773,7 @@ connection attempts to non-0MQ sockets.  Note that when specifying this option
 you may also want to set `ZMQ_HANDSHAKE_IVL` -- the default handshake interval
 is 30000 (30 seconds), which is typically too large.
 
-The 'ZMQ_RECONNECT_STOP_AFTER_DISCONNECT' option will stop reconnection when 
+The 'ZMQ_RECONNECT_STOP_AFTER_DISCONNECT' option will stop reconnection when
 zmq_disconnect() has been called. This can be useful when the user's request failed
 (server not ready), as the socket does not need to continue to reconnect after
 user disconnect actively.

src/options.cpp

@@ -213,7 +213,6 @@ zmq::options_t::options_t () :
     tcp_maxrt (0),
     reconnect_stop (0),
     reconnect_ivl (100),
-    reconnect_ivl_max (0),
     backlog (100),
     maxmsgsize (-1),
     rcvtimeo (-1),
@@ -428,11 +427,7 @@ int zmq::options_t::setsockopt (int option_,
             break;
 
         case ZMQ_RECONNECT_IVL_MAX:
-            if (is_int && value >= 0) {
-                reconnect_ivl_max = value;
-                return 0;
-            }
-            break;
+            return -EOPNOTSUPP;
 
         case ZMQ_BACKLOG:
             if (is_int && value >= 0) {
@@ -1076,11 +1071,7 @@ int zmq::options_t::getsockopt (int option_,
             break;
 
         case ZMQ_RECONNECT_IVL_MAX:
-            if (is_int) {
-                *value = reconnect_ivl_max;
-                return 0;
-            }
-            break;
+            return -EOPNOTSUPP;
 
         case ZMQ_BACKLOG:
             if (is_int) {

src/options.hpp

@@ -127,10 +127,6 @@ struct options_t
     //  Default 100ms
     int reconnect_ivl;
 
-    //  Maximum interval between attempts to reconnect, in milliseconds.
-    //  Default 0 (unused)
-    int reconnect_ivl_max;
-
     //  Maximum backlog for pending connections.
     int backlog;
 

src/stream_connecter_base.cpp

@@ -123,17 +123,6 @@ int zmq::stream_connecter_base_t::get_new_reconnect_ivl ()
         ? _current_reconnect_ivl + random_jitter
         : std::numeric_limits<int>::max ();
 
-    //  Only change the new current reconnect interval if the maximum reconnect
-    //  interval was set and if it's larger than the reconnect interval.
-    if (options.reconnect_ivl_max > 0
-        && options.reconnect_ivl_max > options.reconnect_ivl) {
-        //  Calculate the next interval
-        _current_reconnect_ivl =
-          _current_reconnect_ivl < std::numeric_limits<int>::max () / 2
-            ? std::min (_current_reconnect_ivl * 2, options.reconnect_ivl_max)
-            : options.reconnect_ivl_max;
-    }
-
     return interval;
 }