ZMQ_RECONNECT_IVL socket options added.

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

doc/zmq_getsockopt.txt

@@ -212,8 +212,8 @@ Default value:: 0
 Applicable socket types:: all
 
 
-ZMQ_LINGER: Set linger period for socket shutdown
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ZMQ_LINGER: Retrieve linger period for socket shutdown
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 The 'ZMQ_LINGER' option shall retrieve the period for pending outbound
 messages to linger in memory after closing the socket. Value of -1 means
 infinite. Pending messages will be kept until they are fully transferred to
@@ -227,6 +227,17 @@ Option value unit:: milliseconds
 Default value:: -1
 Applicable socket types:: all
 
+ZMQ_RECONNECT_IVL: Retrieve reconnect period for connection-based transports
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The 'ZMQ_RECONNECT' option shall retrieve the period indicating how long it
+takes for a disconnected underlying connection to attempt to reconnect.
+
+[horizontal]
+Option value type:: int
+Option value unit:: milliseconds
+Default value:: 100
+Applicable socket types:: all
+
 
 ZMQ_FD: Retrieve file descriptor associated with the socket
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

doc/zmq_setsockopt.txt

@@ -232,6 +232,19 @@ Default value:: -1
 Applicable socket types:: all
 
 
+ZMQ_RECONNECT_IVL: Set reconnect period for connection-based transports
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The 'ZMQ_RECONNECT' option shall be set to specify how long it takes for a
+disconnected underlying connection to attempt to reconnect. The interval
+can be randomised to some extent by 0MQ to prevent reconnection storms.
+
+[horizontal]
+Option value type:: int
+Option value unit:: milliseconds
+Default value:: 100
+Applicable socket types:: all
+
+
 RETURN VALUE
 ------------
 The _zmq_setsockopt()_ function shall return zero if successful. Otherwise it

include/zmq.h

@@ -192,6 +192,7 @@ ZMQ_EXPORT int zmq_term (void *context);
 #define ZMQ_EVENTS 15
 #define ZMQ_TYPE 16
 #define ZMQ_LINGER 17
+#define ZMQ_RECONNECT_IVL 18
 
 /*  Send/recv options.                                                        */
 #define ZMQ_NOBLOCK 1

src/config.hpp

@@ -69,9 +69,6 @@ namespace zmq
         //  Maximum number of events the I/O thread can process in one go.
         max_io_events = 256,
 
-        //  How long to wait (milliseconds) till reattempting to connect.
-        reconnect_period = 100,
-
         //  Should initial connection attempts be delayed?
         wait_before_connect = false,
 

src/options.cpp

@@ -35,6 +35,7 @@ zmq::options_t::options_t () :
     rcvbuf (0),
     type (-1),
     linger (-1),
+    reconnect_ivl (100),
     requires_in (false),
     requires_out (false),
     immediate_connect (true)
@@ -137,6 +138,18 @@ int zmq::options_t::setsockopt (int option_, const void *optval_,
         }
         linger = *((int*) optval_);
         return 0;
+
+    case ZMQ_RECONNECT_IVL:
+        if (optvallen_ != sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        if (*((int*) optval_) < 0) {
+            errno = EINVAL;
+            return -1;
+        }
+        reconnect_ivl = *((int*) optval_);
+        return 0;
     }
 
     errno = EINVAL;
@@ -147,24 +160,6 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
 {
     switch (option_) {
 
-    case ZMQ_LINGER:
-        if (*optvallen_ < sizeof (int)) {
-            errno = EINVAL;
-            return -1;
-        }
-        *((int*) optval_) = linger;
-        *optvallen_ = sizeof (int);
-        return 0;
-
-    case ZMQ_TYPE:
-        if (*optvallen_ < sizeof (int)) {
-            errno = EINVAL;
-            return -1;
-        }
-        *((int*) optval_) = type;
-        *optvallen_ = sizeof (int);
-        return 0;
-
     case ZMQ_HWM:
         if (*optvallen_ < sizeof (uint64_t)) {
             errno = EINVAL;
@@ -246,6 +241,34 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
         *((uint64_t*) optval_) = rcvbuf;
         *optvallen_ = sizeof (uint64_t);
         return 0;
+
+    case ZMQ_TYPE:
+        if (*optvallen_ < sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        *((int*) optval_) = type;
+        *optvallen_ = sizeof (int);
+        return 0;
+
+    case ZMQ_LINGER:
+        if (*optvallen_ < sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        *((int*) optval_) = linger;
+        *optvallen_ = sizeof (int);
+        return 0;
+
+    case ZMQ_RECONNECT_IVL:
+        if (*optvallen_ < sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        *((int*) optval_) = reconnect_ivl;
+        *optvallen_ = sizeof (int);
+        return 0;
+
     }
 
     errno = EINVAL;

src/options.hpp

@@ -57,6 +57,9 @@ namespace zmq
         //  Linger time, in milliseconds.
         int linger;
 
+        //  Interval between attempts to reconnect, in milliseconds.
+        int reconnect_ivl;
+
         //  These options are never set by the user directly. Instead they are
         //  provided by the specific socket type.
         bool requires_in;

src/zmq_connecter.cpp

@@ -54,20 +54,21 @@ zmq::zmq_connecter_t::~zmq_connecter_t ()
         rm_fd (handle);
 }
 
-int zmq::zmq_connecter_t::get_reconnect_period ()
+int zmq::zmq_connecter_t::get_reconnect_ivl ()
 {
 #if defined ZMQ_HAVE_WINDOWS
-    return (reconnect_period + (((int)GetCurrentProcessId () * 13)
-        % reconnect_period));
+    return (options.reconnect_ivl + (((int) GetCurrentProcessId () * 13)
+        % options.reconnect_ivl));
 #else
-    return (reconnect_period + (((int)getpid () * 13) % reconnect_period));
+    return (options.reconnect_ivl + (((int) getpid () * 13)
+        % options.reconnect_ivl));
 #endif
 }
 
 void zmq::zmq_connecter_t::process_plug ()
 {
     if (wait)
-        add_timer (get_reconnect_period (), reconnect_timer_id);
+        add_timer (get_reconnect_ivl (), reconnect_timer_id);
     else
         start_connecting ();
 }
@@ -90,7 +91,7 @@ void zmq::zmq_connecter_t::out_event ()
     if (fd == retired_fd) {
         tcp_connecter.close ();
         wait = true;
-        add_timer (get_reconnect_period (), reconnect_timer_id);
+        add_timer (get_reconnect_ivl (), reconnect_timer_id);
         return;
     }
 
@@ -139,5 +140,5 @@ void zmq::zmq_connecter_t::start_connecting ()
 
     //  Handle any other error condition by eventual reconnect.
     wait = true;
-    add_timer (get_reconnect_period (), reconnect_timer_id);
+    add_timer (get_reconnect_ivl (), reconnect_timer_id);
 }

src/zmq_connecter.hpp

@@ -56,7 +56,7 @@ namespace zmq
         void start_connecting ();
 
         //  Internal function to return the reconnect backoff delay.
-        int get_reconnect_period ();
+        int get_reconnect_ivl ();
 
         //  Actual connecting socket.
         tcp_connecter_t tcp_connecter;