Merge pull request #3557 from bluca/docs

Clarify documentation for zmq_unbind/disconnect and new batch options

doc/zmq_disconnect.txt

@@ -25,27 +25,12 @@ associated with the endpoint will be discarded. However, if the socket's linger
 period is non-zero, libzmq will still attempt to transmit these discarded messages,
 until the linger period expires.
 
-Addionally, if the disconnected endpoint was previously connected to
-(as opposed to bound), the incoming message queue associated with the
-endpoint will be discarded. This means that after unbinding an endpoint
-using `disconnect`, it is possible to received messages originating
-from that same endpoint if they were already present in the incoming message
-queue before unbinding. However, this is not the case when disconnecting
-from a connected endpoint.
-
 The 'endpoint' argument is as described in linkzmq:zmq_connect[3]
 
 NOTE: The default setting of _ZMQ_LINGER_ does not discard unsent messages;
 this behaviour may cause the application to block when calling _zmq_ctx_term()_.
 For details refer to linkzmq:zmq_setsockopt[3] and linkzmq:zmq_ctx_term[3].
 
-Unbinding wild-card address from a socket
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-When a wild-card `*` 'endpoint' (described in linkzmq:zmq_tcp[7],
-linkzmq:zmq_ipc[7] and linkzmq:zmq_vmci[7]) was used in _zmq_bind()_, the caller
-should use the real 'endpoint' obtained from the ZMQ_LAST_ENDPOINT socket option
-to unbind this 'endpoint' from a socket.
-
 RETURN VALUE
 ------------
 The _zmq_disconnect()_ function shall return zero if successful. Otherwise it
@@ -78,37 +63,6 @@ rc = zmq_disconnect (socket, "tcp://server001:5555");
 assert (rc == 0);
 ----
 
-.Unbind a subscriber socket from a TCP transport
-----
-/* Create a ZMQ_SUB socket */
-void *socket = zmq_socket (context, ZMQ_SUB);
-assert (socket);
-/* Connect it to the host server001, port 5555 using a TCP transport */
-rc = zmq_bind (socket, "tcp://127.0.0.1:5555");
-assert (rc == 0);
-/* Disconnect from the previously connected endpoint */
-rc = zmq_disconnect(socket, "tcp://127.0.0.1:5555");
-assert (rc == 0);
-----
-
-.Unbind wild-card `*` binded socket
-----
-/* Create a ZMQ_SUB socket */
-void *socket = zmq_socket (context, ZMQ_SUB);
-assert (socket);
-/* Bind it to the system-assigned ephemeral port using a TCP transport */
-rc = zmq_bind (socket, "tcp://127.0.0.1:*");
-assert (rc == 0);
-/* Obtain real endpoint */
-const size_t buf_size = 32;
-char buf[buf_size];
-rc = zmq_getsockopt (socket, ZMQ_LAST_ENDPOINT, buf, (size_t *)&buf_size);
-assert (rc == 0);
-/* Unbind socket by real endpoint */
-rc = zmq_disconnect (socket, buf);
-assert (rc == 0);
-----
-
 SEE ALSO
 --------
 linkzmq:zmq_connect[3]

doc/zmq_getsockopt.txt

@@ -924,9 +924,8 @@ Applicable socket types:: ZMQ_ROUTER
 
 ZMQ_IN_BATCH_SIZE: Maximal receive batch size
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Sets the maximal amount of messages that can be received in a single
+Gets the maximal amount of messages that can be received in a single
-'recv' system call. This can be used to improved throughtput at the expense of
+'recv' system call.
-latency and vice-versa.
 
 Cannot be zero.
 
@@ -936,14 +935,13 @@ NOTE: in DRAFT state, not yet available in stable releases.
 Option value type:: int
 Option value unit:: messages
 Default value:: 8192
-Applicable socket types:: All
+Applicable socket types:: All, when using TCP, IPC, PGM or NORM transport.
 
 
 ZMQ_OUT_BATCH_SIZE: Maximal send batch size
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Sets the maximal amount of messages that can be sent in a single
+Gets the maximal amount of messages that can be sent in a single
-'send' system call. This can be used to improved throughtput at the expense of
+'send' system call.
-latency and vice-versa.
 
 Cannot be zero.
 
@@ -953,7 +951,7 @@ NOTE: in DRAFT state, not yet available in stable releases.
 Option value type:: int
 Option value unit:: messages
 Default value:: 8192
-Applicable socket types:: All
+Applicable socket types:: All, when using TCP, IPC, PGM or NORM transport.
 
 
 

doc/zmq_setsockopt.txt

@@ -1363,10 +1363,12 @@ Applicable socket types:: ZMQ_ROUTER
 
 
 ZMQ_IN_BATCH_SIZE: Maximal receive batch size
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Sets the maximal amount of messages that can be received in a single
-'recv' system call. This can be used to improved throughtput at the expense of
+'recv' system call. WARNING: this option should almost never be changed.
-latency and vice-versa.
+The default has been chosen to offer the best compromise between latency and
+throughtput. In the vast majority of cases, changing this option will result in
+worst result if not outright breakages.
 
 Cannot be zero.
 
@@ -1376,14 +1378,16 @@ NOTE: in DRAFT state, not yet available in stable releases.
 Option value type:: int
 Option value unit:: messages
 Default value:: 8192
-Applicable socket types:: All
+Applicable socket types:: All, when using TCP, IPC, PGM or NORM transport.
 
 
 ZMQ_OUT_BATCH_SIZE: Maximal send batch size
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Sets the maximal amount of messages that can be sent in a single
-'send' system call. This can be used to improved throughtput at the expense of
+'send' system call. WARNING: this option should almost never be changed.
-latency and vice-versa.
+The default has been chosen to offer the best compromise between latency and
+throughtput. In the vast majority of cases, changing this option will result in
+worst result if not outright breakages.
 
 Cannot be zero.
 
@@ -1393,7 +1397,7 @@ NOTE: in DRAFT state, not yet available in stable releases.
 Option value type:: int
 Option value unit:: messages
 Default value:: 8192
-Applicable socket types:: All
+Applicable socket types:: All, when using TCP, IPC, PGM or NORM transport.
 
 
 RETURN VALUE

doc/zmq_unbind.txt

@@ -4,7 +4,7 @@ zmq_unbind(3)
 
 NAME
 ----
-zmq_unbind - Another name for zmq_disconnect
+zmq_unbind - Stop accepting connections on a socket
 
 
 SYNOPSIS
@@ -14,8 +14,81 @@ int zmq_unbind (void '*socket', const char '*endpoint');
 
 DESCRIPTION
 -----------
-The _zmq_unbind()_ has the same exact behavior as _zmq_disconnect()_.
+The _zmq_unbind()_ function shall unbind a socket specified
-Refer to linkzmq:zmq_disconnect[3].
+by the 'socket' argument from the endpoint specified by the 'endpoint'
+argument. 
+
+Addionally the incoming message queue associated with the endpoint will be
+discarded. This means that after unbinding an endpoint it is possible to
+received messages originating from that same endpoint if they were already
+present in the incoming message queue before unbinding.
+
+The 'endpoint' argument is as described in linkzmq:zmq_bind[3]
+
+Unbinding wild-card address from a socket
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+When wild-card `*` 'endpoint' (described in linkzmq:zmq_tcp[7],
+linkzmq:zmq_ipc[7] and linkzmq:zmq_vmci[7]) was used in _zmq_bind()_, the caller should use
+real 'endpoint' obtained from the ZMQ_LAST_ENDPOINT socket option
+to unbind this 'endpoint' from a socket.
+
+RETURN VALUE
+------------
+The _zmq_unbind()_ function shall return zero if successful. Otherwise it
+shall return `-1` and set 'errno' to one of the values defined below.
+
+ERRORS
+------
+*EINVAL*::
+The endpoint supplied is invalid.
+*ETERM*::
+The 0MQ 'context' associated with the specified 'socket' was terminated.
+*ENOTSOCK*::
+The provided 'socket' was invalid.
+*ENOENT*::
+The endpoint supplied was not previously bound.
+
+
+EXAMPLES
+--------
+.Unbind a subscriber socket from a TCP transport
+----
+/* Create a ZMQ_SUB socket */
+void *socket = zmq_socket (context, ZMQ_SUB);
+assert (socket);
+/* Connect it to the host server001, port 5555 using a TCP transport */
+rc = zmq_bind (socket, "tcp://127.0.0.1:5555");
+assert (rc == 0);
+/* Disconnect from the previously connected endpoint */
+rc = zmq_unbind (socket, "tcp://127.0.0.1:5555");
+assert (rc == 0);
+----
+
+.Unbind wild-card `*` binded socket
+----
+/* Create a ZMQ_SUB socket */
+void *socket = zmq_socket (context, ZMQ_SUB);
+assert (socket);
+/* Bind it to the system-assigned ephemeral port using a TCP transport */
+rc = zmq_bind (socket, "tcp://127.0.0.1:*");
+assert (rc == 0);
+/* Obtain real endpoint */
+const size_t buf_size = 32;
+char buf[buf_size];
+rc = zmq_getsockopt (socket, ZMQ_LAST_ENDPOINT, buf, (size_t *)&buf_size);
+assert (rc == 0);
+/* Unbind socket by real endpoint */
+rc = zmq_unbind (socket, buf);
+assert (rc == 0);
+----
+
+NOTE
+----
+
+Note that while the implementation is similar to _zmq_disconnect()_, the
+semantics are different and the two functions should not be used
+interchangeably. Bound sockets should be unbound, and connected sockets should
+be disconnected.
 
 SEE ALSO
 --------