diff options
Diffstat (limited to 'lib/kernel/doc')
| -rw-r--r-- | lib/kernel/doc/src/gen_sctp.xml | 31 | ||||
| -rw-r--r-- | lib/kernel/doc/src/gen_tcp.xml | 6 | ||||
| -rw-r--r-- | lib/kernel/doc/src/gen_udp.xml | 17 | ||||
| -rw-r--r-- | lib/kernel/doc/src/inet.xml | 51 |
4 files changed, 79 insertions, 26 deletions
diff --git a/lib/kernel/doc/src/gen_sctp.xml b/lib/kernel/doc/src/gen_sctp.xml index dacea7a239..986260638d 100644 --- a/lib/kernel/doc/src/gen_sctp.xml +++ b/lib/kernel/doc/src/gen_sctp.xml @@ -496,9 +496,11 @@ orthogonal to the sets of TCP, UDP and generic INET options: only those options which are explicitly listed below are allowed for SCTP sockets. Options can be set on the socket using - <c>gen_sctp:open/1,2</c> or <c>inet:setopts/2</c>, - retrieved using <c>inet:getopts/2</c>, and when calling - <c>gen_sctp:connect/4,5</c> options can be changed.</p> + <seealso marker="#open/1"><c>gen_sctp:open/1,2</c></seealso> + or <seealso marker="inet#setopts/2"><c>inet:setopts/2</c></seealso>, + retrieved using <seealso marker="inet#getopts/2"><c>inet:getopts/2</c></seealso>, + and when calling <seealso marker="#connect/4"><c>gen_sctp:connect/4,5</c></seealso> + options can be changed.</p> <marker id="option-binary"></marker> <marker id="option-list"></marker> <taglist> @@ -507,7 +509,7 @@ <p>Determines the type of data returned from <c>gen_sctp:recv/1,2</c>.</p> <marker id="option-active"></marker> </item> - <tag><c>{active, true|false|once}</c></tag> + <tag><c>{active, true|false|once|N}</c></tag> <item> <list type="bulleted"> <item> @@ -524,11 +526,28 @@ </item> <item> <p>If <c>once</c>, only one message is automatically placed - in the message queue, after that the mode is automatically - re-set to passive. This provides flow control as well as + in the message queue, and after that the mode is automatically + reset to passive. This provides flow control as well as the possibility for the receiver to listen for its incoming SCTP data interleaved with other inter-process messages.</p> </item> + <item> + <p>If <c>active</c> is specified as an integer <c>N</c> in the + range -32768 to 32767 (inclusive), then that number is added to + the socket's count of the number of data messages to be + delivered to the controlling process. If the result of the + addition would be negative, the count is set to 0. Once the + count reaches 0, either through the delivery of messages or by + being explicitly set with <seealso + marker="inet#setopts/2">inet:setopts/2</seealso>, the socket's + mode is automatically reset to passive (<c>{active, + false}</c>) mode. When a socket in this active mode transitions to + passive mode, the message <c>{sctp_passive, Socket}</c> is sent + to the controlling process to notify it that if it wants to + receive more data messages from the socket, it must call + <seealso marker="inet#setopts/2">inet:setopts/2</seealso> to set + the socket back into an active mode.</p> + </item> </list> </item> <tag><c>{tos, integer()}</c></tag> diff --git a/lib/kernel/doc/src/gen_tcp.xml b/lib/kernel/doc/src/gen_tcp.xml index 7afd73f4bf..dbd0d3c815 100644 --- a/lib/kernel/doc/src/gen_tcp.xml +++ b/lib/kernel/doc/src/gen_tcp.xml @@ -148,6 +148,12 @@ do_recv(Sock, Bs) -> as messages:</p> <code type="none"> {tcp, Socket, Data}</code> + <p>If the socket is in <c>{active, N}</c> mode (see <seealso marker="inet#setopts/2"> + inet:setopts/2</seealso> for details) and its message counter + drops to 0, the following message is delivered to indicate that the + socket has transitioned to passive (<c>{active, false}</c>) mode:</p> + <code type="none"> +{tcp_passive, Socket}</code> <p>If the socket is closed, the following message is delivered:</p> <code type="none"> {tcp_closed, Socket}</code> diff --git a/lib/kernel/doc/src/gen_udp.xml b/lib/kernel/doc/src/gen_udp.xml index faca31e928..503725fe18 100644 --- a/lib/kernel/doc/src/gen_udp.xml +++ b/lib/kernel/doc/src/gen_udp.xml @@ -145,14 +145,23 @@ <seealso marker="inet#setopts/2">inet:setopts/2</seealso>.</p> </item> </taglist> - <p>The returned socket <c><anno>Socket</anno></c> is used to send packets - from this port with <c>send/4</c>. When UDP packets arrive at - the opened port, they are delivered as messages:</p> + <p>The returned socket <c><anno>Socket</anno></c> is used to send + packets from this port with <c>send/4</c>. When UDP packets arrive + at the opened port, if the socket is in an active mode the packets + are delivered as messages to the controlling process:</p> <code type="none"> {udp, Socket, IP, InPortNo, Packet}</code> - <p>Note that arriving UDP packets that are longer than + <p>If the socket is not in an active mode, data can be + retrieved via the <seealso marker="#recv/2">recv/2,3</seealso> calls. + Note that arriving UDP packets that are longer than the receive buffer option specifies, might be truncated without warning.</p> + <p>When a socket in <c>{active, N}</c> mode (see <seealso marker="inet#setopts/2"> + inet:setopts/2</seealso> for details) transitions to passive + (<c>{active, false}</c>) mode, the controlling process is notified by a + message of the following form:</p> + <code type="none"> +{udp_passive, Socket}</code> <p><c>IP</c> and <c>InPortNo</c> define the address from which <c>Packet</c> came. <c>Packet</c> is a list of bytes if the option <c>list</c> was specified. <c>Packet</c> is a diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml index e1b0b34888..fb8bf32978 100644 --- a/lib/kernel/doc/src/inet.xml +++ b/lib/kernel/doc/src/inet.xml @@ -456,47 +456,66 @@ fe80::204:acff:fe17:bf38 <p>Sets one or more options for a socket. The following options are available:</p> <taglist> - <tag><c>{active, true | false | once}</c></tag> + <tag><c>{active, true | false | once | N}</c></tag> <item> <p>If the value is <c>true</c>, which is the default, everything received from the socket will be sent as messages to the receiving process. If the value is <c>false</c> (passive mode), the process must explicitly - receive incoming data by calling <c>gen_tcp:recv/2,3</c> - or <c>gen_udp:recv/2,3</c> (depending on the type of - socket).</p> + receive incoming data by calling + <seealso marker="gen_tcp#recv/2"><c>gen_tcp:recv/2,3</c></seealso>, + <seealso marker="gen_udp#recv/2"><c>gen_udp:recv/2,3</c></seealso> + or <seealso marker="gen_sctp#recv/1"><c>gen_sctp:recv/1,2</c></seealso> + (depending on the type of socket).</p> <p>If the value is <c>once</c> (<c>{active, once}</c>), <em>one</em> data message from the socket will be sent to the process. To receive one more message, <c>setopts/2</c> must be called again with the <c>{active, once}</c> option.</p> - <p>When using <c>{active, once}</c>, the socket changes - behaviour automatically when data is received. This can - sometimes be confusing in combination with connection - oriented sockets (i.e. <c>gen_tcp</c>) as a socket with - <c>{active, false}</c> behaviour reports closing + <p>If the value is an integer <c>N</c> in the range -32768 to 32767 + (inclusive), the value is added to the socket's count of data + messages sent to the controlling process. A socket's default + message count is 0. If a negative value is specified and its + magnitude is equal to or greater than the socket's current + message count, the socket's message count is set to 0. Once + the socket's message count reaches 0, either due to sending + received data messages to the process or by being explicitly set, + the process is then notified by a special message, specific to + the type of socket, that the socket has entered passive + mode. Once the socket enters passive mode, to receive more + messages <c>setopts/2</c> must be called again to set the + socket back into an active mode.</p> + <p>When using <c>{active, once}</c> or <c>{active, N}</c>, the + socket changes behaviour automatically when data is received. + This can sometimes be confusing in combination with + connection-oriented sockets (i.e. <c>gen_tcp</c>) as a socket + with <c>{active, false}</c> behaviour reports closing differently than a socket with <c>{active, true}</c> behaviour. To make programming easier, a socket where the peer closed and this was detected while in <c>{active, false}</c> mode, will still generate the message - <c>{tcp_closed,Socket}</c> when set to <c>{active, once}</c> or <c>{active, true}</c> mode. It is therefore + <c>{tcp_closed,Socket}</c> when set to <c>{active, once}</c>, + <c>{active, true}</c> or <c>{active, N}</c> mode. It is therefore safe to assume that the message <c>{tcp_closed,Socket}</c>, possibly followed by socket port termination (depending on the <c>exit_on_close</c> option) will eventually appear when a socket changes back and forth between <c>{active, true}</c> and - <c>{active, false}</c> mode. However, + <c>{active, false}</c> mode. However, <em>when</em> peer closing is detected is all up to the underlying TCP/IP stack and protocol.</p> - <p>Note that <c>{active,true}</c> mode provides no flow + <p>Note that <c>{active, true}</c> mode provides no flow control; a fast sender could easily overflow the - receiver with incoming messages. Use active mode only if + receiver with incoming messages. The same is true of + <c>{active, N}</c> mode while the message count is greater + than zero. Use active mode only if your high-level protocol provides its own flow control (for instance, acknowledging received messages) or the - amount of data exchanged is small. <c>{active,false}</c> - mode or use of the <c>{active, once}</c> mode provides - flow control; the other side will not be able send + amount of data exchanged is small. <c>{active, false}</c> + mode, use of the <c>{active, once}</c> mode or <c>{active, N}</c> + mode with values of <c>N</c> appropriate for the application + provides flow control; the other side will not be able send faster than the receiver can read.</p> </item> |