From 7fbf2c26ac063988818230a0e18a9df48c2fbf2d Mon Sep 17 00:00:00 2001
From: Steve Vinoski
Date: Tue, 27 Aug 2013 11:42:00 -0400
Subject: add {active,N} socket option for TCP, UDP, and SCTP
Add the {active,N} socket option, where N is an integer in the range
-32768..32767, to allow a caller to specify the number of data messages to
be delivered to the controlling process. Once the socket's delivered
message count either reaches 0 or is explicitly set to 0 with
inet:setopts/2 or by including {active,0} as an option when the socket is
created, the socket transitions to passive ({active, false}) mode and the
socket's controlling process receives a message to inform it of the
transition. TCP sockets receive {tcp_passive,Socket}, UDP sockets receive
{udp_passive,Socket} and SCTP sockets receive {sctp_passive,Socket}.
The socket's delivered message counter defaults to 0, but it can be set
using {active,N} via any gen_tcp, gen_udp, or gen_sctp function that takes
socket options as arguments, or via inet:setopts/2. New N values are added
to the socket's current counter value, and negative numbers can be used to
reduce the counter value. Specifying a number that would cause the socket's
counter value to go above 32767 causes an einval error. If a negative
number is specified such that the counter value would become negative, the
socket's counter value is set to 0 and the socket transitions to passive
mode. If the counter value is already 0 and inet:setopts(Socket,
[{active,0}]) is specified, the counter value remains at 0 but the
appropriate passive mode transition message is generated for the socket.
This commit contains a modified preloaded prim_inet.beam due to changes in
prim_inet.erl.
Add tests for {active,N} mode for TCP, UDP, and SCTP sockets.
Add documentation for {active,N} mode for inet, gen_tcp, gen_udp, and
gen_sctp.
---
lib/kernel/doc/src/gen_tcp.xml | 6 ++++++
1 file changed, 6 insertions(+)
(limited to 'lib/kernel/doc/src/gen_tcp.xml')
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:
{tcp, Socket, Data}
+ If the socket is in {active, N} mode (see
+ inet:setopts/2 for details) and its message counter
+ drops to 0, the following message is delivered to indicate that the
+ socket has transitioned to passive ({active, false}) mode:
+
+{tcp_passive, Socket}
If the socket is closed, the following message is delivered:
{tcp_closed, Socket}
--
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