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| author | Igor Slepchin <[email protected]> | 2018-09-24 22:44:03 -0400 |
|---|---|---|
| committer | Igor Slepchin <[email protected]> | 2018-10-11 01:07:19 -0400 |
| commit | 210665e8a252faecf28ccebade999e734ab92582 (patch) | |
| tree | 8b81350cb43fd9a59ea13e34e03017f82fccbef3 /lib | |
| parent | 3daef1a4ee8cfce90d0220be3695809ccbb8ea58 (diff) | |
| download | otp-210665e8a252faecf28ccebade999e734ab92582.tar.gz otp-210665e8a252faecf28ccebade999e734ab92582.tar.bz2 otp-210665e8a252faecf28ccebade999e734ab92582.zip | |
Add nopush TCP socket option
This translates to TCP_CORK on Linux and TCP_NOPUSH on
BSD.
In effect, this acts as super-Nagle: no partial TCP segments
are sent out until this option is turned off. Once turned off,
all accumulated unsent data is sent out immediately. The latter
is *not* the case on OSX, hence the implementation ignores
"nopush" on OSX to reduce confusion.
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/kernel/doc/src/inet.xml | 12 | ||||
| -rw-r--r-- | lib/kernel/src/inet_int.hrl | 1 | ||||
| -rw-r--r-- | lib/kernel/test/inet_sockopt_SUITE.erl | 9 |
3 files changed, 20 insertions, 2 deletions
diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml index ed775d67eb..9fc361a234 100644 --- a/lib/kernel/doc/src/inet.xml +++ b/lib/kernel/doc/src/inet.xml @@ -1039,6 +1039,18 @@ setcap cap_sys_admin,cap_sys_ptrace,cap_dac_read_search+epi beam.smp</code> is turned on for the socket, which means that also small amounts of data are sent immediately.</p> </item> + <tag><c>{nopush, Boolean}</c>(TCP/IP sockets)</tag> + <item> + <p>This translates to <c>TCP_NOPUSH</c> on BSD and + to <c>TCP_CORK</c> on Linux.</p> + <p>If <c>Boolean == true</c>, the corresponding option + is turned on for the socket, which means that small + amounts of data are accumulated until a full MSS-worth + of data is available or this option is turned off.</p> + <p>Note that while <c>TCP_NOPUSH</c> socket option is available on OSX, its semantics + is very different (e.g., unsetting it does not cause immediate send + of accumulated data). Hence, <c>nopush</c> option is intentionally ignored on OSX.</p> + </item> <tag><c>{packet, PacketType}</c>(TCP/IP sockets)</tag> <item> <p><marker id="packet"/>Defines the type of packets to use for a socket. diff --git a/lib/kernel/src/inet_int.hrl b/lib/kernel/src/inet_int.hrl index c8e09d18ad..f6525d7261 100644 --- a/lib/kernel/src/inet_int.hrl +++ b/lib/kernel/src/inet_int.hrl @@ -162,6 +162,7 @@ -define(INET_OPT_PKTOPTIONS, 45). -define(INET_OPT_TTL, 46). -define(INET_OPT_RECVTTL, 47). +-define(TCP_OPT_NOPUSH, 48). % Specific SCTP options: separate range: -define(SCTP_OPT_RTOINFO, 100). -define(SCTP_OPT_ASSOCINFO, 101). diff --git a/lib/kernel/test/inet_sockopt_SUITE.erl b/lib/kernel/test/inet_sockopt_SUITE.erl index ada9c2689c..27ff74e309 100644 --- a/lib/kernel/test/inet_sockopt_SUITE.erl +++ b/lib/kernel/test/inet_sockopt_SUITE.erl @@ -110,9 +110,14 @@ simple(Config) when is_list(Config) -> {S1,S2} = create_socketpair(Opt, Opt), {ok,Opt} = inet:getopts(S1,OptTags), {ok,Opt} = inet:getopts(S2,OptTags), - COpt = [{X,case X of nodelay -> false;_ -> Y end} || {X,Y} <- Opt], + NoPushOpt = case os:type() of + {unix, Osname} when Osname =:= linux; Osname =:= freebsd -> {nopush, true}; + {_,_} -> {nopush, false} + end, + COpt = [{X,case X of nodelay -> false;_ -> Y end} || {X,Y} <- [NoPushOpt|Opt]], + COptTags = [X || {X,_} <- COpt], inet:setopts(S1,COpt), - {ok,COpt} = inet:getopts(S1,OptTags), + {ok,COpt} = inet:getopts(S1,COptTags), {ok,Opt} = inet:getopts(S2,OptTags), gen_tcp:close(S1), gen_tcp:close(S2), |