Commit 4732ca57 authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

CURLOPT_TCP_NODELAY: now enabled by default 

After a few wasted hours hunting down the reason for slowness during a
TLS handshake that turned out to be because of TCP_NODELAY not being
set, I think we have enough motivation to toggle the default for this
option. We now enable TCP_NODELAY by default and allow applications to
switch it off.

This also makes --tcp-nodelay unnecessary, but --no-tcp-nodelay can be
used to disable it.

Thanks-to: Tim Rühsen
Bug: https://curl.haxx.se/mail/lib-2016-06/0143.html
parent edeabf74

docs/libcurl/opts/CURLOPT_TCP_NODELAY.3

+6 −6
Original line number Original line Diff line number Diff line
@@ -5,7 +5,7 @@ 
.\" *                            | (__| |_| |  _ <| |___

.\" *                            | (__| |_| |  _ <| |___

.\" *                             \___|\___/|_| \_\_____|

.\" *                             \___|\___/|_| \_\_____|

.\" *

.\" *

.\" * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.

.\" * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.

.\" *

.\" *

.\" * This software is licensed as described in the file COPYING, which

.\" * This software is licensed as described in the file COPYING, which

.\" * you should have received as part of this distribution. The terms

.\" * you should have received as part of this distribution. The terms
@@ -20,7 +20,7 @@ 
.\" *

.\" *

.\" **************************************************************************

.\" **************************************************************************

.\"

.\"

.TH CURLOPT_TCP_NODELAY 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"

.TH CURLOPT_TCP_NODELAY 3 "30 Jun 2016" "libcurl 7.50.0" "curl_easy_setopt options"

.SH NAME

.SH NAME

CURLOPT_TCP_NODELAY \- set the TCP_NODELAY option

CURLOPT_TCP_NODELAY \- set the TCP_NODELAY option

.SH SYNOPSIS

.SH SYNOPSIS
@@ -29,8 +29,8 @@ CURLOPT_TCP_NODELAY \- set the TCP_NODELAY option 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_NODELAY, long nodelay);

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_NODELAY, long nodelay);

.SH DESCRIPTION

.SH DESCRIPTION

Pass a long specifying whether the TCP_NODELAY option is to be set or cleared

Pass a long specifying whether the TCP_NODELAY option is to be set or cleared

(1 = set, 0 = clear). The option is cleared by default. This will have no

(1 = set, 0 = clear). The option is set by default. This will have no effect

effect after the connection has been established.

after the connection has been established.





Setting this option will disable TCP's Nagle algorithm. The purpose of this

Setting this option will disable TCP's Nagle algorithm. The purpose of this

algorithm is to try to minimize the number of small packets on the network

algorithm is to try to minimize the number of small packets on the network
@@ -43,13 +43,13 @@ need to be sent without delay. This is less efficient than sending larger 
amounts of data at a time, and can contribute to congestion on the network if

amounts of data at a time, and can contribute to congestion on the network if

overdone.

overdone.

.SH DEFAULT

.SH DEFAULT

0

1

.SH PROTOCOLS

.SH PROTOCOLS

All

All

.SH EXAMPLE

.SH EXAMPLE

TODO

TODO

.SH AVAILABILITY

.SH AVAILABILITY

Always

Always. The default was changed to 1 from 0 in 7.50.2.

.SH RETURN VALUE

.SH RETURN VALUE

Returns CURLE_OK

Returns CURLE_OK

.SH "SEE ALSO"

.SH "SEE ALSO"

lib/http2.c

+0 −4
Original line number Original line Diff line number Diff line
@@ -1849,10 +1849,6 @@ CURLcode Curl_http2_setup(struct connectdata *conn) 
  infof(conn->data, "Connection state changed (HTTP/2 confirmed)\n");

  infof(conn->data, "Connection state changed (HTTP/2 confirmed)\n");

  Curl_multi_connchanged(conn->data->multi);

  Curl_multi_connchanged(conn->data->multi);





  /* switch on TCP_NODELAY as we need to send off packets without delay for

     maximum throughput */

  Curl_tcpnodelay(conn, conn->sock[FIRSTSOCKET]);



  return CURLE_OK;

  return CURLE_OK;

}

}

lib/url.c

+1 −0
Original line number Original line Diff line number Diff line
@@ -602,6 +602,7 @@ CURLcode Curl_init_userdefined(struct UserDefined *set) 
  set->tcp_keepintvl = 60;

  set->tcp_keepintvl = 60;

  set->tcp_keepidle = 60;

  set->tcp_keepidle = 60;

  set->tcp_fastopen = FALSE;

  set->tcp_fastopen = FALSE;

  set->tcp_nodelay = TRUE;





  set->ssl_enable_npn = TRUE;

  set->ssl_enable_npn = TRUE;

  set->ssl_enable_alpn = TRUE;

  set->ssl_enable_alpn = TRUE;

src/tool_cfgable.c

+2 −1
Original line number Original line Diff line number Diff line
@@ -5,7 +5,7 @@ 
 *                            | (__| |_| |  _ <| |___

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *                             \___|\___/|_| \_\_____|

 *

 *

 * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.

 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 *

 * This software is licensed as described in the file COPYING, which

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * you should have received as part of this distribution. The terms
@@ -41,6 +41,7 @@ void config_init(struct OperationConfig* config) 
                          CURLPROTO_SMBS);

                          CURLPROTO_SMBS);

  config->proto_redir_present = FALSE;

  config->proto_redir_present = FALSE;

  config->proto_default = NULL;

  config->proto_default = NULL;

  config->tcp_nodelay = TRUE; /* enabled by default */

}

}





static void free_config_fields(struct OperationConfig *config)

static void free_config_fields(struct OperationConfig *config)

src/tool_operate.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -792,8 +792,8 @@ static CURLcode operate_do(struct GlobalConfig *global, 
          set_binmode(stdout);

          set_binmode(stdout);

        }

        }





        if(config->tcp_nodelay)

        if(!config->tcp_nodelay)

          my_setopt(curl, CURLOPT_TCP_NODELAY, 1L);

          my_setopt(curl, CURLOPT_TCP_NODELAY, 0L);





        if(config->tcp_fastopen)

        if(config->tcp_fastopen)

          my_setopt(curl, CURLOPT_TCP_FASTOPEN, 1L);

          my_setopt(curl, CURLOPT_TCP_FASTOPEN, 1L);