Commit 81144375 authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

CURLOPT_PIPEWAIT: added 

By setting this option to 1 libcurl will wait for a connection to reveal
if it is possible to pipeline/multiplex on before it continues.
parent df3a970c

docs/libcurl/opts/CURLOPT_PIPEWAIT.3

0 → 100644
+63 −0
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.\" **************************************************************************

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.\" *

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

.\" *

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

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

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.\"

.TH CURLOPT_PIPEWAIT 3 "12 May 2015" "libcurl 7.43.0" "curl_easy_setopt options"

.SH NAME

CURLOPT_PIPEWAIT \- wait for pipelining/multiplexing

.SH SYNOPSIS

#include <curl/curl.h>



CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PIPEWAIT, long wait);

.SH DESCRIPTION

Set \fIwait\fP to 1L to tell libcurl to prefer to wait for a connection to

confirm or deny that it can do pipelining or multiplexing before continuing.



When about to perform a new transfer that allows pipelining or multiplexing,

libcurl will check for existing connections to re-use and pipeline on. If no

such connection exists it will immediately continue and create a fresh new

connection to use.



By setting this option to 1 - and having \fICURLMOPT_PIPELINE\fP enabled for

the multi handle this transfer is associated with - libcurl will instead wait

for the connection to reveal if it is possible to pipeline/multiplex on before

it continues. This enables libcurl to much better keep the number of

connections to a minimum when using pipelining or multiplexing protocols.



The effect thus becomes that with this option set, libcurl prefers to wait and

re-use an existing connection for pipelining rather than the opposite: prefer

to open a new connection rather than waiting.



The waiting time is as long as it takes for the connection to get up and for

libcurl to get the necessary response back that informs it about its protocol

and support level.

.SH DEFAULT

0 (off)

.SH PROTOCOLS

HTTP(S)

.SH EXAMPLE

.SH AVAILABILITY

Added in 7.43.0

.SH RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

.SH "SEE ALSO"

.BR CURLOPT_FORBID_REUSE "(3), " CURLOPT_FRESH_CONNECT "(3), "

.BR CURLMOPT_PIPELINING "(3), " CURLMOPT_MAX_HOST_CONNECTIONS "(3), "

docs/libcurl/opts/Makefile.am

+5 −3
Original line number Diff line number Diff line
@@ -114,7 +114,7 @@ man_MANS = CURLOPT_ACCEPT_ENCODING.3 CURLOPT_ACCEPTTIMEOUT_MS.3 \ 
 CURLMOPT_SOCKETDATA.3 CURLMOPT_SOCKETFUNCTION.3 CURLMOPT_TIMERDATA.3	\

 CURLMOPT_TIMERFUNCTION.3 CURLOPT_UNIX_SOCKET_PATH.3			\

 CURLOPT_PATH_AS_IS.3 CURLOPT_PROXY_SERVICE_NAME.3			\

 CURLOPT_SERVICE_NAME.3

 CURLOPT_SERVICE_NAME.3 CURLOPT_PIPEWAIT.3



HTMLPAGES = CURLOPT_ACCEPT_ENCODING.html CURLOPT_ACCEPTTIMEOUT_MS.html	\

 CURLOPT_ADDRESS_SCOPE.html CURLOPT_APPEND.html				\
@@ -221,7 +221,8 @@ HTMLPAGES = CURLOPT_ACCEPT_ENCODING.html CURLOPT_ACCEPTTIMEOUT_MS.html \ 
 CURLMOPT_SOCKETDATA.html CURLMOPT_SOCKETFUNCTION.html			\

 CURLMOPT_TIMERDATA.html CURLMOPT_TIMERFUNCTION.html			\

 CURLOPT_UNIX_SOCKET_PATH.html CURLOPT_PATH_AS_IS.html			\

 CURLOPT_PROXY_SERVICE_NAME.html CURLOPT_SERVICE_NAME.html

 CURLOPT_PROXY_SERVICE_NAME.html CURLOPT_SERVICE_NAME.html		\

 CURLOPT_PIPEWAIT.html



PDFPAGES = CURLOPT_ACCEPT_ENCODING.pdf CURLOPT_ACCEPTTIMEOUT_MS.pdf	\

 CURLOPT_ADDRESS_SCOPE.pdf CURLOPT_APPEND.pdf CURLOPT_AUTOREFERER.pdf	\
@@ -326,7 +327,8 @@ PDFPAGES = CURLOPT_ACCEPT_ENCODING.pdf CURLOPT_ACCEPTTIMEOUT_MS.pdf \ 
 CURLMOPT_SOCKETDATA.pdf CURLMOPT_SOCKETFUNCTION.pdf			\

 CURLMOPT_TIMERDATA.pdf CURLMOPT_TIMERFUNCTION.pdf			\

 CURLOPT_UNIX_SOCKET_PATH.pdf CURLOPT_PATH_AS_IS.pdf			\

 CURLOPT_PROXY_SERVICE_NAME.pdf CURLOPT_SERVICE_NAME.pdf

 CURLOPT_PROXY_SERVICE_NAME.pdf CURLOPT_SERVICE_NAME.pdf		\

 CURLOPT_PIPEWAIT.pdf



CLEANFILES = $(HTMLPAGES) $(PDFPAGES)

include/curl/curl.h

+3 −0
Original line number Diff line number Diff line
@@ -1638,6 +1638,9 @@ typedef enum { 
  /* Service Name */

  CINIT(SERVICE_NAME, OBJECTPOINT, 236),



  /* Wait/don't wait for pipe/mutex to clarify */

  CINIT(PIPEWAIT, LONG, 237),



  CURLOPT_LASTENTRY /* the last unused */

} CURLoption;

lib/url.c

+33 −13
Original line number Diff line number Diff line
@@ -2649,6 +2649,9 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option, 
  case CURLOPT_PATH_AS_IS:

    data->set.path_as_is = (0 != va_arg(param, long))?TRUE:FALSE;

    break;

  case CURLOPT_PIPEWAIT:

    data->set.pipewait = (0 != va_arg(param, long))?TRUE:FALSE;

    break;

  default:

    /* unknown tag and its companion, just ignore: */

    result = CURLE_UNKNOWN_OPTION;
@@ -3099,7 +3102,8 @@ static bool 
ConnectionExists(struct SessionHandle *data,

                 struct connectdata *needle,

                 struct connectdata **usethis,

                 bool *force_reuse)

                 bool *force_reuse,

                 bool *waitpipe)

{

  struct connectdata *check;

  struct connectdata *chosen = 0;
@@ -3112,6 +3116,7 @@ ConnectionExists(struct SessionHandle *data, 
  struct connectbundle *bundle;



  *force_reuse = FALSE;

  *waitpipe = FALSE;



  /* We can't pipe if the site is blacklisted */

  if(canPipeline && Curl_pipeline_site_blacklisted(data, needle)) {
@@ -3132,10 +3137,18 @@ ConnectionExists(struct SessionHandle *data, 
          needle->host.name, (void *)bundle);



    /* We can't pipe if we don't know anything about the server */

    if(canPipeline && (bundle->multiuse <= BUNDLE_UNKNOWN)) {

    if(canPipeline) {

      if(bundle->multiuse <= BUNDLE_UNKNOWN) {

        if((bundle->multiuse == BUNDLE_UNKNOWN) && data->set.pipewait) {

          infof(data, "Server doesn't support multi-use yet, wait\n");

          *waitpipe = TRUE;

          return FALSE; /* no re-use */

        }



        infof(data, "Server doesn't support multi-use (yet)\n");

        canPipeline = FALSE;

      }

    }



    curr = bundle->conn_list->head;

    while(curr) {
@@ -5343,8 +5356,9 @@ static CURLcode create_conn(struct SessionHandle *data, 
  bool reuse;

  char *proxy = NULL;

  bool prot_missing = FALSE;

  bool no_connections_available = FALSE;

  bool connections_available = TRUE;

  bool force_reuse = FALSE;

  bool waitpipe = FALSE;

  size_t max_host_connections = Curl_multi_max_host_connections(data->multi);

  size_t max_total_connections = Curl_multi_max_total_connections(data->multi);
@@ -5684,7 +5698,7 @@ static CURLcode create_conn(struct SessionHandle *data, 
  if(data->set.reuse_fresh && !data->state.this_is_a_follow)

    reuse = FALSE;

  else

    reuse = ConnectionExists(data, conn, &conn_temp, &force_reuse);

    reuse = ConnectionExists(data, conn, &conn_temp, &force_reuse, &waitpipe);



  /* If we found a reusable connection, we may still want to

     open a new connection if we are pipelining. */
@@ -5730,9 +5744,15 @@ static CURLcode create_conn(struct SessionHandle *data, 
    /* We have decided that we want a new connection. However, we may not

       be able to do that if we have reached the limit of how many

       connections we are allowed to open. */

    struct connectbundle *bundle;

    struct connectbundle *bundle = NULL;



    if(waitpipe)

      /* There is a connection that *might* become usable for pipelining

         "soon", and we wait for that */

      connections_available = FALSE;

    else

      bundle = Curl_conncache_find_bundle(conn, data->state.conn_cache);



    if(max_host_connections > 0 && bundle &&

       (bundle->num_connections >= max_host_connections)) {

      struct connectdata *conn_candidate;
@@ -5748,11 +5768,12 @@ static CURLcode create_conn(struct SessionHandle *data, 
      else {

        infof(data, "No more connections allowed to host: %d\n",

              max_host_connections);

        no_connections_available = TRUE;

        connections_available = FALSE;

      }

    }



    if(max_total_connections > 0 &&

    if(connections_available &&

       (max_total_connections > 0) &&

       (data->state.conn_cache->num_connections >= max_total_connections)) {

      struct connectdata *conn_candidate;
@@ -5766,12 +5787,11 @@ static CURLcode create_conn(struct SessionHandle *data, 
      }

      else {

        infof(data, "No connections available in cache\n");

        no_connections_available = TRUE;

        connections_available = FALSE;

      }

    }





    if(no_connections_available) {

    if(!connections_available) {

      infof(data, "No connections available.\n");



      conn_free(conn);

lib/urldata.h

+2 −0
Original line number Diff line number Diff line
@@ -1623,6 +1623,8 @@ struct UserDefined { 
  bool ssl_enable_npn;  /* TLS NPN extension? */

  bool ssl_enable_alpn; /* TLS ALPN extension? */

  bool path_as_is;      /* allow dotdots? */

  bool pipewait;        /* wait for pipe/multiplex status before starting a

                           new connection */

  long expect_100_timeout; /* in milliseconds */

};