CURLMOPT_MAX_TOTAL_CONNECTIONS(3) Library Functions Manual
NAME
CURLMOPT_MAX_TOTAL_CONNECTIONS - max simultaneously open connections
SYNOPSIS
#include <curl/curl.h>
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAX_TOTAL_CONNECTIONS,
long amount);
DESCRIPTION
Pass a long for the amount. The set number is used as the maximum
number of simultaneously open connections in total using this multi
handle. For each new session, libcurl might open a new connection up to
the limit set by CURLMOPT_MAX_TOTAL_CONNECTIONS(3). If
CURLMOPT_PIPELINING(3) is enabled, libcurl can try multiplexing if the
host is capable of it.
When more transfers are added to the multi handle than what can be
performed due to the set limit, they get queued up waiting for their
chance.
While a transfer is queued up internally waiting for a connection, the
CURLOPT_TIMEOUT_MS(3) timeout is counted inclusive of the waiting time,
meaning that if you set a too narrow timeout the transfer might never
even start before it times out. The CURLOPT_CONNECTTIMEOUT_MS(3) time
is also similarly still treated as a per-connect timeout and might
expire even before making a new connection is permitted.
Changing this value while there are transfers in progress is possible.
The new value is then used the next time checks are performed. Lowering
the value does not close down any active transfers, it simply does not
allow new ones to get made.
DEFAULT
0, which means that there is no limit. It is then simply controlled by
the number of easy handles added concurrently and how much multiplexing
is being done.
PROTOCOLS
This functionality affects all supported protocols
EXAMPLE
int main(void)
{
CURLM *m = curl_multi_init();
/* never do more than 15 connections */
curl_multi_setopt(m, CURLMOPT_MAX_TOTAL_CONNECTIONS, 15L);
}
AVAILABILITY
Added in curl 7.30.0
RETURN VALUE
Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION
if not.
SEE ALSO
CURLMOPT_MAXCONNECTS(3), CURLMOPT_MAX_HOST_CONNECTIONS(3)
libcurl 2024-12-12 CURLMOPT_MAX_TOTAL_CONNECTIONS(3)
curl 8.11.1 - Generated Fri Dec 13 14:11:43 CST 2024