curl/lib/llist.h
Stefan Eissing 1be704e17e
cpool: rename "connection cache/conncache" to "Connection Pools/cpool"
This is a better match for what they do and the general "cpool"
var/function prefix works well.

The pool now handles very long hostnames correctly.

The following changes have been made:

* 'struct connectdata', e.g. connections, keep new members
  named `destination` and ' destination_len' that fully specifies
  interface+port+hostname of where the connection is going to.
  This is used in the pool for "bundling" of connections with
  the same destination. There is no limit on the length any more.
* Locking: all locks are done inside conncache.c when calling
  into the pool and released on return. This eliminates hazards
  of the callers keeping track.
* 'struct connectbundle' is now internal to the pool. It is no
  longer referenced by a connection.
* 'bundle->multiuse' no longer exists. HTTP/2 and 3 and TLS filters
  no longer need to set it. Instead, the multi checks on leaving
  MSTATE_CONNECT or MSTATE_CONNECTING if the connection is now
  multiplexed and new, e.g. not conn->bits.reuse. In that case
  the processing of pending handles is triggered.
* The pool's init is provided with a callback to invoke on all
  connections being discarded. This allows the cleanups in
  `Curl_disconnect` to run, wherever it is decided to retire
  a connection.
* Several pool operations can now be fully done with one call.
  Pruning dead connections, upkeep and checks on pool limits
  can now directly discard connections and need no longer return
  those to the caller for doing that (as we have now the callback
  described above).
* Finding a connection for reuse is now done via `Curl_cpool_find()`
  and the caller provides callbacks to evaluate the connection
  candidates.
* The 'Curl_cpool_check_limits()' now directly uses the max values
  that may be set in the transfer's multi. No need to pass them
  around. Curl_multi_max_host_connections() and
  Curl_multi_max_total_connections() are gone.
* Add method 'Curl_node_llist()' to get the llist a node is in.
  Used in cpool to verify connection are indeed in the list (or
  not in any list) as they need to.

I left the conncache.[ch] as is for now and also did not touch the
documentation. If we update that outside the feature window, we can
do this in a separate PR.

Multi-thread safety is not achieved by this PR, but since more details
on how pools operate are now "internal" it is a better starting
point to go for this in the future.

Closes #14662
2024-08-28 13:52:49 +02:00

90 lines
3.2 KiB
C

#ifndef HEADER_CURL_LLIST_H
#define HEADER_CURL_LLIST_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#include <stddef.h>
typedef void (*Curl_llist_dtor)(void *user, void *elem);
/* none of these struct members should be referenced directly, use the
dedicated functions */
struct Curl_llist {
struct Curl_llist_node *_head;
struct Curl_llist_node *_tail;
Curl_llist_dtor _dtor;
size_t _size;
#ifdef DEBUGBUILD
int _init; /* detect API usage mistakes */
#endif
};
struct Curl_llist_node {
struct Curl_llist *_list; /* the list where this belongs */
void *_ptr;
struct Curl_llist_node *_prev;
struct Curl_llist_node *_next;
#ifdef DEBUGBUILD
int _init; /* detect API usage mistakes */
#endif
};
void Curl_llist_init(struct Curl_llist *, Curl_llist_dtor);
void Curl_llist_insert_next(struct Curl_llist *, struct Curl_llist_node *,
const void *, struct Curl_llist_node *node);
void Curl_llist_append(struct Curl_llist *,
const void *, struct Curl_llist_node *node);
void Curl_node_uremove(struct Curl_llist_node *, void *);
void Curl_node_remove(struct Curl_llist_node *);
void Curl_llist_destroy(struct Curl_llist *, void *);
/* Curl_llist_head() returns the first 'struct Curl_llist_node *', which
might be NULL */
struct Curl_llist_node *Curl_llist_head(struct Curl_llist *list);
/* Curl_llist_tail() returns the last 'struct Curl_llist_node *', which
might be NULL */
struct Curl_llist_node *Curl_llist_tail(struct Curl_llist *list);
/* Curl_llist_count() returns a size_t the number of nodes in the list */
size_t Curl_llist_count(struct Curl_llist *list);
/* Curl_node_elem() returns the custom data from a Curl_llist_node */
void *Curl_node_elem(struct Curl_llist_node *n);
/* Curl_node_next() returns the next element in a list from a given
Curl_llist_node */
struct Curl_llist_node *Curl_node_next(struct Curl_llist_node *n);
/* Curl_node_prev() returns the previous element in a list from a given
Curl_llist_node */
struct Curl_llist_node *Curl_node_prev(struct Curl_llist_node *n);
/* Curl_node_llist() return the list the node is in or NULL. */
struct Curl_llist *Curl_node_llist(struct Curl_llist_node *n);
#endif /* HEADER_CURL_LLIST_H */