/src/haproxy/include/haproxy/xref.h

Source
/*
 * include/haproxy/xref.h
 * Atomic cross-references between two elements - functions
 *
 * Copyright (C) 2017 Thierry Fournier <thierry.fournier@ozon.io>
 * Copyright (C) 2020 Willy Tarreau - w@1wt.eu
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef __HAPROXY_XREF_H__
#define __HAPROXY_XREF_H__

#include <haproxy/api.h>
#include <haproxy/xref-t.h>

/* xref is used to create relation between two elements.
 * Once an element is released, it breaks the relation. If the
 * relation is already broken, it frees the xref struct.
 * The pointer between two elements is sort of a refcount with
 * max value 1. The relation is only between two elements.
 * The pointer and the type of elements a and b are conventional.
 */

static inline void xref_create(struct xref *xref_a, struct xref *xref_b)
{
  xref_a->peer = xref_b;
  xref_b->peer = xref_a;
}

static inline struct xref *xref_get_peer_and_lock(struct xref *xref)
{
  struct xref *local;
  struct xref *remote;

  while (1) {

    /* Get the local pointer to the peer. */
    local = _HA_ATOMIC_XCHG(&xref->peer, XREF_BUSY);
    __ha_barrier_atomic_store();

    /* If the local pointer is NULL, the peer no longer exists. */
    if (local == NULL) {
      xref->peer = NULL;
      return NULL;
    }

    /* If the local pointeru is BUSY, the peer try to acquire the
     * lock. We retry the process.
     */
    if (local == XREF_BUSY)
      continue;

    /* We are locked, the peer can't disappear, try to acquire
     * the pper's lock. Note that remote can't be NULL.
     */
    remote = _HA_ATOMIC_XCHG(&local->peer, XREF_BUSY);

    /* The remote lock is BUSY, We retry the process. */
    if (remote == XREF_BUSY) {
      xref->peer = local;
      __ha_barrier_store();
      continue;
    }

    /* We have the lock, we return the value of the xref. */
    return local;
  }
}

static inline void xref_unlock(struct xref *xref, struct xref *peer)
{
  /* Release the peer. */
  peer->peer = xref;

  __ha_barrier_store();

  /* Release myself. */
  xref->peer = peer;
}

static inline void xref_disconnect(struct xref *xref, struct xref *peer)
{
  peer->peer = NULL;
  __ha_barrier_store();
  xref->peer = NULL;
}

#endif /* __HAPROXY_XREF_H__ */

Line	Count	Source
1		/*
2		* include/haproxy/xref.h
3		* Atomic cross-references between two elements - functions
4		*
5		* Copyright (C) 2017 Thierry Fournier <thierry.fournier@ozon.io>
6		* Copyright (C) 2020 Willy Tarreau - w@1wt.eu
7		*
8		* Permission is hereby granted, free of charge, to any person obtaining
9		* a copy of this software and associated documentation files (the
10		* "Software"), to deal in the Software without restriction, including
11		* without limitation the rights to use, copy, modify, merge, publish,
12		* distribute, sublicense, and/or sell copies of the Software, and to
13		* permit persons to whom the Software is furnished to do so, subject to
14		* the following conditions:
15		*
16		* The above copyright notice and this permission notice shall be
17		* included in all copies or substantial portions of the Software.
18		*
19		* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20		* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
21		* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22		* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
23		* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
24		* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25		* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26		* OTHER DEALINGS IN THE SOFTWARE.
27		*/
28		#ifndef __HAPROXY_XREF_H__
29		#define __HAPROXY_XREF_H__
30
31		#include <haproxy/api.h>
32		#include <haproxy/xref-t.h>
33
34		/* xref is used to create relation between two elements.
35		* Once an element is released, it breaks the relation. If the
36		* relation is already broken, it frees the xref struct.
37		* The pointer between two elements is sort of a refcount with
38		* max value 1. The relation is only between two elements.
39		* The pointer and the type of elements a and b are conventional.
40		*/
41
42		static inline void xref_create(struct xref xref_a, struct xref xref_b)
43	0	{
44	0	xref_a->peer = xref_b;
45	0	xref_b->peer = xref_a;
46	0	} Unexecuted instantiation: haproxy.c:xref_create Unexecuted instantiation: listener.c:xref_create Unexecuted instantiation: log.c:xref_create Unexecuted instantiation: mworker.c:xref_create Unexecuted instantiation: peers.c:xref_create Unexecuted instantiation: pool.c:xref_create Unexecuted instantiation: proto_sockpair.c:xref_create Unexecuted instantiation: proxy.c:xref_create Unexecuted instantiation: resolvers.c:xref_create Unexecuted instantiation: ring.c:xref_create Unexecuted instantiation: sample.c:xref_create Unexecuted instantiation: server.c:xref_create Unexecuted instantiation: session.c:xref_create Unexecuted instantiation: sink.c:xref_create Unexecuted instantiation: sock.c:xref_create Unexecuted instantiation: stats-proxy.c:xref_create Unexecuted instantiation: stats.c:xref_create Unexecuted instantiation: stick_table.c:xref_create Unexecuted instantiation: stream.c:xref_create Unexecuted instantiation: tcp_rules.c:xref_create Unexecuted instantiation: tcpcheck.c:xref_create Unexecuted instantiation: thread.c:xref_create Unexecuted instantiation: tools.c:xref_create Unexecuted instantiation: trace.c:xref_create Unexecuted instantiation: vars.c:xref_create Unexecuted instantiation: activity.c:xref_create Unexecuted instantiation: applet.c:xref_create Unexecuted instantiation: backend.c:xref_create Unexecuted instantiation: cfgparse-listen.c:xref_create Unexecuted instantiation: cfgparse.c:xref_create Unexecuted instantiation: channel.c:xref_create Unexecuted instantiation: check.c:xref_create Unexecuted instantiation: cli.c:xref_create Unexecuted instantiation: connection.c:xref_create Unexecuted instantiation: debug.c:xref_create Unexecuted instantiation: dns.c:xref_create Unexecuted instantiation: dns_ring.c:xref_create Unexecuted instantiation: errors.c:xref_create Unexecuted instantiation: extcheck.c:xref_create Unexecuted instantiation: fd.c:xref_create Unexecuted instantiation: filters.c:xref_create Unexecuted instantiation: flt_decomp.c:xref_create Unexecuted instantiation: flt_http_comp.c:xref_create Unexecuted instantiation: frontend.c:xref_create Unexecuted instantiation: haterm.c:xref_create Unexecuted instantiation: http_ana.c:xref_create Unexecuted instantiation: http_ext.c:xref_create Unexecuted instantiation: http_htx.c:xref_create Unexecuted instantiation: http_rules.c:xref_create Unexecuted instantiation: limits.c:xref_create Unexecuted instantiation: mux_spop.c:xref_create Unexecuted instantiation: pattern.c:xref_create Unexecuted instantiation: payload.c:xref_create Unexecuted instantiation: proto_rhttp.c:xref_create Unexecuted instantiation: queue.c:xref_create Unexecuted instantiation: stats-html.c:xref_create Unexecuted instantiation: stats-json.c:xref_create Unexecuted instantiation: stconn.c:xref_create Unexecuted instantiation: cache.c:xref_create Unexecuted instantiation: cfgparse-global.c:xref_create Unexecuted instantiation: compression.c:xref_create Unexecuted instantiation: fcgi-app.c:xref_create Unexecuted instantiation: flt_spoe.c:xref_create Unexecuted instantiation: http_fetch.c:xref_create Unexecuted instantiation: proto_tcp.c:xref_create
47
48		static inline struct xref xref_get_peer_and_lock(struct xref xref)
49	0	{
50	0	struct xref *local;
51	0	struct xref *remote;
52
53	0	while (1) {
54
55		/* Get the local pointer to the peer. */
56	0	local = _HA_ATOMIC_XCHG(&xref->peer, XREF_BUSY);
57	0	__ha_barrier_atomic_store();
58
59		/* If the local pointer is NULL, the peer no longer exists. */
60	0	if (local == NULL) {
61	0	xref->peer = NULL;
62	0	return NULL;
63	0	}
64
65		/* If the local pointeru is BUSY, the peer try to acquire the
66		* lock. We retry the process.
67		*/
68	0	if (local == XREF_BUSY)
69	0	continue;
70
71		/* We are locked, the peer can't disappear, try to acquire
72		* the pper's lock. Note that remote can't be NULL.
73		*/
74	0	remote = _HA_ATOMIC_XCHG(&local->peer, XREF_BUSY);
75
76		/* The remote lock is BUSY, We retry the process. */
77	0	if (remote == XREF_BUSY) {
78	0	xref->peer = local;
79	0	__ha_barrier_store();
80	0	continue;
81	0	}
82
83		/* We have the lock, we return the value of the xref. */
84	0	return local;
85	0	}
86	0	} Unexecuted instantiation: haproxy.c:xref_get_peer_and_lock Unexecuted instantiation: listener.c:xref_get_peer_and_lock Unexecuted instantiation: log.c:xref_get_peer_and_lock Unexecuted instantiation: mworker.c:xref_get_peer_and_lock Unexecuted instantiation: peers.c:xref_get_peer_and_lock Unexecuted instantiation: pool.c:xref_get_peer_and_lock Unexecuted instantiation: proto_sockpair.c:xref_get_peer_and_lock Unexecuted instantiation: proxy.c:xref_get_peer_and_lock Unexecuted instantiation: resolvers.c:xref_get_peer_and_lock Unexecuted instantiation: ring.c:xref_get_peer_and_lock Unexecuted instantiation: sample.c:xref_get_peer_and_lock Unexecuted instantiation: server.c:xref_get_peer_and_lock Unexecuted instantiation: session.c:xref_get_peer_and_lock Unexecuted instantiation: sink.c:xref_get_peer_and_lock Unexecuted instantiation: sock.c:xref_get_peer_and_lock Unexecuted instantiation: stats-proxy.c:xref_get_peer_and_lock Unexecuted instantiation: stats.c:xref_get_peer_and_lock Unexecuted instantiation: stick_table.c:xref_get_peer_and_lock Unexecuted instantiation: stream.c:xref_get_peer_and_lock Unexecuted instantiation: tcp_rules.c:xref_get_peer_and_lock Unexecuted instantiation: tcpcheck.c:xref_get_peer_and_lock Unexecuted instantiation: thread.c:xref_get_peer_and_lock Unexecuted instantiation: tools.c:xref_get_peer_and_lock Unexecuted instantiation: trace.c:xref_get_peer_and_lock Unexecuted instantiation: vars.c:xref_get_peer_and_lock Unexecuted instantiation: activity.c:xref_get_peer_and_lock Unexecuted instantiation: applet.c:xref_get_peer_and_lock Unexecuted instantiation: backend.c:xref_get_peer_and_lock Unexecuted instantiation: cfgparse-listen.c:xref_get_peer_and_lock Unexecuted instantiation: cfgparse.c:xref_get_peer_and_lock Unexecuted instantiation: channel.c:xref_get_peer_and_lock Unexecuted instantiation: check.c:xref_get_peer_and_lock Unexecuted instantiation: cli.c:xref_get_peer_and_lock Unexecuted instantiation: connection.c:xref_get_peer_and_lock Unexecuted instantiation: debug.c:xref_get_peer_and_lock Unexecuted instantiation: dns.c:xref_get_peer_and_lock Unexecuted instantiation: dns_ring.c:xref_get_peer_and_lock Unexecuted instantiation: errors.c:xref_get_peer_and_lock Unexecuted instantiation: extcheck.c:xref_get_peer_and_lock Unexecuted instantiation: fd.c:xref_get_peer_and_lock Unexecuted instantiation: filters.c:xref_get_peer_and_lock Unexecuted instantiation: flt_decomp.c:xref_get_peer_and_lock Unexecuted instantiation: flt_http_comp.c:xref_get_peer_and_lock Unexecuted instantiation: frontend.c:xref_get_peer_and_lock Unexecuted instantiation: haterm.c:xref_get_peer_and_lock Unexecuted instantiation: http_ana.c:xref_get_peer_and_lock Unexecuted instantiation: http_ext.c:xref_get_peer_and_lock Unexecuted instantiation: http_htx.c:xref_get_peer_and_lock Unexecuted instantiation: http_rules.c:xref_get_peer_and_lock Unexecuted instantiation: limits.c:xref_get_peer_and_lock Unexecuted instantiation: mux_spop.c:xref_get_peer_and_lock Unexecuted instantiation: pattern.c:xref_get_peer_and_lock Unexecuted instantiation: payload.c:xref_get_peer_and_lock Unexecuted instantiation: proto_rhttp.c:xref_get_peer_and_lock Unexecuted instantiation: queue.c:xref_get_peer_and_lock Unexecuted instantiation: stats-html.c:xref_get_peer_and_lock Unexecuted instantiation: stats-json.c:xref_get_peer_and_lock Unexecuted instantiation: stconn.c:xref_get_peer_and_lock Unexecuted instantiation: cache.c:xref_get_peer_and_lock Unexecuted instantiation: cfgparse-global.c:xref_get_peer_and_lock Unexecuted instantiation: compression.c:xref_get_peer_and_lock Unexecuted instantiation: fcgi-app.c:xref_get_peer_and_lock Unexecuted instantiation: flt_spoe.c:xref_get_peer_and_lock Unexecuted instantiation: http_fetch.c:xref_get_peer_and_lock Unexecuted instantiation: proto_tcp.c:xref_get_peer_and_lock
87
88		static inline void xref_unlock(struct xref xref, struct xref peer)
89	0	{
90		/* Release the peer. */
91	0	peer->peer = xref;
92
93	0	__ha_barrier_store();
94
95		/* Release myself. */
96	0	xref->peer = peer;
97	0	} Unexecuted instantiation: haproxy.c:xref_unlock Unexecuted instantiation: listener.c:xref_unlock Unexecuted instantiation: log.c:xref_unlock Unexecuted instantiation: mworker.c:xref_unlock Unexecuted instantiation: peers.c:xref_unlock Unexecuted instantiation: pool.c:xref_unlock Unexecuted instantiation: proto_sockpair.c:xref_unlock Unexecuted instantiation: proxy.c:xref_unlock Unexecuted instantiation: resolvers.c:xref_unlock Unexecuted instantiation: ring.c:xref_unlock Unexecuted instantiation: sample.c:xref_unlock Unexecuted instantiation: server.c:xref_unlock Unexecuted instantiation: session.c:xref_unlock Unexecuted instantiation: sink.c:xref_unlock Unexecuted instantiation: sock.c:xref_unlock Unexecuted instantiation: stats-proxy.c:xref_unlock Unexecuted instantiation: stats.c:xref_unlock Unexecuted instantiation: stick_table.c:xref_unlock Unexecuted instantiation: stream.c:xref_unlock Unexecuted instantiation: tcp_rules.c:xref_unlock Unexecuted instantiation: tcpcheck.c:xref_unlock Unexecuted instantiation: thread.c:xref_unlock Unexecuted instantiation: tools.c:xref_unlock Unexecuted instantiation: trace.c:xref_unlock Unexecuted instantiation: vars.c:xref_unlock Unexecuted instantiation: activity.c:xref_unlock Unexecuted instantiation: applet.c:xref_unlock Unexecuted instantiation: backend.c:xref_unlock Unexecuted instantiation: cfgparse-listen.c:xref_unlock Unexecuted instantiation: cfgparse.c:xref_unlock Unexecuted instantiation: channel.c:xref_unlock Unexecuted instantiation: check.c:xref_unlock Unexecuted instantiation: cli.c:xref_unlock Unexecuted instantiation: connection.c:xref_unlock Unexecuted instantiation: debug.c:xref_unlock Unexecuted instantiation: dns.c:xref_unlock Unexecuted instantiation: dns_ring.c:xref_unlock Unexecuted instantiation: errors.c:xref_unlock Unexecuted instantiation: extcheck.c:xref_unlock Unexecuted instantiation: fd.c:xref_unlock Unexecuted instantiation: filters.c:xref_unlock Unexecuted instantiation: flt_decomp.c:xref_unlock Unexecuted instantiation: flt_http_comp.c:xref_unlock Unexecuted instantiation: frontend.c:xref_unlock Unexecuted instantiation: haterm.c:xref_unlock Unexecuted instantiation: http_ana.c:xref_unlock Unexecuted instantiation: http_ext.c:xref_unlock Unexecuted instantiation: http_htx.c:xref_unlock Unexecuted instantiation: http_rules.c:xref_unlock Unexecuted instantiation: limits.c:xref_unlock Unexecuted instantiation: mux_spop.c:xref_unlock Unexecuted instantiation: pattern.c:xref_unlock Unexecuted instantiation: payload.c:xref_unlock Unexecuted instantiation: proto_rhttp.c:xref_unlock Unexecuted instantiation: queue.c:xref_unlock Unexecuted instantiation: stats-html.c:xref_unlock Unexecuted instantiation: stats-json.c:xref_unlock Unexecuted instantiation: stconn.c:xref_unlock Unexecuted instantiation: cache.c:xref_unlock Unexecuted instantiation: cfgparse-global.c:xref_unlock Unexecuted instantiation: compression.c:xref_unlock Unexecuted instantiation: fcgi-app.c:xref_unlock Unexecuted instantiation: flt_spoe.c:xref_unlock Unexecuted instantiation: http_fetch.c:xref_unlock Unexecuted instantiation: proto_tcp.c:xref_unlock
98
99		static inline void xref_disconnect(struct xref xref, struct xref peer)
100	0	{
101	0	peer->peer = NULL;
102	0	__ha_barrier_store();
103		xref->peer = NULL;
104	0	} Unexecuted instantiation: haproxy.c:xref_disconnect Unexecuted instantiation: listener.c:xref_disconnect Unexecuted instantiation: log.c:xref_disconnect Unexecuted instantiation: mworker.c:xref_disconnect Unexecuted instantiation: peers.c:xref_disconnect Unexecuted instantiation: pool.c:xref_disconnect Unexecuted instantiation: proto_sockpair.c:xref_disconnect Unexecuted instantiation: proxy.c:xref_disconnect Unexecuted instantiation: resolvers.c:xref_disconnect Unexecuted instantiation: ring.c:xref_disconnect Unexecuted instantiation: sample.c:xref_disconnect Unexecuted instantiation: server.c:xref_disconnect Unexecuted instantiation: session.c:xref_disconnect Unexecuted instantiation: sink.c:xref_disconnect Unexecuted instantiation: sock.c:xref_disconnect Unexecuted instantiation: stats-proxy.c:xref_disconnect Unexecuted instantiation: stats.c:xref_disconnect Unexecuted instantiation: stick_table.c:xref_disconnect Unexecuted instantiation: stream.c:xref_disconnect Unexecuted instantiation: tcp_rules.c:xref_disconnect Unexecuted instantiation: tcpcheck.c:xref_disconnect Unexecuted instantiation: thread.c:xref_disconnect Unexecuted instantiation: tools.c:xref_disconnect Unexecuted instantiation: trace.c:xref_disconnect Unexecuted instantiation: vars.c:xref_disconnect Unexecuted instantiation: activity.c:xref_disconnect Unexecuted instantiation: applet.c:xref_disconnect Unexecuted instantiation: backend.c:xref_disconnect Unexecuted instantiation: cfgparse-listen.c:xref_disconnect Unexecuted instantiation: cfgparse.c:xref_disconnect Unexecuted instantiation: channel.c:xref_disconnect Unexecuted instantiation: check.c:xref_disconnect Unexecuted instantiation: cli.c:xref_disconnect Unexecuted instantiation: connection.c:xref_disconnect Unexecuted instantiation: debug.c:xref_disconnect Unexecuted instantiation: dns.c:xref_disconnect Unexecuted instantiation: dns_ring.c:xref_disconnect Unexecuted instantiation: errors.c:xref_disconnect Unexecuted instantiation: extcheck.c:xref_disconnect Unexecuted instantiation: fd.c:xref_disconnect Unexecuted instantiation: filters.c:xref_disconnect Unexecuted instantiation: flt_decomp.c:xref_disconnect Unexecuted instantiation: flt_http_comp.c:xref_disconnect Unexecuted instantiation: frontend.c:xref_disconnect Unexecuted instantiation: haterm.c:xref_disconnect Unexecuted instantiation: http_ana.c:xref_disconnect Unexecuted instantiation: http_ext.c:xref_disconnect Unexecuted instantiation: http_htx.c:xref_disconnect Unexecuted instantiation: http_rules.c:xref_disconnect Unexecuted instantiation: limits.c:xref_disconnect Unexecuted instantiation: mux_spop.c:xref_disconnect Unexecuted instantiation: pattern.c:xref_disconnect Unexecuted instantiation: payload.c:xref_disconnect Unexecuted instantiation: proto_rhttp.c:xref_disconnect Unexecuted instantiation: queue.c:xref_disconnect Unexecuted instantiation: stats-html.c:xref_disconnect Unexecuted instantiation: stats-json.c:xref_disconnect Unexecuted instantiation: stconn.c:xref_disconnect Unexecuted instantiation: cache.c:xref_disconnect Unexecuted instantiation: cfgparse-global.c:xref_disconnect Unexecuted instantiation: compression.c:xref_disconnect Unexecuted instantiation: fcgi-app.c:xref_disconnect Unexecuted instantiation: flt_spoe.c:xref_disconnect Unexecuted instantiation: http_fetch.c:xref_disconnect Unexecuted instantiation: proto_tcp.c:xref_disconnect
105
106		#endif /* __HAPROXY_XREF_H__ */

Coverage Report

Created: 2026-09-01 07:17