FreeBSD/Linux Kernel Cross Reference
sys/sys/socketvar2.h
1 /*-
2 * Copyright (c) 1982, 1986, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)socketvar.h 8.3 (Berkeley) 2/19/95
34 * $FreeBSD: src/sys/sys/socketvar.h,v 1.46.2.10 2003/08/24 08:24:39 hsu Exp $
35 */
36
37 #ifndef _SYS_SOCKETVAR2_H_
38 #define _SYS_SOCKETVAR2_H_
39
40 #ifndef _SYS_SOCKETVAR_H_
41 #include <sys/socketvar.h>
42 #endif
43 #ifndef _SYS_SYSTM_H_
44 #include <sys/systm.h>
45 #endif
46 #ifndef _SYS_MALLOC_H_
47 #include <sys/malloc.h>
48 #endif
49 #include <machine/atomic.h>
50
51 /*
52 * Acquire a lock on a signalsockbuf, sleep if the lock is already held.
53 * The sleep is interruptable unless SSB_NOINTR is set in the ssb.
54 *
55 * We also acquire the token on success. This token is used to interlock
56 * frontend/backend operations until the sockbuf itself can be made mpsafe.
57 *
58 * Returns 0 on success, non-zero if the lock could not be acquired.
59 */
60 static __inline int
61 ssb_lock(struct signalsockbuf *ssb, int wf)
62 {
63 uint32_t flags;
64
65 for (;;) {
66 flags = ssb->ssb_flags;
67 cpu_ccfence();
68 if (flags & SSB_LOCK) {
69 if (wf == M_WAITOK)
70 return _ssb_lock(ssb);
71 return EWOULDBLOCK;
72 }
73 if (atomic_cmpset_int(&ssb->ssb_flags, flags, flags|SSB_LOCK)) {
74 lwkt_gettoken(&ssb->ssb_token);
75 return(0);
76 }
77 }
78 }
79
80 /*
81 * Release a previously acquired lock on a signalsockbuf.
82 *
83 * Interlocked wakeup if SSB_WANT was also set.
84 */
85 static __inline void
86 ssb_unlock(struct signalsockbuf *ssb)
87 {
88 uint32_t flags;
89
90 KKASSERT(ssb->ssb_flags & SSB_LOCK);
91 lwkt_reltoken(&ssb->ssb_token);
92 for (;;) {
93 flags = ssb->ssb_flags;
94 cpu_ccfence();
95 if (atomic_cmpset_int(&ssb->ssb_flags, flags,
96 flags & ~(SSB_LOCK | SSB_WANT))) {
97 if (flags & SSB_WANT)
98 wakeup(&ssb->ssb_flags);
99 break;
100 }
101 }
102 }
103
104 static __inline void
105 sosetstate(struct socket *so, short state)
106 {
107 atomic_set_short(&so->so_state, state);
108 }
109
110 static __inline void
111 soclrstate(struct socket *so, short state)
112 {
113 atomic_clear_short(&so->so_state, state);
114 }
115
116 static __inline void
117 soreference(struct socket *so)
118 {
119 atomic_add_int(&so->so_refs, 1);
120 }
121
122 #endif
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