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 123