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 * $DragonFly: src/sys/sys/socketvar2.h,v 1.1 2007/11/07 18:24:04 dillon Exp $ 36 */ 37 38 #ifndef _SYS_SOCKETVAR2_H_ 39 #define _SYS_SOCKETVAR2_H_ 40 41 #ifndef _SYS_SOCKETVAR_H_ 42 #include <sys/socketvar.h> 43 #endif 44 #ifndef _SYS_SYSTM_H_ 45 #include <sys/systm.h> 46 #endif 47 #ifndef _SYS_MALLOC_H_ 48 #include <sys/malloc.h> 49 #endif 50 #ifndef _MACHINE_ATOMIC_H_ 51 #include <machine/atomic.h> 52 #endif 53 54 /* 55 * Acquire a lock on a signalsockbuf, sleep if the lock is already held. 56 * The sleep is interruptable unless SSB_NOINTR is set in the ssb. 57 * 58 * We also acquire the token on success. This token is used to interlock 59 * frontend/backend operations until the sockbuf itself can be made mpsafe. 60 * 61 * Returns 0 on success, non-zero if the lock could not be acquired. 62 */ 63 static __inline int 64 ssb_lock(struct signalsockbuf *ssb, int wf) 65 { 66 uint32_t flags; 67 68 for (;;) { 69 flags = ssb->ssb_flags; 70 cpu_ccfence(); 71 if (flags & SSB_LOCK) { 72 if (wf == M_WAITOK) 73 return _ssb_lock(ssb); 74 return EWOULDBLOCK; 75 } 76 if (atomic_cmpset_int(&ssb->ssb_flags, flags, flags|SSB_LOCK)) { 77 lwkt_gettoken(&ssb->ssb_token); 78 return(0); 79 } 80 } 81 } 82 83 /* 84 * Release a previously acquired lock on a signalsockbuf. 85 * 86 * Interlocked wakeup if SSB_WANT was also set. 87 */ 88 static __inline void 89 ssb_unlock(struct signalsockbuf *ssb) 90 { 91 uint32_t flags; 92 93 KKASSERT(ssb->ssb_flags & SSB_LOCK); 94 lwkt_reltoken(&ssb->ssb_token); 95 for (;;) { 96 flags = ssb->ssb_flags; 97 cpu_ccfence(); 98 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 99 flags & ~(SSB_LOCK | SSB_WANT))) { 100 if (flags & SSB_WANT) 101 wakeup(&ssb->ssb_flags); 102 break; 103 } 104 } 105 } 106 107 static __inline void 108 sosetstate(struct socket *so, short state) 109 { 110 atomic_set_short(&so->so_state, state); 111 } 112 113 static __inline void 114 soclrstate(struct socket *so, short state) 115 { 116 atomic_clear_short(&so->so_state, state); 117 } 118 119 static __inline void 120 soreference(struct socket *so) 121 { 122 atomic_add_int(&so->so_refs, 1); 123 } 124 125 #endif 126