sx.h revision 78872
1/* 2 * Copyright (C) 2001 Jason Evans <jasone@freebsd.org>. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice(s), this list of conditions and the following disclaimer as 9 * the first lines of this file unmodified other than the possible 10 * addition of one or more copyright notices. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice(s), this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25 * DAMAGE. 26 * 27 * $FreeBSD: head/sys/sys/sx.h 78872 2001-06-27 06:39:37Z jhb $ 28 */ 29 30#ifndef _SYS_SX_H_ 31#define _SYS_SX_H_ 32 33#ifndef LOCORE 34#include <sys/_mutex.h> 35#include <sys/condvar.h> /* XXX */ 36 37struct sx { 38 struct lock_object sx_object; /* Common lock properties. */ 39 struct mtx sx_lock; /* General protection lock. */ 40 int sx_cnt; /* -1: xlock, > 0: slock count. */ 41 struct cv sx_shrd_cv; /* slock waiters. */ 42 int sx_shrd_wcnt; /* Number of slock waiters. */ 43 struct cv sx_excl_cv; /* xlock waiters. */ 44 int sx_excl_wcnt; /* Number of xlock waiters. */ 45 struct proc *sx_xholder; /* Thread presently holding xlock. */ 46}; 47 48#ifdef _KERNEL 49void sx_init(struct sx *sx, const char *description); 50void sx_destroy(struct sx *sx); 51void _sx_slock(struct sx *sx, const char *file, int line); 52void _sx_xlock(struct sx *sx, const char *file, int line); 53int _sx_try_slock(struct sx *sx, const char *file, int line); 54int _sx_try_xlock(struct sx *sx, const char *file, int line); 55void _sx_sunlock(struct sx *sx, const char *file, int line); 56void _sx_xunlock(struct sx *sx, const char *file, int line); 57 58#define sx_slock(sx) _sx_slock((sx), __FILE__, __LINE__) 59#define sx_xlock(sx) _sx_xlock((sx), __FILE__, __LINE__) 60#define sx_try_slock(sx) _sx_try_slock((sx), __FILE__, __LINE__) 61#define sx_try_xlock(sx) _sx_try_xlock((sx), __FILE__, __LINE__) 62#define sx_sunlock(sx) _sx_sunlock((sx), __FILE__, __LINE__) 63#define sx_xunlock(sx) _sx_xunlock((sx), __FILE__, __LINE__) 64 65#ifdef INVARIANTS 66/* 67 * In the non-WITNESS case, SX_ASSERT_LOCKED() and SX_ASSERT_SLOCKED() 68 * can only detect that at least *some* thread owns an slock, but it cannot 69 * guarantee that *this* thread owns an slock. 70 */ 71#ifdef WITNESS 72#define _SX_ASSERT_LOCKED(sx, file, line) \ 73 witness_assert(&(sx)->sx_object, LA_LOCKED, file, line) 74#define _SX_ASSERT_SLOCKED(sx, file, line) \ 75 witness_assert(&(sx)->sx_object, LA_SLOCKED, file, line) 76#else 77#define _SX_ASSERT_LOCKED(sx, file, line) do { \ 78 KASSERT(((sx)->sx_cnt > 0 || (sx)->sx_xholder == curproc), \ 79 ("Lock %s not locked @ %s:%d", (sx)->sx_object.lo_name, \ 80 file, line)); \ 81} while (0) 82#define _SX_ASSERT_SLOCKED(sx, file, line) do { \ 83 KASSERT(((sx)->sx_cnt > 0), ("Lock %s not share locked @ %s:%d",\ 84 (sx)->sx_object.lo_name, file, line)); \ 85} while (0) 86#endif 87#define SX_ASSERT_LOCKED(sx) _SX_ASSERT_LOCKED((sx), __FILE__, __LINE__) 88#define SX_ASSERT_SLOCKED(sx) _SX_ASSERT_SLOCKED((sx), __FILE__, __LINE__) 89 90/* 91 * SX_ASSERT_XLOCKED() detects and guarantees that *we* own the xlock. 92 */ 93#define _SX_ASSERT_XLOCKED(sx, file, line) do { \ 94 KASSERT(((sx)->sx_xholder == curproc), \ 95 ("Lock %s not exclusively locked @ %s:%d", \ 96 (sx)->sx_object.lo_name, file, line)); \ 97} while (0) 98#define SX_ASSERT_XLOCKED(sx) _SX_ASSERT_XLOCKED((sx), __FILE__, __LINE__) 99 100#else /* INVARIANTS */ 101#define SX_ASSERT_SLOCKED(sx) 102#define SX_ASSERT_XLOCKED(sx) 103#define _SX_ASSERT_SLOCKED(sx, file, line) 104#define _SX_ASSERT_XLOCKED(sx, file, line) 105#endif /* INVARIANTS */ 106 107#endif /* _KERNEL */ 108#endif /* !LOCORE */ 109#endif /* _SYS_SX_H_ */ 110