lock.h revision 83593
1/*- 2 * Copyright (c) 1997 Berkeley Software Design, Inc. 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, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Berkeley Software Design Inc's name may not be used to endorse or 13 * promote products derived from this software without specific prior 14 * written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $ 29 * $FreeBSD: head/sys/sys/lock.h 83593 2001-09-17 21:21:02Z jhb $ 30 */ 31 32#ifndef _SYS_LOCK_H_ 33#define _SYS_LOCK_H_ 34 35/* 36 * XXX - compatability until lockmgr() goes away or all the #includes are 37 * updated. 38 */ 39#include <sys/lockmgr.h> 40 41#include <sys/queue.h> 42#include <sys/_lock.h> 43 44/* 45 * Lock classes. Each lock has a class which describes characteristics 46 * common to all types of locks of a given class. 47 * 48 * Spin locks in general must always protect against preemption, as it is 49 * an error to perform any type of context switch while holding a spin lock. 50 * Also, for an individual lock to be recursable, its class must allow 51 * recursion and the lock itself must explicitly allow recursion. 52 */ 53 54struct lock_class { 55 const char *lc_name; 56 u_int lc_flags; 57}; 58 59#define LC_SLEEPLOCK 0x00000001 /* Sleep lock. */ 60#define LC_SPINLOCK 0x00000002 /* Spin lock. */ 61#define LC_SLEEPABLE 0x00000004 /* Sleeping allowed with this lock. */ 62#define LC_RECURSABLE 0x00000008 /* Locks of this type may recurse. */ 63#define LC_UPGRADABLE 0x00000010 /* Upgrades and downgrades permitted. */ 64 65#define LO_CLASSFLAGS 0x0000ffff /* Class specific flags. */ 66#define LO_INITIALIZED 0x00010000 /* Lock has been initialized. */ 67#define LO_WITNESS 0x00020000 /* Should witness monitor this lock. */ 68#define LO_QUIET 0x00040000 /* Don't log locking operations. */ 69#define LO_RECURSABLE 0x00080000 /* Lock may recurse. */ 70#define LO_SLEEPABLE 0x00100000 /* Lock may be held while sleeping. */ 71#define LO_UPGRADABLE 0x00200000 /* Lock may be upgraded/downgraded. */ 72 73#define LI_RECURSEMASK 0x0000ffff /* Recursion depth of lock instance. */ 74#define LI_SLEPT 0x00010000 /* Lock instance has been slept with. */ 75#define LI_EXCLUSIVE 0x00020000 /* Exclusive lock instance. */ 76 77/* 78 * Option flags passed to lock operations that witness also needs to know 79 * about or that are generic across all locks. 80 */ 81#define LOP_NOSWITCH 0x00000001 /* Lock doesn't switch on release. */ 82#define LOP_QUIET 0x00000002 /* Don't log locking operations. */ 83#define LOP_TRYLOCK 0x00000004 /* Don't check lock order. */ 84#define LOP_EXCLUSIVE 0x00000008 /* Exclusive lock. */ 85 86/* Flags passed to witness_assert. */ 87#define LA_UNLOCKED 0x00000000 /* Lock is unlocked. */ 88#define LA_LOCKED 0x00000001 /* Lock is at least share locked. */ 89#define LA_SLOCKED 0x00000002 /* Lock is exactly share locked. */ 90#define LA_XLOCKED 0x00000004 /* Lock is exclusively locked. */ 91#define LA_RECURSED 0x00000008 /* Lock is recursed. */ 92#define LA_NOTRECURSED 0x00000010 /* Lock is not recursed. */ 93 94#ifdef _KERNEL 95/* 96 * Lock instances. A lock instance is the data associated with a lock while 97 * it is held by witness. For example, a lock instance will hold the 98 * recursion count of a lock. Lock instances are held in lists. Spin locks 99 * are held in a per-cpu list while sleep locks are held in per-process list. 100 */ 101struct lock_instance { 102 struct lock_object *li_lock; 103 const char *li_file; /* File and line of last acquire. */ 104 int li_line; 105 u_int li_flags; /* Recursion count and LI_* flags. */ 106}; 107 108/* 109 * A simple list type used to build the list of locks held by a process 110 * or CPU. We can't simply embed the list in struct lock_object since a 111 * lock may be held by more than one process if it is a shared lock. Locks 112 * are added to the head of the list, so we fill up each list entry from 113 * "the back" logically. To ease some of the arithmetic, we actually fill 114 * in each list entry the normal way (childer[0] then children[1], etc.) but 115 * when we traverse the list we read children[count-1] as the first entry 116 * down to children[0] as the final entry. 117 */ 118#define LOCK_NCHILDREN 3 119 120struct lock_list_entry { 121 struct lock_list_entry *ll_next; 122 struct lock_instance ll_children[LOCK_NCHILDREN]; 123 u_int ll_count; 124}; 125 126/* 127 * If any of WITNESS, INVARIANTS, or KTR_LOCK KTR tracing has been enabled, 128 * then turn on LOCK_DEBUG. When this option is on, extra debugging 129 * facilities such as tracking the file and line number of lock operations 130 * are enabled. Also, mutex locking operations are not inlined to avoid 131 * bloat from all the extra debugging code. We also have to turn on all the 132 * calling conventions for this debugging code in modules so that modules can 133 * work with both debug and non-debug kernels. 134 */ 135#if defined(KLD_MODULE) || defined(WITNESS) || defined(INVARIANTS) || defined(INVARIANT_SUPPORT) || (defined(KTR) && (KTR_COMPILE & KTR_LOCK)) 136#define LOCK_DEBUG 137#endif 138 139/* 140 * In the LOCK_DEBUG case, use the filename and line numbers for debugging 141 * operations. Otherwise, use default values to avoid the unneeded bloat. 142 */ 143#ifdef LOCK_DEBUG 144#define LOCK_FILE __FILE__ 145#define LOCK_LINE __LINE__ 146#else 147#define LOCK_FILE NULL 148#define LOCK_LINE 0 149#endif 150 151/* 152 * Macros for KTR_LOCK tracing. 153 * 154 * opname - name of this operation (LOCK/UNLOCK/SLOCK, etc.) 155 * lo - struct lock_object * for this lock 156 * flags - flags passed to the lock operation 157 * recurse - this locks recursion level (or 0 if class is not recursable) 158 * result - result of a try lock operation 159 * file - file name 160 * line - line number 161 */ 162#define LOCK_LOG_TEST(lo, flags) \ 163 (((flags) & LOP_QUIET) == 0 && ((lo)->lo_flags & LO_QUIET) == 0) 164 165#define LOCK_LOG_LOCK(opname, lo, flags, recurse, file, line) do { \ 166 if (LOCK_LOG_TEST((lo), (flags))) \ 167 CTR5(KTR_LOCK, opname " (%s) %s r = %d at %s:%d", \ 168 (lo)->lo_class->lc_name, (lo)->lo_name, \ 169 (u_int)(recurse), (file), (line)); \ 170} while (0) 171 172#define LOCK_LOG_TRY(opname, lo, flags, result, file, line) do { \ 173 if (LOCK_LOG_TEST((lo), (flags))) \ 174 CTR5(KTR_LOCK, "TRY_" opname " (%s) %s result=%d at %s:%d",\ 175 (lo)->lo_class->lc_name, (lo)->lo_name, \ 176 (u_int)(result), (file), (line)); \ 177} while (0) 178 179#define LOCK_LOG_INIT(lo, flags) do { \ 180 if (LOCK_LOG_TEST((lo), (flags))) \ 181 CTR3(KTR_LOCK, __func__ ": %p (%s) %s", (lo), \ 182 (lo)->lo_class->lc_name, (lo)->lo_name); \ 183} while (0) 184 185#define LOCK_LOG_DESTROY(lo, flags) LOCK_LOG_INIT(lo, flags) 186 187/* 188 * Helpful macros for quickly coming up with assertions with informative 189 * panic messages. 190 */ 191#define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__) 192#define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__) 193#define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line) 194#define MPASS4(ex, what, file, line) \ 195 KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line)) 196 197extern struct lock_class lock_class_mtx_sleep; 198extern struct lock_class lock_class_mtx_spin; 199extern struct lock_class lock_class_sx; 200 201void witness_init(struct lock_object *); 202void witness_destroy(struct lock_object *); 203void witness_lock(struct lock_object *, int, const char *, int); 204void witness_upgrade(struct lock_object *, int, const char *, int); 205void witness_downgrade(struct lock_object *, int, const char *, int); 206void witness_unlock(struct lock_object *, int, const char *, int); 207void witness_save(struct lock_object *, const char **, int *); 208void witness_restore(struct lock_object *, const char *, int); 209int witness_list_locks(struct lock_list_entry **); 210int witness_list(struct thread *); 211int witness_sleep(int, struct lock_object *, const char *, int); 212void witness_assert(struct lock_object *, int, const char *, int); 213 214#ifdef WITNESS 215#define WITNESS_INIT(lock) \ 216 witness_init((lock)) 217 218#define WITNESS_DESTROY(lock) \ 219 witness_destroy(lock) 220 221#define WITNESS_LOCK(lock, flags, file, line) \ 222 witness_lock((lock), (flags), (file), (line)) 223 224#define WITNESS_UPGRADE(lock, flags, file, line) \ 225 witness_upgrade((lock), (flags), (file), (line)) 226 227#define WITNESS_DOWNGRADE(lock, flags, file, line) \ 228 witness_downgrade((lock), (flags), (file), (line)) 229 230#define WITNESS_UNLOCK(lock, flags, file, line) \ 231 witness_unlock((lock), (flags), (file), (line)) 232 233#define WITNESS_SLEEP(check, lock) \ 234 witness_sleep((check), (lock), __FILE__, __LINE__) 235 236#define WITNESS_SAVE_DECL(n) \ 237 const char * __CONCAT(n, __wf); \ 238 int __CONCAT(n, __wl) 239 240#define WITNESS_SAVE(lock, n) \ 241 witness_save((lock), &__CONCAT(n, __wf), &__CONCAT(n, __wl)) 242 243#define WITNESS_RESTORE(lock, n) \ 244 witness_restore((lock), __CONCAT(n, __wf), __CONCAT(n, __wl)) 245 246#else /* WITNESS */ 247#define WITNESS_INIT(lock) (lock)->lo_flags |= LO_INITIALIZED 248#define WITNESS_DESTROY(lock) (lock)->lo_flags &= ~LO_INITIALIZED 249#define WITNESS_LOCK(lock, flags, file, line) 250#define WITNESS_UPGRADE(lock, flags, file, line) 251#define WITNESS_DOWNGRADE(lock, flags, file, line) 252#define WITNESS_UNLOCK(lock, flags, file, line) 253#define WITNESS_SLEEP(check, lock) 254#define WITNESS_SAVE_DECL(n) 255#define WITNESS_SAVE(lock, n) 256#define WITNESS_RESTORE(lock, n) 257#endif /* WITNESS */ 258 259#endif /* _KERNEL */ 260#endif /* _SYS_LOCK_H_ */ 261