| kern_sx.c (164246) | kern_sx.c (167012) |
|---|---|
| 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 --- 20 unchanged lines hidden (view full) --- 29 * Shared/exclusive locks. This implementation assures deterministic lock 30 * granting behavior, so that slocks and xlocks are interleaved. 31 * 32 * Priority propagation will not generally raise the priority of lock holders, 33 * so should not be relied upon in combination with sx locks. 34 */ 35 36#include <sys/cdefs.h> | 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 --- 20 unchanged lines hidden (view full) --- 29 * Shared/exclusive locks. This implementation assures deterministic lock 30 * granting behavior, so that slocks and xlocks are interleaved. 31 * 32 * Priority propagation will not generally raise the priority of lock holders, 33 * so should not be relied upon in combination with sx locks. 34 */ 35 36#include <sys/cdefs.h> |
| 37__FBSDID("$FreeBSD: head/sys/kern/kern_sx.c 164246 2006-11-13 05:41:46Z kmacy $"); | 37__FBSDID("$FreeBSD: head/sys/kern/kern_sx.c 167012 2007-02-26 08:26:44Z kmacy $"); |
| 38 39#include "opt_ddb.h" 40 41#include <sys/param.h> 42#include <sys/systm.h> 43#include <sys/ktr.h> 44#include <sys/linker_set.h> 45#include <sys/condvar.h> --- 60 unchanged lines hidden (view full) --- 106 lock_profile_object_destroy(&sx->sx_object); 107 lock_destroy(&sx->sx_object); 108} 109 110void 111_sx_slock(struct sx *sx, const char *file, int line) 112{ 113 uint64_t waittime = 0; | 38 39#include "opt_ddb.h" 40 41#include <sys/param.h> 42#include <sys/systm.h> 43#include <sys/ktr.h> 44#include <sys/linker_set.h> 45#include <sys/condvar.h> --- 60 unchanged lines hidden (view full) --- 106 lock_profile_object_destroy(&sx->sx_object); 107 lock_destroy(&sx->sx_object); 108} 109 110void 111_sx_slock(struct sx *sx, const char *file, int line) 112{ 113 uint64_t waittime = 0; |
| 114 int contested; | 114 int contested = 0; |
| 115 116 mtx_lock(sx->sx_lock); 117 KASSERT(sx->sx_xholder != curthread, 118 ("%s (%s): slock while xlock is held @ %s:%d\n", __func__, 119 sx->sx_object.lo_name, file, line)); 120 WITNESS_CHECKORDER(&sx->sx_object, LOP_NEWORDER, file, line); 121 122 /* 123 * Loop in case we lose the race for lock acquisition. 124 */ | 115 116 mtx_lock(sx->sx_lock); 117 KASSERT(sx->sx_xholder != curthread, 118 ("%s (%s): slock while xlock is held @ %s:%d\n", __func__, 119 sx->sx_object.lo_name, file, line)); 120 WITNESS_CHECKORDER(&sx->sx_object, LOP_NEWORDER, file, line); 121 122 /* 123 * Loop in case we lose the race for lock acquisition. 124 */ |
| 125 if (sx->sx_cnt < 0) 126 lock_profile_waitstart(&waittime); | |
| 127 while (sx->sx_cnt < 0) { 128 sx->sx_shrd_wcnt++; | 125 while (sx->sx_cnt < 0) { 126 sx->sx_shrd_wcnt++; |
| 129 lock_profile_obtain_lock_failed(&sx->sx_object, &contested); | 127 lock_profile_obtain_lock_failed(&sx->sx_object, &contested, &waittime); |
| 130 cv_wait(&sx->sx_shrd_cv, sx->sx_lock); 131 sx->sx_shrd_wcnt--; 132 } 133 134 /* Acquire a shared lock. */ 135 sx->sx_cnt++; 136 137 if (sx->sx_cnt == 1) | 128 cv_wait(&sx->sx_shrd_cv, sx->sx_lock); 129 sx->sx_shrd_wcnt--; 130 } 131 132 /* Acquire a shared lock. */ 133 sx->sx_cnt++; 134 135 if (sx->sx_cnt == 1) |
| 138 lock_profile_obtain_lock_success(&sx->sx_object, waittime, file, line); | 136 lock_profile_obtain_lock_success(&sx->sx_object, contested, waittime, file, line); |
| 139 140 LOCK_LOG_LOCK("SLOCK", &sx->sx_object, 0, 0, file, line); 141 WITNESS_LOCK(&sx->sx_object, 0, file, line); 142 curthread->td_locks++; 143 144 mtx_unlock(sx->sx_lock); 145} 146 --- 14 unchanged lines hidden (view full) --- 161 mtx_unlock(sx->sx_lock); 162 return (0); 163 } 164} 165 166void 167_sx_xlock(struct sx *sx, const char *file, int line) 168{ | 137 138 LOCK_LOG_LOCK("SLOCK", &sx->sx_object, 0, 0, file, line); 139 WITNESS_LOCK(&sx->sx_object, 0, file, line); 140 curthread->td_locks++; 141 142 mtx_unlock(sx->sx_lock); 143} 144 --- 14 unchanged lines hidden (view full) --- 159 mtx_unlock(sx->sx_lock); 160 return (0); 161 } 162} 163 164void 165_sx_xlock(struct sx *sx, const char *file, int line) 166{ |
| 169 int contested; | 167 int contested = 0; |
| 170 uint64_t waittime = 0; 171 172 mtx_lock(sx->sx_lock); 173 174 /* 175 * With sx locks, we're absolutely not permitted to recurse on 176 * xlocks, as it is fatal (deadlock). Normally, recursion is handled 177 * by WITNESS, but as it is not semantically correct to hold the 178 * xlock while in here, we consider it API abuse and put it under 179 * INVARIANTS. 180 */ 181 KASSERT(sx->sx_xholder != curthread, 182 ("%s (%s): xlock already held @ %s:%d", __func__, 183 sx->sx_object.lo_name, file, line)); 184 WITNESS_CHECKORDER(&sx->sx_object, LOP_NEWORDER | LOP_EXCLUSIVE, file, 185 line); 186 | 168 uint64_t waittime = 0; 169 170 mtx_lock(sx->sx_lock); 171 172 /* 173 * With sx locks, we're absolutely not permitted to recurse on 174 * xlocks, as it is fatal (deadlock). Normally, recursion is handled 175 * by WITNESS, but as it is not semantically correct to hold the 176 * xlock while in here, we consider it API abuse and put it under 177 * INVARIANTS. 178 */ 179 KASSERT(sx->sx_xholder != curthread, 180 ("%s (%s): xlock already held @ %s:%d", __func__, 181 sx->sx_object.lo_name, file, line)); 182 WITNESS_CHECKORDER(&sx->sx_object, LOP_NEWORDER | LOP_EXCLUSIVE, file, 183 line); 184 |
| 187 if (sx->sx_cnt) 188 lock_profile_waitstart(&waittime); | |
| 189 /* Loop in case we lose the race for lock acquisition. */ 190 while (sx->sx_cnt != 0) { 191 sx->sx_excl_wcnt++; | 185 /* Loop in case we lose the race for lock acquisition. */ 186 while (sx->sx_cnt != 0) { 187 sx->sx_excl_wcnt++; |
| 192 lock_profile_obtain_lock_failed(&sx->sx_object, &contested); | 188 lock_profile_obtain_lock_failed(&sx->sx_object, &contested, &waittime); |
| 193 cv_wait(&sx->sx_excl_cv, sx->sx_lock); 194 sx->sx_excl_wcnt--; 195 } 196 197 MPASS(sx->sx_cnt == 0); 198 199 /* Acquire an exclusive lock. */ 200 sx->sx_cnt--; 201 sx->sx_xholder = curthread; 202 | 189 cv_wait(&sx->sx_excl_cv, sx->sx_lock); 190 sx->sx_excl_wcnt--; 191 } 192 193 MPASS(sx->sx_cnt == 0); 194 195 /* Acquire an exclusive lock. */ 196 sx->sx_cnt--; 197 sx->sx_xholder = curthread; 198 |
| 203 lock_profile_obtain_lock_success(&sx->sx_object, waittime, file, line); | 199 lock_profile_obtain_lock_success(&sx->sx_object, contested, waittime, file, line); |
| 204 LOCK_LOG_LOCK("XLOCK", &sx->sx_object, 0, 0, file, line); 205 WITNESS_LOCK(&sx->sx_object, LOP_EXCLUSIVE, file, line); 206 curthread->td_locks++; 207 208 mtx_unlock(sx->sx_lock); 209} 210 211int --- 260 unchanged lines hidden --- | 200 LOCK_LOG_LOCK("XLOCK", &sx->sx_object, 0, 0, file, line); 201 WITNESS_LOCK(&sx->sx_object, LOP_EXCLUSIVE, file, line); 202 curthread->td_locks++; 203 204 mtx_unlock(sx->sx_lock); 205} 206 207int --- 260 unchanged lines hidden --- |