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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 | /* Copyright (C) 2003, 2004, 2006-2008, 2009 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ #ifndef _LOWLEVELLOCK_H #define _LOWLEVELLOCK_H 1 #include <time.h> #include <sys/param.h> #include <bits/pthreadtypes.h> #include <atomic.h> #include <bits/kernel-features.h> #include <sysdep.h> #ifndef __NR_futex # define __NR_futex 221 #endif #define FUTEX_WAIT 0 #define FUTEX_WAKE 1 #define FUTEX_REQUEUE 3 #define FUTEX_CMP_REQUEUE 4 #define FUTEX_WAKE_OP 5 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) #define FUTEX_LOCK_PI 6 #define FUTEX_UNLOCK_PI 7 #define FUTEX_TRYLOCK_PI 8 #define FUTEX_WAIT_BITSET 9 #define FUTEX_WAKE_BITSET 10 #define FUTEX_PRIVATE_FLAG 128 #define FUTEX_CLOCK_REALTIME 256 #define FUTEX_BITSET_MATCH_ANY 0xffffffff /* Values for 'private' parameter of locking macros. Yes, the definition seems to be backwards. But it is not. The bit will be reversed before passing to the system call. */ #define LLL_PRIVATE 0 #define LLL_SHARED FUTEX_PRIVATE_FLAG #if !defined NOT_IN_libc || defined IS_IN_rtld /* In libc.so or ld.so all futexes are private. */ # ifdef __ASSUME_PRIVATE_FUTEX # define __lll_private_flag(fl, private) \ ((fl) | FUTEX_PRIVATE_FLAG) # else # define __lll_private_flag(fl, private) \ ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) # endif #else # ifdef __ASSUME_PRIVATE_FUTEX # define __lll_private_flag(fl, private) \ (((fl) | FUTEX_PRIVATE_FLAG) ^ (private)) # else # define __lll_private_flag(fl, private) \ (__builtin_constant_p (private) \ ? ((private) == 0 \ ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \ : (fl)) \ : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG) \ & THREAD_GETMEM (THREAD_SELF, header.private_futex)))) # endif #endif #define lll_futex_wait(futexp, val, private) \ lll_futex_timed_wait (futexp, val, NULL, private) #define lll_futex_timed_wait(futexp, val, timespec, private) \ ({ \ INTERNAL_SYSCALL_DECL (__err); \ long int __ret; \ \ __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \ __lll_private_flag (FUTEX_WAIT, private), \ (val), (timespec)); \ INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret; \ }) #define lll_futex_wake(futexp, nr, private) \ ({ \ INTERNAL_SYSCALL_DECL (__err); \ long int __ret; \ \ __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \ __lll_private_flag (FUTEX_WAKE, private), \ (nr), 0); \ INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret; \ }) #define lll_robust_dead(futexv, private) \ do \ { \ INTERNAL_SYSCALL_DECL (__err); \ int *__futexp = &(futexv); \ \ atomic_or (__futexp, FUTEX_OWNER_DIED); \ INTERNAL_SYSCALL (futex, __err, 4, __futexp, \ __lll_private_flag (FUTEX_WAKE, private), 1, 0); \ } \ while (0) /* Returns non-zero if error happened, zero if success. */ #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ ({ \ INTERNAL_SYSCALL_DECL (__err); \ long int __ret; \ \ __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ __lll_private_flag (FUTEX_CMP_REQUEUE, private),\ (nr_wake), (nr_move), (mutex), (val)); \ INTERNAL_SYSCALL_ERROR_P (__ret, __err); \ }) /* Returns non-zero if error happened, zero if success. */ #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ ({ \ INTERNAL_SYSCALL_DECL (__err); \ long int __ret; \ \ __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ __lll_private_flag (FUTEX_WAKE_OP, private), \ (nr_wake), (nr_wake2), (futexp2), \ FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \ INTERNAL_SYSCALL_ERROR_P (__ret, __err); \ }) #ifdef UP # define __lll_acq_instr "" # define __lll_rel_instr "" #else # define __lll_acq_instr "isync" # ifdef _ARCH_PWR4 /* * Newer powerpc64 processors support the new "light weight" sync (lwsync) * So if the build is using -mcpu=[power4,power5,power5+,970] we can * safely use lwsync. */ # define __lll_rel_instr "lwsync" # else /* * Older powerpc32 processors don't support the new "light weight" * sync (lwsync). So the only safe option is to use normal sync * for all powerpc32 applications. */ # define __lll_rel_instr "sync" # endif #endif /* Set *futex to ID if it is 0, atomically. Returns the old value */ #define __lll_robust_trylock(futex, id) \ ({ int __val; \ __asm__ __volatile__ ("1: lwarx %0,0,%2" MUTEX_HINT_ACQ "\n" \ " cmpwi 0,%0,0\n" \ " bne 2f\n" \ " stwcx. %3,0,%2\n" \ " bne- 1b\n" \ "2: " __lll_acq_instr \ : "=&r" (__val), "=m" (*futex) \ : "r" (futex), "r" (id), "m" (*futex) \ : "cr0", "memory"); \ __val; \ }) #define lll_robust_trylock(lock, id) __lll_robust_trylock (&(lock), id) /* Set *futex to 1 if it is 0, atomically. Returns the old value */ #define __lll_trylock(futex) __lll_robust_trylock (futex, 1) #define lll_trylock(lock) __lll_trylock (&(lock)) /* Set *futex to 2 if it is 0, atomically. Returns the old value */ #define __lll_cond_trylock(futex) __lll_robust_trylock (futex, 2) #define lll_cond_trylock(lock) __lll_cond_trylock (&(lock)) extern void __lll_lock_wait_private (int *futex) attribute_hidden; extern void __lll_lock_wait (int *futex, int private) attribute_hidden; extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; #define lll_lock(lock, private) \ (void) ({ \ int *__futex = &(lock); \ if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\ 0) != 0) \ { \ if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \ __lll_lock_wait_private (__futex); \ else \ __lll_lock_wait (__futex, private); \ } \ }) #define lll_robust_lock(lock, id, private) \ ({ \ int *__futex = &(lock); \ int __val = 0; \ if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \ 0), 0)) \ __val = __lll_robust_lock_wait (__futex, private); \ __val; \ }) #define lll_cond_lock(lock, private) \ (void) ({ \ int *__futex = &(lock); \ if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 2, 0),\ 0) != 0) \ __lll_lock_wait (__futex, private); \ }) #define lll_robust_cond_lock(lock, id, private) \ ({ \ int *__futex = &(lock); \ int __val = 0; \ int __id = id | FUTEX_WAITERS; \ if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, __id,\ 0), 0)) \ __val = __lll_robust_lock_wait (__futex, private); \ __val; \ }) extern int __lll_timedlock_wait (int *futex, const struct timespec *, int private) attribute_hidden; extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, int private) attribute_hidden; #define lll_timedlock(lock, abstime, private) \ ({ \ int *__futex = &(lock); \ int __val = 0; \ if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\ 0) != 0) \ __val = __lll_timedlock_wait (__futex, abstime, private); \ __val; \ }) #define lll_robust_timedlock(lock, abstime, id, private) \ ({ \ int *__futex = &(lock); \ int __val = 0; \ if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \ 0), 0)) \ __val = __lll_robust_timedlock_wait (__futex, abstime, private); \ __val; \ }) #define lll_unlock(lock, private) \ ((void) ({ \ int *__futex = &(lock); \ int __val = atomic_exchange_rel (__futex, 0); \ if (__builtin_expect (__val > 1, 0)) \ lll_futex_wake (__futex, 1, private); \ })) #define lll_robust_unlock(lock, private) \ ((void) ({ \ int *__futex = &(lock); \ int __val = atomic_exchange_rel (__futex, 0); \ if (__builtin_expect (__val & FUTEX_WAITERS, 0)) \ lll_futex_wake (__futex, 1, private); \ })) #define lll_islocked(futex) \ (futex != 0) /* Initializers for lock. */ #define LLL_LOCK_INITIALIZER (0) #define LLL_LOCK_INITIALIZER_LOCKED (1) /* The states of a lock are: 0 - untaken 1 - taken by one user >1 - taken by more users */ /* The kernel notifies a process which uses CLONE_CLEARTID via futex wakeup when the clone terminates. The memory location contains the thread ID while the clone is running and is reset to zero afterwards. */ #define lll_wait_tid(tid) \ do { \ __typeof (tid) __tid; \ while ((__tid = (tid)) != 0) \ lll_futex_wait (&(tid), __tid, LLL_SHARED); \ } while (0) extern int __lll_timedwait_tid (int *, const struct timespec *) attribute_hidden; #define lll_timedwait_tid(tid, abstime) \ ({ \ int __res = 0; \ if ((tid) != 0) \ __res = __lll_timedwait_tid (&(tid), (abstime)); \ __res; \ }) #endif /* lowlevellock.h */ |