sysdeps/unix/sysv/linux/alpha/nptl/lowlevellock.h

   1 /* Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Libr    \ary; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _LOWLEVELLOCK_H
  20 #define _LOWLEVELLOCK_H 1
  21
  22 #include <time.h>
  23 #include <sys/param.h>
  24 #include <bits/pthreadtypes.h>
  25 #include <atomic.h>
  26 #include <sysdep.h>
  27
  28
  29 #define __NR_futex              394
  30 #define FUTEX_WAIT              0
  31 #define FUTEX_WAKE              1
  32 #define FUTEX_REQUEUE           3
  33 #define FUTEX_CMP_REQUEUE       4
  34 #define FUTEX_WAKE_OP           5
  35 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE   ((4 << 24) | 1)
  36
  37 /* Initializer for compatibility lock.  */
  38 #define LLL_MUTEX_LOCK_INITIALIZER (0)
  39
  40 #define lll_futex_wait(futexp, val) \
  41   ({                                                                          \
  42     INTERNAL_SYSCALL_DECL (__err);                                            \
  43     long int __ret;                                                           \
  44     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  45                               (futexp), FUTEX_WAIT, (val), 0);                \
  46     INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret;                  \
  47   })
  48
  49 #define lll_futex_timed_wait(futexp, val, timespec) \
  50   ({                                                                          \
  51     INTERNAL_SYSCALL_DECL (__err);                                            \
  52     long int __ret;                                                           \
  53     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  54                               (futexp), FUTEX_WAIT, (val), (timespec));       \
  55     INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret;                  \
  56   })
  57
  58 #define lll_futex_wake(futexp, nr) \
  59   ({                                                                          \
  60     INTERNAL_SYSCALL_DECL (__err);                                            \
  61     long int __ret;                                                           \
  62     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  63                               (futexp), FUTEX_WAKE, (nr), 0);                 \
  64     INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret;                  \
  65   })
  66
  67 #define lll_robust_mutex_dead(futexv) \
  68   do                                                                          \
  69     {                                                                         \
  70       int *__futexp = &(futexv);                                              \
  71       atomic_or (__futexp, FUTEX_OWNER_DIED);                                 \
  72       lll_futex_wake (__futexp, 1);                                           \
  73     }                                                                         \
  74   while (0)
  75
  76 /* Returns non-zero if error happened, zero if success.  */
  77 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val) \
  78   ({                                                                          \
  79     INTERNAL_SYSCALL_DECL (__err);                                            \
  80     long int __ret;                                                           \
  81     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
  82                               (futexp), FUTEX_CMP_REQUEUE, (nr_wake),         \
  83                               (nr_move), (mutex), (val));                     \
  84     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
  85   })
  86
  87 /* Returns non-zero if error happened, zero if success.  */
  88 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2) \
  89   ({                                                                          \
  90     INTERNAL_SYSCALL_DECL (__err);                                            \
  91     long int __ret;                                                           \
  92     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
  93                               (futexp), FUTEX_WAKE_OP, (nr_wake),             \
  94                               (nr_wake2), (futexp2),                          \
  95                               FUTEX_OP_CLEAR_WAKE_IF_GT_ONE);                 \
  96     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
  97   })
  98
  99
 100
 101
 102 static inline int __attribute__((always_inline))
 103 __lll_mutex_trylock(int *futex)
 104 {
 105   return atomic_compare_and_exchange_val_acq (futex, 1, 0) != 0;
 106 }
 107 #define lll_mutex_trylock(lock) __lll_mutex_trylock (&(lock))
 108
 109
 110 static inline int __attribute__((always_inline))
 111 __lll_mutex_cond_trylock(int *futex)
 112 {
 113   return atomic_compare_and_exchange_val_acq (futex, 2, 0) != 0;
 114 }
 115 #define lll_mutex_cond_trylock(lock)    __lll_mutex_cond_trylock (&(lock))
 116
 117
 118 static inline int __attribute__((always_inline))
 119 __lll_robust_mutex_trylock(int *futex, int id)
 120 {
 121   return atomic_compare_and_exchange_val_acq (futex, id, 0) != 0;
 122 }
 123 #define lll_robust_mutex_trylock(lock, id) \
 124   __lll_robust_mutex_trylock (&(lock), id)
 125
 126 extern void __lll_lock_wait (int *futex) attribute_hidden;
 127 extern int __lll_robust_lock_wait (int *futex) attribute_hidden;
 128
 129 static inline void __attribute__((always_inline))
 130 __lll_mutex_lock(int *futex)
 131 {
 132   if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0)
 133     __lll_lock_wait (futex);
 134 }
 135 #define lll_mutex_lock(futex) __lll_mutex_lock (&(futex))
 136
 137
 138 static inline int __attribute__ ((always_inline))
 139 __lll_robust_mutex_lock (int *futex, int id)
 140 {
 141   int result = 0;
 142   if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0)
 143     result = __lll_robust_lock_wait (futex);
 144   return result;
 145 }
 146 #define lll_robust_mutex_lock(futex, id) \
 147   __lll_robust_mutex_lock (&(futex), id)
 148
 149
 150 static inline void __attribute__ ((always_inline))
 151 __lll_mutex_cond_lock (int *futex)
 152 {
 153   if (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0)
 154     __lll_lock_wait (futex);
 155 }
 156 #define lll_mutex_cond_lock(futex) __lll_mutex_cond_lock (&(futex))
 157
 158
 159 #define lll_robust_mutex_cond_lock(futex, id) \
 160   __lll_robust_mutex_lock (&(futex), (id) | FUTEX_WAITERS)
 161
 162
 163 extern int __lll_timedlock_wait (int *futex, const struct timespec *)
 164         attribute_hidden;
 165 extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *)
 166         attribute_hidden;
 167
 168 static inline int __attribute__ ((always_inline))
 169 __lll_mutex_timedlock (int *futex, const struct timespec *abstime)
 170 {
 171   int result = 0;
 172   if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0)
 173     result = __lll_timedlock_wait (futex, abstime);
 174   return result;
 175 }
 176 #define lll_mutex_timedlock(futex, abstime) \
 177   __lll_mutex_timedlock (&(futex), abstime)
 178
 179
 180 static inline int __attribute__ ((always_inline))
 181 __lll_robust_mutex_timedlock (int *futex, const struct timespec *abstime,
 182                               int id)
 183 {
 184   int result = 0;
 185   if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0)
 186     result = __lll_robust_timedlock_wait (futex, abstime);
 187   return result;
 188 }
 189 #define lll_robust_mutex_timedlock(futex, abstime, id) \
 190   __lll_robust_mutex_timedlock (&(futex), abstime, id)
 191
 192
 193 static inline void __attribute__ ((always_inline))
 194 __lll_mutex_unlock (int *futex)
 195 {
 196   int val = atomic_exchange_rel (futex, 0);
 197   if (__builtin_expect (val > 1, 0))
 198     lll_futex_wake (futex, 1);
 199 }
 200 #define lll_mutex_unlock(futex) __lll_mutex_unlock(&(futex))
 201
 202
 203 static inline void __attribute__ ((always_inline))
 204 __lll_robust_mutex_unlock (int *futex, int mask)
 205 {
 206   int val = atomic_exchange_rel (futex, 0);
 207   if (__builtin_expect (val & mask, 0))
 208     lll_futex_wake (futex, 1);
 209 }
 210 #define lll_robust_mutex_unlock(futex) \
 211   __lll_robust_mutex_unlock(&(futex), FUTEX_WAITERS)
 212
 213
 214 static inline void __attribute__ ((always_inline))
 215 __lll_mutex_unlock_force (int *futex)
 216 {
 217   (void) atomic_exchange_rel (futex, 0);
 218   lll_futex_wake (futex, 1);
 219 }
 220 #define lll_mutex_unlock_force(futex) __lll_mutex_unlock_force(&(futex))
 221
 222
 223 #define lll_mutex_islocked(futex) \
 224   (futex != 0)
 225
 226
 227 /* Our internal lock implementation is identical to the binary-compatible
 228    mutex implementation. */
 229
 230 /* Type for lock object.  */
 231 typedef int lll_lock_t;
 232
 233 /* Initializers for lock.  */
 234 #define LLL_LOCK_INITIALIZER            (0)
 235 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 236
 237 extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
 238
 239 /* The states of a lock are:
 240     0  -  untaken
 241     1  -  taken by one user
 242    >1  -  taken by more users */
 243
 244 #define lll_trylock(lock)       lll_mutex_trylock (lock)
 245 #define lll_lock(lock)          lll_mutex_lock (lock)
 246 #define lll_unlock(lock)        lll_mutex_unlock (lock)
 247 #define lll_islocked(lock)      lll_mutex_islocked (lock)
 248
 249 /* The kernel notifies a process which uses CLONE_CLEARTID via futex
 250    wakeup when the clone terminates.  The memory location contains the
 251    thread ID while the clone is running and is reset to zero
 252    afterwards.  */
 253 #define lll_wait_tid(tid) \
 254   do {                                  \
 255     __typeof (tid) __tid;               \
 256     while ((__tid = (tid)) != 0)        \
 257       lll_futex_wait (&(tid), __tid);   \
 258   } while (0)
 259
 260 extern int __lll_timedwait_tid (int *, const struct timespec *)
 261      attribute_hidden;
 262
 263 #define lll_timedwait_tid(tid, abstime) \
 264   ({                                                    \
 265     int __res = 0;                                      \
 266     if ((tid) != 0)                                     \
 267       __res = __lll_timedwait_tid (&(tid), (abstime));  \
 268     __res;                                              \
 269   })
 270
 271
 272 /* Conditional variable handling.  */
 273
 274 extern void __lll_cond_wait (pthread_cond_t *cond)
 275      attribute_hidden;
 276 extern int __lll_cond_timedwait (pthread_cond_t *cond,
 277                                  const struct timespec *abstime)
 278      attribute_hidden;
 279 extern void __lll_cond_wake (pthread_cond_t *cond)
 280      attribute_hidden;
 281 extern void __lll_cond_broadcast (pthread_cond_t *cond)
 282      attribute_hidden;
 283
 284 #define lll_cond_wait(cond) \
 285   __lll_cond_wait (cond)
 286 #define lll_cond_timedwait(cond, abstime) \
 287   __lll_cond_timedwait (cond, abstime)
 288 #define lll_cond_wake(cond) \
 289   __lll_cond_wake (cond)
 290 #define lll_cond_broadcast(cond) \
 291   __lll_cond_broadcast (cond)
 292
 293 #endif  /* lowlevellock.h */