sysdeps/unix/sysv/linux/sparc/lowlevellock.h

   1 /* Copyright (C) 2003-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  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 <kernel-features.h>
  27
  28
  29 #define FUTEX_WAIT              0
  30 #define FUTEX_WAKE              1
  31 #define FUTEX_REQUEUE           3
  32 #define FUTEX_CMP_REQUEUE       4
  33 #define FUTEX_WAKE_OP           5
  34 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE   ((4 << 24) | 1)
  35 #define FUTEX_LOCK_PI           6
  36 #define FUTEX_UNLOCK_PI         7
  37 #define FUTEX_TRYLOCK_PI        8
  38 #define FUTEX_WAIT_BITSET       9
  39 #define FUTEX_WAKE_BITSET       10
  40 #define FUTEX_WAIT_REQUEUE_PI   11
  41 #define FUTEX_CMP_REQUEUE_PI    12
  42 #define FUTEX_PRIVATE_FLAG      128
  43 #define FUTEX_CLOCK_REALTIME    256
  44
  45 #define FUTEX_BITSET_MATCH_ANY  0xffffffff
  46
  47
  48 /* Values for 'private' parameter of locking macros.  Yes, the
  49    definition seems to be backwards.  But it is not.  The bit will be
  50    reversed before passing to the system call.  */
  51 #define LLL_PRIVATE     0
  52 #define LLL_SHARED      FUTEX_PRIVATE_FLAG
  53
  54 #ifndef __sparc32_atomic_do_lock
  55 /* Delay in spinlock loop.  */
  56 extern void __cpu_relax (void);
  57 #define BUSY_WAIT_NOP   __cpu_relax ()
  58 #endif
  59
  60 #if IS_IN (libc) || IS_IN (rtld)
  61 /* In libc.so or ld.so all futexes are private.  */
  62 # ifdef __ASSUME_PRIVATE_FUTEX
  63 #  define __lll_private_flag(fl, private) \
  64   ((fl) | FUTEX_PRIVATE_FLAG)
  65 # else
  66 #  define __lll_private_flag(fl, private) \
  67   ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
  68 # endif
  69 #else
  70 # ifdef __ASSUME_PRIVATE_FUTEX
  71 #  define __lll_private_flag(fl, private) \
  72   (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
  73 # else
  74 #  define __lll_private_flag(fl, private) \
  75   (__builtin_constant_p (private)                                             \
  76    ? ((private) == 0                                                          \
  77       ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))            \
  78       : (fl))                                                                 \
  79    : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG)                                \
  80               & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
  81 # endif
  82 #endif
  83
  84
  85 #define lll_futex_wait(futexp, val, private) \
  86   lll_futex_timed_wait (futexp, val, NULL, private)
  87
  88 #define lll_futex_timed_wait(futexp, val, timespec, private) \
  89   ({                                                                          \
  90     INTERNAL_SYSCALL_DECL (__err);                                            \
  91     long int __ret;                                                           \
  92                                                                               \
  93     __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),                      \
  94                               __lll_private_flag (FUTEX_WAIT, private),       \
  95                               (val), (timespec));                             \
  96     __ret;                                                                    \
  97   })
  98
  99 #define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
 100   ({                                                                          \
 101     INTERNAL_SYSCALL_DECL (__err);                                            \
 102     long int __ret;                                                           \
 103     int __op = FUTEX_WAIT_BITSET | clockbit;                                  \
 104                                                                               \
 105     __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),                      \
 106                               __lll_private_flag (__op, private),             \
 107                               (val), (timespec), NULL /* Unused.  */,         \
 108                               FUTEX_BITSET_MATCH_ANY);                        \
 109     __ret;                                                                    \
 110   })
 111
 112 #define lll_futex_wake(futexp, nr, private) \
 113   ({                                                                          \
 114     INTERNAL_SYSCALL_DECL (__err);                                            \
 115     long int __ret;                                                           \
 116                                                                               \
 117     __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),                      \
 118                               __lll_private_flag (FUTEX_WAKE, private),       \
 119                               (nr), 0);                                       \
 120     __ret;                                                                    \
 121   })
 122
 123 /* Returns non-zero if error happened, zero if success.  */
 124 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
 125   ({                                                                          \
 126     INTERNAL_SYSCALL_DECL (__err);                                            \
 127     long int __ret;                                                           \
 128                                                                               \
 129     __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),                      \
 130                               __lll_private_flag (FUTEX_CMP_REQUEUE, private),\
 131                               (nr_wake), (nr_move), (mutex), (val));          \
 132     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
 133   })
 134
 135 /* Returns non-zero if error happened, zero if success.  */
 136 #ifdef __sparc32_atomic_do_lock
 137 /* Avoid FUTEX_WAKE_OP if supporting pre-v9 CPUs.  */
 138 # define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) 1
 139 #else
 140 # define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
 141   ({                                                                          \
 142     INTERNAL_SYSCALL_DECL (__err);                                            \
 143     long int __ret;                                                           \
 144                                                                               \
 145     __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),                      \
 146                               __lll_private_flag (FUTEX_WAKE_OP, private),    \
 147                               (nr_wake), (nr_wake2), (futexp2),               \
 148                               FUTEX_OP_CLEAR_WAKE_IF_GT_ONE);                 \
 149     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
 150   })
 151 #endif
 152
 153 /* Priority Inheritance support.  */
 154 #define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
 155   lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
 156
 157 #define lll_futex_timed_wait_requeue_pi(futexp, val, timespec, clockbit,      \
 158                                         mutex, private)                       \
 159   ({                                                                          \
 160     INTERNAL_SYSCALL_DECL (__err);                                            \
 161     long int __ret;                                                           \
 162     int __op = FUTEX_WAIT_REQUEUE_PI | clockbit;                              \
 163                                                                               \
 164     __ret = INTERNAL_SYSCALL (futex, __err, 5, (futexp),                      \
 165                               __lll_private_flag (__op, private),             \
 166                               (val), (timespec), mutex);                      \
 167     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
 168   })
 169
 170 #define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv)  \
 171   ({                                                                          \
 172     INTERNAL_SYSCALL_DECL (__err);                                            \
 173     long int __ret;                                                           \
 174                                                                               \
 175     __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),                      \
 176                               __lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv),\
 177                               (nr_wake), (nr_move), (mutex), (val));          \
 178     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
 179   })
 180
 181 static inline int
 182 __attribute__ ((always_inline))
 183 __lll_trylock (int *futex)
 184 {
 185   return atomic_compare_and_exchange_val_24_acq (futex, 1, 0) != 0;
 186 }
 187 #define lll_trylock(futex) __lll_trylock (&(futex))
 188
 189 static inline int
 190 __attribute__ ((always_inline))
 191 __lll_cond_trylock (int *futex)
 192 {
 193   return atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0;
 194 }
 195 #define lll_cond_trylock(futex) __lll_cond_trylock (&(futex))
 196
 197
 198 extern void __lll_lock_wait_private (int *futex) attribute_hidden;
 199 extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
 200 extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;
 201
 202 static inline void
 203 __attribute__ ((always_inline))
 204 __lll_lock (int *futex, int private)
 205 {
 206   int val = atomic_compare_and_exchange_val_24_acq (futex, 1, 0);
 207
 208   if (__glibc_unlikely (val != 0))
 209     {
 210       if (__builtin_constant_p (private) && private == LLL_PRIVATE)
 211         __lll_lock_wait_private (futex);
 212       else
 213         __lll_lock_wait (futex, private);
 214     }
 215 }
 216 #define lll_lock(futex, private) __lll_lock (&(futex), private)
 217
 218 static inline int
 219 __attribute__ ((always_inline))
 220 __lll_robust_lock (int *futex, int id, int private)
 221 {
 222   int result = 0;
 223   if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0)
 224     result = __lll_robust_lock_wait (futex, private);
 225   return result;
 226 }
 227 #define lll_robust_lock(futex, id, private) \
 228   __lll_robust_lock (&(futex), id, private)
 229
 230 static inline void
 231 __attribute__ ((always_inline))
 232 __lll_cond_lock (int *futex, int private)
 233 {
 234   int val = atomic_compare_and_exchange_val_24_acq (futex, 2, 0);
 235
 236   if (__glibc_unlikely (val != 0))
 237     __lll_lock_wait (futex, private);
 238 }
 239 #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)
 240
 241 #define lll_robust_cond_lock(futex, id, private) \
 242   __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private)
 243
 244
 245 extern int __lll_timedlock_wait (int *futex, const struct timespec *,
 246                                  int private) attribute_hidden;
 247 extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *,
 248                                         int private) attribute_hidden;
 249
 250 static inline int
 251 __attribute__ ((always_inline))
 252 __lll_timedlock (int *futex, const struct timespec *abstime, int private)
 253 {
 254   int val = atomic_compare_and_exchange_val_24_acq (futex, 1, 0);
 255   int result = 0;
 256
 257   if (__glibc_unlikely (val != 0))
 258     result = __lll_timedlock_wait (futex, abstime, private);
 259   return result;
 260 }
 261 #define lll_timedlock(futex, abstime, private) \
 262   __lll_timedlock (&(futex), abstime, private)
 263
 264 static inline int
 265 __attribute__ ((always_inline))
 266 __lll_robust_timedlock (int *futex, const struct timespec *abstime,
 267                         int id, int private)
 268 {
 269   int result = 0;
 270   if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0)
 271     result = __lll_robust_timedlock_wait (futex, abstime, private);
 272   return result;
 273 }
 274 #define lll_robust_timedlock(futex, abstime, id, private) \
 275   __lll_robust_timedlock (&(futex), abstime, id, private)
 276
 277 #define lll_unlock(lock, private) \
 278   ((void) ({                                                                  \
 279     int *__futex = &(lock);                                                   \
 280     int __val = atomic_exchange_24_rel (__futex, 0);                          \
 281     if (__glibc_unlikely (__val > 1))                                         \
 282       lll_futex_wake (__futex, 1, private);                                   \
 283   }))
 284
 285 #define lll_robust_unlock(lock, private) \
 286   ((void) ({                                                                  \
 287     int *__futex = &(lock);                                                   \
 288     int __val = atomic_exchange_rel (__futex, 0);                             \
 289     if (__glibc_unlikely (__val & FUTEX_WAITERS))                             \
 290       lll_futex_wake (__futex, 1, private);                                   \
 291   }))
 292
 293 #define lll_islocked(futex) \
 294   (futex != 0)
 295
 296 /* Initializers for lock.  */
 297 #define LLL_LOCK_INITIALIZER            (0)
 298 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 299
 300 /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
 301    wakeup when the clone terminates.  The memory location contains the
 302    thread ID while the clone is running and is reset to zero
 303    afterwards.  */
 304 #define lll_wait_tid(tid) \
 305   do                                                    \
 306     {                                                   \
 307       __typeof (tid) __tid;                             \
 308       while ((__tid = (tid)) != 0)                      \
 309         lll_futex_wait (&(tid), __tid, LLL_SHARED);     \
 310     }                                                   \
 311   while (0)
 312
 313 extern int __lll_timedwait_tid (int *, const struct timespec *)
 314      attribute_hidden;
 315
 316 #define lll_timedwait_tid(tid, abstime) \
 317   ({                                                    \
 318     int __res = 0;                                      \
 319     if ((tid) != 0)                                     \
 320       __res = __lll_timedwait_tid (&(tid), (abstime));  \
 321     __res;                                              \
 322   })
 323
 324 #endif  /* lowlevellock.h */