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

   1 /* Copyright (C) 2003, 2004 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 Libr    \ary; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _LOWLEVELLOCK_H
  21 #define _LOWLEVELLOCK_H 1
  22
  23 #include <time.h>
  24 #include <sys/param.h>
  25 #include <bits/pthreadtypes.h>
  26 #include <atomic.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
  36 /* Initializer for compatibility lock.  */
  37 #define LLL_MUTEX_LOCK_INITIALIZER (0)
  38
  39 #define lll_futex_wait(futexp, val) \
  40   ({                                                                          \
  41     INTERNAL_SYSCALL_DECL (__err);                                            \
  42     long int __ret;                                                           \
  43                                                                               \
  44     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  45                               (futexp), FUTEX_WAIT, (val), 0);                \
  46     __ret;                                                                    \
  47   })
  48
  49 #define lll_futex_timed_wait(futexp, val, timespec) \
  50   ({                                                                          \
  51     INTERNAL_SYSCALL_DECL (__err);                                            \
  52     long int __ret;                                                           \
  53                                                                               \
  54     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  55                               (futexp), FUTEX_WAIT, (val), (timespec));       \
  56     __ret;                                                                    \
  57   })
  58
  59 #define lll_futex_wake(futexp, nr) \
  60   ({                                                                          \
  61     INTERNAL_SYSCALL_DECL (__err);                                            \
  62     long int __ret;                                                           \
  63                                                                               \
  64     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  65                               (futexp), FUTEX_WAKE, (nr), 0);                 \
  66     __ret;                                                                    \
  67   })
  68
  69 /* Returns non-zero if error happened, zero if success.  */
  70 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val) \
  71   ({                                                                          \
  72     INTERNAL_SYSCALL_DECL (__err);                                            \
  73     long int __ret;                                                           \
  74                                                                               \
  75     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
  76                               (futexp), FUTEX_CMP_REQUEUE, (nr_wake),         \
  77                               (nr_move), (mutex), (val));                     \
  78     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
  79   })
  80
  81 /* Returns non-zero if error happened, zero if success.  */
  82 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2) \
  83   ({                                                                          \
  84     INTERNAL_SYSCALL_DECL (__err);                                            \
  85     long int __ret;                                                           \
  86                                                                               \
  87     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
  88                               (futexp), FUTEX_WAKE_OP, (nr_wake),             \
  89                               (nr_wake2), (futexp2),                          \
  90                               FUTEX_OP_CLEAR_WAKE_IF_GT_ONE);                 \
  91     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
  92   })
  93
  94 #ifdef __sparc32_atomic_do_lock
  95 #error SPARC < v9 does not support compare and swap which is essential for futex based locking
  96 #endif
  97
  98 static inline int
  99 __attribute__ ((always_inline))
 100 __lll_mutex_trylock (int *futex)
 101 {
 102   return atomic_compare_and_exchange_val_acq (futex, 1, 0) != 0;
 103 }
 104 #define lll_mutex_trylock(futex) __lll_mutex_trylock (&(futex))
 105
 106 static inline int
 107 __attribute__ ((always_inline))
 108 __lll_mutex_cond_trylock (int *futex)
 109 {
 110   return atomic_compare_and_exchange_val_acq (futex, 2, 0) != 0;
 111 }
 112 #define lll_mutex_cond_trylock(futex) __lll_mutex_cond_trylock (&(futex))
 113
 114
 115 extern void __lll_lock_wait (int *futex) attribute_hidden;
 116
 117
 118 static inline void
 119 __attribute__ ((always_inline))
 120 __lll_mutex_lock (int *futex)
 121 {
 122   int val = atomic_compare_and_exchange_val_acq (futex, 1, 0);
 123
 124   if (__builtin_expect (val != 0, 0))
 125     __lll_lock_wait (futex);
 126 }
 127 #define lll_mutex_lock(futex) __lll_mutex_lock (&(futex))
 128
 129
 130 static inline void
 131 __attribute__ ((always_inline))
 132 __lll_mutex_cond_lock (int *futex)
 133 {
 134   int val = atomic_compare_and_exchange_val_acq (futex, 2, 0);
 135
 136   if (__builtin_expect (val != 0, 0))
 137     __lll_lock_wait (futex);
 138 }
 139 #define lll_mutex_cond_lock(futex) __lll_mutex_cond_lock (&(futex))
 140
 141
 142 extern int __lll_timedlock_wait (int *futex, const struct timespec *)
 143      attribute_hidden;
 144
 145
 146 static inline int
 147 __attribute__ ((always_inline))
 148 __lll_mutex_timedlock (int *futex, const struct timespec *abstime)
 149 {
 150   int val = atomic_compare_and_exchange_val_acq (futex, 1, 0);
 151   int result = 0;
 152
 153   if (__builtin_expect (val != 0, 0))
 154     result = __lll_timedlock_wait (futex, abstime);
 155   return result;
 156 }
 157 #define lll_mutex_timedlock(futex, abstime) \
 158   __lll_mutex_timedlock (&(futex), abstime)
 159
 160 #define lll_mutex_unlock(lock) \
 161   ((void) ({                                                                  \
 162     int *__futex = &(lock);                                                   \
 163     int __val = atomic_exchange_rel (__futex, 0);                             \
 164     if (__builtin_expect (__val > 1, 0))                                      \
 165       lll_futex_wake (__futex, 1);                                            \
 166   }))
 167
 168 #define lll_mutex_unlock_force(lock) \
 169   ((void) ({                                                                  \
 170     int *__futex = &(lock);                                                   \
 171     (void) atomic_exchange_rel (__futex, 0);                                  \
 172     lll_futex_wake (__futex, 1);                                              \
 173   }))
 174
 175 #define lll_mutex_islocked(futex) \
 176   (futex != 0)
 177
 178
 179 /* We have a separate internal lock implementation which is not tied
 180    to binary compatibility.  We can use the lll_mutex_*.  */
 181
 182 /* Type for lock object.  */
 183 typedef int lll_lock_t;
 184
 185 extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
 186
 187 /* Initializers for lock.  */
 188 #define LLL_LOCK_INITIALIZER            (0)
 189 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 190
 191 #define lll_trylock(futex)      lll_mutex_trylock (futex)
 192 #define lll_lock(futex)         lll_mutex_lock (futex)
 193 #define lll_unlock(futex)       lll_mutex_unlock (futex)
 194 #define lll_islocked(futex)     lll_mutex_islocked (futex)
 195
 196
 197 /* The kernel notifies a process with uses CLONE_CLEARTID via futex
 198    wakeup when the clone terminates.  The memory location contains the
 199    thread ID while the clone is running and is reset to zero
 200    afterwards.  */
 201 #define lll_wait_tid(tid) \
 202   do                                            \
 203     {                                           \
 204       __typeof (tid) __tid;                     \
 205       while ((__tid = (tid)) != 0)              \
 206         lll_futex_wait (&(tid), __tid);         \
 207     }                                           \
 208   while (0)
 209
 210 extern int __lll_timedwait_tid (int *, const struct timespec *)
 211      attribute_hidden;
 212
 213 #define lll_timedwait_tid(tid, abstime) \
 214   ({                                                    \
 215     int __res = 0;                                      \
 216     if ((tid) != 0)                                     \
 217       __res = __lll_timedwait_tid (&(tid), (abstime));  \
 218     __res;                                              \
 219   })
 220
 221
 222 /* Conditional variable handling.  */
 223
 224 extern void __lll_cond_wait (pthread_cond_t *cond)
 225      attribute_hidden;
 226 extern int __lll_cond_timedwait (pthread_cond_t *cond,
 227                                  const struct timespec *abstime)
 228      attribute_hidden;
 229 extern void __lll_cond_wake (pthread_cond_t *cond)
 230      attribute_hidden;
 231 extern void __lll_cond_broadcast (pthread_cond_t *cond)
 232      attribute_hidden;
 233
 234 #define lll_cond_wait(cond) \
 235   __lll_cond_wait (cond)
 236 #define lll_cond_timedwait(cond, abstime) \
 237   __lll_cond_timedwait (cond, abstime)
 238 #define lll_cond_wake(cond) \
 239   __lll_cond_wake (cond)
 240 #define lll_cond_broadcast(cond) \
 241   __lll_cond_broadcast (cond)
 242
 243 #endif  /* lowlevellock.h */