nptl/sysdeps/unix/sysv/linux/sparc/sparc32/lowlevellock.c

   1 /* low level locking for pthread library.  SPARC version.
   2    Copyright (C) 2003-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <sysdep.h>
  22 #include <lowlevellock.h>
  23 #include <sys/time.h>
  24
  25
  26 void
  27 __lll_lock_wait_private (int *futex)
  28 {
  29   do
  30     {
  31       int oldval = atomic_compare_and_exchange_val_24_acq (futex, 2, 1);
  32       if (oldval != 0)
  33         lll_futex_wait (futex, 2, LLL_PRIVATE);
  34     }
  35   while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
  36 }
  37
  38
  39 /* These functions don't get included in libc.so  */
  40 #ifdef IS_IN_libpthread
  41 void
  42 __lll_lock_wait (int *futex, int private)
  43 {
  44   do
  45     {
  46       int oldval = atomic_compare_and_exchange_val_24_acq (futex, 2, 1);
  47       if (oldval != 0)
  48         lll_futex_wait (futex, 2, private);
  49     }
  50   while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
  51 }
  52
  53
  54 int
  55 __lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
  56 {
  57   /* Reject invalid timeouts.  */
  58   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
  59     return EINVAL;
  60
  61   do
  62     {
  63       struct timeval tv;
  64       struct timespec rt;
  65
  66       /* Get the current time.  */
  67       (void) __gettimeofday (&tv, NULL);
  68
  69       /* Compute relative timeout.  */
  70       rt.tv_sec = abstime->tv_sec - tv.tv_sec;
  71       rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
  72       if (rt.tv_nsec < 0)
  73         {
  74           rt.tv_nsec += 1000000000;
  75           --rt.tv_sec;
  76         }
  77
  78       /* Already timed out?  */
  79       if (rt.tv_sec < 0)
  80         return ETIMEDOUT;
  81
  82       /* Wait.  */
  83       int oldval = atomic_compare_and_exchange_val_24_acq (futex, 2, 1);
  84       if (oldval != 0)
  85         lll_futex_timed_wait (futex, 2, &rt, private);
  86     }
  87   while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
  88
  89   return 0;
  90 }
  91
  92
  93 int
  94 __lll_timedwait_tid (int *tidp, const struct timespec *abstime)
  95 {
  96   int tid;
  97
  98   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
  99     return EINVAL;
 100
 101   /* Repeat until thread terminated.  */
 102   while ((tid = *tidp) != 0)
 103     {
 104       struct timeval tv;
 105       struct timespec rt;
 106
 107       /* Get the current time.  */
 108       (void) __gettimeofday (&tv, NULL);
 109
 110       /* Compute relative timeout.  */
 111       rt.tv_sec = abstime->tv_sec - tv.tv_sec;
 112       rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
 113       if (rt.tv_nsec < 0)
 114         {
 115           rt.tv_nsec += 1000000000;
 116           --rt.tv_sec;
 117         }
 118
 119       /* Already timed out?  */
 120       if (rt.tv_sec < 0)
 121         return ETIMEDOUT;
 122
 123       /* Wait until thread terminates.  The kernel so far does not use
 124          the private futex operations for this.  */
 125       if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT)
 126         return ETIMEDOUT;
 127     }
 128
 129   return 0;
 130 }
 131 #endif