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

   1 /* low level locking for pthread library.  SPARC version.
   2    Copyright (C) 2003, 2006, 2007 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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <sysdep.h>
  23 #include <lowlevellock.h>
  24 #include <sys/time.h>
  25
  26
  27 void
  28 __lll_lock_wait_private (int *futex)
  29 {
  30   do
  31     {
  32       int oldval = atomic_compare_and_exchange_val_24_acq (futex, 2, 1);
  33       if (oldval != 0)
  34         lll_futex_wait (futex, 2, LLL_PRIVATE);
  35     }
  36   while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
  37 }
  38
  39
  40 /* These functions don't get included in libc.so  */
  41 #ifdef IS_IN_libpthread
  42 void
  43 __lll_lock_wait (int *futex, int private)
  44 {
  45   do
  46     {
  47       int oldval = atomic_compare_and_exchange_val_24_acq (futex, 2, 1);
  48       if (oldval != 0)
  49         lll_futex_wait (futex, 2, private);
  50     }
  51   while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
  52 }
  53
  54
  55 int
  56 __lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
  57 {
  58   /* Reject invalid timeouts.  */
  59   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
  60     return EINVAL;
  61
  62   do
  63     {
  64       struct timeval tv;
  65       struct timespec rt;
  66
  67       /* Get the current time.  */
  68       (void) __gettimeofday (&tv, NULL);
  69
  70       /* Compute relative timeout.  */
  71       rt.tv_sec = abstime->tv_sec - tv.tv_sec;
  72       rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
  73       if (rt.tv_nsec < 0)
  74         {
  75           rt.tv_nsec += 1000000000;
  76           --rt.tv_sec;
  77         }
  78
  79       /* Already timed out?  */
  80       if (rt.tv_sec < 0)
  81         return ETIMEDOUT;
  82
  83       /* Wait.  */
  84       int oldval = atomic_compare_and_exchange_val_24_acq (futex, 2, 1);
  85       if (oldval != 0)
  86         lll_futex_timed_wait (futex, 2, &rt, private);
  87     }
  88   while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
  89
  90   return 0;
  91 }
  92
  93
  94 int
  95 __lll_timedwait_tid (int *tidp, const struct timespec *abstime)
  96 {
  97   int tid;
  98
  99   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
 100     return EINVAL;
 101
 102   /* Repeat until thread terminated.  */
 103   while ((tid = *tidp) != 0)
 104     {
 105       struct timeval tv;
 106       struct timespec rt;
 107
 108       /* Get the current time.  */
 109       (void) __gettimeofday (&tv, NULL);
 110
 111       /* Compute relative timeout.  */
 112       rt.tv_sec = abstime->tv_sec - tv.tv_sec;
 113       rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
 114       if (rt.tv_nsec < 0)
 115         {
 116           rt.tv_nsec += 1000000000;
 117           --rt.tv_sec;
 118         }
 119
 120       /* Already timed out?  */
 121       if (rt.tv_sec < 0)
 122         return ETIMEDOUT;
 123
 124       /* Wait until thread terminates.  The kernel so far does not use
 125          the private futex operations for this.  */
 126       if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT)
 127         return ETIMEDOUT;
 128     }
 129
 130   return 0;
 131 }
 132 #endif