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glibc  2.9
pspinlock.c
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00001 /* POSIX spinlock implementation.  CRIS version.
00002    Copyright (C) 2000, 2001 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public License as
00007    published by the Free Software Foundation; either version 2.1 of the
00008    License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; see the file COPYING.LIB.  If not,
00017    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
00018    Boston, MA 02111-1307, USA.  */
00019 
00020 #include <errno.h>
00021 #include <pthread.h>
00022 #include "internals.h"
00023 
00024 /* FIXME: These are just dummies.  I don't know why or if they're needed;
00025    configury should default to these definitions.  We just follow the
00026    crowd here.  */
00027 
00028 int
00029 __pthread_spin_lock (pthread_spinlock_t *lock)
00030 {
00031   while (testandset (lock) != 0)
00032     ;
00033 
00034   return 0;
00035 }
00036 weak_alias (__pthread_spin_lock, pthread_spin_lock)
00037 
00038 
00039 int
00040 __pthread_spin_trylock (pthread_spinlock_t *lock)
00041 {
00042   return testandset (lock) != 0 ? EBUSY : 0;
00043 }
00044 weak_alias (__pthread_spin_trylock, pthread_spin_trylock)
00045 
00046 
00047 int
00048 __pthread_spin_unlock (pthread_spinlock_t *lock)
00049 {
00050   return *lock = 0;
00051 }
00052 weak_alias (__pthread_spin_unlock, pthread_spin_unlock)
00053 
00054 
00055 int
00056 __pthread_spin_init (pthread_spinlock_t *lock, int pshared)
00057 {
00058   /* We can ignore the `pshared' parameter.  Since we are busy-waiting
00059      all processes which can access the memory location `lock' points
00060      to can use the spinlock.  */
00061   return *lock = 0;
00062 }
00063 weak_alias (__pthread_spin_init, pthread_spin_init)
00064 
00065 
00066 int
00067 __pthread_spin_destroy (pthread_spinlock_t *lock)
00068 {
00069   /* Nothing to do.  */
00070   return 0;
00071 }
00072 weak_alias (__pthread_spin_destroy, pthread_spin_destroy)