/*****************************************************************************************
 Copyright (c) 2002-2004 The UbixOS Project
 All rights reserved.

 Redistribution and use in source and binary forms, with or without modification, are
 permitted provided that the following conditions are met:

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 conditions, the following disclaimer and the list of authors.  Redistributions in binary
 form must reproduce the above copyright notice, this list of conditions, the following
 disclaimer and the list of authors in the documentation and/or other materials provided
 with the distribution. Neither the name of the UbixOS Project nor the names of its
 contributors may be used to endorse or promote products derived from this software
 without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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 THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
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 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 $Id$

*****************************************************************************************/

#include <ubixos/spinlock.h>
#include <ubixos/sched.h>

void spinLockInit(spinLock_t *lock) {
  *lock = SPIN_LOCK_INITIALIZER;
  }

void spinUnlock(spinLock_t *lock) {
  *lock = 0x0;
  /*
  register int unlocked;
  asm volatile(
    "xchgl %0, %1"
    : "=&r" (unlocked), "=m" (*lock) : "0" (0)
    );
  */
  }

int spinTryLock(spinLock_t *lock) {
  register int locked;
  asm volatile("xchgl %0, %1"
    : "=&r" (locked), "=m" (*lock) : "0" (1)
    );
  return(!locked);
  }

void spinLock(spinLock_t *lock) {
  while (!spinTryLock(lock))
  {
    while (*lock == 1)
    	sched_yield();
  }
}

void spinLock_scheduler(spinLock_t *lock) {
  while (!spinTryLock(lock))
    while (*lock == 1);
  }


int spinLockLocked(spinLock_t *lock) {
  return(*lock != 0);
  }

 
/***
 $Log$
 Revision 1.13  2004/07/29 21:32:16  reddawg
 My quick lunchs breaks worth of updates....

 Revision 1.12  2004/07/28 22:35:24  reddawg
 ok couldn't resist last commit hopefully it doesnt cause any bugs but if it does
 in spinlock.c take the while (*lock == 1) schedYield(); and just make it
 while (*lock == 1); however I felt spining burns cpu time so if we yield it will
 run a new task should make stress a bit faster

 Revision 1.11  2004/07/21 17:11:18  reddawg
 A Quick tweak I'm going to clean up some unused variables in sched.h

 Revision 1.10  2004/07/20 21:17:05  reddawg
 CFLAGS: I updated cflags so optimizations are consistant on all files different optimization levels maybe the source of some of our problems?

 Revision 1.9  2004/07/20 20:25:57  reddawg
 Works perfectly here

 Revision 1.8  2004/07/20 20:20:19  reddawg
 spinlock: made them non inline functions I think this actually fixed the problem

 Revision 1.7  2004/07/18 05:24:15  reddawg
 Fixens

 Revision 1.6  2004/07/18 03:01:44  reddawg
 Few changes to spinlock hopefully it will cure our deadlock

 Revision 1.5  2004/07/17 16:43:10  reddawg
 shell: fixed stress testing
 ubistry: fixed some segfaults
 spinlock: added assert()

 Revision 1.4  2004/05/21 12:42:32  reddawg
 Cleaned Up

 Revision 1.3  2004/05/15 02:30:28  reddawg
 Lots of changes

 Revision 1.2  2004/05/02 14:34:21  reddawg
 SMP Support Thanks To Some Help From Slowcoder now to make it interface
 well with the rest of the kernel

 Revision 1.1  2004/05/02 03:19:51  reddawg
 Added Spinlock Provision For SMP

 END
 ***/