asolock.c revision 3f54fd611f536639ec30dd53c48e5ec1897cc7d9
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2011 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
#include "asohdr.h"
#if defined(_UWIN) && defined(_BLD_ast)
NoN(asolock)
#else
int
asolock(unsigned int volatile* lock, unsigned int key, int type)
{
unsigned int k;
if (key)
switch (type)
{
case ASO_UNLOCK:
return *lock == 0 ? 0 : asocasint(lock, key, 0) == key ? 0 : -1;
case ASO_TRYLOCK:
return *lock == key ? 0 : asocasint(lock, 0, key) == 0 ? 0 : -1;
case ASO_LOCK:
if (*lock == key)
return 0;
/*FALLTHROUGH*/
case ASO_SPINLOCK:
for (k = 0; asocasint(lock, 0, key) != 0; ASOLOOP(k));
return 0;
}
return -1;
}
#endif