1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2012 AT&T Intellectual Property * 5 * and is licensed under the * 6 * Eclipse Public License, Version 1.0 * 7 * by AT&T Intellectual Property * 8 * * 9 * A copy of the License is available at * 10 * http://www.eclipse.org/org/documents/epl-v10.html * 11 * (with md5 checksum b35adb5213ca9657e911e9befb180842) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * Phong Vo <kpv@research.att.com> * 20 * * 21 ***********************************************************************/ 22 #pragma prototyped 23 24 #include <aso.h> 25 26 int 27 asolock(unsigned int volatile* lock, unsigned int key, int type) 28 { 29 unsigned int k; 30 31 if (key) 32 switch (type) 33 { 34 case ASO_UNLOCK: 35 if (*lock != 0) 36 { 37 if (*lock != key) 38 return -1; 39 *lock = 0; 40 } 41 return 0; 42 case ASO_TRYLOCK: 43 if (*lock != key) 44 { 45 if (*lock != 0) 46 return -1; 47 *lock = key; 48 } 49 return 0; 50 case ASO_LOCK: 51 case ASO_SPINLOCK: 52 *lock = key; 53 return 0; 54 } 55 return -1; 56 } 57