1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 .file "_lwp_mutex_unlock.s" 28 29#include "SYS.h" 30#include <../assym.h> 31 32 ENTRY(_lwp_mutex_unlock) 33 membar #LoadStore|#StoreStore 34 add %o0, MUTEX_LOCK_WORD, %o1 35 ld [%o1], %o2 361: 37 clr %o3 ! clear lock/get waiter field 38 cas [%o1], %o2, %o3 ! atomically 39 cmp %o2, %o3 40 bne,a,pn %icc, 1b 41 mov %o3, %o2 42 btst WAITER_MASK, %o3 ! check for waiters 43 beq,a,pt %icc,2f ! if no waiters 44 clr %o0 ! return 0 45 ! else (note that %o0 is still 46 ! &mutex) 47 clr %o1 ! call kernel to wakeup waiter: 48 SYSTRAP_RVAL1(lwp_mutex_wakeup) ! lwp_mutex_wakeup(mp, 0) 49 SYSLWPERR 502: RET 51 SET_SIZE(_lwp_mutex_unlock) 52