1 /*- 2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $DragonFly: src/lib/libthread_xu/thread/thr_umtx.h,v 1.5 2008/04/14 20:12:41 dillon Exp $ 27 * $DragonFly: src/lib/libsysvipc/lock_generic.h,v 1 2013/09/20 Larisa Grigore<lariisagrigore@gmail.com> 28 */ 29 30 #ifndef _SYSV_DFLY_UMTX_H_ 31 #define _SYSV_DFLY_UMTX_H_ 32 33 #include <unistd.h> 34 #include <machine/atomic.h> 35 36 #define SYSV_TIMEOUT 4000 37 38 typedef int umtx_t; 39 40 int __sysv_umtx_lock(volatile umtx_t *mtx, int timo); 41 void __sysv_umtx_unlock(volatile umtx_t *mtx); 42 43 static inline void 44 _sysv_umtx_init(volatile umtx_t *mtx) 45 { 46 *mtx = 0; 47 } 48 49 static inline int 50 _sysv_umtx_lock(volatile umtx_t *mtx) 51 { 52 if (atomic_cmpset_acq_int(mtx, 0, 1)) 53 return (0); 54 return (__sysv_umtx_lock(mtx, 0)); 55 } 56 57 static inline void 58 _sysv_umtx_unlock(volatile umtx_t *mtx) 59 { 60 if (atomic_cmpset_acq_int(mtx, 1, 0)) 61 return; 62 __sysv_umtx_unlock(mtx); 63 } 64 65 #endif 66