1 /* $NetBSD: atomic_is_lock_free.c,v 1.3 2023/04/03 16:45:46 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2023 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __RCSID("$NetBSD: atomic_is_lock_free.c,v 1.3 2023/04/03 16:45:46 riastradh Exp $"); 31 32 #include <sys/types.h> 33 34 #include <sys/stdbool.h> 35 36 /* 37 * XXX Work around clang's built-in __atomic_is_lock_free by having the 38 * C name be different but using an asm rename to define the right 39 * symbol. 40 */ 41 bool __atomic_is_lock_free_hack(size_t, const volatile void *) 42 __RENAME(__atomic_is_lock_free); 43 #define __atomic_is_lock_free __atomic_is_lock_free_hack 44 45 bool 46 __atomic_is_lock_free(size_t n, const volatile void *p __unused) 47 { 48 49 switch (n) { 50 case 1: 51 return __atomic_always_lock_free(1, 0); 52 case 2: 53 return __atomic_always_lock_free(2, 0); 54 case 4: 55 return __atomic_always_lock_free(4, 0); 56 case 8: 57 return __atomic_always_lock_free(8, 0); 58 case 16: 59 return __atomic_always_lock_free(16, 0); 60 default: 61 return false; 62 } 63 } 64