1/* 2 * Copyright 2010-2015 Samy Al Bahra. 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 27#ifndef CK_SPINLOCK_FAS_H 28#define CK_SPINLOCK_FAS_H 29 30#include <ck_backoff.h> 31#include <ck_cc.h> 32#include <ck_elide.h> 33#include <ck_pr.h> 34#include <ck_stdbool.h> 35 36#ifndef CK_F_SPINLOCK_FAS 37#define CK_F_SPINLOCK_FAS 38 39struct ck_spinlock_fas { 40 unsigned int value; 41}; 42typedef struct ck_spinlock_fas ck_spinlock_fas_t; 43 44#define CK_SPINLOCK_FAS_INITIALIZER {false} 45 46CK_CC_INLINE static void 47ck_spinlock_fas_init(struct ck_spinlock_fas *lock) 48{ 49 50 lock->value = false; 51 ck_pr_barrier(); 52 return; 53} 54 55CK_CC_INLINE static bool 56ck_spinlock_fas_trylock(struct ck_spinlock_fas *lock) 57{ 58 bool value; 59 60 value = ck_pr_fas_uint(&lock->value, true); 61 ck_pr_fence_lock(); 62 63 return !value; 64} 65 66CK_CC_INLINE static bool 67ck_spinlock_fas_locked(struct ck_spinlock_fas *lock) 68{ 69 bool r; 70 71 r = ck_pr_load_uint(&lock->value); 72 ck_pr_fence_acquire(); 73 return r; 74} 75 76CK_CC_INLINE static void 77ck_spinlock_fas_lock(struct ck_spinlock_fas *lock) 78{ 79 80 while (ck_pr_fas_uint(&lock->value, true) == true) { 81 while (ck_pr_load_uint(&lock->value) == true) 82 ck_pr_stall(); 83 } 84 85 ck_pr_fence_lock(); 86 return; 87} 88 89CK_CC_INLINE static void 90ck_spinlock_fas_lock_eb(struct ck_spinlock_fas *lock) 91{ 92 ck_backoff_t backoff = CK_BACKOFF_INITIALIZER; 93 94 while (ck_pr_fas_uint(&lock->value, true) == true) 95 ck_backoff_eb(&backoff); 96 97 ck_pr_fence_lock(); 98 return; 99} 100 101CK_CC_INLINE static void 102ck_spinlock_fas_unlock(struct ck_spinlock_fas *lock) 103{ 104 105 ck_pr_fence_unlock(); 106 ck_pr_store_uint(&lock->value, false); 107 return; 108} 109 110CK_ELIDE_PROTOTYPE(ck_spinlock_fas, ck_spinlock_fas_t, 111 ck_spinlock_fas_locked, ck_spinlock_fas_lock, 112 ck_spinlock_fas_locked, ck_spinlock_fas_unlock) 113 114CK_ELIDE_TRYLOCK_PROTOTYPE(ck_spinlock_fas, ck_spinlock_fas_t, 115 ck_spinlock_fas_locked, ck_spinlock_fas_trylock) 116 117#endif /* CK_F_SPINLOCK_FAS */ 118#endif /* CK_SPINLOCK_FAS_H */ 119