1 /*- 2 * Copyright (c) 2005 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 */ 27 28 #ifndef _THR_DFLY_UMTX_H_ 29 #define _THR_DFLY_UMTX_H_ 30 31 #include <unistd.h> 32 33 #define cpu_pause() __asm __volatile("pause":::"memory") 34 35 typedef int umtx_t; 36 37 int __thr_umtx_lock(volatile umtx_t *mtx, int id, int timo); 38 int __thr_umtx_timedlock(volatile umtx_t *mtx, int id, 39 const struct timespec *timeout); 40 void __thr_umtx_unlock(volatile umtx_t *mtx, int v, int id); 41 42 static inline void 43 _thr_umtx_init(volatile umtx_t *mtx) 44 { 45 *mtx = 0; 46 } 47 48 static inline int 49 _thr_umtx_trylock(volatile umtx_t *mtx, int id, int temporary) 50 { 51 if (temporary) 52 sigblockall(); 53 if (atomic_cmpset_acq_int(mtx, 0, id)) 54 return (0); 55 cpu_pause(); 56 if (atomic_cmpset_acq_int(mtx, 0, id)) 57 return (0); 58 cpu_pause(); 59 if (atomic_cmpset_acq_int(mtx, 0, id)) 60 return (0); 61 if (temporary) 62 sigunblockall(); 63 return (EBUSY); 64 } 65 66 static inline int 67 _thr_umtx_lock(volatile umtx_t *mtx, int id, int temporary) 68 { 69 int res; 70 71 if (temporary) 72 sigblockall(); 73 if (atomic_cmpset_acq_int(mtx, 0, id)) 74 return (0); 75 res = __thr_umtx_lock(mtx, id, 0); 76 if (res && temporary) 77 sigunblockall(); 78 return res; 79 } 80 81 static inline int 82 _thr_umtx_timedlock(volatile umtx_t *mtx, int id, 83 const struct timespec *timeout, int temporary) 84 { 85 int res; 86 87 if (temporary) 88 sigblockall(); 89 if (atomic_cmpset_acq_int(mtx, 0, id)) { 90 return (0); 91 } 92 res = __thr_umtx_timedlock(mtx, id, timeout); 93 if (res && temporary) 94 sigunblockall(); 95 return res; 96 } 97 98 static inline void 99 _thr_umtx_unlock(volatile umtx_t *mtx, int id, int temporary) 100 { 101 int v; 102 103 v = atomic_swap_int(mtx, 0); 104 if (v != id) 105 __thr_umtx_unlock(mtx, v, id); 106 if (temporary) 107 sigunblockall(); 108 } 109 110 int _thr_umtx_wait(volatile umtx_t *mtx, umtx_t exp, 111 const struct timespec *timeout, int clockid); 112 int _thr_umtx_wait_intr(volatile umtx_t *mtx, umtx_t exp); 113 void _thr_umtx_wake(volatile umtx_t *mtx, int count); 114 #endif 115