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 #ifndef _SYS_CONDVAR_IMPL_H 28 #define _SYS_CONDVAR_IMPL_H 29 30 /* 31 * Implementation-private definitions for condition variables 32 */ 33 34 #ifndef _ASM 35 #include <sys/types.h> 36 #include <sys/thread.h> 37 #endif /* _ASM */ 38 39 #ifdef __cplusplus 40 extern "C" { 41 #endif 42 43 #ifndef _ASM 44 45 /* 46 * Condtion variables. 47 */ 48 49 typedef struct _condvar_impl { 50 ushort_t cv_waiters; 51 } condvar_impl_t; 52 53 #define CV_HAS_WAITERS(cvp) (((condvar_impl_t *)(cvp))->cv_waiters != 0) 54 55 #endif /* _ASM */ 56 57 58 typedef struct cvwaitlock_s { 59 kmutex_t cvw_lock; 60 kcondvar_t cvw_waiter; 61 int cvw_refcnt; 62 } cvwaitlock_t; 63 64 65 #define CVW_INIT(_c) { \ 66 mutex_init(&(_c)->cvw_lock, NULL, MUTEX_DRIVER, NULL); \ 67 cv_init(&(_c)->cvw_waiter, NULL, CV_DRIVER, NULL); \ 68 (_c)->cvw_refcnt = 0; \ 69 } 70 71 #define CVW_ENTER_READ(_c) { \ 72 mutex_enter(&(_c)->cvw_lock); \ 73 while ((_c)->cvw_refcnt < 0) \ 74 cv_wait(&((_c)->cvw_waiter), &(_c)->cvw_lock); \ 75 (_c)->cvw_refcnt++; \ 76 mutex_exit(&(_c)->cvw_lock); \ 77 } 78 79 #define CVW_ENTER_WRITE(_c) { \ 80 mutex_enter(&(_c)->cvw_lock); \ 81 while ((_c)->cvw_refcnt != 0) \ 82 cv_wait(&((_c)->cvw_waiter), &(_c)->cvw_lock); \ 83 (_c)->cvw_refcnt = -1; \ 84 mutex_exit(&(_c)->cvw_lock); \ 85 } 86 87 #define CVW_EXIT_READ(_c) { \ 88 mutex_enter(&(_c)->cvw_lock); \ 89 ASSERT((_c)->cvw_refcnt > 0); \ 90 if ((--((_c)->cvw_refcnt)) == 0) \ 91 cv_broadcast(&(_c)->cvw_waiter); \ 92 mutex_exit(&(_c)->cvw_lock); \ 93 } 94 95 #define CVW_EXIT_WRITE(_c) { \ 96 mutex_enter(&(_c)->cvw_lock); \ 97 ASSERT((_c)->cvw_refcnt == -1); \ 98 (_c)->cvw_refcnt = 0; \ 99 cv_broadcast(&(_c)->cvw_waiter); \ 100 mutex_exit(&(_c)->cvw_lock); \ 101 } 102 103 #define CVW_WRITE_TO_READ(_c) { \ 104 mutex_enter(&(_c)->cvw_lock); \ 105 ASSERT((_c)->cvw_refcnt == -1); \ 106 (_c)->cvw_refcnt = 1; \ 107 cv_broadcast(&(_c)->cvw_waiter); \ 108 mutex_exit(&(_c)->cvw_lock); \ 109 } 110 111 #define CVW_DESTROY(_c) { \ 112 mutex_destroy(&(_c)->cvw_lock); \ 113 cv_destroy(&(_c)->cvw_waiter); \ 114 } 115 116 #ifdef __cplusplus 117 } 118 #endif 119 120 #endif /* _SYS_CONDVAR_IMPL_H */ 121