1 /* $NetBSD: sleepq.c,v 1.16 2014/04/24 12:04:28 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2008 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: sleepq.c,v 1.16 2014/04/24 12:04:28 pooka Exp $"); 30 31 #include <sys/param.h> 32 #include <sys/condvar.h> 33 #include <sys/mutex.h> 34 #include <sys/once.h> 35 #include <sys/queue.h> 36 #include <sys/sleepq.h> 37 #include <sys/syncobj.h> 38 #include <sys/atomic.h> 39 40 #include "rump_private.h" 41 42 syncobj_t sleep_syncobj; 43 static kcondvar_t sq_cv; 44 45 static int 46 sqinit1(void) 47 { 48 49 cv_init(&sq_cv, "sleepq"); 50 51 return 0; 52 } 53 54 void 55 sleepq_init(sleepq_t *sq) 56 { 57 static ONCE_DECL(sqctl); 58 59 RUN_ONCE(&sqctl, sqinit1); 60 61 TAILQ_INIT(sq); 62 } 63 64 void 65 sleepq_enqueue(sleepq_t *sq, wchan_t wc, const char *wmsg, syncobj_t *sob) 66 { 67 struct lwp *l = curlwp; 68 69 l->l_wchan = wc; 70 l->l_wmesg = wmsg; 71 l->l_sleepq = sq; 72 TAILQ_INSERT_TAIL(sq, l, l_sleepchain); 73 } 74 75 int 76 sleepq_block(int timo, bool catch) 77 { 78 struct lwp *l = curlwp; 79 int error = 0; 80 kmutex_t *mp = l->l_mutex; 81 int biglocks = l->l_biglocks; 82 83 while (l->l_wchan) { 84 l->l_mutex = mp; /* keep sleepq lock until woken up */ 85 error = cv_timedwait(&sq_cv, mp, timo); 86 if (error == EWOULDBLOCK || error == EINTR) { 87 if (l->l_wchan) { 88 TAILQ_REMOVE(l->l_sleepq, l, l_sleepchain); 89 l->l_wchan = NULL; 90 l->l_wmesg = NULL; 91 } 92 } 93 } 94 mutex_spin_exit(mp); 95 96 if (biglocks) 97 KERNEL_LOCK(biglocks, curlwp); 98 99 return error; 100 } 101 102 void 103 sleepq_wake(sleepq_t *sq, wchan_t wchan, u_int expected, kmutex_t *mp) 104 { 105 struct lwp *l, *l_next; 106 bool found = false; 107 108 for (l = TAILQ_FIRST(sq); l; l = l_next) { 109 l_next = TAILQ_NEXT(l, l_sleepchain); 110 if (l->l_wchan == wchan) { 111 found = true; 112 l->l_wchan = NULL; 113 l->l_wmesg = NULL; 114 TAILQ_REMOVE(sq, l, l_sleepchain); 115 if (--expected == 0) 116 break; 117 } 118 } 119 if (found) 120 cv_broadcast(&sq_cv); 121 122 mutex_spin_exit(mp); 123 } 124 125 void 126 sleepq_unsleep(struct lwp *l, bool cleanup) 127 { 128 129 l->l_wchan = NULL; 130 l->l_wmesg = NULL; 131 TAILQ_REMOVE(l->l_sleepq, l, l_sleepchain); 132 cv_broadcast(&sq_cv); 133 134 if (cleanup) { 135 mutex_spin_exit(l->l_mutex); 136 } 137 } 138 139 /* 140 * Thread scheduler handles priorities. Therefore no action here. 141 * (maybe do something if we're deperate?) 142 */ 143 void 144 sleepq_changepri(struct lwp *l, pri_t pri) 145 { 146 147 } 148 149 void 150 sleepq_lendpri(struct lwp *l, pri_t pri) 151 { 152 153 } 154 155 struct lwp * 156 syncobj_noowner(wchan_t wc) 157 { 158 159 return NULL; 160 } 161 162 void 163 lwp_unlock_to(struct lwp *l, kmutex_t *new) 164 { 165 kmutex_t *old; 166 167 KASSERT(mutex_owned(l->l_mutex)); 168 169 old = l->l_mutex; 170 membar_exit(); 171 l->l_mutex = new; 172 mutex_spin_exit(old); 173 } 174