1 /* $NetBSD: pgfs_waitq.c,v 1.1 2011/10/12 01:05:00 yamt Exp $ */ 2 3 /*- 4 * Copyright (c)2010,2011 YAMAMOTO Takashi, 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 AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * a dumb wait queue on puffs_cc 31 */ 32 33 #include <sys/cdefs.h> 34 #ifndef lint 35 __RCSID("$NetBSD: pgfs_waitq.c,v 1.1 2011/10/12 01:05:00 yamt Exp $"); 36 #endif /* not lint */ 37 38 #include <assert.h> 39 #include <puffs.h> 40 41 #include "pgfs_waitq.h" 42 #include "pgfs_debug.h" 43 44 struct waiter { 45 TAILQ_ENTRY(waiter) list; 46 struct puffs_cc *cc; 47 }; 48 49 void 50 waitq_init(struct waitq *wq) 51 { 52 53 TAILQ_INIT(wq); 54 } 55 56 void 57 waiton(struct waitq *wq, struct puffs_cc *cc) 58 { 59 struct waiter w; 60 61 /* 62 * insert to the tail of the queue. 63 * some users rely on the FIFO behaviour. 64 */ 65 w.cc = cc; 66 TAILQ_INSERT_TAIL(wq, &w, list); 67 puffs_cc_yield(cc); 68 } 69 70 struct puffs_cc * 71 wakeup_one(struct waitq *wq) 72 { 73 74 struct waiter *w; 75 76 w = TAILQ_FIRST(wq); 77 if (w != NULL) { 78 TAILQ_REMOVE(wq, w, list); 79 puffs_cc_schedule(w->cc); 80 DPRINTF("waking up %p\n", w->cc); 81 return w->cc; 82 } 83 return NULL; 84 } 85 86 #if 0 87 static void 88 wakeup(struct waitq *wq) 89 { 90 91 struct waiter *w; 92 93 TAILQ_FOREACH(w, wq, list) { 94 puffs_cc_schedule(w->cc); 95 DPRINTF("waking up %p\n", w->cc); 96 } 97 TAILQ_INIT(wq); 98 } 99 #endif 100