1 /* 2 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. 3 * Copyright (C) 2007 The Regents of the University of California. 4 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). 5 * Written by Brian Behlendorf <behlendorf1@llnl.gov>. 6 * UCRL-CODE-235197 7 * 8 * This file is part of the SPL, Solaris Porting Layer. 9 * 10 * The SPL is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the 12 * Free Software Foundation; either version 2 of the License, or (at your 13 * option) any later version. 14 * 15 * The SPL is distributed in the hope that it will be useful, but WITHOUT 16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 18 * for more details. 19 * 20 * You should have received a copy of the GNU General Public License along 21 * with the SPL. If not, see <http://www.gnu.org/licenses/>. 22 */ 23 24 #ifndef _SPL_CONDVAR_H 25 #define _SPL_CONDVAR_H 26 27 #include <linux/module.h> 28 #include <sys/kmem.h> 29 #include <sys/mutex.h> 30 #include <sys/callo.h> 31 #include <sys/wait.h> 32 #include <sys/time.h> 33 34 /* 35 * cv_timedwait() is similar to cv_wait() except that it additionally expects 36 * a timeout value specified in ticks. When woken by cv_signal() or 37 * cv_broadcast() it returns 1, otherwise when the timeout is reached -1 is 38 * returned. 39 * 40 * cv_timedwait_sig() behaves the same as cv_timedwait() but blocks 41 * interruptibly and can be woken by a signal (EINTR, ERESTART). When 42 * this occurs 0 is returned. 43 * 44 * cv_timedwait_io() and cv_timedwait_sig_io() are variants of cv_timedwait() 45 * and cv_timedwait_sig() which should be used when waiting for outstanding 46 * IO to complete. They are responsible for updating the iowait accounting 47 * when this is supported by the platform. 48 * 49 * cv_timedwait_hires() and cv_timedwait_sig_hires() are high resolution 50 * versions of cv_timedwait() and cv_timedwait_sig(). They expect the timeout 51 * to be specified as a hrtime_t allowing for timeouts of less than a tick. 52 * 53 * N.B. The return values differ slightly from the illumos implementation 54 * which returns the time remaining, instead of 1, when woken. They both 55 * return -1 on timeout. Consumers which need to know the time remaining 56 * are responsible for tracking it themselves. 57 */ 58 59 60 /* 61 * The kcondvar_t struct is protected by mutex taken externally before 62 * calling any of the wait/signal funs, and passed into the wait funs. 63 */ 64 #define CV_MAGIC 0x346545f4 65 #define CV_DESTROY 0x346545f5 66 67 typedef struct { 68 int cv_magic; 69 wait_queue_head_t cv_event; 70 wait_queue_head_t cv_destroy; 71 atomic_t cv_refs; 72 atomic_t cv_waiters; 73 kmutex_t *cv_mutex; 74 } kcondvar_t; 75 76 typedef enum { CV_DEFAULT = 0, CV_DRIVER } kcv_type_t; 77 78 extern void __cv_init(kcondvar_t *, char *, kcv_type_t, void *); 79 extern void __cv_destroy(kcondvar_t *); 80 extern void __cv_wait(kcondvar_t *, kmutex_t *); 81 extern void __cv_wait_io(kcondvar_t *, kmutex_t *); 82 extern void __cv_wait_idle(kcondvar_t *, kmutex_t *); 83 extern int __cv_wait_io_sig(kcondvar_t *, kmutex_t *); 84 extern int __cv_wait_sig(kcondvar_t *, kmutex_t *); 85 extern int __cv_timedwait(kcondvar_t *, kmutex_t *, clock_t); 86 extern int __cv_timedwait_io(kcondvar_t *, kmutex_t *, clock_t); 87 extern int __cv_timedwait_sig(kcondvar_t *, kmutex_t *, clock_t); 88 extern int __cv_timedwait_idle(kcondvar_t *, kmutex_t *, clock_t); 89 extern int cv_timedwait_hires(kcondvar_t *, kmutex_t *, hrtime_t, 90 hrtime_t res, int flag); 91 extern int cv_timedwait_sig_hires(kcondvar_t *, kmutex_t *, hrtime_t, 92 hrtime_t res, int flag); 93 extern int cv_timedwait_idle_hires(kcondvar_t *, kmutex_t *, hrtime_t, 94 hrtime_t res, int flag); 95 extern void __cv_signal(kcondvar_t *); 96 extern void __cv_broadcast(kcondvar_t *c); 97 98 #define cv_init(cvp, name, type, arg) __cv_init(cvp, name, type, arg) 99 #define cv_destroy(cvp) __cv_destroy(cvp) 100 #define cv_wait(cvp, mp) __cv_wait(cvp, mp) 101 #define cv_wait_io(cvp, mp) __cv_wait_io(cvp, mp) 102 #define cv_wait_idle(cvp, mp) __cv_wait_idle(cvp, mp) 103 #define cv_wait_io_sig(cvp, mp) __cv_wait_io_sig(cvp, mp) 104 #define cv_wait_sig(cvp, mp) __cv_wait_sig(cvp, mp) 105 #define cv_signal(cvp) __cv_signal(cvp) 106 #define cv_broadcast(cvp) __cv_broadcast(cvp) 107 108 /* 109 * NB: There is no way to reliably distinguish between having been signalled 110 * and having timed out on Linux. If the client code needs to reliably 111 * distinguish between the two it should use the hires variant. 112 */ 113 #define cv_timedwait(cvp, mp, t) __cv_timedwait(cvp, mp, t) 114 #define cv_timedwait_io(cvp, mp, t) __cv_timedwait_io(cvp, mp, t) 115 #define cv_timedwait_sig(cvp, mp, t) __cv_timedwait_sig(cvp, mp, t) 116 #define cv_timedwait_idle(cvp, mp, t) __cv_timedwait_idle(cvp, mp, t) 117 118 119 #endif /* _SPL_CONDVAR_H */ 120