1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 23*0Sstevel@tonic-gate /* All Rights Reserved */ 24*0Sstevel@tonic-gate 25*0Sstevel@tonic-gate 26*0Sstevel@tonic-gate /* 27*0Sstevel@tonic-gate * Copyright (c) 1997-1998 by Sun Microsystems, Inc. 28*0Sstevel@tonic-gate * All rights reserved. 29*0Sstevel@tonic-gate */ 30*0Sstevel@tonic-gate 31*0Sstevel@tonic-gate #ifndef _SYS_CALLO_H 32*0Sstevel@tonic-gate #define _SYS_CALLO_H 33*0Sstevel@tonic-gate 34*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 35*0Sstevel@tonic-gate 36*0Sstevel@tonic-gate #include <sys/t_lock.h> 37*0Sstevel@tonic-gate #include <sys/taskq.h> 38*0Sstevel@tonic-gate 39*0Sstevel@tonic-gate #ifdef __cplusplus 40*0Sstevel@tonic-gate extern "C" { 41*0Sstevel@tonic-gate #endif 42*0Sstevel@tonic-gate 43*0Sstevel@tonic-gate typedef long callout_id_t; /* internal form of timeout_id_t */ 44*0Sstevel@tonic-gate 45*0Sstevel@tonic-gate /* 46*0Sstevel@tonic-gate * The callout mechanism provides general-purpose event scheduling: 47*0Sstevel@tonic-gate * an arbitrary function is called in a specified amount of time. 48*0Sstevel@tonic-gate */ 49*0Sstevel@tonic-gate typedef struct callout { 50*0Sstevel@tonic-gate struct callout *c_idnext; /* next in ID hash, or on freelist */ 51*0Sstevel@tonic-gate struct callout *c_idprev; /* prev in ID hash */ 52*0Sstevel@tonic-gate struct callout *c_lbnext; /* next in lbolt hash */ 53*0Sstevel@tonic-gate struct callout *c_lbprev; /* prev in lbolt hash */ 54*0Sstevel@tonic-gate callout_id_t c_xid; /* extended callout ID; see below */ 55*0Sstevel@tonic-gate clock_t c_runtime; /* absolute run time */ 56*0Sstevel@tonic-gate void (*c_func)(void *); /* function to call */ 57*0Sstevel@tonic-gate void *c_arg; /* argument to function */ 58*0Sstevel@tonic-gate kthread_id_t c_executor; /* thread executing callout */ 59*0Sstevel@tonic-gate kcondvar_t c_done; /* signal callout completion */ 60*0Sstevel@tonic-gate } callout_t; 61*0Sstevel@tonic-gate 62*0Sstevel@tonic-gate /* 63*0Sstevel@tonic-gate * The extended callout ID consists of the callout ID (as returned by 64*0Sstevel@tonic-gate * timeout()) plus a bit indicating whether the callout is executing. 65*0Sstevel@tonic-gate * 66*0Sstevel@tonic-gate * The callout ID uniquely identifies a callout. It contains a table ID, 67*0Sstevel@tonic-gate * indicating which callout table the callout belongs to, a bit indicating 68*0Sstevel@tonic-gate * whether this is a short-term or long-term callout, and a running counter. 69*0Sstevel@tonic-gate * The highest bit of the running counter is always set; this ensures that 70*0Sstevel@tonic-gate * the callout ID is always non-zero, thus eliminating the need for an 71*0Sstevel@tonic-gate * explicit wrap-around test during ID generation. 72*0Sstevel@tonic-gate * 73*0Sstevel@tonic-gate * The long-term bit exists to address the problem of callout ID collision. 74*0Sstevel@tonic-gate * This is an issue because the system typically generates a large number of 75*0Sstevel@tonic-gate * timeout() requests, which means that callout IDs eventually get recycled. 76*0Sstevel@tonic-gate * Most timeouts are very short-lived, so that ID recycling isn't a problem; 77*0Sstevel@tonic-gate * but there are a handful of timeouts which are sufficiently long-lived to 78*0Sstevel@tonic-gate * see their own IDs reused. We use the long-term bit to partition the 79*0Sstevel@tonic-gate * ID namespace into pieces; the short-term space gets all the heavy traffic 80*0Sstevel@tonic-gate * and can wrap frequently (i.e., on the order of a day) with no ill effects; 81*0Sstevel@tonic-gate * the long-term space gets very little traffic and thus never wraps. 82*0Sstevel@tonic-gate */ 83*0Sstevel@tonic-gate #define CALLOUT_EXECUTING (1UL << (8 * sizeof (long) - 1)) 84*0Sstevel@tonic-gate #define CALLOUT_LONGTERM (1UL << (8 * sizeof (long) - 2)) 85*0Sstevel@tonic-gate #define CALLOUT_COUNTER_HIGH (1UL << (8 * sizeof (long) - 3)) 86*0Sstevel@tonic-gate #define CALLOUT_FANOUT_BITS 3 87*0Sstevel@tonic-gate #define CALLOUT_TYPE_BITS 1 88*0Sstevel@tonic-gate #define CALLOUT_NTYPES (1 << CALLOUT_TYPE_BITS) 89*0Sstevel@tonic-gate #define CALLOUT_FANOUT (1 << CALLOUT_FANOUT_BITS) 90*0Sstevel@tonic-gate #define CALLOUT_FANOUT_MASK (CALLOUT_FANOUT - 1) 91*0Sstevel@tonic-gate #define CALLOUT_COUNTER_SHIFT (CALLOUT_TYPE_BITS + CALLOUT_FANOUT_BITS) 92*0Sstevel@tonic-gate #define CALLOUT_COUNTER_LOW (1 << CALLOUT_COUNTER_SHIFT) 93*0Sstevel@tonic-gate #define CALLOUT_TABLES CALLOUT_COUNTER_LOW 94*0Sstevel@tonic-gate #define CALLOUT_TABLE_MASK (CALLOUT_TABLES - 1) 95*0Sstevel@tonic-gate #define CALLOUT_TABLE(t, f) \ 96*0Sstevel@tonic-gate (((t) << CALLOUT_FANOUT_BITS) + ((f) & CALLOUT_FANOUT_MASK)) 97*0Sstevel@tonic-gate 98*0Sstevel@tonic-gate /* 99*0Sstevel@tonic-gate * We assume that during any period of CALLOUT_LONGTERM_TICKS ticks, at most 100*0Sstevel@tonic-gate * (CALLOUT_COUNTER_HIGH / CALLOUT_COUNTER_LOW) callouts will be generated. 101*0Sstevel@tonic-gate */ 102*0Sstevel@tonic-gate #define CALLOUT_LONGTERM_TICKS 0x4000 103*0Sstevel@tonic-gate #define CALLOUT_BUCKETS 512 /* MUST be a power of 2 */ 104*0Sstevel@tonic-gate #define CALLOUT_BUCKET_MASK (CALLOUT_BUCKETS - 1) 105*0Sstevel@tonic-gate #define CALLOUT_HASH(x) ((x) & CALLOUT_BUCKET_MASK) 106*0Sstevel@tonic-gate #define CALLOUT_IDHASH(x) CALLOUT_HASH((x) >> CALLOUT_COUNTER_SHIFT) 107*0Sstevel@tonic-gate #define CALLOUT_LBHASH(x) CALLOUT_HASH(x) 108*0Sstevel@tonic-gate 109*0Sstevel@tonic-gate #define CALLOUT_THREADS 2 /* keep it simple for now */ 110*0Sstevel@tonic-gate 111*0Sstevel@tonic-gate #define CALLOUT_REALTIME 0 /* realtime callout type */ 112*0Sstevel@tonic-gate #define CALLOUT_NORMAL 1 /* normal callout type */ 113*0Sstevel@tonic-gate 114*0Sstevel@tonic-gate /* 115*0Sstevel@tonic-gate * All of the state information associated with a callout table. 116*0Sstevel@tonic-gate * The fields are ordered with cache performance in mind. 117*0Sstevel@tonic-gate */ 118*0Sstevel@tonic-gate typedef struct callout_table { 119*0Sstevel@tonic-gate kmutex_t ct_lock; /* protects all callout state */ 120*0Sstevel@tonic-gate callout_t *ct_freelist; /* free callout structures */ 121*0Sstevel@tonic-gate clock_t ct_curtime; /* current time; tracks lbolt */ 122*0Sstevel@tonic-gate clock_t ct_runtime; /* the callouts we're running now */ 123*0Sstevel@tonic-gate taskq_t *ct_taskq; /* taskq to execute normal callouts */ 124*0Sstevel@tonic-gate callout_id_t ct_short_id; /* most recently issued short-term ID */ 125*0Sstevel@tonic-gate callout_id_t ct_long_id; /* most recently issued long-term ID */ 126*0Sstevel@tonic-gate callout_t *ct_idhash[CALLOUT_BUCKETS]; /* ID hash chains */ 127*0Sstevel@tonic-gate callout_t *ct_lbhash[CALLOUT_BUCKETS]; /* lbolt hash chains */ 128*0Sstevel@tonic-gate } callout_table_t; 129*0Sstevel@tonic-gate 130*0Sstevel@tonic-gate #ifdef _KERNEL 131*0Sstevel@tonic-gate extern void callout_init(void); 132*0Sstevel@tonic-gate extern void callout_schedule(void); 133*0Sstevel@tonic-gate #endif 134*0Sstevel@tonic-gate 135*0Sstevel@tonic-gate #ifdef __cplusplus 136*0Sstevel@tonic-gate } 137*0Sstevel@tonic-gate #endif 138*0Sstevel@tonic-gate 139*0Sstevel@tonic-gate #endif /* _SYS_CALLO_H */ 140