17c478bd9Sstevel@tonic-gate /* 27c478bd9Sstevel@tonic-gate * CDDL HEADER START 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 52db6c79fSstevel * Common Development and Distribution License (the "License"). 62db6c79fSstevel * You may not use this file except in compliance with the License. 77c478bd9Sstevel@tonic-gate * 87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 117c478bd9Sstevel@tonic-gate * and limitations under the License. 127c478bd9Sstevel@tonic-gate * 137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 187c478bd9Sstevel@tonic-gate * 197c478bd9Sstevel@tonic-gate * CDDL HEADER END 207c478bd9Sstevel@tonic-gate */ 21*a574db85Sraf 227c478bd9Sstevel@tonic-gate /* 23*a574db85Sraf * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 247c478bd9Sstevel@tonic-gate * Use is subject to license terms. 257c478bd9Sstevel@tonic-gate */ 267c478bd9Sstevel@tonic-gate 277c478bd9Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 287c478bd9Sstevel@tonic-gate 297c478bd9Sstevel@tonic-gate #include <sys/thread.h> 307c478bd9Sstevel@tonic-gate #include <sys/proc.h> 317c478bd9Sstevel@tonic-gate #include <sys/debug.h> 327c478bd9Sstevel@tonic-gate #include <sys/cmn_err.h> 337c478bd9Sstevel@tonic-gate #include <sys/systm.h> 347c478bd9Sstevel@tonic-gate #include <sys/sobject.h> 357c478bd9Sstevel@tonic-gate #include <sys/sleepq.h> 367c478bd9Sstevel@tonic-gate #include <sys/cpuvar.h> 377c478bd9Sstevel@tonic-gate #include <sys/condvar.h> 387c478bd9Sstevel@tonic-gate #include <sys/condvar_impl.h> 397c478bd9Sstevel@tonic-gate #include <sys/schedctl.h> 407c478bd9Sstevel@tonic-gate #include <sys/procfs.h> 417c478bd9Sstevel@tonic-gate #include <sys/sdt.h> 427c478bd9Sstevel@tonic-gate 437c478bd9Sstevel@tonic-gate /* 447c478bd9Sstevel@tonic-gate * CV_MAX_WAITERS is the maximum number of waiters we track; once 457c478bd9Sstevel@tonic-gate * the number becomes higher than that, we look at the sleepq to 467c478bd9Sstevel@tonic-gate * see whether there are *really* any waiters. 477c478bd9Sstevel@tonic-gate */ 487c478bd9Sstevel@tonic-gate #define CV_MAX_WAITERS 1024 /* must be power of 2 */ 497c478bd9Sstevel@tonic-gate #define CV_WAITERS_MASK (CV_MAX_WAITERS - 1) 507c478bd9Sstevel@tonic-gate 517c478bd9Sstevel@tonic-gate /* 527c478bd9Sstevel@tonic-gate * Threads don't "own" condition variables. 537c478bd9Sstevel@tonic-gate */ 547c478bd9Sstevel@tonic-gate /* ARGSUSED */ 557c478bd9Sstevel@tonic-gate static kthread_t * 567c478bd9Sstevel@tonic-gate cv_owner(void *cvp) 577c478bd9Sstevel@tonic-gate { 587c478bd9Sstevel@tonic-gate return (NULL); 597c478bd9Sstevel@tonic-gate } 607c478bd9Sstevel@tonic-gate 617c478bd9Sstevel@tonic-gate /* 627c478bd9Sstevel@tonic-gate * Unsleep a thread that's blocked on a condition variable. 637c478bd9Sstevel@tonic-gate */ 647c478bd9Sstevel@tonic-gate static void 657c478bd9Sstevel@tonic-gate cv_unsleep(kthread_t *t) 667c478bd9Sstevel@tonic-gate { 677c478bd9Sstevel@tonic-gate condvar_impl_t *cvp = (condvar_impl_t *)t->t_wchan; 687c478bd9Sstevel@tonic-gate sleepq_head_t *sqh = SQHASH(cvp); 697c478bd9Sstevel@tonic-gate 707c478bd9Sstevel@tonic-gate ASSERT(THREAD_LOCK_HELD(t)); 717c478bd9Sstevel@tonic-gate 727c478bd9Sstevel@tonic-gate if (cvp == NULL) 737c478bd9Sstevel@tonic-gate panic("cv_unsleep: thread %p not on sleepq %p", t, sqh); 742db6c79fSstevel DTRACE_SCHED1(wakeup, kthread_t *, t); 757c478bd9Sstevel@tonic-gate sleepq_unsleep(t); 767c478bd9Sstevel@tonic-gate if (cvp->cv_waiters != CV_MAX_WAITERS) 777c478bd9Sstevel@tonic-gate cvp->cv_waiters--; 787c478bd9Sstevel@tonic-gate disp_lock_exit_high(&sqh->sq_lock); 797c478bd9Sstevel@tonic-gate CL_SETRUN(t); 807c478bd9Sstevel@tonic-gate } 817c478bd9Sstevel@tonic-gate 827c478bd9Sstevel@tonic-gate /* 837c478bd9Sstevel@tonic-gate * Change the priority of a thread that's blocked on a condition variable. 847c478bd9Sstevel@tonic-gate */ 857c478bd9Sstevel@tonic-gate static void 867c478bd9Sstevel@tonic-gate cv_change_pri(kthread_t *t, pri_t pri, pri_t *t_prip) 877c478bd9Sstevel@tonic-gate { 887c478bd9Sstevel@tonic-gate condvar_impl_t *cvp = (condvar_impl_t *)t->t_wchan; 897c478bd9Sstevel@tonic-gate sleepq_t *sqp = t->t_sleepq; 907c478bd9Sstevel@tonic-gate 917c478bd9Sstevel@tonic-gate ASSERT(THREAD_LOCK_HELD(t)); 927c478bd9Sstevel@tonic-gate ASSERT(&SQHASH(cvp)->sq_queue == sqp); 937c478bd9Sstevel@tonic-gate 947c478bd9Sstevel@tonic-gate if (cvp == NULL) 957c478bd9Sstevel@tonic-gate panic("cv_change_pri: %p not on sleep queue", t); 967c478bd9Sstevel@tonic-gate sleepq_dequeue(t); 977c478bd9Sstevel@tonic-gate *t_prip = pri; 987c478bd9Sstevel@tonic-gate sleepq_insert(sqp, t); 997c478bd9Sstevel@tonic-gate } 1007c478bd9Sstevel@tonic-gate 1017c478bd9Sstevel@tonic-gate /* 1027c478bd9Sstevel@tonic-gate * The sobj_ops vector exports a set of functions needed when a thread 1037c478bd9Sstevel@tonic-gate * is asleep on a synchronization object of this type. 1047c478bd9Sstevel@tonic-gate */ 1057c478bd9Sstevel@tonic-gate static sobj_ops_t cv_sobj_ops = { 1067c478bd9Sstevel@tonic-gate SOBJ_CV, cv_owner, cv_unsleep, cv_change_pri 1077c478bd9Sstevel@tonic-gate }; 1087c478bd9Sstevel@tonic-gate 1097c478bd9Sstevel@tonic-gate /* ARGSUSED */ 1107c478bd9Sstevel@tonic-gate void 1117c478bd9Sstevel@tonic-gate cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg) 1127c478bd9Sstevel@tonic-gate { 1137c478bd9Sstevel@tonic-gate ((condvar_impl_t *)cvp)->cv_waiters = 0; 1147c478bd9Sstevel@tonic-gate } 1157c478bd9Sstevel@tonic-gate 1167c478bd9Sstevel@tonic-gate /* 1177c478bd9Sstevel@tonic-gate * cv_destroy is not currently needed, but is part of the DDI. 1187c478bd9Sstevel@tonic-gate * This is in case cv_init ever needs to allocate something for a cv. 1197c478bd9Sstevel@tonic-gate */ 1207c478bd9Sstevel@tonic-gate /* ARGSUSED */ 1217c478bd9Sstevel@tonic-gate void 1227c478bd9Sstevel@tonic-gate cv_destroy(kcondvar_t *cvp) 1237c478bd9Sstevel@tonic-gate { 1247c478bd9Sstevel@tonic-gate ASSERT((((condvar_impl_t *)cvp)->cv_waiters & CV_WAITERS_MASK) == 0); 1257c478bd9Sstevel@tonic-gate } 1267c478bd9Sstevel@tonic-gate 1277c478bd9Sstevel@tonic-gate /* 1287c478bd9Sstevel@tonic-gate * The cv_block() function blocks a thread on a condition variable 1297c478bd9Sstevel@tonic-gate * by putting it in a hashed sleep queue associated with the 1307c478bd9Sstevel@tonic-gate * synchronization object. 1317c478bd9Sstevel@tonic-gate * 1327c478bd9Sstevel@tonic-gate * Threads are taken off the hashed sleep queues via calls to 1337c478bd9Sstevel@tonic-gate * cv_signal(), cv_broadcast(), or cv_unsleep(). 1347c478bd9Sstevel@tonic-gate */ 1357c478bd9Sstevel@tonic-gate static void 1367c478bd9Sstevel@tonic-gate cv_block(condvar_impl_t *cvp) 1377c478bd9Sstevel@tonic-gate { 1387c478bd9Sstevel@tonic-gate kthread_t *t = curthread; 1397c478bd9Sstevel@tonic-gate klwp_t *lwp = ttolwp(t); 1407c478bd9Sstevel@tonic-gate sleepq_head_t *sqh; 1417c478bd9Sstevel@tonic-gate 1427c478bd9Sstevel@tonic-gate ASSERT(THREAD_LOCK_HELD(t)); 1437c478bd9Sstevel@tonic-gate ASSERT(t != CPU->cpu_idle_thread); 1447c478bd9Sstevel@tonic-gate ASSERT(CPU_ON_INTR(CPU) == 0); 1457c478bd9Sstevel@tonic-gate ASSERT(t->t_wchan0 == NULL && t->t_wchan == NULL); 1467c478bd9Sstevel@tonic-gate ASSERT(t->t_state == TS_ONPROC); 1477c478bd9Sstevel@tonic-gate 1487c478bd9Sstevel@tonic-gate t->t_schedflag &= ~TS_SIGNALLED; 1497c478bd9Sstevel@tonic-gate CL_SLEEP(t); /* assign kernel priority */ 1507c478bd9Sstevel@tonic-gate t->t_wchan = (caddr_t)cvp; 1517c478bd9Sstevel@tonic-gate t->t_sobj_ops = &cv_sobj_ops; 1527c478bd9Sstevel@tonic-gate DTRACE_SCHED(sleep); 1537c478bd9Sstevel@tonic-gate 1547c478bd9Sstevel@tonic-gate /* 1557c478bd9Sstevel@tonic-gate * The check for t_intr is to avoid doing the 1567c478bd9Sstevel@tonic-gate * account for an interrupt thread on the still-pinned 1577c478bd9Sstevel@tonic-gate * lwp's statistics. 1587c478bd9Sstevel@tonic-gate */ 1597c478bd9Sstevel@tonic-gate if (lwp != NULL && t->t_intr == NULL) { 1607c478bd9Sstevel@tonic-gate lwp->lwp_ru.nvcsw++; 1617c478bd9Sstevel@tonic-gate (void) new_mstate(t, LMS_SLEEP); 1627c478bd9Sstevel@tonic-gate } 1637c478bd9Sstevel@tonic-gate 1647c478bd9Sstevel@tonic-gate sqh = SQHASH(cvp); 1657c478bd9Sstevel@tonic-gate disp_lock_enter_high(&sqh->sq_lock); 1667c478bd9Sstevel@tonic-gate if (cvp->cv_waiters < CV_MAX_WAITERS) 1677c478bd9Sstevel@tonic-gate cvp->cv_waiters++; 1687c478bd9Sstevel@tonic-gate ASSERT(cvp->cv_waiters <= CV_MAX_WAITERS); 1697c478bd9Sstevel@tonic-gate THREAD_SLEEP(t, &sqh->sq_lock); 1707c478bd9Sstevel@tonic-gate sleepq_insert(&sqh->sq_queue, t); 1717c478bd9Sstevel@tonic-gate /* 1727c478bd9Sstevel@tonic-gate * THREAD_SLEEP() moves curthread->t_lockp to point to the 1737c478bd9Sstevel@tonic-gate * lock sqh->sq_lock. This lock is later released by the caller 1747c478bd9Sstevel@tonic-gate * when it calls thread_unlock() on curthread. 1757c478bd9Sstevel@tonic-gate */ 1767c478bd9Sstevel@tonic-gate } 1777c478bd9Sstevel@tonic-gate 1787c478bd9Sstevel@tonic-gate #define cv_block_sig(t, cvp) \ 1797c478bd9Sstevel@tonic-gate { (t)->t_flag |= T_WAKEABLE; cv_block(cvp); } 1807c478bd9Sstevel@tonic-gate 1817c478bd9Sstevel@tonic-gate /* 1827c478bd9Sstevel@tonic-gate * Block on the indicated condition variable and release the 1837c478bd9Sstevel@tonic-gate * associated kmutex while blocked. 1847c478bd9Sstevel@tonic-gate */ 1857c478bd9Sstevel@tonic-gate void 1867c478bd9Sstevel@tonic-gate cv_wait(kcondvar_t *cvp, kmutex_t *mp) 1877c478bd9Sstevel@tonic-gate { 1887c478bd9Sstevel@tonic-gate if (panicstr) 1897c478bd9Sstevel@tonic-gate return; 1907c478bd9Sstevel@tonic-gate 1917c478bd9Sstevel@tonic-gate ASSERT(curthread->t_schedflag & TS_DONT_SWAP); 1927c478bd9Sstevel@tonic-gate thread_lock(curthread); /* lock the thread */ 1937c478bd9Sstevel@tonic-gate cv_block((condvar_impl_t *)cvp); 1947c478bd9Sstevel@tonic-gate thread_unlock_nopreempt(curthread); /* unlock the waiters field */ 1957c478bd9Sstevel@tonic-gate mutex_exit(mp); 1967c478bd9Sstevel@tonic-gate swtch(); 1977c478bd9Sstevel@tonic-gate mutex_enter(mp); 1987c478bd9Sstevel@tonic-gate } 1997c478bd9Sstevel@tonic-gate 2007c478bd9Sstevel@tonic-gate /* 2017c478bd9Sstevel@tonic-gate * Same as cv_wait except the thread will unblock at 'tim' 2027c478bd9Sstevel@tonic-gate * (an absolute time) if it hasn't already unblocked. 2037c478bd9Sstevel@tonic-gate * 2047c478bd9Sstevel@tonic-gate * Returns the amount of time left from the original 'tim' value 2057c478bd9Sstevel@tonic-gate * when it was unblocked. 2067c478bd9Sstevel@tonic-gate */ 2077c478bd9Sstevel@tonic-gate clock_t 2087c478bd9Sstevel@tonic-gate cv_timedwait(kcondvar_t *cvp, kmutex_t *mp, clock_t tim) 2097c478bd9Sstevel@tonic-gate { 2107c478bd9Sstevel@tonic-gate kthread_t *t = curthread; 2117c478bd9Sstevel@tonic-gate timeout_id_t id; 2127c478bd9Sstevel@tonic-gate clock_t timeleft; 2137c478bd9Sstevel@tonic-gate int signalled; 2147c478bd9Sstevel@tonic-gate 2157c478bd9Sstevel@tonic-gate if (panicstr) 2167c478bd9Sstevel@tonic-gate return (-1); 2177c478bd9Sstevel@tonic-gate 2187c478bd9Sstevel@tonic-gate timeleft = tim - lbolt; 2197c478bd9Sstevel@tonic-gate if (timeleft <= 0) 2207c478bd9Sstevel@tonic-gate return (-1); 2217c478bd9Sstevel@tonic-gate id = realtime_timeout((void (*)(void *))setrun, t, timeleft); 2227c478bd9Sstevel@tonic-gate thread_lock(t); /* lock the thread */ 2237c478bd9Sstevel@tonic-gate cv_block((condvar_impl_t *)cvp); 2247c478bd9Sstevel@tonic-gate thread_unlock_nopreempt(t); 2257c478bd9Sstevel@tonic-gate mutex_exit(mp); 2267c478bd9Sstevel@tonic-gate if ((tim - lbolt) <= 0) /* allow for wrap */ 2277c478bd9Sstevel@tonic-gate setrun(t); 2287c478bd9Sstevel@tonic-gate swtch(); 2297c478bd9Sstevel@tonic-gate signalled = (t->t_schedflag & TS_SIGNALLED); 2307c478bd9Sstevel@tonic-gate /* 2317c478bd9Sstevel@tonic-gate * Get the time left. untimeout() returns -1 if the timeout has 2327c478bd9Sstevel@tonic-gate * occured or the time remaining. If the time remaining is zero, 2337c478bd9Sstevel@tonic-gate * the timeout has occured between when we were awoken and 2347c478bd9Sstevel@tonic-gate * we called untimeout. We will treat this as if the timeout 2357c478bd9Sstevel@tonic-gate * has occured and set timeleft to -1. 2367c478bd9Sstevel@tonic-gate */ 2377c478bd9Sstevel@tonic-gate timeleft = untimeout(id); 2387c478bd9Sstevel@tonic-gate mutex_enter(mp); 2397c478bd9Sstevel@tonic-gate if (timeleft <= 0) { 2407c478bd9Sstevel@tonic-gate timeleft = -1; 2417c478bd9Sstevel@tonic-gate if (signalled) /* avoid consuming the cv_signal() */ 2427c478bd9Sstevel@tonic-gate cv_signal(cvp); 2437c478bd9Sstevel@tonic-gate } 2447c478bd9Sstevel@tonic-gate return (timeleft); 2457c478bd9Sstevel@tonic-gate } 2467c478bd9Sstevel@tonic-gate 2477c478bd9Sstevel@tonic-gate int 2487c478bd9Sstevel@tonic-gate cv_wait_sig(kcondvar_t *cvp, kmutex_t *mp) 2497c478bd9Sstevel@tonic-gate { 2507c478bd9Sstevel@tonic-gate kthread_t *t = curthread; 2517c478bd9Sstevel@tonic-gate proc_t *p = ttoproc(t); 2527c478bd9Sstevel@tonic-gate klwp_t *lwp = ttolwp(t); 253*a574db85Sraf int cancel_pending; 2547c478bd9Sstevel@tonic-gate int rval = 1; 2557c478bd9Sstevel@tonic-gate int signalled = 0; 2567c478bd9Sstevel@tonic-gate 2577c478bd9Sstevel@tonic-gate if (panicstr) 2587c478bd9Sstevel@tonic-gate return (rval); 2597c478bd9Sstevel@tonic-gate 2607c478bd9Sstevel@tonic-gate /* 2617c478bd9Sstevel@tonic-gate * The check for t_intr is to catch an interrupt thread 2627c478bd9Sstevel@tonic-gate * that has not yet unpinned the thread underneath. 2637c478bd9Sstevel@tonic-gate */ 2647c478bd9Sstevel@tonic-gate if (lwp == NULL || t->t_intr) { 2657c478bd9Sstevel@tonic-gate cv_wait(cvp, mp); 2667c478bd9Sstevel@tonic-gate return (rval); 2677c478bd9Sstevel@tonic-gate } 2687c478bd9Sstevel@tonic-gate 2697c478bd9Sstevel@tonic-gate ASSERT(curthread->t_schedflag & TS_DONT_SWAP); 270*a574db85Sraf cancel_pending = schedctl_cancel_pending(); 2717c478bd9Sstevel@tonic-gate lwp->lwp_asleep = 1; 2727c478bd9Sstevel@tonic-gate lwp->lwp_sysabort = 0; 2737c478bd9Sstevel@tonic-gate thread_lock(t); 2747c478bd9Sstevel@tonic-gate cv_block_sig(t, (condvar_impl_t *)cvp); 2757c478bd9Sstevel@tonic-gate thread_unlock_nopreempt(t); 2767c478bd9Sstevel@tonic-gate mutex_exit(mp); 277*a574db85Sraf if (ISSIG(t, JUSTLOOKING) || MUSTRETURN(p, t) || cancel_pending) 2787c478bd9Sstevel@tonic-gate setrun(t); 2797c478bd9Sstevel@tonic-gate /* ASSERT(no locks are held) */ 2807c478bd9Sstevel@tonic-gate swtch(); 2817c478bd9Sstevel@tonic-gate signalled = (t->t_schedflag & TS_SIGNALLED); 2827c478bd9Sstevel@tonic-gate t->t_flag &= ~T_WAKEABLE; 2837c478bd9Sstevel@tonic-gate mutex_enter(mp); 2847c478bd9Sstevel@tonic-gate if (ISSIG_PENDING(t, lwp, p)) { 2857c478bd9Sstevel@tonic-gate mutex_exit(mp); 2867c478bd9Sstevel@tonic-gate if (issig(FORREAL)) 2877c478bd9Sstevel@tonic-gate rval = 0; 2887c478bd9Sstevel@tonic-gate mutex_enter(mp); 2897c478bd9Sstevel@tonic-gate } 2907c478bd9Sstevel@tonic-gate if (lwp->lwp_sysabort || MUSTRETURN(p, t)) 2917c478bd9Sstevel@tonic-gate rval = 0; 292*a574db85Sraf if (rval != 0 && cancel_pending) { 293*a574db85Sraf schedctl_cancel_eintr(); 294*a574db85Sraf rval = 0; 295*a574db85Sraf } 2967c478bd9Sstevel@tonic-gate lwp->lwp_asleep = 0; 2977c478bd9Sstevel@tonic-gate lwp->lwp_sysabort = 0; 2987c478bd9Sstevel@tonic-gate if (rval == 0 && signalled) /* avoid consuming the cv_signal() */ 2997c478bd9Sstevel@tonic-gate cv_signal(cvp); 3007c478bd9Sstevel@tonic-gate return (rval); 3017c478bd9Sstevel@tonic-gate } 3027c478bd9Sstevel@tonic-gate 3037c478bd9Sstevel@tonic-gate /* 3047c478bd9Sstevel@tonic-gate * Returns: 3057c478bd9Sstevel@tonic-gate * Function result in order of presidence: 3067c478bd9Sstevel@tonic-gate * 0 if a signal was received 3077c478bd9Sstevel@tonic-gate * -1 if timeout occured 3087c478bd9Sstevel@tonic-gate * >0 if awakened via cv_signal() or cv_broadcast(). 3097c478bd9Sstevel@tonic-gate * (returns time remaining) 3107c478bd9Sstevel@tonic-gate * 3117c478bd9Sstevel@tonic-gate * cv_timedwait_sig() is now part of the DDI. 3127c478bd9Sstevel@tonic-gate */ 3137c478bd9Sstevel@tonic-gate clock_t 3147c478bd9Sstevel@tonic-gate cv_timedwait_sig(kcondvar_t *cvp, kmutex_t *mp, clock_t tim) 3157c478bd9Sstevel@tonic-gate { 3167c478bd9Sstevel@tonic-gate kthread_t *t = curthread; 3177c478bd9Sstevel@tonic-gate proc_t *p = ttoproc(t); 3187c478bd9Sstevel@tonic-gate klwp_t *lwp = ttolwp(t); 319*a574db85Sraf int cancel_pending = 0; 3207c478bd9Sstevel@tonic-gate timeout_id_t id; 3217c478bd9Sstevel@tonic-gate clock_t rval = 1; 3227c478bd9Sstevel@tonic-gate clock_t timeleft; 3237c478bd9Sstevel@tonic-gate int signalled = 0; 3247c478bd9Sstevel@tonic-gate 3257c478bd9Sstevel@tonic-gate if (panicstr) 3267c478bd9Sstevel@tonic-gate return (rval); 3277c478bd9Sstevel@tonic-gate 3287c478bd9Sstevel@tonic-gate /* 3297c478bd9Sstevel@tonic-gate * If there is no lwp, then we don't need to wait for a signal. 3307c478bd9Sstevel@tonic-gate * The check for t_intr is to catch an interrupt thread 3317c478bd9Sstevel@tonic-gate * that has not yet unpinned the thread underneath. 3327c478bd9Sstevel@tonic-gate */ 3337c478bd9Sstevel@tonic-gate if (lwp == NULL || t->t_intr) 3347c478bd9Sstevel@tonic-gate return (cv_timedwait(cvp, mp, tim)); 3357c478bd9Sstevel@tonic-gate 3367c478bd9Sstevel@tonic-gate /* 3377c478bd9Sstevel@tonic-gate * If tim is less than or equal to lbolt, then the timeout 3387c478bd9Sstevel@tonic-gate * has already occured. So just check to see if there is a signal 3397c478bd9Sstevel@tonic-gate * pending. If so return 0 indicating that there is a signal pending. 3407c478bd9Sstevel@tonic-gate * Else return -1 indicating that the timeout occured. No need to 3417c478bd9Sstevel@tonic-gate * wait on anything. 3427c478bd9Sstevel@tonic-gate */ 3437c478bd9Sstevel@tonic-gate timeleft = tim - lbolt; 3447c478bd9Sstevel@tonic-gate if (timeleft <= 0) { 3457c478bd9Sstevel@tonic-gate lwp->lwp_asleep = 1; 3467c478bd9Sstevel@tonic-gate lwp->lwp_sysabort = 0; 3477c478bd9Sstevel@tonic-gate rval = -1; 3487c478bd9Sstevel@tonic-gate goto out; 3497c478bd9Sstevel@tonic-gate } 3507c478bd9Sstevel@tonic-gate 3517c478bd9Sstevel@tonic-gate /* 3527c478bd9Sstevel@tonic-gate * Set the timeout and wait. 3537c478bd9Sstevel@tonic-gate */ 354*a574db85Sraf cancel_pending = schedctl_cancel_pending(); 3557c478bd9Sstevel@tonic-gate id = realtime_timeout((void (*)(void *))setrun, t, timeleft); 3567c478bd9Sstevel@tonic-gate lwp->lwp_asleep = 1; 3577c478bd9Sstevel@tonic-gate lwp->lwp_sysabort = 0; 3587c478bd9Sstevel@tonic-gate thread_lock(t); 3597c478bd9Sstevel@tonic-gate cv_block_sig(t, (condvar_impl_t *)cvp); 3607c478bd9Sstevel@tonic-gate thread_unlock_nopreempt(t); 3617c478bd9Sstevel@tonic-gate mutex_exit(mp); 362*a574db85Sraf if (ISSIG(t, JUSTLOOKING) || MUSTRETURN(p, t) || cancel_pending || 363*a574db85Sraf (tim - lbolt <= 0)) 3647c478bd9Sstevel@tonic-gate setrun(t); 3657c478bd9Sstevel@tonic-gate /* ASSERT(no locks are held) */ 3667c478bd9Sstevel@tonic-gate swtch(); 3677c478bd9Sstevel@tonic-gate signalled = (t->t_schedflag & TS_SIGNALLED); 3687c478bd9Sstevel@tonic-gate t->t_flag &= ~T_WAKEABLE; 3697c478bd9Sstevel@tonic-gate mutex_enter(mp); 3707c478bd9Sstevel@tonic-gate 3717c478bd9Sstevel@tonic-gate /* 3727c478bd9Sstevel@tonic-gate * Untimeout the thread. untimeout() returns -1 if the timeout has 3737c478bd9Sstevel@tonic-gate * occured or the time remaining. If the time remaining is zero, 3747c478bd9Sstevel@tonic-gate * the timeout has occured between when we were awoken and 3757c478bd9Sstevel@tonic-gate * we called untimeout. We will treat this as if the timeout 3767c478bd9Sstevel@tonic-gate * has occured and set rval to -1. 3777c478bd9Sstevel@tonic-gate */ 3787c478bd9Sstevel@tonic-gate rval = untimeout(id); 3797c478bd9Sstevel@tonic-gate if (rval <= 0) 3807c478bd9Sstevel@tonic-gate rval = -1; 3817c478bd9Sstevel@tonic-gate 3827c478bd9Sstevel@tonic-gate /* 3837c478bd9Sstevel@tonic-gate * Check to see if a signal is pending. If so, regardless of whether 3847c478bd9Sstevel@tonic-gate * or not we were awoken due to the signal, the signal is now pending 3857c478bd9Sstevel@tonic-gate * and a return of 0 has the highest priority. 3867c478bd9Sstevel@tonic-gate */ 3877c478bd9Sstevel@tonic-gate out: 3887c478bd9Sstevel@tonic-gate if (ISSIG_PENDING(t, lwp, p)) { 3897c478bd9Sstevel@tonic-gate mutex_exit(mp); 3907c478bd9Sstevel@tonic-gate if (issig(FORREAL)) 3917c478bd9Sstevel@tonic-gate rval = 0; 3927c478bd9Sstevel@tonic-gate mutex_enter(mp); 3937c478bd9Sstevel@tonic-gate } 3947c478bd9Sstevel@tonic-gate if (lwp->lwp_sysabort || MUSTRETURN(p, t)) 3957c478bd9Sstevel@tonic-gate rval = 0; 396*a574db85Sraf if (rval != 0 && cancel_pending) { 397*a574db85Sraf schedctl_cancel_eintr(); 398*a574db85Sraf rval = 0; 399*a574db85Sraf } 4007c478bd9Sstevel@tonic-gate lwp->lwp_asleep = 0; 4017c478bd9Sstevel@tonic-gate lwp->lwp_sysabort = 0; 4027c478bd9Sstevel@tonic-gate if (rval <= 0 && signalled) /* avoid consuming the cv_signal() */ 4037c478bd9Sstevel@tonic-gate cv_signal(cvp); 4047c478bd9Sstevel@tonic-gate return (rval); 4057c478bd9Sstevel@tonic-gate } 4067c478bd9Sstevel@tonic-gate 4077c478bd9Sstevel@tonic-gate /* 4087c478bd9Sstevel@tonic-gate * Like cv_wait_sig_swap but allows the caller to indicate (with a 4097c478bd9Sstevel@tonic-gate * non-NULL sigret) that they will take care of signalling the cv 4107c478bd9Sstevel@tonic-gate * after wakeup, if necessary. This is a vile hack that should only 4117c478bd9Sstevel@tonic-gate * be used when no other option is available; almost all callers 4127c478bd9Sstevel@tonic-gate * should just use cv_wait_sig_swap (which takes care of the cv_signal 4137c478bd9Sstevel@tonic-gate * stuff automatically) instead. 4147c478bd9Sstevel@tonic-gate */ 4157c478bd9Sstevel@tonic-gate int 4167c478bd9Sstevel@tonic-gate cv_wait_sig_swap_core(kcondvar_t *cvp, kmutex_t *mp, int *sigret) 4177c478bd9Sstevel@tonic-gate { 4187c478bd9Sstevel@tonic-gate kthread_t *t = curthread; 4197c478bd9Sstevel@tonic-gate proc_t *p = ttoproc(t); 4207c478bd9Sstevel@tonic-gate klwp_t *lwp = ttolwp(t); 421*a574db85Sraf int cancel_pending; 4227c478bd9Sstevel@tonic-gate int rval = 1; 4237c478bd9Sstevel@tonic-gate int signalled = 0; 4247c478bd9Sstevel@tonic-gate 4257c478bd9Sstevel@tonic-gate if (panicstr) 4267c478bd9Sstevel@tonic-gate return (rval); 4277c478bd9Sstevel@tonic-gate 4287c478bd9Sstevel@tonic-gate /* 4297c478bd9Sstevel@tonic-gate * The check for t_intr is to catch an interrupt thread 4307c478bd9Sstevel@tonic-gate * that has not yet unpinned the thread underneath. 4317c478bd9Sstevel@tonic-gate */ 4327c478bd9Sstevel@tonic-gate if (lwp == NULL || t->t_intr) { 4337c478bd9Sstevel@tonic-gate cv_wait(cvp, mp); 4347c478bd9Sstevel@tonic-gate return (rval); 4357c478bd9Sstevel@tonic-gate } 4367c478bd9Sstevel@tonic-gate 437*a574db85Sraf cancel_pending = schedctl_cancel_pending(); 4387c478bd9Sstevel@tonic-gate lwp->lwp_asleep = 1; 4397c478bd9Sstevel@tonic-gate lwp->lwp_sysabort = 0; 4407c478bd9Sstevel@tonic-gate thread_lock(t); 4417c478bd9Sstevel@tonic-gate t->t_kpri_req = 0; /* don't need kernel priority */ 4427c478bd9Sstevel@tonic-gate cv_block_sig(t, (condvar_impl_t *)cvp); 4437c478bd9Sstevel@tonic-gate /* I can be swapped now */ 4447c478bd9Sstevel@tonic-gate curthread->t_schedflag &= ~TS_DONT_SWAP; 4457c478bd9Sstevel@tonic-gate thread_unlock_nopreempt(t); 4467c478bd9Sstevel@tonic-gate mutex_exit(mp); 447*a574db85Sraf if (ISSIG(t, JUSTLOOKING) || MUSTRETURN(p, t) || cancel_pending) 4487c478bd9Sstevel@tonic-gate setrun(t); 4497c478bd9Sstevel@tonic-gate /* ASSERT(no locks are held) */ 4507c478bd9Sstevel@tonic-gate swtch(); 4517c478bd9Sstevel@tonic-gate signalled = (t->t_schedflag & TS_SIGNALLED); 4527c478bd9Sstevel@tonic-gate t->t_flag &= ~T_WAKEABLE; 4537c478bd9Sstevel@tonic-gate /* TS_DONT_SWAP set by disp() */ 4547c478bd9Sstevel@tonic-gate ASSERT(curthread->t_schedflag & TS_DONT_SWAP); 4557c478bd9Sstevel@tonic-gate mutex_enter(mp); 4567c478bd9Sstevel@tonic-gate if (ISSIG_PENDING(t, lwp, p)) { 4577c478bd9Sstevel@tonic-gate mutex_exit(mp); 4587c478bd9Sstevel@tonic-gate if (issig(FORREAL)) 4597c478bd9Sstevel@tonic-gate rval = 0; 4607c478bd9Sstevel@tonic-gate mutex_enter(mp); 4617c478bd9Sstevel@tonic-gate } 4627c478bd9Sstevel@tonic-gate if (lwp->lwp_sysabort || MUSTRETURN(p, t)) 4637c478bd9Sstevel@tonic-gate rval = 0; 464*a574db85Sraf if (rval != 0 && cancel_pending) { 465*a574db85Sraf schedctl_cancel_eintr(); 466*a574db85Sraf rval = 0; 467*a574db85Sraf } 4687c478bd9Sstevel@tonic-gate lwp->lwp_asleep = 0; 4697c478bd9Sstevel@tonic-gate lwp->lwp_sysabort = 0; 4707c478bd9Sstevel@tonic-gate if (rval == 0) { 4717c478bd9Sstevel@tonic-gate if (sigret != NULL) 4727c478bd9Sstevel@tonic-gate *sigret = signalled; /* just tell the caller */ 4737c478bd9Sstevel@tonic-gate else if (signalled) 4747c478bd9Sstevel@tonic-gate cv_signal(cvp); /* avoid consuming the cv_signal() */ 4757c478bd9Sstevel@tonic-gate } 4767c478bd9Sstevel@tonic-gate return (rval); 4777c478bd9Sstevel@tonic-gate } 4787c478bd9Sstevel@tonic-gate 4797c478bd9Sstevel@tonic-gate /* 4807c478bd9Sstevel@tonic-gate * Same as cv_wait_sig but the thread can be swapped out while waiting. 4817c478bd9Sstevel@tonic-gate * This should only be used when we know we aren't holding any locks. 4827c478bd9Sstevel@tonic-gate */ 4837c478bd9Sstevel@tonic-gate int 4847c478bd9Sstevel@tonic-gate cv_wait_sig_swap(kcondvar_t *cvp, kmutex_t *mp) 4857c478bd9Sstevel@tonic-gate { 4867c478bd9Sstevel@tonic-gate return (cv_wait_sig_swap_core(cvp, mp, NULL)); 4877c478bd9Sstevel@tonic-gate } 4887c478bd9Sstevel@tonic-gate 4897c478bd9Sstevel@tonic-gate void 4907c478bd9Sstevel@tonic-gate cv_signal(kcondvar_t *cvp) 4917c478bd9Sstevel@tonic-gate { 4927c478bd9Sstevel@tonic-gate condvar_impl_t *cp = (condvar_impl_t *)cvp; 4937c478bd9Sstevel@tonic-gate 4947c478bd9Sstevel@tonic-gate /* make sure the cv_waiters field looks sane */ 4957c478bd9Sstevel@tonic-gate ASSERT(cp->cv_waiters <= CV_MAX_WAITERS); 4967c478bd9Sstevel@tonic-gate if (cp->cv_waiters > 0) { 4977c478bd9Sstevel@tonic-gate sleepq_head_t *sqh = SQHASH(cp); 4987c478bd9Sstevel@tonic-gate disp_lock_enter(&sqh->sq_lock); 4997c478bd9Sstevel@tonic-gate ASSERT(CPU_ON_INTR(CPU) == 0); 5007c478bd9Sstevel@tonic-gate if (cp->cv_waiters & CV_WAITERS_MASK) { 5017c478bd9Sstevel@tonic-gate kthread_t *t; 5027c478bd9Sstevel@tonic-gate cp->cv_waiters--; 5037c478bd9Sstevel@tonic-gate t = sleepq_wakeone_chan(&sqh->sq_queue, cp); 5047c478bd9Sstevel@tonic-gate /* 5057c478bd9Sstevel@tonic-gate * If cv_waiters is non-zero (and less than 5067c478bd9Sstevel@tonic-gate * CV_MAX_WAITERS) there should be a thread 5077c478bd9Sstevel@tonic-gate * in the queue. 5087c478bd9Sstevel@tonic-gate */ 5097c478bd9Sstevel@tonic-gate ASSERT(t != NULL); 5107c478bd9Sstevel@tonic-gate } else if (sleepq_wakeone_chan(&sqh->sq_queue, cp) == NULL) { 5117c478bd9Sstevel@tonic-gate cp->cv_waiters = 0; 5127c478bd9Sstevel@tonic-gate } 5137c478bd9Sstevel@tonic-gate disp_lock_exit(&sqh->sq_lock); 5147c478bd9Sstevel@tonic-gate } 5157c478bd9Sstevel@tonic-gate } 5167c478bd9Sstevel@tonic-gate 5177c478bd9Sstevel@tonic-gate void 5187c478bd9Sstevel@tonic-gate cv_broadcast(kcondvar_t *cvp) 5197c478bd9Sstevel@tonic-gate { 5207c478bd9Sstevel@tonic-gate condvar_impl_t *cp = (condvar_impl_t *)cvp; 5217c478bd9Sstevel@tonic-gate 5227c478bd9Sstevel@tonic-gate /* make sure the cv_waiters field looks sane */ 5237c478bd9Sstevel@tonic-gate ASSERT(cp->cv_waiters <= CV_MAX_WAITERS); 5247c478bd9Sstevel@tonic-gate if (cp->cv_waiters > 0) { 5257c478bd9Sstevel@tonic-gate sleepq_head_t *sqh = SQHASH(cp); 5267c478bd9Sstevel@tonic-gate disp_lock_enter(&sqh->sq_lock); 5277c478bd9Sstevel@tonic-gate ASSERT(CPU_ON_INTR(CPU) == 0); 5287c478bd9Sstevel@tonic-gate sleepq_wakeall_chan(&sqh->sq_queue, cp); 5297c478bd9Sstevel@tonic-gate cp->cv_waiters = 0; 5307c478bd9Sstevel@tonic-gate disp_lock_exit(&sqh->sq_lock); 5317c478bd9Sstevel@tonic-gate } 5327c478bd9Sstevel@tonic-gate } 5337c478bd9Sstevel@tonic-gate 5347c478bd9Sstevel@tonic-gate /* 5357c478bd9Sstevel@tonic-gate * Same as cv_wait(), but wakes up (after wakeup_time milliseconds) to check 5367c478bd9Sstevel@tonic-gate * for requests to stop, like cv_wait_sig() but without dealing with signals. 5377c478bd9Sstevel@tonic-gate * This is a horrible kludge. It is evil. It is vile. It is swill. 5387c478bd9Sstevel@tonic-gate * If your code has to call this function then your code is the same. 5397c478bd9Sstevel@tonic-gate */ 5407c478bd9Sstevel@tonic-gate void 5417c478bd9Sstevel@tonic-gate cv_wait_stop(kcondvar_t *cvp, kmutex_t *mp, int wakeup_time) 5427c478bd9Sstevel@tonic-gate { 5437c478bd9Sstevel@tonic-gate kthread_t *t = curthread; 5447c478bd9Sstevel@tonic-gate klwp_t *lwp = ttolwp(t); 5457c478bd9Sstevel@tonic-gate proc_t *p = ttoproc(t); 5467c478bd9Sstevel@tonic-gate timeout_id_t id; 5477c478bd9Sstevel@tonic-gate clock_t tim; 5487c478bd9Sstevel@tonic-gate 5497c478bd9Sstevel@tonic-gate if (panicstr) 5507c478bd9Sstevel@tonic-gate return; 5517c478bd9Sstevel@tonic-gate 5527c478bd9Sstevel@tonic-gate /* 5537c478bd9Sstevel@tonic-gate * If there is no lwp, then we don't need to eventually stop it 5547c478bd9Sstevel@tonic-gate * The check for t_intr is to catch an interrupt thread 5557c478bd9Sstevel@tonic-gate * that has not yet unpinned the thread underneath. 5567c478bd9Sstevel@tonic-gate */ 5577c478bd9Sstevel@tonic-gate if (lwp == NULL || t->t_intr) { 5587c478bd9Sstevel@tonic-gate cv_wait(cvp, mp); 5597c478bd9Sstevel@tonic-gate return; 5607c478bd9Sstevel@tonic-gate } 5617c478bd9Sstevel@tonic-gate 5627c478bd9Sstevel@tonic-gate /* 5637c478bd9Sstevel@tonic-gate * Wakeup in wakeup_time milliseconds, i.e., human time. 5647c478bd9Sstevel@tonic-gate */ 5657c478bd9Sstevel@tonic-gate tim = lbolt + MSEC_TO_TICK(wakeup_time); 5667c478bd9Sstevel@tonic-gate id = realtime_timeout((void (*)(void *))setrun, t, tim - lbolt); 5677c478bd9Sstevel@tonic-gate thread_lock(t); /* lock the thread */ 5687c478bd9Sstevel@tonic-gate cv_block((condvar_impl_t *)cvp); 5697c478bd9Sstevel@tonic-gate thread_unlock_nopreempt(t); 5707c478bd9Sstevel@tonic-gate mutex_exit(mp); 5717c478bd9Sstevel@tonic-gate /* ASSERT(no locks are held); */ 5727c478bd9Sstevel@tonic-gate if ((tim - lbolt) <= 0) /* allow for wrap */ 5737c478bd9Sstevel@tonic-gate setrun(t); 5747c478bd9Sstevel@tonic-gate swtch(); 5757c478bd9Sstevel@tonic-gate (void) untimeout(id); 5767c478bd9Sstevel@tonic-gate 5777c478bd9Sstevel@tonic-gate /* 5788548bf79Snr * Check for reasons to stop, if lwp_nostop is not true. 5797c478bd9Sstevel@tonic-gate * See issig_forreal() for explanations of the various stops. 5807c478bd9Sstevel@tonic-gate */ 5817c478bd9Sstevel@tonic-gate mutex_enter(&p->p_lock); 5828548bf79Snr while (lwp->lwp_nostop == 0 && !(p->p_flag & SEXITLWPS)) { 5837c478bd9Sstevel@tonic-gate /* 5847c478bd9Sstevel@tonic-gate * Hold the lwp here for watchpoint manipulation. 5857c478bd9Sstevel@tonic-gate */ 5868548bf79Snr if (t->t_proc_flag & TP_PAUSE) { 5877c478bd9Sstevel@tonic-gate stop(PR_SUSPENDED, SUSPEND_PAUSE); 5887c478bd9Sstevel@tonic-gate continue; 5897c478bd9Sstevel@tonic-gate } 5907c478bd9Sstevel@tonic-gate /* 5917c478bd9Sstevel@tonic-gate * System checkpoint. 5927c478bd9Sstevel@tonic-gate */ 5938548bf79Snr if (t->t_proc_flag & TP_CHKPT) { 5947c478bd9Sstevel@tonic-gate stop(PR_CHECKPOINT, 0); 5957c478bd9Sstevel@tonic-gate continue; 5967c478bd9Sstevel@tonic-gate } 5977c478bd9Sstevel@tonic-gate /* 5987c478bd9Sstevel@tonic-gate * Honor fork1(), watchpoint activity (remapping a page), 5998548bf79Snr * and lwp_suspend() requests. 6007c478bd9Sstevel@tonic-gate */ 6018548bf79Snr if ((p->p_flag & (SHOLDFORK1|SHOLDWATCH)) || 6028548bf79Snr (t->t_proc_flag & TP_HOLDLWP)) { 6037c478bd9Sstevel@tonic-gate stop(PR_SUSPENDED, SUSPEND_NORMAL); 6047c478bd9Sstevel@tonic-gate continue; 6057c478bd9Sstevel@tonic-gate } 6067c478bd9Sstevel@tonic-gate /* 6077c478bd9Sstevel@tonic-gate * Honor /proc requested stop. 6087c478bd9Sstevel@tonic-gate */ 6098548bf79Snr if (t->t_proc_flag & TP_PRSTOP) { 6107c478bd9Sstevel@tonic-gate stop(PR_REQUESTED, 0); 6117c478bd9Sstevel@tonic-gate } 6127c478bd9Sstevel@tonic-gate /* 6137c478bd9Sstevel@tonic-gate * If some lwp in the process has already stopped 6147c478bd9Sstevel@tonic-gate * showing PR_JOBCONTROL, stop in sympathy with it. 6157c478bd9Sstevel@tonic-gate */ 6168548bf79Snr if (p->p_stopsig && t != p->p_agenttp) { 6177c478bd9Sstevel@tonic-gate stop(PR_JOBCONTROL, p->p_stopsig); 6187c478bd9Sstevel@tonic-gate continue; 6197c478bd9Sstevel@tonic-gate } 6207c478bd9Sstevel@tonic-gate break; 6217c478bd9Sstevel@tonic-gate } 6227c478bd9Sstevel@tonic-gate mutex_exit(&p->p_lock); 6237c478bd9Sstevel@tonic-gate mutex_enter(mp); 6247c478bd9Sstevel@tonic-gate } 6257c478bd9Sstevel@tonic-gate 6267c478bd9Sstevel@tonic-gate /* 6277c478bd9Sstevel@tonic-gate * Like cv_timedwait_sig(), but takes an absolute hires future time 6287c478bd9Sstevel@tonic-gate * rather than a future time in clock ticks. Will not return showing 6297c478bd9Sstevel@tonic-gate * that a timeout occurred until the future time is passed. 6307c478bd9Sstevel@tonic-gate * If 'when' is a NULL pointer, no timeout will occur. 6317c478bd9Sstevel@tonic-gate * Returns: 6327c478bd9Sstevel@tonic-gate * Function result in order of presidence: 6337c478bd9Sstevel@tonic-gate * 0 if a signal was received 6347c478bd9Sstevel@tonic-gate * -1 if timeout occured 6357c478bd9Sstevel@tonic-gate * >0 if awakened via cv_signal() or cv_broadcast() 6367c478bd9Sstevel@tonic-gate * or by a spurious wakeup. 6377c478bd9Sstevel@tonic-gate * (might return time remaining) 6383348528fSdm * As a special test, if someone abruptly resets the system time 6393348528fSdm * (but not through adjtime(2); drifting of the clock is allowed and 6403348528fSdm * expected [see timespectohz_adj()]), then we force a return of -1 6413348528fSdm * so the caller can return a premature timeout to the calling process 6423348528fSdm * so it can reevaluate the situation in light of the new system time. 6433348528fSdm * (The system clock has been reset if timecheck != timechanged.) 6447c478bd9Sstevel@tonic-gate */ 6457c478bd9Sstevel@tonic-gate int 6463348528fSdm cv_waituntil_sig(kcondvar_t *cvp, kmutex_t *mp, 6473348528fSdm timestruc_t *when, int timecheck) 6487c478bd9Sstevel@tonic-gate { 6497c478bd9Sstevel@tonic-gate timestruc_t now; 650b2a1c443Svb timestruc_t delta; 6517c478bd9Sstevel@tonic-gate int rval; 6527c478bd9Sstevel@tonic-gate 6537c478bd9Sstevel@tonic-gate if (when == NULL) 6547c478bd9Sstevel@tonic-gate return (cv_wait_sig_swap(cvp, mp)); 6557c478bd9Sstevel@tonic-gate 6567c478bd9Sstevel@tonic-gate gethrestime(&now); 657b2a1c443Svb delta = *when; 658b2a1c443Svb timespecsub(&delta, &now); 659b2a1c443Svb if (delta.tv_sec < 0 || (delta.tv_sec == 0 && delta.tv_nsec == 0)) { 6607c478bd9Sstevel@tonic-gate /* 6617c478bd9Sstevel@tonic-gate * We have already reached the absolute future time. 6627c478bd9Sstevel@tonic-gate * Call cv_timedwait_sig() just to check for signals. 6637c478bd9Sstevel@tonic-gate * We will return immediately with either 0 or -1. 6647c478bd9Sstevel@tonic-gate */ 6657c478bd9Sstevel@tonic-gate rval = cv_timedwait_sig(cvp, mp, lbolt); 6667c478bd9Sstevel@tonic-gate } else { 6673348528fSdm if (timecheck == timechanged) { 6683348528fSdm rval = cv_timedwait_sig(cvp, mp, 669*a574db85Sraf lbolt + timespectohz_adj(when, now)); 6703348528fSdm } else { 6713348528fSdm /* 6723348528fSdm * Someone reset the system time; 6733348528fSdm * just force an immediate timeout. 6743348528fSdm */ 6753348528fSdm rval = -1; 6763348528fSdm } 6773348528fSdm if (rval == -1 && timecheck == timechanged) { 6783348528fSdm /* 6793348528fSdm * Even though cv_timedwait_sig() returned showing a 6803348528fSdm * timeout, the future time may not have passed yet. 6813348528fSdm * If not, change rval to indicate a normal wakeup. 6823348528fSdm */ 6833348528fSdm gethrestime(&now); 6843348528fSdm delta = *when; 6853348528fSdm timespecsub(&delta, &now); 6863348528fSdm if (delta.tv_sec > 0 || (delta.tv_sec == 0 && 6873348528fSdm delta.tv_nsec > 0)) 6887c478bd9Sstevel@tonic-gate rval = 1; 6893348528fSdm } 6907c478bd9Sstevel@tonic-gate } 6917c478bd9Sstevel@tonic-gate return (rval); 6927c478bd9Sstevel@tonic-gate } 693