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 /* 23*0Sstevel@tonic-gate * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24*0Sstevel@tonic-gate * Use is subject to license terms. 25*0Sstevel@tonic-gate */ 26*0Sstevel@tonic-gate 27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate #include "lint.h" 30*0Sstevel@tonic-gate #include "thr_uberdata.h" 31*0Sstevel@tonic-gate 32*0Sstevel@tonic-gate static uint32_t _semvaluemax; 33*0Sstevel@tonic-gate 34*0Sstevel@tonic-gate /* 35*0Sstevel@tonic-gate * Check to see if anyone is waiting for this semaphore. 36*0Sstevel@tonic-gate */ 37*0Sstevel@tonic-gate #pragma weak sema_held = _sema_held 38*0Sstevel@tonic-gate int 39*0Sstevel@tonic-gate _sema_held(sema_t *sp) 40*0Sstevel@tonic-gate { 41*0Sstevel@tonic-gate return (sp->count == 0); 42*0Sstevel@tonic-gate } 43*0Sstevel@tonic-gate 44*0Sstevel@tonic-gate #pragma weak sema_init = _sema_init 45*0Sstevel@tonic-gate /* ARGSUSED2 */ 46*0Sstevel@tonic-gate int 47*0Sstevel@tonic-gate _sema_init(sema_t *sp, unsigned int count, int type, void *arg) 48*0Sstevel@tonic-gate { 49*0Sstevel@tonic-gate if (_semvaluemax == 0) 50*0Sstevel@tonic-gate _semvaluemax = (uint32_t)_sysconf(_SC_SEM_VALUE_MAX); 51*0Sstevel@tonic-gate if ((type != USYNC_THREAD && type != USYNC_PROCESS) || 52*0Sstevel@tonic-gate (count > _semvaluemax)) 53*0Sstevel@tonic-gate return (EINVAL); 54*0Sstevel@tonic-gate (void) _memset(sp, 0, sizeof (*sp)); 55*0Sstevel@tonic-gate sp->count = count; 56*0Sstevel@tonic-gate sp->type = (uint16_t)type; 57*0Sstevel@tonic-gate sp->magic = SEMA_MAGIC; 58*0Sstevel@tonic-gate return (0); 59*0Sstevel@tonic-gate } 60*0Sstevel@tonic-gate 61*0Sstevel@tonic-gate #pragma weak sema_destroy = _sema_destroy 62*0Sstevel@tonic-gate int 63*0Sstevel@tonic-gate _sema_destroy(sema_t *sp) 64*0Sstevel@tonic-gate { 65*0Sstevel@tonic-gate sp->magic = 0; 66*0Sstevel@tonic-gate tdb_sync_obj_deregister(sp); 67*0Sstevel@tonic-gate return (0); 68*0Sstevel@tonic-gate } 69*0Sstevel@tonic-gate 70*0Sstevel@tonic-gate static int 71*0Sstevel@tonic-gate sema_wait_impl(sema_t *sp, timespec_t *tsp) 72*0Sstevel@tonic-gate { 73*0Sstevel@tonic-gate lwp_sema_t *lsp = (lwp_sema_t *)sp; 74*0Sstevel@tonic-gate ulwp_t *self = curthread; 75*0Sstevel@tonic-gate uberdata_t *udp = self->ul_uberdata; 76*0Sstevel@tonic-gate tdb_sema_stats_t *ssp = SEMA_STATS(sp, udp); 77*0Sstevel@tonic-gate hrtime_t begin_sleep = 0; 78*0Sstevel@tonic-gate uint_t count; 79*0Sstevel@tonic-gate int error = 0; 80*0Sstevel@tonic-gate 81*0Sstevel@tonic-gate /* 82*0Sstevel@tonic-gate * All variations of sema_wait() are cancellation points. 83*0Sstevel@tonic-gate */ 84*0Sstevel@tonic-gate _cancelon(); 85*0Sstevel@tonic-gate 86*0Sstevel@tonic-gate if (ssp) 87*0Sstevel@tonic-gate tdb_incr(ssp->sema_wait); 88*0Sstevel@tonic-gate 89*0Sstevel@tonic-gate self->ul_sp = stkptr(); 90*0Sstevel@tonic-gate self->ul_wchan = lsp; 91*0Sstevel@tonic-gate if (__td_event_report(self, TD_SLEEP, udp)) { 92*0Sstevel@tonic-gate self->ul_td_evbuf.eventnum = TD_SLEEP; 93*0Sstevel@tonic-gate self->ul_td_evbuf.eventdata = lsp; 94*0Sstevel@tonic-gate tdb_event(TD_SLEEP, udp); 95*0Sstevel@tonic-gate } 96*0Sstevel@tonic-gate /* just a guess, but it looks like we will sleep */ 97*0Sstevel@tonic-gate if (ssp && lsp->count == 0) { 98*0Sstevel@tonic-gate begin_sleep = gethrtime(); 99*0Sstevel@tonic-gate if (lsp->count == 0) /* still looks like sleep */ 100*0Sstevel@tonic-gate tdb_incr(ssp->sema_wait_sleep); 101*0Sstevel@tonic-gate else /* we changed our mind */ 102*0Sstevel@tonic-gate begin_sleep = 0; 103*0Sstevel@tonic-gate } 104*0Sstevel@tonic-gate 105*0Sstevel@tonic-gate if (lsp->type == USYNC_PROCESS) { /* kernel-level */ 106*0Sstevel@tonic-gate set_parking_flag(self, 1); 107*0Sstevel@tonic-gate if (self->ul_cursig != 0 || 108*0Sstevel@tonic-gate (self->ul_cancelable && self->ul_cancel_pending)) 109*0Sstevel@tonic-gate set_parking_flag(self, 0); 110*0Sstevel@tonic-gate /* the kernel always does FIFO queueing */ 111*0Sstevel@tonic-gate error = ___lwp_sema_timedwait(lsp, tsp, 1); 112*0Sstevel@tonic-gate set_parking_flag(self, 0); 113*0Sstevel@tonic-gate } else if (!udp->uberflags.uf_mt && /* single threaded */ 114*0Sstevel@tonic-gate lsp->count != 0) { /* and non-blocking */ 115*0Sstevel@tonic-gate /* 116*0Sstevel@tonic-gate * Since we are single-threaded, we don't need the 117*0Sstevel@tonic-gate * protection of queue_lock(). However, we do need 118*0Sstevel@tonic-gate * to block signals while modifying the count. 119*0Sstevel@tonic-gate */ 120*0Sstevel@tonic-gate sigoff(self); 121*0Sstevel@tonic-gate lsp->count--; 122*0Sstevel@tonic-gate sigon(self); 123*0Sstevel@tonic-gate } else { /* multithreaded or blocking */ 124*0Sstevel@tonic-gate queue_head_t *qp; 125*0Sstevel@tonic-gate ulwp_t *ulwp; 126*0Sstevel@tonic-gate int more; 127*0Sstevel@tonic-gate lwpid_t lwpid = 0; 128*0Sstevel@tonic-gate 129*0Sstevel@tonic-gate qp = queue_lock(lsp, CV); 130*0Sstevel@tonic-gate while (error == 0 && lsp->count == 0) { 131*0Sstevel@tonic-gate /* 132*0Sstevel@tonic-gate * SUSV3 requires FIFO queueing for semaphores, 133*0Sstevel@tonic-gate * at least for SCHED_FIFO and SCHED_RR scheduling. 134*0Sstevel@tonic-gate */ 135*0Sstevel@tonic-gate enqueue(qp, self, lsp, CV | FIFOQ); 136*0Sstevel@tonic-gate lsp->sema_waiters = 1; 137*0Sstevel@tonic-gate set_parking_flag(self, 1); 138*0Sstevel@tonic-gate queue_unlock(qp); 139*0Sstevel@tonic-gate /* 140*0Sstevel@tonic-gate * We may have received SIGCANCEL before we 141*0Sstevel@tonic-gate * called queue_lock(). If so and we are 142*0Sstevel@tonic-gate * cancelable we should return EINTR. 143*0Sstevel@tonic-gate */ 144*0Sstevel@tonic-gate if (self->ul_cursig != 0 || 145*0Sstevel@tonic-gate (self->ul_cancelable && self->ul_cancel_pending)) 146*0Sstevel@tonic-gate set_parking_flag(self, 0); 147*0Sstevel@tonic-gate error = __lwp_park(tsp, 0); 148*0Sstevel@tonic-gate set_parking_flag(self, 0); 149*0Sstevel@tonic-gate qp = queue_lock(lsp, CV); 150*0Sstevel@tonic-gate if (self->ul_sleepq) /* timeout or spurious wakeup */ 151*0Sstevel@tonic-gate lsp->sema_waiters = dequeue_self(qp, lsp); 152*0Sstevel@tonic-gate } 153*0Sstevel@tonic-gate if (error == 0) 154*0Sstevel@tonic-gate lsp->count--; 155*0Sstevel@tonic-gate if (lsp->count != 0 && lsp->sema_waiters) { 156*0Sstevel@tonic-gate if ((ulwp = dequeue(qp, lsp, &more)) == NULL) 157*0Sstevel@tonic-gate lsp->sema_waiters = 0; 158*0Sstevel@tonic-gate else { 159*0Sstevel@tonic-gate no_preempt(self); 160*0Sstevel@tonic-gate lwpid = ulwp->ul_lwpid; 161*0Sstevel@tonic-gate lsp->sema_waiters = (more? 1 : 0); 162*0Sstevel@tonic-gate } 163*0Sstevel@tonic-gate } 164*0Sstevel@tonic-gate queue_unlock(qp); 165*0Sstevel@tonic-gate if (lwpid) { 166*0Sstevel@tonic-gate (void) __lwp_unpark(lwpid); 167*0Sstevel@tonic-gate preempt(self); 168*0Sstevel@tonic-gate } 169*0Sstevel@tonic-gate } 170*0Sstevel@tonic-gate 171*0Sstevel@tonic-gate self->ul_wchan = NULL; 172*0Sstevel@tonic-gate self->ul_sp = 0; 173*0Sstevel@tonic-gate if (ssp) { 174*0Sstevel@tonic-gate if (error == 0) { 175*0Sstevel@tonic-gate /* we just decremented the count */ 176*0Sstevel@tonic-gate count = lsp->count; 177*0Sstevel@tonic-gate if (ssp->sema_min_count > count) 178*0Sstevel@tonic-gate ssp->sema_min_count = count; 179*0Sstevel@tonic-gate } 180*0Sstevel@tonic-gate if (begin_sleep) 181*0Sstevel@tonic-gate ssp->sema_wait_sleep_time += gethrtime() - begin_sleep; 182*0Sstevel@tonic-gate } 183*0Sstevel@tonic-gate 184*0Sstevel@tonic-gate if (error == EINTR) 185*0Sstevel@tonic-gate _canceloff(); 186*0Sstevel@tonic-gate else 187*0Sstevel@tonic-gate _canceloff_nocancel(); 188*0Sstevel@tonic-gate return (error); 189*0Sstevel@tonic-gate } 190*0Sstevel@tonic-gate 191*0Sstevel@tonic-gate #pragma weak sema_wait = _sema_wait 192*0Sstevel@tonic-gate int 193*0Sstevel@tonic-gate _sema_wait(sema_t *sp) 194*0Sstevel@tonic-gate { 195*0Sstevel@tonic-gate ASSERT(!curthread->ul_critical || curthread->ul_bindflags); 196*0Sstevel@tonic-gate return (sema_wait_impl(sp, NULL)); 197*0Sstevel@tonic-gate } 198*0Sstevel@tonic-gate 199*0Sstevel@tonic-gate #pragma weak sema_reltimedwait = _sema_reltimedwait 200*0Sstevel@tonic-gate int 201*0Sstevel@tonic-gate _sema_reltimedwait(sema_t *sp, timespec_t *reltime) 202*0Sstevel@tonic-gate { 203*0Sstevel@tonic-gate timespec_t tslocal = *reltime; 204*0Sstevel@tonic-gate 205*0Sstevel@tonic-gate ASSERT(!curthread->ul_critical || curthread->ul_bindflags); 206*0Sstevel@tonic-gate return (sema_wait_impl(sp, &tslocal)); 207*0Sstevel@tonic-gate } 208*0Sstevel@tonic-gate 209*0Sstevel@tonic-gate #pragma weak sema_timedwait = _sema_timedwait 210*0Sstevel@tonic-gate int 211*0Sstevel@tonic-gate _sema_timedwait(sema_t *sp, timespec_t *abstime) 212*0Sstevel@tonic-gate { 213*0Sstevel@tonic-gate timespec_t tslocal; 214*0Sstevel@tonic-gate 215*0Sstevel@tonic-gate ASSERT(!curthread->ul_critical || curthread->ul_bindflags); 216*0Sstevel@tonic-gate abstime_to_reltime(CLOCK_REALTIME, abstime, &tslocal); 217*0Sstevel@tonic-gate return (sema_wait_impl(sp, &tslocal)); 218*0Sstevel@tonic-gate } 219*0Sstevel@tonic-gate 220*0Sstevel@tonic-gate #pragma weak sema_trywait = _sema_trywait 221*0Sstevel@tonic-gate int 222*0Sstevel@tonic-gate _sema_trywait(sema_t *sp) 223*0Sstevel@tonic-gate { 224*0Sstevel@tonic-gate lwp_sema_t *lsp = (lwp_sema_t *)sp; 225*0Sstevel@tonic-gate ulwp_t *self = curthread; 226*0Sstevel@tonic-gate uberdata_t *udp = self->ul_uberdata; 227*0Sstevel@tonic-gate tdb_sema_stats_t *ssp = SEMA_STATS(sp, udp); 228*0Sstevel@tonic-gate uint_t count; 229*0Sstevel@tonic-gate int error = 0; 230*0Sstevel@tonic-gate 231*0Sstevel@tonic-gate ASSERT(!curthread->ul_critical || curthread->ul_bindflags); 232*0Sstevel@tonic-gate 233*0Sstevel@tonic-gate if (ssp) 234*0Sstevel@tonic-gate tdb_incr(ssp->sema_trywait); 235*0Sstevel@tonic-gate 236*0Sstevel@tonic-gate if (lsp->type == USYNC_PROCESS) { /* kernel-level */ 237*0Sstevel@tonic-gate error = __lwp_sema_trywait(lsp); 238*0Sstevel@tonic-gate } else if (!udp->uberflags.uf_mt) { /* single threaded */ 239*0Sstevel@tonic-gate sigoff(self); 240*0Sstevel@tonic-gate if (lsp->count == 0) 241*0Sstevel@tonic-gate error = EBUSY; 242*0Sstevel@tonic-gate else 243*0Sstevel@tonic-gate lsp->count--; 244*0Sstevel@tonic-gate sigon(self); 245*0Sstevel@tonic-gate } else { /* multithreaded */ 246*0Sstevel@tonic-gate queue_head_t *qp; 247*0Sstevel@tonic-gate ulwp_t *ulwp; 248*0Sstevel@tonic-gate int more; 249*0Sstevel@tonic-gate lwpid_t lwpid = 0; 250*0Sstevel@tonic-gate 251*0Sstevel@tonic-gate qp = queue_lock(lsp, CV); 252*0Sstevel@tonic-gate if (lsp->count == 0) 253*0Sstevel@tonic-gate error = EBUSY; 254*0Sstevel@tonic-gate else if (--lsp->count != 0 && lsp->sema_waiters) { 255*0Sstevel@tonic-gate if ((ulwp = dequeue(qp, lsp, &more)) == NULL) 256*0Sstevel@tonic-gate lsp->sema_waiters = 0; 257*0Sstevel@tonic-gate else { 258*0Sstevel@tonic-gate no_preempt(self); 259*0Sstevel@tonic-gate lwpid = ulwp->ul_lwpid; 260*0Sstevel@tonic-gate lsp->sema_waiters = (more? 1 : 0); 261*0Sstevel@tonic-gate } 262*0Sstevel@tonic-gate } 263*0Sstevel@tonic-gate queue_unlock(qp); 264*0Sstevel@tonic-gate if (lwpid) { 265*0Sstevel@tonic-gate (void) __lwp_unpark(lwpid); 266*0Sstevel@tonic-gate preempt(self); 267*0Sstevel@tonic-gate } 268*0Sstevel@tonic-gate } 269*0Sstevel@tonic-gate 270*0Sstevel@tonic-gate if (error == 0) { 271*0Sstevel@tonic-gate if (ssp) { 272*0Sstevel@tonic-gate /* we just decremented the count */ 273*0Sstevel@tonic-gate count = lsp->count; 274*0Sstevel@tonic-gate if (ssp->sema_min_count > count) 275*0Sstevel@tonic-gate ssp->sema_min_count = count; 276*0Sstevel@tonic-gate } 277*0Sstevel@tonic-gate } else { 278*0Sstevel@tonic-gate if (ssp) 279*0Sstevel@tonic-gate tdb_incr(ssp->sema_trywait_fail); 280*0Sstevel@tonic-gate if (__td_event_report(self, TD_LOCK_TRY, udp)) { 281*0Sstevel@tonic-gate self->ul_td_evbuf.eventnum = TD_LOCK_TRY; 282*0Sstevel@tonic-gate tdb_event(TD_LOCK_TRY, udp); 283*0Sstevel@tonic-gate } 284*0Sstevel@tonic-gate } 285*0Sstevel@tonic-gate 286*0Sstevel@tonic-gate return (error); 287*0Sstevel@tonic-gate } 288*0Sstevel@tonic-gate 289*0Sstevel@tonic-gate #pragma weak sema_post = _sema_post 290*0Sstevel@tonic-gate int 291*0Sstevel@tonic-gate _sema_post(sema_t *sp) 292*0Sstevel@tonic-gate { 293*0Sstevel@tonic-gate lwp_sema_t *lsp = (lwp_sema_t *)sp; 294*0Sstevel@tonic-gate ulwp_t *self = curthread; 295*0Sstevel@tonic-gate uberdata_t *udp = self->ul_uberdata; 296*0Sstevel@tonic-gate tdb_sema_stats_t *ssp = SEMA_STATS(sp, udp); 297*0Sstevel@tonic-gate uint_t count; 298*0Sstevel@tonic-gate int error = 0; 299*0Sstevel@tonic-gate 300*0Sstevel@tonic-gate if (ssp) 301*0Sstevel@tonic-gate tdb_incr(ssp->sema_post); 302*0Sstevel@tonic-gate if (_semvaluemax == 0) 303*0Sstevel@tonic-gate _semvaluemax = (uint32_t)_sysconf(_SC_SEM_VALUE_MAX); 304*0Sstevel@tonic-gate 305*0Sstevel@tonic-gate if (lsp->type == USYNC_PROCESS) { /* kernel-level */ 306*0Sstevel@tonic-gate error = __lwp_sema_post(lsp); 307*0Sstevel@tonic-gate } else if (!udp->uberflags.uf_mt) { /* single threaded */ 308*0Sstevel@tonic-gate sigoff(self); 309*0Sstevel@tonic-gate if (lsp->count >= _semvaluemax) 310*0Sstevel@tonic-gate error = EOVERFLOW; 311*0Sstevel@tonic-gate else 312*0Sstevel@tonic-gate lsp->count++; 313*0Sstevel@tonic-gate sigon(self); 314*0Sstevel@tonic-gate } else { /* multithreaded */ 315*0Sstevel@tonic-gate queue_head_t *qp; 316*0Sstevel@tonic-gate ulwp_t *ulwp; 317*0Sstevel@tonic-gate int more; 318*0Sstevel@tonic-gate lwpid_t lwpid = 0; 319*0Sstevel@tonic-gate 320*0Sstevel@tonic-gate qp = queue_lock(lsp, CV); 321*0Sstevel@tonic-gate if (lsp->count >= _semvaluemax) 322*0Sstevel@tonic-gate error = EOVERFLOW; 323*0Sstevel@tonic-gate else if (lsp->count++ == 0 && lsp->sema_waiters) { 324*0Sstevel@tonic-gate if ((ulwp = dequeue(qp, lsp, &more)) == NULL) 325*0Sstevel@tonic-gate lsp->sema_waiters = 0; 326*0Sstevel@tonic-gate else { 327*0Sstevel@tonic-gate no_preempt(self); 328*0Sstevel@tonic-gate lwpid = ulwp->ul_lwpid; 329*0Sstevel@tonic-gate lsp->sema_waiters = (more? 1 : 0); 330*0Sstevel@tonic-gate } 331*0Sstevel@tonic-gate } 332*0Sstevel@tonic-gate queue_unlock(qp); 333*0Sstevel@tonic-gate if (lwpid) { 334*0Sstevel@tonic-gate (void) __lwp_unpark(lwpid); 335*0Sstevel@tonic-gate preempt(self); 336*0Sstevel@tonic-gate } 337*0Sstevel@tonic-gate } 338*0Sstevel@tonic-gate 339*0Sstevel@tonic-gate if (error == 0) { 340*0Sstevel@tonic-gate if (ssp) { 341*0Sstevel@tonic-gate /* we just incremented the count */ 342*0Sstevel@tonic-gate count = lsp->count; 343*0Sstevel@tonic-gate if (ssp->sema_max_count < count) 344*0Sstevel@tonic-gate ssp->sema_max_count = count; 345*0Sstevel@tonic-gate } 346*0Sstevel@tonic-gate } 347*0Sstevel@tonic-gate 348*0Sstevel@tonic-gate return (error); 349*0Sstevel@tonic-gate } 350