thr_kern.c revision 149617
1/* 2 * Copyright (C) 2003 Daniel M. Eischen <deischen@freebsd.org> 3 * Copyright (C) 2002 Jonathon Mini <mini@freebsd.org> 4 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 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 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by John Birrell. 18 * 4. Neither the name of the author nor the names of any co-contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 */ 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: head/lib/libkse/thread/thr_kern.c 149617 2005-08-30 12:42:00Z deischen $"); 37 38#include <sys/types.h> 39#include <sys/kse.h> 40#include <sys/ptrace.h> 41#include <sys/signalvar.h> 42#include <sys/queue.h> 43#include <machine/atomic.h> 44#include <machine/sigframe.h> 45 46#include <assert.h> 47#include <errno.h> 48#include <signal.h> 49#include <stdlib.h> 50#include <string.h> 51#include <time.h> 52#include <ucontext.h> 53#include <unistd.h> 54 55#include "atomic_ops.h" 56#include "thr_private.h" 57#include "libc_private.h" 58 59/* #define DEBUG_THREAD_KERN */ 60#ifdef DEBUG_THREAD_KERN 61#define DBG_MSG stdout_debug 62#else 63#define DBG_MSG(x...) 64#endif 65 66/* 67 * Define a high water mark for the maximum number of threads that 68 * will be cached. Once this level is reached, any extra threads 69 * will be free()'d. 70 */ 71#define MAX_CACHED_THREADS 100 72/* 73 * Define high water marks for the maximum number of KSEs and KSE groups 74 * that will be cached. Because we support 1:1 threading, there could have 75 * same number of KSEs and KSE groups as threads. Once these levels are 76 * reached, any extra KSE and KSE groups will be free()'d. 77 */ 78#define MAX_CACHED_KSES ((_thread_scope_system <= 0) ? 50 : 100) 79#define MAX_CACHED_KSEGS ((_thread_scope_system <= 0) ? 50 : 100) 80 81#define KSE_SET_MBOX(kse, thrd) \ 82 (kse)->k_kcb->kcb_kmbx.km_curthread = &(thrd)->tcb->tcb_tmbx 83 84#define KSE_SET_EXITED(kse) (kse)->k_flags |= KF_EXITED 85 86/* 87 * Macros for manipulating the run queues. The priority queue 88 * routines use the thread's pqe link and also handle the setting 89 * and clearing of the thread's THR_FLAGS_IN_RUNQ flag. 90 */ 91#define KSE_RUNQ_INSERT_HEAD(kse, thrd) \ 92 _pq_insert_head(&(kse)->k_schedq->sq_runq, thrd) 93#define KSE_RUNQ_INSERT_TAIL(kse, thrd) \ 94 _pq_insert_tail(&(kse)->k_schedq->sq_runq, thrd) 95#define KSE_RUNQ_REMOVE(kse, thrd) \ 96 _pq_remove(&(kse)->k_schedq->sq_runq, thrd) 97#define KSE_RUNQ_FIRST(kse) \ 98 ((_libkse_debug == 0) ? \ 99 _pq_first(&(kse)->k_schedq->sq_runq) : \ 100 _pq_first_debug(&(kse)->k_schedq->sq_runq)) 101 102#define KSE_RUNQ_THREADS(kse) ((kse)->k_schedq->sq_runq.pq_threads) 103 104#define THR_NEED_CANCEL(thrd) \ 105 (((thrd)->cancelflags & THR_CANCELLING) != 0 && \ 106 ((thrd)->cancelflags & PTHREAD_CANCEL_DISABLE) == 0 && \ 107 (((thrd)->cancelflags & THR_AT_CANCEL_POINT) != 0 || \ 108 ((thrd)->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0)) 109 110#define THR_NEED_ASYNC_CANCEL(thrd) \ 111 (((thrd)->cancelflags & THR_CANCELLING) != 0 && \ 112 ((thrd)->cancelflags & PTHREAD_CANCEL_DISABLE) == 0 && \ 113 (((thrd)->cancelflags & THR_AT_CANCEL_POINT) == 0 && \ 114 ((thrd)->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0)) 115 116/* 117 * We've got to keep track of everything that is allocated, not only 118 * to have a speedy free list, but also so they can be deallocated 119 * after a fork(). 120 */ 121static TAILQ_HEAD(, kse) active_kseq; 122static TAILQ_HEAD(, kse) free_kseq; 123static TAILQ_HEAD(, kse_group) free_kse_groupq; 124static TAILQ_HEAD(, kse_group) active_kse_groupq; 125static TAILQ_HEAD(, kse_group) gc_ksegq; 126static struct lock kse_lock; /* also used for kseg queue */ 127static int free_kse_count = 0; 128static int free_kseg_count = 0; 129static TAILQ_HEAD(, pthread) free_threadq; 130static struct lock thread_lock; 131static int free_thread_count = 0; 132static int inited = 0; 133static int active_kse_count = 0; 134static int active_kseg_count = 0; 135static u_int64_t next_uniqueid = 1; 136 137LIST_HEAD(thread_hash_head, pthread); 138#define THREAD_HASH_QUEUES 127 139static struct thread_hash_head thr_hashtable[THREAD_HASH_QUEUES]; 140#define THREAD_HASH(thrd) ((unsigned long)thrd % THREAD_HASH_QUEUES) 141 142/* Lock for thread tcb constructor/destructor */ 143static pthread_mutex_t _tcb_mutex; 144 145#ifdef DEBUG_THREAD_KERN 146static void dump_queues(struct kse *curkse); 147#endif 148static void kse_check_completed(struct kse *kse); 149static void kse_check_waitq(struct kse *kse); 150static void kse_fini(struct kse *curkse); 151static void kse_reinit(struct kse *kse, int sys_scope); 152static void kse_sched_multi(struct kse_mailbox *kmbx); 153static void kse_sched_single(struct kse_mailbox *kmbx); 154static void kse_switchout_thread(struct kse *kse, struct pthread *thread); 155static void kse_wait(struct kse *kse, struct pthread *td_wait, int sigseq); 156static void kse_free_unlocked(struct kse *kse); 157static void kse_destroy(struct kse *kse); 158static void kseg_free_unlocked(struct kse_group *kseg); 159static void kseg_init(struct kse_group *kseg); 160static void kseg_reinit(struct kse_group *kseg); 161static void kseg_destroy(struct kse_group *kseg); 162static void kse_waitq_insert(struct pthread *thread); 163static void kse_wakeup_multi(struct kse *curkse); 164static struct kse_mailbox *kse_wakeup_one(struct pthread *thread); 165static void thr_cleanup(struct kse *kse, struct pthread *curthread); 166static void thr_link(struct pthread *thread); 167static void thr_resume_wrapper(int sig, siginfo_t *, ucontext_t *); 168static void thr_resume_check(struct pthread *curthread, ucontext_t *ucp); 169static int thr_timedout(struct pthread *thread, struct timespec *curtime); 170static void thr_unlink(struct pthread *thread); 171static void thr_destroy(struct pthread *curthread, struct pthread *thread); 172static void thread_gc(struct pthread *thread); 173static void kse_gc(struct pthread *thread); 174static void kseg_gc(struct pthread *thread); 175 176static void __inline 177thr_accounting(struct pthread *thread) 178{ 179 if ((thread->slice_usec != -1) && 180 (thread->slice_usec <= TIMESLICE_USEC) && 181 (thread->attr.sched_policy != SCHED_FIFO)) { 182 thread->slice_usec += (thread->tcb->tcb_tmbx.tm_uticks 183 + thread->tcb->tcb_tmbx.tm_sticks) * _clock_res_usec; 184 /* Check for time quantum exceeded: */ 185 if (thread->slice_usec > TIMESLICE_USEC) 186 thread->slice_usec = -1; 187 } 188 thread->tcb->tcb_tmbx.tm_uticks = 0; 189 thread->tcb->tcb_tmbx.tm_sticks = 0; 190} 191 192/* 193 * This is called after a fork(). 194 * No locks need to be taken here since we are guaranteed to be 195 * single threaded. 196 * 197 * XXX 198 * POSIX says for threaded process, fork() function is used 199 * only to run new programs, and the effects of calling functions 200 * that require certain resources between the call to fork() and 201 * the call to an exec function are undefined. 202 * 203 * It is not safe to free memory after fork(), because these data 204 * structures may be in inconsistent state. 205 */ 206void 207_kse_single_thread(struct pthread *curthread) 208{ 209#ifdef NOTYET 210 struct kse *kse; 211 struct kse_group *kseg; 212 struct pthread *thread; 213 kse_critical_t crit; 214 int i; 215 216 if (__isthreaded) { 217 _thr_rtld_fini(); 218 _thr_signal_deinit(); 219 } 220 __isthreaded = 0; 221 /* 222 * Restore signal mask early, so any memory problems could 223 * dump core. 224 */ 225 sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 226 _thread_active_threads = 1; 227 228 /* 229 * Enter a loop to remove and free all threads other than 230 * the running thread from the active thread list: 231 */ 232 while ((thread = TAILQ_FIRST(&_thread_list)) != NULL) { 233 THR_GCLIST_REMOVE(thread); 234 /* 235 * Remove this thread from the list (the current 236 * thread will be removed but re-added by libpthread 237 * initialization. 238 */ 239 TAILQ_REMOVE(&_thread_list, thread, tle); 240 /* Make sure this isn't the running thread: */ 241 if (thread != curthread) { 242 _thr_stack_free(&thread->attr); 243 if (thread->specific != NULL) 244 free(thread->specific); 245 thr_destroy(curthread, thread); 246 } 247 } 248 249 TAILQ_INIT(&curthread->mutexq); /* initialize mutex queue */ 250 curthread->joiner = NULL; /* no joining threads yet */ 251 curthread->refcount = 0; 252 SIGEMPTYSET(curthread->sigpend); /* clear pending signals */ 253 if (curthread->specific != NULL) { 254 free(curthread->specific); 255 curthread->specific = NULL; 256 curthread->specific_data_count = 0; 257 } 258 259 /* Free the free KSEs: */ 260 while ((kse = TAILQ_FIRST(&free_kseq)) != NULL) { 261 TAILQ_REMOVE(&free_kseq, kse, k_qe); 262 kse_destroy(kse); 263 } 264 free_kse_count = 0; 265 266 /* Free the active KSEs: */ 267 while ((kse = TAILQ_FIRST(&active_kseq)) != NULL) { 268 TAILQ_REMOVE(&active_kseq, kse, k_qe); 269 kse_destroy(kse); 270 } 271 active_kse_count = 0; 272 273 /* Free the free KSEGs: */ 274 while ((kseg = TAILQ_FIRST(&free_kse_groupq)) != NULL) { 275 TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe); 276 kseg_destroy(kseg); 277 } 278 free_kseg_count = 0; 279 280 /* Free the active KSEGs: */ 281 while ((kseg = TAILQ_FIRST(&active_kse_groupq)) != NULL) { 282 TAILQ_REMOVE(&active_kse_groupq, kseg, kg_qe); 283 kseg_destroy(kseg); 284 } 285 active_kseg_count = 0; 286 287 /* Free the free threads. */ 288 while ((thread = TAILQ_FIRST(&free_threadq)) != NULL) { 289 TAILQ_REMOVE(&free_threadq, thread, tle); 290 thr_destroy(curthread, thread); 291 } 292 free_thread_count = 0; 293 294 /* Free the to-be-gc'd threads. */ 295 while ((thread = TAILQ_FIRST(&_thread_gc_list)) != NULL) { 296 TAILQ_REMOVE(&_thread_gc_list, thread, gcle); 297 thr_destroy(curthread, thread); 298 } 299 TAILQ_INIT(&gc_ksegq); 300 _gc_count = 0; 301 302 if (inited != 0) { 303 /* 304 * Destroy these locks; they'll be recreated to assure they 305 * are in the unlocked state. 306 */ 307 _lock_destroy(&kse_lock); 308 _lock_destroy(&thread_lock); 309 _lock_destroy(&_thread_list_lock); 310 inited = 0; 311 } 312 313 /* 314 * After a fork(), the leftover thread goes back to being 315 * scope process. 316 */ 317 curthread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; 318 curthread->attr.flags |= PTHREAD_SCOPE_PROCESS; 319 320 /* 321 * After a fork, we are still operating on the thread's original 322 * stack. Don't clear the THR_FLAGS_USER from the thread's 323 * attribute flags. 324 */ 325 326 /* Initialize the threads library. */ 327 curthread->kse = NULL; 328 curthread->kseg = NULL; 329 _kse_initial = NULL; 330 _libpthread_init(curthread); 331#else 332 int i; 333 334 /* Reset the current thread and KSE lock data. */ 335 for (i = 0; i < curthread->locklevel; i++) { 336 _lockuser_reinit(&curthread->lockusers[i], (void *)curthread); 337 } 338 curthread->locklevel = 0; 339 for (i = 0; i < curthread->kse->k_locklevel; i++) { 340 _lockuser_reinit(&curthread->kse->k_lockusers[i], 341 (void *)curthread->kse); 342 _LCK_SET_PRIVATE2(&curthread->kse->k_lockusers[i], NULL); 343 } 344 curthread->kse->k_locklevel = 0; 345 _thr_spinlock_init(); 346 if (__isthreaded) { 347 _thr_rtld_fini(); 348 _thr_signal_deinit(); 349 } 350 __isthreaded = 0; 351 curthread->kse->k_kcb->kcb_kmbx.km_curthread = NULL; 352 curthread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 353 354 /* After a fork(), there child should have no pending signals. */ 355 sigemptyset(&curthread->sigpend); 356 357 /* 358 * Restore signal mask early, so any memory problems could 359 * dump core. 360 */ 361 sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 362 _thread_active_threads = 1; 363#endif 364} 365 366/* 367 * This is used to initialize housekeeping and to initialize the 368 * KSD for the KSE. 369 */ 370void 371_kse_init(void) 372{ 373 if (inited == 0) { 374 TAILQ_INIT(&active_kseq); 375 TAILQ_INIT(&active_kse_groupq); 376 TAILQ_INIT(&free_kseq); 377 TAILQ_INIT(&free_kse_groupq); 378 TAILQ_INIT(&free_threadq); 379 TAILQ_INIT(&gc_ksegq); 380 if (_lock_init(&kse_lock, LCK_ADAPTIVE, 381 _kse_lock_wait, _kse_lock_wakeup) != 0) 382 PANIC("Unable to initialize free KSE queue lock"); 383 if (_lock_init(&thread_lock, LCK_ADAPTIVE, 384 _kse_lock_wait, _kse_lock_wakeup) != 0) 385 PANIC("Unable to initialize free thread queue lock"); 386 if (_lock_init(&_thread_list_lock, LCK_ADAPTIVE, 387 _kse_lock_wait, _kse_lock_wakeup) != 0) 388 PANIC("Unable to initialize thread list lock"); 389 _pthread_mutex_init(&_tcb_mutex, NULL); 390 active_kse_count = 0; 391 active_kseg_count = 0; 392 _gc_count = 0; 393 inited = 1; 394 } 395} 396 397/* 398 * This is called when the first thread (other than the initial 399 * thread) is created. 400 */ 401int 402_kse_setthreaded(int threaded) 403{ 404 sigset_t sigset; 405 406 if ((threaded != 0) && (__isthreaded == 0)) { 407 SIGFILLSET(sigset); 408 __sys_sigprocmask(SIG_SETMASK, &sigset, &_thr_initial->sigmask); 409 410 /* 411 * Tell the kernel to create a KSE for the initial thread 412 * and enable upcalls in it. 413 */ 414 _kse_initial->k_flags |= KF_STARTED; 415 416 if (_thread_scope_system <= 0) { 417 _thr_initial->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; 418 _kse_initial->k_kseg->kg_flags &= ~KGF_SINGLE_THREAD; 419 _kse_initial->k_kcb->kcb_kmbx.km_curthread = NULL; 420 } 421 else { 422 /* 423 * For bound thread, kernel reads mailbox pointer 424 * once, we'd set it here before calling kse_create. 425 */ 426 _tcb_set(_kse_initial->k_kcb, _thr_initial->tcb); 427 KSE_SET_MBOX(_kse_initial, _thr_initial); 428 _kse_initial->k_kcb->kcb_kmbx.km_flags |= KMF_BOUND; 429 } 430 431 /* 432 * Locking functions in libc are required when there are 433 * threads other than the initial thread. 434 */ 435 _thr_rtld_init(); 436 437 __isthreaded = 1; 438 if (kse_create(&_kse_initial->k_kcb->kcb_kmbx, 0) != 0) { 439 _kse_initial->k_flags &= ~KF_STARTED; 440 __isthreaded = 0; 441 PANIC("kse_create() failed\n"); 442 return (-1); 443 } 444 _thr_initial->tcb->tcb_tmbx.tm_lwp = 445 _kse_initial->k_kcb->kcb_kmbx.km_lwp; 446 _thread_activated = 1; 447 448#ifndef SYSTEM_SCOPE_ONLY 449 if (_thread_scope_system <= 0) { 450 /* Set current thread to initial thread */ 451 _tcb_set(_kse_initial->k_kcb, _thr_initial->tcb); 452 KSE_SET_MBOX(_kse_initial, _thr_initial); 453 _thr_start_sig_daemon(); 454 _thr_setmaxconcurrency(); 455 } 456 else 457#endif 458 __sys_sigprocmask(SIG_SETMASK, &_thr_initial->sigmask, 459 NULL); 460 } 461 return (0); 462} 463 464/* 465 * Lock wait and wakeup handlers for KSE locks. These are only used by 466 * KSEs, and should never be used by threads. KSE locks include the 467 * KSE group lock (used for locking the scheduling queue) and the 468 * kse_lock defined above. 469 * 470 * When a KSE lock attempt blocks, the entire KSE blocks allowing another 471 * KSE to run. For the most part, it doesn't make much sense to try and 472 * schedule another thread because you need to lock the scheduling queue 473 * in order to do that. And since the KSE lock is used to lock the scheduling 474 * queue, you would just end up blocking again. 475 */ 476void 477_kse_lock_wait(struct lock *lock, struct lockuser *lu) 478{ 479 struct kse *curkse = (struct kse *)_LCK_GET_PRIVATE(lu); 480 struct timespec ts; 481 int saved_flags; 482 483 if (curkse->k_kcb->kcb_kmbx.km_curthread != NULL) 484 PANIC("kse_lock_wait does not disable upcall.\n"); 485 /* 486 * Enter a loop to wait until we get the lock. 487 */ 488 ts.tv_sec = 0; 489 ts.tv_nsec = 1000000; /* 1 sec */ 490 while (!_LCK_GRANTED(lu)) { 491 /* 492 * Yield the kse and wait to be notified when the lock 493 * is granted. 494 */ 495 saved_flags = curkse->k_kcb->kcb_kmbx.km_flags; 496 curkse->k_kcb->kcb_kmbx.km_flags |= KMF_NOUPCALL | 497 KMF_NOCOMPLETED; 498 kse_release(&ts); 499 curkse->k_kcb->kcb_kmbx.km_flags = saved_flags; 500 } 501} 502 503void 504_kse_lock_wakeup(struct lock *lock, struct lockuser *lu) 505{ 506 struct kse *curkse; 507 struct kse *kse; 508 struct kse_mailbox *mbx; 509 510 curkse = _get_curkse(); 511 kse = (struct kse *)_LCK_GET_PRIVATE(lu); 512 513 if (kse == curkse) 514 PANIC("KSE trying to wake itself up in lock"); 515 else { 516 mbx = &kse->k_kcb->kcb_kmbx; 517 _lock_grant(lock, lu); 518 /* 519 * Notify the owning kse that it has the lock. 520 * It is safe to pass invalid address to kse_wakeup 521 * even if the mailbox is not in kernel at all, 522 * and waking up a wrong kse is also harmless. 523 */ 524 kse_wakeup(mbx); 525 } 526} 527 528/* 529 * Thread wait and wakeup handlers for thread locks. These are only used 530 * by threads, never by KSEs. Thread locks include the per-thread lock 531 * (defined in its structure), and condition variable and mutex locks. 532 */ 533void 534_thr_lock_wait(struct lock *lock, struct lockuser *lu) 535{ 536 struct pthread *curthread = (struct pthread *)lu->lu_private; 537 538 do { 539 THR_LOCK_SWITCH(curthread); 540 THR_SET_STATE(curthread, PS_LOCKWAIT); 541 _thr_sched_switch_unlocked(curthread); 542 } while (!_LCK_GRANTED(lu)); 543} 544 545void 546_thr_lock_wakeup(struct lock *lock, struct lockuser *lu) 547{ 548 struct pthread *thread; 549 struct pthread *curthread; 550 struct kse_mailbox *kmbx; 551 552 curthread = _get_curthread(); 553 thread = (struct pthread *)_LCK_GET_PRIVATE(lu); 554 555 THR_SCHED_LOCK(curthread, thread); 556 _lock_grant(lock, lu); 557 kmbx = _thr_setrunnable_unlocked(thread); 558 THR_SCHED_UNLOCK(curthread, thread); 559 if (kmbx != NULL) 560 kse_wakeup(kmbx); 561} 562 563kse_critical_t 564_kse_critical_enter(void) 565{ 566 kse_critical_t crit; 567 568 crit = (kse_critical_t)_kcb_critical_enter(); 569 return (crit); 570} 571 572void 573_kse_critical_leave(kse_critical_t crit) 574{ 575 struct pthread *curthread; 576 577 _kcb_critical_leave((struct kse_thr_mailbox *)crit); 578 if ((crit != NULL) && ((curthread = _get_curthread()) != NULL)) 579 THR_YIELD_CHECK(curthread); 580} 581 582int 583_kse_in_critical(void) 584{ 585 return (_kcb_in_critical()); 586} 587 588void 589_thr_critical_enter(struct pthread *thread) 590{ 591 thread->critical_count++; 592} 593 594void 595_thr_critical_leave(struct pthread *thread) 596{ 597 thread->critical_count--; 598 THR_YIELD_CHECK(thread); 599} 600 601void 602_thr_sched_switch(struct pthread *curthread) 603{ 604 struct kse *curkse; 605 606 (void)_kse_critical_enter(); 607 curkse = _get_curkse(); 608 KSE_SCHED_LOCK(curkse, curkse->k_kseg); 609 _thr_sched_switch_unlocked(curthread); 610} 611 612/* 613 * XXX - We may need to take the scheduling lock before calling 614 * this, or perhaps take the lock within here before 615 * doing anything else. 616 */ 617void 618_thr_sched_switch_unlocked(struct pthread *curthread) 619{ 620 struct kse *curkse; 621 volatile int resume_once = 0; 622 ucontext_t *uc; 623 624 /* We're in the scheduler, 5 by 5: */ 625 curkse = curthread->kse; 626 627 curthread->need_switchout = 1; /* The thread yielded on its own. */ 628 curthread->critical_yield = 0; /* No need to yield anymore. */ 629 630 /* Thread can unlock the scheduler lock. */ 631 curthread->lock_switch = 1; 632 633 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) 634 kse_sched_single(&curkse->k_kcb->kcb_kmbx); 635 else { 636 if (__predict_false(_libkse_debug != 0)) { 637 /* 638 * Because debugger saves single step status in thread 639 * mailbox's tm_dflags, we can safely clear single 640 * step status here. the single step status will be 641 * restored by kse_switchin when the thread is 642 * switched in again. This also lets uts run in full 643 * speed. 644 */ 645 ptrace(PT_CLEARSTEP, curkse->k_kcb->kcb_kmbx.km_lwp, 646 (caddr_t) 1, 0); 647 } 648 649 KSE_SET_SWITCH(curkse); 650 _thread_enter_uts(curthread->tcb, curkse->k_kcb); 651 } 652 653 /* 654 * Unlock the scheduling queue and leave the 655 * critical region. 656 */ 657 /* Don't trust this after a switch! */ 658 curkse = curthread->kse; 659 660 curthread->lock_switch = 0; 661 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 662 _kse_critical_leave(&curthread->tcb->tcb_tmbx); 663 664 /* 665 * This thread is being resumed; check for cancellations. 666 */ 667 if (THR_NEED_ASYNC_CANCEL(curthread) && !THR_IN_CRITICAL(curthread)) { 668 uc = alloca(sizeof(ucontext_t)); 669 resume_once = 0; 670 THR_GETCONTEXT(uc); 671 if (resume_once == 0) { 672 resume_once = 1; 673 curthread->check_pending = 0; 674 thr_resume_check(curthread, uc); 675 } 676 } 677 THR_ACTIVATE_LAST_LOCK(curthread); 678} 679 680/* 681 * This is the scheduler for a KSE which runs a scope system thread. 682 * The multi-thread KSE scheduler should also work for a single threaded 683 * KSE, but we use a separate scheduler so that it can be fine-tuned 684 * to be more efficient (and perhaps not need a separate stack for 685 * the KSE, allowing it to use the thread's stack). 686 */ 687 688static void 689kse_sched_single(struct kse_mailbox *kmbx) 690{ 691 struct kse *curkse; 692 struct pthread *curthread; 693 struct timespec ts; 694 sigset_t sigmask; 695 int i, sigseqno, level, first = 0; 696 697 curkse = (struct kse *)kmbx->km_udata; 698 curthread = curkse->k_curthread; 699 700 if (__predict_false((curkse->k_flags & KF_INITIALIZED) == 0)) { 701 /* Setup this KSEs specific data. */ 702 _kcb_set(curkse->k_kcb); 703 _tcb_set(curkse->k_kcb, curthread->tcb); 704 curkse->k_flags |= KF_INITIALIZED; 705 first = 1; 706 curthread->active = 1; 707 708 /* Setup kernel signal masks for new thread. */ 709 __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 710 /* 711 * Enter critical region, this is meanless for bound thread, 712 * It is used to let other code work, those code want mailbox 713 * to be cleared. 714 */ 715 (void)_kse_critical_enter(); 716 } else { 717 /* 718 * Bound thread always has tcb set, this prevent some 719 * code from blindly setting bound thread tcb to NULL, 720 * buggy code ? 721 */ 722 _tcb_set(curkse->k_kcb, curthread->tcb); 723 } 724 725 curthread->critical_yield = 0; 726 curthread->need_switchout = 0; 727 728 /* 729 * Lock the scheduling queue. 730 * 731 * There is no scheduling queue for single threaded KSEs, 732 * but we need a lock for protection regardless. 733 */ 734 if (curthread->lock_switch == 0) 735 KSE_SCHED_LOCK(curkse, curkse->k_kseg); 736 737 /* 738 * This has to do the job of kse_switchout_thread(), only 739 * for a single threaded KSE/KSEG. 740 */ 741 742 switch (curthread->state) { 743 case PS_MUTEX_WAIT: 744 case PS_COND_WAIT: 745 if (THR_NEED_CANCEL(curthread)) { 746 curthread->interrupted = 1; 747 curthread->continuation = _thr_finish_cancellation; 748 THR_SET_STATE(curthread, PS_RUNNING); 749 } 750 break; 751 752 case PS_LOCKWAIT: 753 /* 754 * This state doesn't timeout. 755 */ 756 curthread->wakeup_time.tv_sec = -1; 757 curthread->wakeup_time.tv_nsec = -1; 758 level = curthread->locklevel - 1; 759 if (_LCK_GRANTED(&curthread->lockusers[level])) 760 THR_SET_STATE(curthread, PS_RUNNING); 761 break; 762 763 case PS_DEAD: 764 curthread->check_pending = 0; 765 /* Unlock the scheduling queue and exit the KSE and thread. */ 766 thr_cleanup(curkse, curthread); 767 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 768 PANIC("bound thread shouldn't get here\n"); 769 break; 770 771 case PS_JOIN: 772 if (THR_NEED_CANCEL(curthread)) { 773 curthread->join_status.thread = NULL; 774 THR_SET_STATE(curthread, PS_RUNNING); 775 } else { 776 /* 777 * This state doesn't timeout. 778 */ 779 curthread->wakeup_time.tv_sec = -1; 780 curthread->wakeup_time.tv_nsec = -1; 781 } 782 break; 783 784 case PS_SUSPENDED: 785 if (THR_NEED_CANCEL(curthread)) { 786 curthread->interrupted = 1; 787 THR_SET_STATE(curthread, PS_RUNNING); 788 } else { 789 /* 790 * These states don't timeout. 791 */ 792 curthread->wakeup_time.tv_sec = -1; 793 curthread->wakeup_time.tv_nsec = -1; 794 } 795 break; 796 797 case PS_RUNNING: 798 if ((curthread->flags & THR_FLAGS_SUSPENDED) != 0 && 799 !THR_NEED_CANCEL(curthread)) { 800 THR_SET_STATE(curthread, PS_SUSPENDED); 801 /* 802 * These states don't timeout. 803 */ 804 curthread->wakeup_time.tv_sec = -1; 805 curthread->wakeup_time.tv_nsec = -1; 806 } 807 break; 808 809 case PS_SIGWAIT: 810 PANIC("bound thread does not have SIGWAIT state\n"); 811 812 case PS_SLEEP_WAIT: 813 PANIC("bound thread does not have SLEEP_WAIT state\n"); 814 815 case PS_SIGSUSPEND: 816 PANIC("bound thread does not have SIGSUSPEND state\n"); 817 818 case PS_DEADLOCK: 819 /* 820 * These states don't timeout and don't need 821 * to be in the waiting queue. 822 */ 823 curthread->wakeup_time.tv_sec = -1; 824 curthread->wakeup_time.tv_nsec = -1; 825 break; 826 827 default: 828 PANIC("Unknown state\n"); 829 break; 830 } 831 832 while (curthread->state != PS_RUNNING) { 833 sigseqno = curkse->k_sigseqno; 834 if (curthread->check_pending != 0) { 835 /* 836 * Install pending signals into the frame, possible 837 * cause mutex or condvar backout. 838 */ 839 curthread->check_pending = 0; 840 SIGFILLSET(sigmask); 841 842 /* 843 * Lock out kernel signal code when we are processing 844 * signals, and get a fresh copy of signal mask. 845 */ 846 __sys_sigprocmask(SIG_SETMASK, &sigmask, 847 &curthread->sigmask); 848 for (i = 1; i <= _SIG_MAXSIG; i++) { 849 if (SIGISMEMBER(curthread->sigmask, i)) 850 continue; 851 if (SIGISMEMBER(curthread->sigpend, i)) 852 (void)_thr_sig_add(curthread, i, 853 &curthread->siginfo[i-1]); 854 } 855 __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, 856 NULL); 857 /* The above code might make thread runnable */ 858 if (curthread->state == PS_RUNNING) 859 break; 860 } 861 THR_DEACTIVATE_LAST_LOCK(curthread); 862 kse_wait(curkse, curthread, sigseqno); 863 THR_ACTIVATE_LAST_LOCK(curthread); 864 if (curthread->wakeup_time.tv_sec >= 0) { 865 KSE_GET_TOD(curkse, &ts); 866 if (thr_timedout(curthread, &ts)) { 867 /* Indicate the thread timedout: */ 868 curthread->timeout = 1; 869 /* Make the thread runnable. */ 870 THR_SET_STATE(curthread, PS_RUNNING); 871 } 872 } 873 } 874 875 if (curthread->lock_switch == 0) { 876 /* Unlock the scheduling queue. */ 877 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 878 } 879 880 DBG_MSG("Continuing bound thread %p\n", curthread); 881 if (first) { 882 _kse_critical_leave(&curthread->tcb->tcb_tmbx); 883 pthread_exit(curthread->start_routine(curthread->arg)); 884 } 885} 886 887#ifdef DEBUG_THREAD_KERN 888static void 889dump_queues(struct kse *curkse) 890{ 891 struct pthread *thread; 892 893 DBG_MSG("Threads in waiting queue:\n"); 894 TAILQ_FOREACH(thread, &curkse->k_kseg->kg_schedq.sq_waitq, pqe) { 895 DBG_MSG(" thread %p, state %d, blocked %d\n", 896 thread, thread->state, thread->blocked); 897 } 898} 899#endif 900 901/* 902 * This is the scheduler for a KSE which runs multiple threads. 903 */ 904static void 905kse_sched_multi(struct kse_mailbox *kmbx) 906{ 907 struct kse *curkse; 908 struct pthread *curthread, *td_wait; 909 int ret; 910 911 curkse = (struct kse *)kmbx->km_udata; 912 THR_ASSERT(curkse->k_kcb->kcb_kmbx.km_curthread == NULL, 913 "Mailbox not null in kse_sched_multi"); 914 915 /* Check for first time initialization: */ 916 if (__predict_false((curkse->k_flags & KF_INITIALIZED) == 0)) { 917 /* Setup this KSEs specific data. */ 918 _kcb_set(curkse->k_kcb); 919 920 /* Set this before grabbing the context. */ 921 curkse->k_flags |= KF_INITIALIZED; 922 } 923 924 /* 925 * No current thread anymore, calling _get_curthread in UTS 926 * should dump core 927 */ 928 _tcb_set(curkse->k_kcb, NULL); 929 930 /* If this is an upcall; take the scheduler lock. */ 931 if (!KSE_IS_SWITCH(curkse)) 932 KSE_SCHED_LOCK(curkse, curkse->k_kseg); 933 else 934 KSE_CLEAR_SWITCH(curkse); 935 936 if (KSE_IS_IDLE(curkse)) { 937 KSE_CLEAR_IDLE(curkse); 938 curkse->k_kseg->kg_idle_kses--; 939 } 940 941 /* 942 * Now that the scheduler lock is held, get the current 943 * thread. The KSE's current thread cannot be safely 944 * examined without the lock because it could have returned 945 * as completed on another KSE. See kse_check_completed(). 946 */ 947 curthread = curkse->k_curthread; 948 949 /* 950 * If the current thread was completed in another KSE, then 951 * it will be in the run queue. Don't mark it as being blocked. 952 */ 953 if ((curthread != NULL) && 954 ((curthread->flags & THR_FLAGS_IN_RUNQ) == 0) && 955 (curthread->need_switchout == 0)) { 956 /* 957 * Assume the current thread is blocked; when the 958 * completed threads are checked and if the current 959 * thread is among the completed, the blocked flag 960 * will be cleared. 961 */ 962 curthread->blocked = 1; 963 DBG_MSG("Running thread %p is now blocked in kernel.\n", 964 curthread); 965 } 966 967 /* Check for any unblocked threads in the kernel. */ 968 kse_check_completed(curkse); 969 970 /* 971 * Check for threads that have timed-out. 972 */ 973 kse_check_waitq(curkse); 974 975 /* 976 * Switchout the current thread, if necessary, as the last step 977 * so that it is inserted into the run queue (if it's runnable) 978 * _after_ any other threads that were added to it above. 979 */ 980 if (curthread == NULL) 981 ; /* Nothing to do here. */ 982 else if ((curthread->need_switchout == 0) && DBG_CAN_RUN(curthread) && 983 (curthread->blocked == 0) && (THR_IN_CRITICAL(curthread))) { 984 /* 985 * Resume the thread and tell it to yield when 986 * it leaves the critical region. 987 */ 988 curthread->critical_yield = 1; 989 curthread->active = 1; 990 if ((curthread->flags & THR_FLAGS_IN_RUNQ) != 0) 991 KSE_RUNQ_REMOVE(curkse, curthread); 992 curkse->k_curthread = curthread; 993 curthread->kse = curkse; 994 DBG_MSG("Continuing thread %p in critical region\n", 995 curthread); 996 kse_wakeup_multi(curkse); 997 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 998 ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1); 999 if (ret != 0) 1000 PANIC("Can't resume thread in critical region\n"); 1001 } 1002 else if ((curthread->flags & THR_FLAGS_IN_RUNQ) == 0) { 1003 curthread->tcb->tcb_tmbx.tm_lwp = 0; 1004 kse_switchout_thread(curkse, curthread); 1005 } 1006 curkse->k_curthread = NULL; 1007 1008#ifdef DEBUG_THREAD_KERN 1009 dump_queues(curkse); 1010#endif 1011 1012 /* Check if there are no threads ready to run: */ 1013 while (((curthread = KSE_RUNQ_FIRST(curkse)) == NULL) && 1014 (curkse->k_kseg->kg_threadcount != 0) && 1015 ((curkse->k_flags & KF_TERMINATED) == 0)) { 1016 /* 1017 * Wait for a thread to become active or until there are 1018 * no more threads. 1019 */ 1020 td_wait = KSE_WAITQ_FIRST(curkse); 1021 kse_wait(curkse, td_wait, 0); 1022 kse_check_completed(curkse); 1023 kse_check_waitq(curkse); 1024 } 1025 1026 /* Check for no more threads: */ 1027 if ((curkse->k_kseg->kg_threadcount == 0) || 1028 ((curkse->k_flags & KF_TERMINATED) != 0)) { 1029 /* 1030 * Normally this shouldn't return, but it will if there 1031 * are other KSEs running that create new threads that 1032 * are assigned to this KSE[G]. For instance, if a scope 1033 * system thread were to create a scope process thread 1034 * and this kse[g] is the initial kse[g], then that newly 1035 * created thread would be assigned to us (the initial 1036 * kse[g]). 1037 */ 1038 kse_wakeup_multi(curkse); 1039 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 1040 kse_fini(curkse); 1041 /* never returns */ 1042 } 1043 1044 THR_ASSERT(curthread != NULL, 1045 "Return from kse_wait/fini without thread."); 1046 THR_ASSERT(curthread->state != PS_DEAD, 1047 "Trying to resume dead thread!"); 1048 KSE_RUNQ_REMOVE(curkse, curthread); 1049 1050 /* 1051 * Make the selected thread the current thread. 1052 */ 1053 curkse->k_curthread = curthread; 1054 1055 /* 1056 * Make sure the current thread's kse points to this kse. 1057 */ 1058 curthread->kse = curkse; 1059 1060 /* 1061 * Reset the time slice if this thread is running for the first 1062 * time or running again after using its full time slice allocation. 1063 */ 1064 if (curthread->slice_usec == -1) 1065 curthread->slice_usec = 0; 1066 1067 /* Mark the thread active. */ 1068 curthread->active = 1; 1069 1070 /* 1071 * The thread's current signal frame will only be NULL if it 1072 * is being resumed after being blocked in the kernel. In 1073 * this case, and if the thread needs to run down pending 1074 * signals or needs a cancellation check, we need to add a 1075 * signal frame to the thread's context. 1076 */ 1077 if (curthread->lock_switch == 0 && curthread->state == PS_RUNNING && 1078 (curthread->check_pending != 0 || 1079 THR_NEED_ASYNC_CANCEL(curthread)) && 1080 !THR_IN_CRITICAL(curthread)) { 1081 curthread->check_pending = 0; 1082 signalcontext(&curthread->tcb->tcb_tmbx.tm_context, 0, 1083 (__sighandler_t *)thr_resume_wrapper); 1084 } 1085 kse_wakeup_multi(curkse); 1086 /* 1087 * Continue the thread at its current frame: 1088 */ 1089 if (curthread->lock_switch != 0) { 1090 /* 1091 * This thread came from a scheduler switch; it will 1092 * unlock the scheduler lock and set the mailbox. 1093 */ 1094 ret = _thread_switch(curkse->k_kcb, curthread->tcb, 0); 1095 } else { 1096 /* This thread won't unlock the scheduler lock. */ 1097 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 1098 ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1); 1099 } 1100 if (ret != 0) 1101 PANIC("Thread has returned from _thread_switch"); 1102 1103 /* This point should not be reached. */ 1104 PANIC("Thread has returned from _thread_switch"); 1105} 1106 1107static void 1108thr_resume_wrapper(int sig, siginfo_t *siginfo, ucontext_t *ucp) 1109{ 1110 struct pthread *curthread = _get_curthread(); 1111 struct kse *curkse; 1112 int ret, err_save = errno; 1113 1114 DBG_MSG(">>> sig wrapper\n"); 1115 if (curthread->lock_switch) 1116 PANIC("thr_resume_wrapper, lock_switch != 0\n"); 1117 thr_resume_check(curthread, ucp); 1118 errno = err_save; 1119 _kse_critical_enter(); 1120 curkse = curthread->kse; 1121 curthread->tcb->tcb_tmbx.tm_context = *ucp; 1122 ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1); 1123 if (ret != 0) 1124 PANIC("thr_resume_wrapper: thread has returned " 1125 "from _thread_switch"); 1126 /* THR_SETCONTEXT(ucp); */ /* not work, why ? */ 1127} 1128 1129static void 1130thr_resume_check(struct pthread *curthread, ucontext_t *ucp) 1131{ 1132 _thr_sig_rundown(curthread, ucp); 1133 1134 if (THR_NEED_ASYNC_CANCEL(curthread)) 1135 pthread_testcancel(); 1136} 1137 1138/* 1139 * Clean up a thread. This must be called with the thread's KSE 1140 * scheduling lock held. The thread must be a thread from the 1141 * KSE's group. 1142 */ 1143static void 1144thr_cleanup(struct kse *curkse, struct pthread *thread) 1145{ 1146 struct pthread *joiner; 1147 struct kse_mailbox *kmbx = NULL; 1148 int sys_scope; 1149 1150 if ((joiner = thread->joiner) != NULL) { 1151 /* Joinee scheduler lock held; joiner won't leave. */ 1152 if (joiner->kseg == curkse->k_kseg) { 1153 if (joiner->join_status.thread == thread) { 1154 joiner->join_status.thread = NULL; 1155 joiner->join_status.ret = thread->ret; 1156 (void)_thr_setrunnable_unlocked(joiner); 1157 } 1158 } else { 1159 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 1160 /* The joiner may have removed itself and exited. */ 1161 if (_thr_ref_add(thread, joiner, 0) == 0) { 1162 KSE_SCHED_LOCK(curkse, joiner->kseg); 1163 if (joiner->join_status.thread == thread) { 1164 joiner->join_status.thread = NULL; 1165 joiner->join_status.ret = thread->ret; 1166 kmbx = _thr_setrunnable_unlocked(joiner); 1167 } 1168 KSE_SCHED_UNLOCK(curkse, joiner->kseg); 1169 _thr_ref_delete(thread, joiner); 1170 if (kmbx != NULL) 1171 kse_wakeup(kmbx); 1172 } 1173 KSE_SCHED_LOCK(curkse, curkse->k_kseg); 1174 } 1175 thread->attr.flags |= PTHREAD_DETACHED; 1176 } 1177 1178 if (!(sys_scope = (thread->attr.flags & PTHREAD_SCOPE_SYSTEM))) { 1179 /* 1180 * Remove the thread from the KSEG's list of threads. 1181 */ 1182 KSEG_THRQ_REMOVE(thread->kseg, thread); 1183 /* 1184 * Migrate the thread to the main KSE so that this 1185 * KSE and KSEG can be cleaned when their last thread 1186 * exits. 1187 */ 1188 thread->kseg = _kse_initial->k_kseg; 1189 thread->kse = _kse_initial; 1190 } 1191 1192 /* 1193 * We can't hold the thread list lock while holding the 1194 * scheduler lock. 1195 */ 1196 KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); 1197 DBG_MSG("Adding thread %p to GC list\n", thread); 1198 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); 1199 thread->tlflags |= TLFLAGS_GC_SAFE; 1200 THR_GCLIST_ADD(thread); 1201 KSE_LOCK_RELEASE(curkse, &_thread_list_lock); 1202 if (sys_scope) { 1203 /* 1204 * System scope thread is single thread group, 1205 * when thread is exited, its kse and ksegrp should 1206 * be recycled as well. 1207 * kse upcall stack belongs to thread, clear it here. 1208 */ 1209 curkse->k_stack.ss_sp = 0; 1210 curkse->k_stack.ss_size = 0; 1211 kse_exit(); 1212 PANIC("kse_exit() failed for system scope thread"); 1213 } 1214 KSE_SCHED_LOCK(curkse, curkse->k_kseg); 1215} 1216 1217void 1218_thr_gc(struct pthread *curthread) 1219{ 1220 thread_gc(curthread); 1221 kse_gc(curthread); 1222 kseg_gc(curthread); 1223} 1224 1225static void 1226thread_gc(struct pthread *curthread) 1227{ 1228 struct pthread *td, *td_next; 1229 kse_critical_t crit; 1230 TAILQ_HEAD(, pthread) worklist; 1231 1232 TAILQ_INIT(&worklist); 1233 crit = _kse_critical_enter(); 1234 KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock); 1235 1236 /* Check the threads waiting for GC. */ 1237 for (td = TAILQ_FIRST(&_thread_gc_list); td != NULL; td = td_next) { 1238 td_next = TAILQ_NEXT(td, gcle); 1239 if ((td->tlflags & TLFLAGS_GC_SAFE) == 0) 1240 continue; 1241 else if (((td->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) && 1242 ((td->kse->k_kcb->kcb_kmbx.km_flags & KMF_DONE) == 0)) { 1243 /* 1244 * The thread and KSE are operating on the same 1245 * stack. Wait for the KSE to exit before freeing 1246 * the thread's stack as well as everything else. 1247 */ 1248 continue; 1249 } 1250 /* 1251 * Remove the thread from the GC list. If the thread 1252 * isn't yet detached, it will get added back to the 1253 * GC list at a later time. 1254 */ 1255 THR_GCLIST_REMOVE(td); 1256 DBG_MSG("Freeing thread %p stack\n", td); 1257 /* 1258 * We can free the thread stack since it's no longer 1259 * in use. 1260 */ 1261 _thr_stack_free(&td->attr); 1262 if (((td->attr.flags & PTHREAD_DETACHED) != 0) && 1263 (td->refcount == 0)) { 1264 /* 1265 * The thread has detached and is no longer 1266 * referenced. It is safe to remove all 1267 * remnants of the thread. 1268 */ 1269 THR_LIST_REMOVE(td); 1270 TAILQ_INSERT_HEAD(&worklist, td, gcle); 1271 } 1272 } 1273 KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock); 1274 _kse_critical_leave(crit); 1275 1276 while ((td = TAILQ_FIRST(&worklist)) != NULL) { 1277 TAILQ_REMOVE(&worklist, td, gcle); 1278 /* 1279 * XXX we don't free initial thread and its kse 1280 * (if thread is a bound thread), because there might 1281 * have some code referencing initial thread and kse. 1282 */ 1283 if (td == _thr_initial) { 1284 DBG_MSG("Initial thread won't be freed\n"); 1285 continue; 1286 } 1287 1288 if ((td->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) { 1289 crit = _kse_critical_enter(); 1290 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 1291 kse_free_unlocked(td->kse); 1292 kseg_free_unlocked(td->kseg); 1293 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 1294 _kse_critical_leave(crit); 1295 } 1296 DBG_MSG("Freeing thread %p\n", td); 1297 _thr_free(curthread, td); 1298 } 1299} 1300 1301static void 1302kse_gc(struct pthread *curthread) 1303{ 1304 kse_critical_t crit; 1305 TAILQ_HEAD(, kse) worklist; 1306 struct kse *kse; 1307 1308 if (free_kse_count <= MAX_CACHED_KSES) 1309 return; 1310 TAILQ_INIT(&worklist); 1311 crit = _kse_critical_enter(); 1312 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 1313 while (free_kse_count > MAX_CACHED_KSES) { 1314 kse = TAILQ_FIRST(&free_kseq); 1315 TAILQ_REMOVE(&free_kseq, kse, k_qe); 1316 TAILQ_INSERT_HEAD(&worklist, kse, k_qe); 1317 free_kse_count--; 1318 } 1319 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 1320 _kse_critical_leave(crit); 1321 1322 while ((kse = TAILQ_FIRST(&worklist))) { 1323 TAILQ_REMOVE(&worklist, kse, k_qe); 1324 kse_destroy(kse); 1325 } 1326} 1327 1328static void 1329kseg_gc(struct pthread *curthread) 1330{ 1331 kse_critical_t crit; 1332 TAILQ_HEAD(, kse_group) worklist; 1333 struct kse_group *kseg; 1334 1335 if (free_kseg_count <= MAX_CACHED_KSEGS) 1336 return; 1337 crit = _kse_critical_enter(); 1338 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 1339 while (free_kseg_count > MAX_CACHED_KSEGS) { 1340 kseg = TAILQ_FIRST(&free_kse_groupq); 1341 TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe); 1342 free_kseg_count--; 1343 TAILQ_INSERT_HEAD(&worklist, kseg, kg_qe); 1344 } 1345 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 1346 _kse_critical_leave(crit); 1347 1348 while ((kseg = TAILQ_FIRST(&worklist))) { 1349 TAILQ_REMOVE(&worklist, kseg, kg_qe); 1350 kseg_destroy(kseg); 1351 } 1352} 1353 1354/* 1355 * Only new threads that are running or suspended may be scheduled. 1356 */ 1357int 1358_thr_schedule_add(struct pthread *curthread, struct pthread *newthread) 1359{ 1360 kse_critical_t crit; 1361 int ret; 1362 1363 /* Add the new thread. */ 1364 thr_link(newthread); 1365 1366 /* 1367 * If this is the first time creating a thread, make sure 1368 * the mailbox is set for the current thread. 1369 */ 1370 if ((newthread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) { 1371 /* We use the thread's stack as the KSE's stack. */ 1372 newthread->kse->k_kcb->kcb_kmbx.km_stack.ss_sp = 1373 newthread->attr.stackaddr_attr; 1374 newthread->kse->k_kcb->kcb_kmbx.km_stack.ss_size = 1375 newthread->attr.stacksize_attr; 1376 1377 /* 1378 * No need to lock the scheduling queue since the 1379 * KSE/KSEG pair have not yet been started. 1380 */ 1381 KSEG_THRQ_ADD(newthread->kseg, newthread); 1382 /* this thread never gives up kse */ 1383 newthread->active = 1; 1384 newthread->kse->k_curthread = newthread; 1385 newthread->kse->k_kcb->kcb_kmbx.km_flags = KMF_BOUND; 1386 newthread->kse->k_kcb->kcb_kmbx.km_func = 1387 (kse_func_t *)kse_sched_single; 1388 newthread->kse->k_kcb->kcb_kmbx.km_quantum = 0; 1389 KSE_SET_MBOX(newthread->kse, newthread); 1390 /* 1391 * This thread needs a new KSE and KSEG. 1392 */ 1393 newthread->kse->k_flags &= ~KF_INITIALIZED; 1394 newthread->kse->k_flags |= KF_STARTED; 1395 /* Fire up! */ 1396 ret = kse_create(&newthread->kse->k_kcb->kcb_kmbx, 1); 1397 if (ret != 0) 1398 ret = errno; 1399 } 1400 else { 1401 /* 1402 * Lock the KSE and add the new thread to its list of 1403 * assigned threads. If the new thread is runnable, also 1404 * add it to the KSE's run queue. 1405 */ 1406 crit = _kse_critical_enter(); 1407 KSE_SCHED_LOCK(curthread->kse, newthread->kseg); 1408 KSEG_THRQ_ADD(newthread->kseg, newthread); 1409 if (newthread->state == PS_RUNNING) 1410 THR_RUNQ_INSERT_TAIL(newthread); 1411 if ((newthread->kse->k_flags & KF_STARTED) == 0) { 1412 /* 1413 * This KSE hasn't been started yet. Start it 1414 * outside of holding the lock. 1415 */ 1416 newthread->kse->k_flags |= KF_STARTED; 1417 newthread->kse->k_kcb->kcb_kmbx.km_func = 1418 (kse_func_t *)kse_sched_multi; 1419 newthread->kse->k_kcb->kcb_kmbx.km_flags = 0; 1420 kse_create(&newthread->kse->k_kcb->kcb_kmbx, 0); 1421 } else if ((newthread->state == PS_RUNNING) && 1422 KSE_IS_IDLE(newthread->kse)) { 1423 /* 1424 * The thread is being scheduled on another KSEG. 1425 */ 1426 kse_wakeup_one(newthread); 1427 } 1428 KSE_SCHED_UNLOCK(curthread->kse, newthread->kseg); 1429 _kse_critical_leave(crit); 1430 ret = 0; 1431 } 1432 if (ret != 0) 1433 thr_unlink(newthread); 1434 1435 return (ret); 1436} 1437 1438void 1439kse_waitq_insert(struct pthread *thread) 1440{ 1441 struct pthread *td; 1442 1443 if (thread->wakeup_time.tv_sec == -1) 1444 TAILQ_INSERT_TAIL(&thread->kse->k_schedq->sq_waitq, thread, 1445 pqe); 1446 else { 1447 td = TAILQ_FIRST(&thread->kse->k_schedq->sq_waitq); 1448 while ((td != NULL) && (td->wakeup_time.tv_sec != -1) && 1449 ((td->wakeup_time.tv_sec < thread->wakeup_time.tv_sec) || 1450 ((td->wakeup_time.tv_sec == thread->wakeup_time.tv_sec) && 1451 (td->wakeup_time.tv_nsec <= thread->wakeup_time.tv_nsec)))) 1452 td = TAILQ_NEXT(td, pqe); 1453 if (td == NULL) 1454 TAILQ_INSERT_TAIL(&thread->kse->k_schedq->sq_waitq, 1455 thread, pqe); 1456 else 1457 TAILQ_INSERT_BEFORE(td, thread, pqe); 1458 } 1459 thread->flags |= THR_FLAGS_IN_WAITQ; 1460} 1461 1462/* 1463 * This must be called with the scheduling lock held. 1464 */ 1465static void 1466kse_check_completed(struct kse *kse) 1467{ 1468 struct pthread *thread; 1469 struct kse_thr_mailbox *completed; 1470 int sig; 1471 1472 if ((completed = kse->k_kcb->kcb_kmbx.km_completed) != NULL) { 1473 kse->k_kcb->kcb_kmbx.km_completed = NULL; 1474 while (completed != NULL) { 1475 thread = completed->tm_udata; 1476 DBG_MSG("Found completed thread %p, name %s\n", 1477 thread, 1478 (thread->name == NULL) ? "none" : thread->name); 1479 thread->blocked = 0; 1480 if (thread != kse->k_curthread) { 1481 thr_accounting(thread); 1482 if ((thread->flags & THR_FLAGS_SUSPENDED) != 0) 1483 THR_SET_STATE(thread, PS_SUSPENDED); 1484 else 1485 KSE_RUNQ_INSERT_TAIL(kse, thread); 1486 if ((thread->kse != kse) && 1487 (thread->kse->k_curthread == thread)) { 1488 /* 1489 * Remove this thread from its 1490 * previous KSE so that it (the KSE) 1491 * doesn't think it is still active. 1492 */ 1493 thread->kse->k_curthread = NULL; 1494 thread->active = 0; 1495 } 1496 } 1497 if ((sig = thread->tcb->tcb_tmbx.tm_syncsig.si_signo) 1498 != 0) { 1499 if (SIGISMEMBER(thread->sigmask, sig)) 1500 SIGADDSET(thread->sigpend, sig); 1501 else if (THR_IN_CRITICAL(thread)) 1502 kse_thr_interrupt(NULL, KSE_INTR_SIGEXIT, sig); 1503 else 1504 (void)_thr_sig_add(thread, sig, 1505 &thread->tcb->tcb_tmbx.tm_syncsig); 1506 thread->tcb->tcb_tmbx.tm_syncsig.si_signo = 0; 1507 } 1508 completed = completed->tm_next; 1509 } 1510 } 1511} 1512 1513/* 1514 * This must be called with the scheduling lock held. 1515 */ 1516static void 1517kse_check_waitq(struct kse *kse) 1518{ 1519 struct pthread *pthread; 1520 struct timespec ts; 1521 1522 KSE_GET_TOD(kse, &ts); 1523 1524 /* 1525 * Wake up threads that have timedout. This has to be 1526 * done before adding the current thread to the run queue 1527 * so that a CPU intensive thread doesn't get preference 1528 * over waiting threads. 1529 */ 1530 while (((pthread = KSE_WAITQ_FIRST(kse)) != NULL) && 1531 thr_timedout(pthread, &ts)) { 1532 /* Remove the thread from the wait queue: */ 1533 KSE_WAITQ_REMOVE(kse, pthread); 1534 DBG_MSG("Found timedout thread %p in waitq\n", pthread); 1535 1536 /* Indicate the thread timedout: */ 1537 pthread->timeout = 1; 1538 1539 /* Add the thread to the priority queue: */ 1540 if ((pthread->flags & THR_FLAGS_SUSPENDED) != 0) 1541 THR_SET_STATE(pthread, PS_SUSPENDED); 1542 else { 1543 THR_SET_STATE(pthread, PS_RUNNING); 1544 KSE_RUNQ_INSERT_TAIL(kse, pthread); 1545 } 1546 } 1547} 1548 1549static int 1550thr_timedout(struct pthread *thread, struct timespec *curtime) 1551{ 1552 if (thread->wakeup_time.tv_sec < 0) 1553 return (0); 1554 else if (thread->wakeup_time.tv_sec > curtime->tv_sec) 1555 return (0); 1556 else if ((thread->wakeup_time.tv_sec == curtime->tv_sec) && 1557 (thread->wakeup_time.tv_nsec > curtime->tv_nsec)) 1558 return (0); 1559 else 1560 return (1); 1561} 1562 1563/* 1564 * This must be called with the scheduling lock held. 1565 * 1566 * Each thread has a time slice, a wakeup time (used when it wants 1567 * to wait for a specified amount of time), a run state, and an 1568 * active flag. 1569 * 1570 * When a thread gets run by the scheduler, the active flag is 1571 * set to non-zero (1). When a thread performs an explicit yield 1572 * or schedules a state change, it enters the scheduler and the 1573 * active flag is cleared. When the active flag is still seen 1574 * set in the scheduler, that means that the thread is blocked in 1575 * the kernel (because it is cleared before entering the scheduler 1576 * in all other instances). 1577 * 1578 * The wakeup time is only set for those states that can timeout. 1579 * It is set to (-1, -1) for all other instances. 1580 * 1581 * The thread's run state, aside from being useful when debugging, 1582 * is used to place the thread in an appropriate queue. There 1583 * are 2 basic queues: 1584 * 1585 * o run queue - queue ordered by priority for all threads 1586 * that are runnable 1587 * o waiting queue - queue sorted by wakeup time for all threads 1588 * that are not otherwise runnable (not blocked 1589 * in kernel, not waiting for locks) 1590 * 1591 * The thread's time slice is used for round-robin scheduling 1592 * (the default scheduling policy). While a SCHED_RR thread 1593 * is runnable it's time slice accumulates. When it reaches 1594 * the time slice interval, it gets reset and added to the end 1595 * of the queue of threads at its priority. When a thread no 1596 * longer becomes runnable (blocks in kernel, waits, etc), its 1597 * time slice is reset. 1598 * 1599 * The job of kse_switchout_thread() is to handle all of the above. 1600 */ 1601static void 1602kse_switchout_thread(struct kse *kse, struct pthread *thread) 1603{ 1604 int level; 1605 int i; 1606 int restart; 1607 siginfo_t siginfo; 1608 1609 /* 1610 * Place the currently running thread into the 1611 * appropriate queue(s). 1612 */ 1613 DBG_MSG("Switching out thread %p, state %d\n", thread, thread->state); 1614 1615 THR_DEACTIVATE_LAST_LOCK(thread); 1616 if (thread->blocked != 0) { 1617 thread->active = 0; 1618 thread->need_switchout = 0; 1619 /* This thread must have blocked in the kernel. */ 1620 /* 1621 * Check for pending signals and cancellation for 1622 * this thread to see if we need to interrupt it 1623 * in the kernel. 1624 */ 1625 if (THR_NEED_CANCEL(thread)) { 1626 kse_thr_interrupt(&thread->tcb->tcb_tmbx, 1627 KSE_INTR_INTERRUPT, 0); 1628 } else if (thread->check_pending != 0) { 1629 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1630 if (SIGISMEMBER(thread->sigpend, i) && 1631 !SIGISMEMBER(thread->sigmask, i)) { 1632 restart = _thread_sigact[i - 1].sa_flags & SA_RESTART; 1633 kse_thr_interrupt(&thread->tcb->tcb_tmbx, 1634 restart ? KSE_INTR_RESTART : KSE_INTR_INTERRUPT, 0); 1635 break; 1636 } 1637 } 1638 } 1639 } 1640 else { 1641 switch (thread->state) { 1642 case PS_MUTEX_WAIT: 1643 case PS_COND_WAIT: 1644 if (THR_NEED_CANCEL(thread)) { 1645 thread->interrupted = 1; 1646 thread->continuation = _thr_finish_cancellation; 1647 THR_SET_STATE(thread, PS_RUNNING); 1648 } else { 1649 /* Insert into the waiting queue: */ 1650 KSE_WAITQ_INSERT(kse, thread); 1651 } 1652 break; 1653 1654 case PS_LOCKWAIT: 1655 /* 1656 * This state doesn't timeout. 1657 */ 1658 thread->wakeup_time.tv_sec = -1; 1659 thread->wakeup_time.tv_nsec = -1; 1660 level = thread->locklevel - 1; 1661 if (!_LCK_GRANTED(&thread->lockusers[level])) 1662 KSE_WAITQ_INSERT(kse, thread); 1663 else 1664 THR_SET_STATE(thread, PS_RUNNING); 1665 break; 1666 1667 case PS_SLEEP_WAIT: 1668 case PS_SIGWAIT: 1669 if (THR_NEED_CANCEL(thread)) { 1670 thread->interrupted = 1; 1671 THR_SET_STATE(thread, PS_RUNNING); 1672 } else { 1673 KSE_WAITQ_INSERT(kse, thread); 1674 } 1675 break; 1676 1677 case PS_JOIN: 1678 if (THR_NEED_CANCEL(thread)) { 1679 thread->join_status.thread = NULL; 1680 THR_SET_STATE(thread, PS_RUNNING); 1681 } else { 1682 /* 1683 * This state doesn't timeout. 1684 */ 1685 thread->wakeup_time.tv_sec = -1; 1686 thread->wakeup_time.tv_nsec = -1; 1687 1688 /* Insert into the waiting queue: */ 1689 KSE_WAITQ_INSERT(kse, thread); 1690 } 1691 break; 1692 1693 case PS_SIGSUSPEND: 1694 case PS_SUSPENDED: 1695 if (THR_NEED_CANCEL(thread)) { 1696 thread->interrupted = 1; 1697 THR_SET_STATE(thread, PS_RUNNING); 1698 } else { 1699 /* 1700 * These states don't timeout. 1701 */ 1702 thread->wakeup_time.tv_sec = -1; 1703 thread->wakeup_time.tv_nsec = -1; 1704 1705 /* Insert into the waiting queue: */ 1706 KSE_WAITQ_INSERT(kse, thread); 1707 } 1708 break; 1709 1710 case PS_DEAD: 1711 /* 1712 * The scheduler is operating on a different 1713 * stack. It is safe to do garbage collecting 1714 * here. 1715 */ 1716 thread->active = 0; 1717 thread->need_switchout = 0; 1718 thread->lock_switch = 0; 1719 thr_cleanup(kse, thread); 1720 return; 1721 break; 1722 1723 case PS_RUNNING: 1724 if ((thread->flags & THR_FLAGS_SUSPENDED) != 0 && 1725 !THR_NEED_CANCEL(thread)) 1726 THR_SET_STATE(thread, PS_SUSPENDED); 1727 break; 1728 1729 case PS_DEADLOCK: 1730 /* 1731 * These states don't timeout. 1732 */ 1733 thread->wakeup_time.tv_sec = -1; 1734 thread->wakeup_time.tv_nsec = -1; 1735 1736 /* Insert into the waiting queue: */ 1737 KSE_WAITQ_INSERT(kse, thread); 1738 break; 1739 1740 default: 1741 PANIC("Unknown state\n"); 1742 break; 1743 } 1744 1745 thr_accounting(thread); 1746 if (thread->state == PS_RUNNING) { 1747 if (thread->slice_usec == -1) { 1748 /* 1749 * The thread exceeded its time quantum or 1750 * it yielded the CPU; place it at the tail 1751 * of the queue for its priority. 1752 */ 1753 KSE_RUNQ_INSERT_TAIL(kse, thread); 1754 } else { 1755 /* 1756 * The thread hasn't exceeded its interval 1757 * Place it at the head of the queue for its 1758 * priority. 1759 */ 1760 KSE_RUNQ_INSERT_HEAD(kse, thread); 1761 } 1762 } 1763 } 1764 thread->active = 0; 1765 thread->need_switchout = 0; 1766 if (thread->check_pending != 0) { 1767 /* Install pending signals into the frame. */ 1768 thread->check_pending = 0; 1769 KSE_LOCK_ACQUIRE(kse, &_thread_signal_lock); 1770 for (i = 1; i <= _SIG_MAXSIG; i++) { 1771 if (SIGISMEMBER(thread->sigmask, i)) 1772 continue; 1773 if (SIGISMEMBER(thread->sigpend, i)) 1774 (void)_thr_sig_add(thread, i, 1775 &thread->siginfo[i-1]); 1776 else if (SIGISMEMBER(_thr_proc_sigpending, i) && 1777 _thr_getprocsig_unlocked(i, &siginfo)) { 1778 (void)_thr_sig_add(thread, i, &siginfo); 1779 } 1780 } 1781 KSE_LOCK_RELEASE(kse, &_thread_signal_lock); 1782 } 1783} 1784 1785/* 1786 * This function waits for the smallest timeout value of any waiting 1787 * thread, or until it receives a message from another KSE. 1788 * 1789 * This must be called with the scheduling lock held. 1790 */ 1791static void 1792kse_wait(struct kse *kse, struct pthread *td_wait, int sigseqno) 1793{ 1794 struct timespec ts, ts_sleep; 1795 int saved_flags; 1796 1797 if ((td_wait == NULL) || (td_wait->wakeup_time.tv_sec < 0)) { 1798 /* Limit sleep to no more than 1 minute. */ 1799 ts_sleep.tv_sec = 60; 1800 ts_sleep.tv_nsec = 0; 1801 } else { 1802 KSE_GET_TOD(kse, &ts); 1803 TIMESPEC_SUB(&ts_sleep, &td_wait->wakeup_time, &ts); 1804 if (ts_sleep.tv_sec > 60) { 1805 ts_sleep.tv_sec = 60; 1806 ts_sleep.tv_nsec = 0; 1807 } 1808 } 1809 /* Don't sleep for negative times. */ 1810 if ((ts_sleep.tv_sec >= 0) && (ts_sleep.tv_nsec >= 0)) { 1811 KSE_SET_IDLE(kse); 1812 kse->k_kseg->kg_idle_kses++; 1813 KSE_SCHED_UNLOCK(kse, kse->k_kseg); 1814 if ((kse->k_kseg->kg_flags & KGF_SINGLE_THREAD) && 1815 (kse->k_sigseqno != sigseqno)) 1816 ; /* don't sleep */ 1817 else { 1818 saved_flags = kse->k_kcb->kcb_kmbx.km_flags; 1819 kse->k_kcb->kcb_kmbx.km_flags |= KMF_NOUPCALL; 1820 kse_release(&ts_sleep); 1821 kse->k_kcb->kcb_kmbx.km_flags = saved_flags; 1822 } 1823 KSE_SCHED_LOCK(kse, kse->k_kseg); 1824 if (KSE_IS_IDLE(kse)) { 1825 KSE_CLEAR_IDLE(kse); 1826 kse->k_kseg->kg_idle_kses--; 1827 } 1828 } 1829} 1830 1831/* 1832 * Avoid calling this kse_exit() so as not to confuse it with the 1833 * system call of the same name. 1834 */ 1835static void 1836kse_fini(struct kse *kse) 1837{ 1838 /* struct kse_group *free_kseg = NULL; */ 1839 struct timespec ts; 1840 struct pthread *td; 1841 1842 /* 1843 * Check to see if this is one of the main kses. 1844 */ 1845 if (kse->k_kseg != _kse_initial->k_kseg) { 1846 PANIC("shouldn't get here"); 1847 /* This is for supporting thread groups. */ 1848#ifdef NOT_YET 1849 /* Remove this KSE from the KSEG's list of KSEs. */ 1850 KSE_SCHED_LOCK(kse, kse->k_kseg); 1851 TAILQ_REMOVE(&kse->k_kseg->kg_kseq, kse, k_kgqe); 1852 kse->k_kseg->kg_ksecount--; 1853 if (TAILQ_EMPTY(&kse->k_kseg->kg_kseq)) 1854 free_kseg = kse->k_kseg; 1855 KSE_SCHED_UNLOCK(kse, kse->k_kseg); 1856 1857 /* 1858 * Add this KSE to the list of free KSEs along with 1859 * the KSEG if is now orphaned. 1860 */ 1861 KSE_LOCK_ACQUIRE(kse, &kse_lock); 1862 if (free_kseg != NULL) 1863 kseg_free_unlocked(free_kseg); 1864 kse_free_unlocked(kse); 1865 KSE_LOCK_RELEASE(kse, &kse_lock); 1866 kse_exit(); 1867 /* Never returns. */ 1868 PANIC("kse_exit()"); 1869#endif 1870 } else { 1871 /* 1872 * We allow program to kill kse in initial group (by 1873 * lowering the concurrency). 1874 */ 1875 if ((kse != _kse_initial) && 1876 ((kse->k_flags & KF_TERMINATED) != 0)) { 1877 KSE_SCHED_LOCK(kse, kse->k_kseg); 1878 TAILQ_REMOVE(&kse->k_kseg->kg_kseq, kse, k_kgqe); 1879 kse->k_kseg->kg_ksecount--; 1880 /* 1881 * Migrate thread to _kse_initial if its lastest 1882 * kse it ran on is the kse. 1883 */ 1884 td = TAILQ_FIRST(&kse->k_kseg->kg_threadq); 1885 while (td != NULL) { 1886 if (td->kse == kse) 1887 td->kse = _kse_initial; 1888 td = TAILQ_NEXT(td, kle); 1889 } 1890 KSE_SCHED_UNLOCK(kse, kse->k_kseg); 1891 KSE_LOCK_ACQUIRE(kse, &kse_lock); 1892 kse_free_unlocked(kse); 1893 KSE_LOCK_RELEASE(kse, &kse_lock); 1894 /* Make sure there is always at least one is awake */ 1895 KSE_WAKEUP(_kse_initial); 1896 kse_exit(); 1897 /* Never returns. */ 1898 PANIC("kse_exit() failed for initial kseg"); 1899 } 1900 KSE_SCHED_LOCK(kse, kse->k_kseg); 1901 KSE_SET_IDLE(kse); 1902 kse->k_kseg->kg_idle_kses++; 1903 KSE_SCHED_UNLOCK(kse, kse->k_kseg); 1904 ts.tv_sec = 120; 1905 ts.tv_nsec = 0; 1906 kse->k_kcb->kcb_kmbx.km_flags = 0; 1907 kse_release(&ts); 1908 /* Never reach */ 1909 } 1910} 1911 1912void 1913_thr_set_timeout(const struct timespec *timeout) 1914{ 1915 struct pthread *curthread = _get_curthread(); 1916 struct timespec ts; 1917 1918 /* Reset the timeout flag for the running thread: */ 1919 curthread->timeout = 0; 1920 1921 /* Check if the thread is to wait forever: */ 1922 if (timeout == NULL) { 1923 /* 1924 * Set the wakeup time to something that can be recognised as 1925 * different to an actual time of day: 1926 */ 1927 curthread->wakeup_time.tv_sec = -1; 1928 curthread->wakeup_time.tv_nsec = -1; 1929 } 1930 /* Check if no waiting is required: */ 1931 else if ((timeout->tv_sec == 0) && (timeout->tv_nsec == 0)) { 1932 /* Set the wake up time to 'immediately': */ 1933 curthread->wakeup_time.tv_sec = 0; 1934 curthread->wakeup_time.tv_nsec = 0; 1935 } else { 1936 /* Calculate the time for the current thread to wakeup: */ 1937 KSE_GET_TOD(curthread->kse, &ts); 1938 TIMESPEC_ADD(&curthread->wakeup_time, &ts, timeout); 1939 } 1940} 1941 1942void 1943_thr_panic_exit(char *file, int line, char *msg) 1944{ 1945 char buf[256]; 1946 1947 snprintf(buf, sizeof(buf), "(%s:%d) %s\n", file, line, msg); 1948 __sys_write(2, buf, strlen(buf)); 1949 abort(); 1950} 1951 1952void 1953_thr_setrunnable(struct pthread *curthread, struct pthread *thread) 1954{ 1955 kse_critical_t crit; 1956 struct kse_mailbox *kmbx; 1957 1958 crit = _kse_critical_enter(); 1959 KSE_SCHED_LOCK(curthread->kse, thread->kseg); 1960 kmbx = _thr_setrunnable_unlocked(thread); 1961 KSE_SCHED_UNLOCK(curthread->kse, thread->kseg); 1962 _kse_critical_leave(crit); 1963 if ((kmbx != NULL) && (__isthreaded != 0)) 1964 kse_wakeup(kmbx); 1965} 1966 1967struct kse_mailbox * 1968_thr_setrunnable_unlocked(struct pthread *thread) 1969{ 1970 struct kse_mailbox *kmbx = NULL; 1971 1972 if ((thread->kseg->kg_flags & KGF_SINGLE_THREAD) != 0) { 1973 /* No silly queues for these threads. */ 1974 if ((thread->flags & THR_FLAGS_SUSPENDED) != 0) 1975 THR_SET_STATE(thread, PS_SUSPENDED); 1976 else { 1977 THR_SET_STATE(thread, PS_RUNNING); 1978 kmbx = kse_wakeup_one(thread); 1979 } 1980 1981 } else if (thread->state != PS_RUNNING) { 1982 if ((thread->flags & THR_FLAGS_IN_WAITQ) != 0) 1983 KSE_WAITQ_REMOVE(thread->kse, thread); 1984 if ((thread->flags & THR_FLAGS_SUSPENDED) != 0) 1985 THR_SET_STATE(thread, PS_SUSPENDED); 1986 else { 1987 THR_SET_STATE(thread, PS_RUNNING); 1988 if ((thread->blocked == 0) && (thread->active == 0) && 1989 (thread->flags & THR_FLAGS_IN_RUNQ) == 0) 1990 THR_RUNQ_INSERT_TAIL(thread); 1991 /* 1992 * XXX - Threads are not yet assigned to specific 1993 * KSEs; they are assigned to the KSEG. So 1994 * the fact that a thread's KSE is waiting 1995 * doesn't necessarily mean that it will be 1996 * the KSE that runs the thread after the 1997 * lock is granted. But we don't know if the 1998 * other KSEs within the same KSEG are also 1999 * in a waiting state or not so we err on the 2000 * side of caution and wakeup the thread's 2001 * last known KSE. We ensure that the 2002 * threads KSE doesn't change while it's 2003 * scheduling lock is held so it is safe to 2004 * reference it (the KSE). If the KSE wakes 2005 * up and doesn't find any more work it will 2006 * again go back to waiting so no harm is 2007 * done. 2008 */ 2009 kmbx = kse_wakeup_one(thread); 2010 } 2011 } 2012 return (kmbx); 2013} 2014 2015static struct kse_mailbox * 2016kse_wakeup_one(struct pthread *thread) 2017{ 2018 struct kse *ke; 2019 2020 if (KSE_IS_IDLE(thread->kse)) { 2021 KSE_CLEAR_IDLE(thread->kse); 2022 thread->kseg->kg_idle_kses--; 2023 return (&thread->kse->k_kcb->kcb_kmbx); 2024 } else { 2025 TAILQ_FOREACH(ke, &thread->kseg->kg_kseq, k_kgqe) { 2026 if (KSE_IS_IDLE(ke)) { 2027 KSE_CLEAR_IDLE(ke); 2028 ke->k_kseg->kg_idle_kses--; 2029 return (&ke->k_kcb->kcb_kmbx); 2030 } 2031 } 2032 } 2033 return (NULL); 2034} 2035 2036static void 2037kse_wakeup_multi(struct kse *curkse) 2038{ 2039 struct kse *ke; 2040 int tmp; 2041 2042 if ((tmp = KSE_RUNQ_THREADS(curkse)) && curkse->k_kseg->kg_idle_kses) { 2043 TAILQ_FOREACH(ke, &curkse->k_kseg->kg_kseq, k_kgqe) { 2044 if (KSE_IS_IDLE(ke)) { 2045 KSE_CLEAR_IDLE(ke); 2046 ke->k_kseg->kg_idle_kses--; 2047 KSE_WAKEUP(ke); 2048 if (--tmp == 0) 2049 break; 2050 } 2051 } 2052 } 2053} 2054 2055/* 2056 * Allocate a new KSEG. 2057 * 2058 * We allow the current thread to be NULL in the case that this 2059 * is the first time a KSEG is being created (library initialization). 2060 * In this case, we don't need to (and can't) take any locks. 2061 */ 2062struct kse_group * 2063_kseg_alloc(struct pthread *curthread) 2064{ 2065 struct kse_group *kseg = NULL; 2066 kse_critical_t crit; 2067 2068 if ((curthread != NULL) && (free_kseg_count > 0)) { 2069 /* Use the kse lock for the kseg queue. */ 2070 crit = _kse_critical_enter(); 2071 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 2072 if ((kseg = TAILQ_FIRST(&free_kse_groupq)) != NULL) { 2073 TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe); 2074 free_kseg_count--; 2075 active_kseg_count++; 2076 TAILQ_INSERT_TAIL(&active_kse_groupq, kseg, kg_qe); 2077 } 2078 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 2079 _kse_critical_leave(crit); 2080 if (kseg) 2081 kseg_reinit(kseg); 2082 } 2083 2084 /* 2085 * If requested, attempt to allocate a new KSE group only if the 2086 * KSE allocation was successful and a KSE group wasn't found in 2087 * the free list. 2088 */ 2089 if ((kseg == NULL) && 2090 ((kseg = (struct kse_group *)malloc(sizeof(*kseg))) != NULL)) { 2091 if (_pq_alloc(&kseg->kg_schedq.sq_runq, 2092 THR_MIN_PRIORITY, THR_LAST_PRIORITY) != 0) { 2093 free(kseg); 2094 kseg = NULL; 2095 } else { 2096 kseg_init(kseg); 2097 /* Add the KSEG to the list of active KSEGs. */ 2098 if (curthread != NULL) { 2099 crit = _kse_critical_enter(); 2100 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 2101 active_kseg_count++; 2102 TAILQ_INSERT_TAIL(&active_kse_groupq, 2103 kseg, kg_qe); 2104 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 2105 _kse_critical_leave(crit); 2106 } else { 2107 active_kseg_count++; 2108 TAILQ_INSERT_TAIL(&active_kse_groupq, 2109 kseg, kg_qe); 2110 } 2111 } 2112 } 2113 return (kseg); 2114} 2115 2116static void 2117kseg_init(struct kse_group *kseg) 2118{ 2119 kseg_reinit(kseg); 2120 _lock_init(&kseg->kg_lock, LCK_ADAPTIVE, _kse_lock_wait, 2121 _kse_lock_wakeup); 2122} 2123 2124static void 2125kseg_reinit(struct kse_group *kseg) 2126{ 2127 TAILQ_INIT(&kseg->kg_kseq); 2128 TAILQ_INIT(&kseg->kg_threadq); 2129 TAILQ_INIT(&kseg->kg_schedq.sq_waitq); 2130 kseg->kg_threadcount = 0; 2131 kseg->kg_ksecount = 0; 2132 kseg->kg_idle_kses = 0; 2133 kseg->kg_flags = 0; 2134} 2135 2136/* 2137 * This must be called with the kse lock held and when there are 2138 * no more threads that reference it. 2139 */ 2140static void 2141kseg_free_unlocked(struct kse_group *kseg) 2142{ 2143 TAILQ_REMOVE(&active_kse_groupq, kseg, kg_qe); 2144 TAILQ_INSERT_HEAD(&free_kse_groupq, kseg, kg_qe); 2145 free_kseg_count++; 2146 active_kseg_count--; 2147} 2148 2149void 2150_kseg_free(struct kse_group *kseg) 2151{ 2152 struct kse *curkse; 2153 kse_critical_t crit; 2154 2155 crit = _kse_critical_enter(); 2156 curkse = _get_curkse(); 2157 KSE_LOCK_ACQUIRE(curkse, &kse_lock); 2158 kseg_free_unlocked(kseg); 2159 KSE_LOCK_RELEASE(curkse, &kse_lock); 2160 _kse_critical_leave(crit); 2161} 2162 2163static void 2164kseg_destroy(struct kse_group *kseg) 2165{ 2166 _lock_destroy(&kseg->kg_lock); 2167 _pq_free(&kseg->kg_schedq.sq_runq); 2168 free(kseg); 2169} 2170 2171/* 2172 * Allocate a new KSE. 2173 * 2174 * We allow the current thread to be NULL in the case that this 2175 * is the first time a KSE is being created (library initialization). 2176 * In this case, we don't need to (and can't) take any locks. 2177 */ 2178struct kse * 2179_kse_alloc(struct pthread *curthread, int sys_scope) 2180{ 2181 struct kse *kse = NULL; 2182 char *stack; 2183 kse_critical_t crit; 2184 int i; 2185 2186 if ((curthread != NULL) && (free_kse_count > 0)) { 2187 crit = _kse_critical_enter(); 2188 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 2189 /* Search for a finished KSE. */ 2190 kse = TAILQ_FIRST(&free_kseq); 2191 while ((kse != NULL) && 2192 ((kse->k_kcb->kcb_kmbx.km_flags & KMF_DONE) == 0)) { 2193 kse = TAILQ_NEXT(kse, k_qe); 2194 } 2195 if (kse != NULL) { 2196 DBG_MSG("found an unused kse.\n"); 2197 TAILQ_REMOVE(&free_kseq, kse, k_qe); 2198 free_kse_count--; 2199 TAILQ_INSERT_TAIL(&active_kseq, kse, k_qe); 2200 active_kse_count++; 2201 } 2202 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 2203 _kse_critical_leave(crit); 2204 if (kse != NULL) 2205 kse_reinit(kse, sys_scope); 2206 } 2207 if ((kse == NULL) && 2208 ((kse = (struct kse *)malloc(sizeof(*kse))) != NULL)) { 2209 if (sys_scope != 0) 2210 stack = NULL; 2211 else if ((stack = malloc(KSE_STACKSIZE)) == NULL) { 2212 free(kse); 2213 return (NULL); 2214 } 2215 bzero(kse, sizeof(*kse)); 2216 2217 /* Initialize KCB without the lock. */ 2218 if ((kse->k_kcb = _kcb_ctor(kse)) == NULL) { 2219 if (stack != NULL) 2220 free(stack); 2221 free(kse); 2222 return (NULL); 2223 } 2224 2225 /* Initialize the lockusers. */ 2226 for (i = 0; i < MAX_KSE_LOCKLEVEL; i++) { 2227 _lockuser_init(&kse->k_lockusers[i], (void *)kse); 2228 _LCK_SET_PRIVATE2(&kse->k_lockusers[i], NULL); 2229 } 2230 /* _lock_init(kse->k_lock, ...) */ 2231 2232 if (curthread != NULL) { 2233 crit = _kse_critical_enter(); 2234 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 2235 } 2236 kse->k_flags = 0; 2237 TAILQ_INSERT_TAIL(&active_kseq, kse, k_qe); 2238 active_kse_count++; 2239 if (curthread != NULL) { 2240 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 2241 _kse_critical_leave(crit); 2242 } 2243 /* 2244 * Create the KSE context. 2245 * Scope system threads (one thread per KSE) are not required 2246 * to have a stack for an unneeded kse upcall. 2247 */ 2248 if (!sys_scope) { 2249 kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_multi; 2250 kse->k_stack.ss_sp = stack; 2251 kse->k_stack.ss_size = KSE_STACKSIZE; 2252 } else { 2253 kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_single; 2254 kse->k_stack.ss_sp = NULL; 2255 kse->k_stack.ss_size = 0; 2256 } 2257 kse->k_kcb->kcb_kmbx.km_udata = (void *)kse; 2258 kse->k_kcb->kcb_kmbx.km_quantum = 20000; 2259 /* 2260 * We need to keep a copy of the stack in case it 2261 * doesn't get used; a KSE running a scope system 2262 * thread will use that thread's stack. 2263 */ 2264 kse->k_kcb->kcb_kmbx.km_stack = kse->k_stack; 2265 } 2266 return (kse); 2267} 2268 2269static void 2270kse_reinit(struct kse *kse, int sys_scope) 2271{ 2272 if (!sys_scope) { 2273 kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_multi; 2274 if (kse->k_stack.ss_sp == NULL) { 2275 /* XXX check allocation failure */ 2276 kse->k_stack.ss_sp = (char *) malloc(KSE_STACKSIZE); 2277 kse->k_stack.ss_size = KSE_STACKSIZE; 2278 } 2279 kse->k_kcb->kcb_kmbx.km_quantum = 20000; 2280 } else { 2281 kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_single; 2282 if (kse->k_stack.ss_sp) 2283 free(kse->k_stack.ss_sp); 2284 kse->k_stack.ss_sp = NULL; 2285 kse->k_stack.ss_size = 0; 2286 kse->k_kcb->kcb_kmbx.km_quantum = 0; 2287 } 2288 kse->k_kcb->kcb_kmbx.km_stack = kse->k_stack; 2289 kse->k_kcb->kcb_kmbx.km_udata = (void *)kse; 2290 kse->k_kcb->kcb_kmbx.km_curthread = NULL; 2291 kse->k_kcb->kcb_kmbx.km_flags = 0; 2292 kse->k_curthread = NULL; 2293 kse->k_kseg = 0; 2294 kse->k_schedq = 0; 2295 kse->k_locklevel = 0; 2296 kse->k_flags = 0; 2297 kse->k_error = 0; 2298 kse->k_cpu = 0; 2299 kse->k_sigseqno = 0; 2300} 2301 2302void 2303kse_free_unlocked(struct kse *kse) 2304{ 2305 TAILQ_REMOVE(&active_kseq, kse, k_qe); 2306 active_kse_count--; 2307 kse->k_kseg = NULL; 2308 kse->k_kcb->kcb_kmbx.km_quantum = 20000; 2309 kse->k_flags = 0; 2310 TAILQ_INSERT_HEAD(&free_kseq, kse, k_qe); 2311 free_kse_count++; 2312} 2313 2314void 2315_kse_free(struct pthread *curthread, struct kse *kse) 2316{ 2317 kse_critical_t crit; 2318 2319 if (curthread == NULL) 2320 kse_free_unlocked(kse); 2321 else { 2322 crit = _kse_critical_enter(); 2323 KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); 2324 kse_free_unlocked(kse); 2325 KSE_LOCK_RELEASE(curthread->kse, &kse_lock); 2326 _kse_critical_leave(crit); 2327 } 2328} 2329 2330static void 2331kse_destroy(struct kse *kse) 2332{ 2333 int i; 2334 2335 if (kse->k_stack.ss_sp != NULL) 2336 free(kse->k_stack.ss_sp); 2337 _kcb_dtor(kse->k_kcb); 2338 for (i = 0; i < MAX_KSE_LOCKLEVEL; ++i) 2339 _lockuser_destroy(&kse->k_lockusers[i]); 2340 _lock_destroy(&kse->k_lock); 2341 free(kse); 2342} 2343 2344struct pthread * 2345_thr_alloc(struct pthread *curthread) 2346{ 2347 kse_critical_t crit; 2348 struct pthread *thread = NULL; 2349 int i; 2350 2351 if (curthread != NULL) { 2352 if (GC_NEEDED()) 2353 _thr_gc(curthread); 2354 if (free_thread_count > 0) { 2355 crit = _kse_critical_enter(); 2356 KSE_LOCK_ACQUIRE(curthread->kse, &thread_lock); 2357 if ((thread = TAILQ_FIRST(&free_threadq)) != NULL) { 2358 TAILQ_REMOVE(&free_threadq, thread, tle); 2359 free_thread_count--; 2360 } 2361 KSE_LOCK_RELEASE(curthread->kse, &thread_lock); 2362 _kse_critical_leave(crit); 2363 } 2364 } 2365 if ((thread == NULL) && 2366 ((thread = malloc(sizeof(struct pthread))) != NULL)) { 2367 bzero(thread, sizeof(struct pthread)); 2368 thread->siginfo = calloc(_SIG_MAXSIG, sizeof(siginfo_t)); 2369 if (thread->siginfo == NULL) { 2370 free(thread); 2371 return (NULL); 2372 } 2373 if (curthread) { 2374 _pthread_mutex_lock(&_tcb_mutex); 2375 thread->tcb = _tcb_ctor(thread, 0 /* not initial tls */); 2376 _pthread_mutex_unlock(&_tcb_mutex); 2377 } else { 2378 thread->tcb = _tcb_ctor(thread, 1 /* initial tls */); 2379 } 2380 if (thread->tcb == NULL) { 2381 free(thread->siginfo); 2382 free(thread); 2383 return (NULL); 2384 } 2385 /* 2386 * Initialize thread locking. 2387 * Lock initializing needs malloc, so don't 2388 * enter critical region before doing this! 2389 */ 2390 if (_lock_init(&thread->lock, LCK_ADAPTIVE, 2391 _thr_lock_wait, _thr_lock_wakeup) != 0) 2392 PANIC("Cannot initialize thread lock"); 2393 for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { 2394 _lockuser_init(&thread->lockusers[i], (void *)thread); 2395 _LCK_SET_PRIVATE2(&thread->lockusers[i], 2396 (void *)thread); 2397 } 2398 } 2399 return (thread); 2400} 2401 2402void 2403_thr_free(struct pthread *curthread, struct pthread *thread) 2404{ 2405 kse_critical_t crit; 2406 2407 DBG_MSG("Freeing thread %p\n", thread); 2408 if (thread->name) { 2409 free(thread->name); 2410 thread->name = NULL; 2411 } 2412 if ((curthread == NULL) || (free_thread_count >= MAX_CACHED_THREADS)) { 2413 thr_destroy(curthread, thread); 2414 } else { 2415 /* Add the thread to the free thread list. */ 2416 crit = _kse_critical_enter(); 2417 KSE_LOCK_ACQUIRE(curthread->kse, &thread_lock); 2418 TAILQ_INSERT_TAIL(&free_threadq, thread, tle); 2419 free_thread_count++; 2420 KSE_LOCK_RELEASE(curthread->kse, &thread_lock); 2421 _kse_critical_leave(crit); 2422 } 2423} 2424 2425static void 2426thr_destroy(struct pthread *curthread, struct pthread *thread) 2427{ 2428 int i; 2429 2430 for (i = 0; i < MAX_THR_LOCKLEVEL; i++) 2431 _lockuser_destroy(&thread->lockusers[i]); 2432 _lock_destroy(&thread->lock); 2433 if (curthread) { 2434 _pthread_mutex_lock(&_tcb_mutex); 2435 _tcb_dtor(thread->tcb); 2436 _pthread_mutex_unlock(&_tcb_mutex); 2437 } else { 2438 _tcb_dtor(thread->tcb); 2439 } 2440 free(thread->siginfo); 2441 free(thread); 2442} 2443 2444/* 2445 * Add an active thread: 2446 * 2447 * o Assign the thread a unique id (which GDB uses to track 2448 * threads. 2449 * o Add the thread to the list of all threads and increment 2450 * number of active threads. 2451 */ 2452static void 2453thr_link(struct pthread *thread) 2454{ 2455 kse_critical_t crit; 2456 struct kse *curkse; 2457 2458 crit = _kse_critical_enter(); 2459 curkse = _get_curkse(); 2460 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); 2461 /* 2462 * Initialize the unique id (which GDB uses to track 2463 * threads), add the thread to the list of all threads, 2464 * and 2465 */ 2466 thread->uniqueid = next_uniqueid++; 2467 THR_LIST_ADD(thread); 2468 _thread_active_threads++; 2469 KSE_LOCK_RELEASE(curkse, &_thread_list_lock); 2470 _kse_critical_leave(crit); 2471} 2472 2473/* 2474 * Remove an active thread. 2475 */ 2476static void 2477thr_unlink(struct pthread *thread) 2478{ 2479 kse_critical_t crit; 2480 struct kse *curkse; 2481 2482 crit = _kse_critical_enter(); 2483 curkse = _get_curkse(); 2484 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); 2485 THR_LIST_REMOVE(thread); 2486 _thread_active_threads--; 2487 KSE_LOCK_RELEASE(curkse, &_thread_list_lock); 2488 _kse_critical_leave(crit); 2489} 2490 2491void 2492_thr_hash_add(struct pthread *thread) 2493{ 2494 struct thread_hash_head *head; 2495 2496 head = &thr_hashtable[THREAD_HASH(thread)]; 2497 LIST_INSERT_HEAD(head, thread, hle); 2498} 2499 2500void 2501_thr_hash_remove(struct pthread *thread) 2502{ 2503 LIST_REMOVE(thread, hle); 2504} 2505 2506struct pthread * 2507_thr_hash_find(struct pthread *thread) 2508{ 2509 struct pthread *td; 2510 struct thread_hash_head *head; 2511 2512 head = &thr_hashtable[THREAD_HASH(thread)]; 2513 LIST_FOREACH(td, head, hle) { 2514 if (td == thread) 2515 return (thread); 2516 } 2517 return (NULL); 2518} 2519 2520void 2521_thr_debug_check_yield(struct pthread *curthread) 2522{ 2523 /* 2524 * Note that TMDF_SUSPEND is set after process is suspended. 2525 * When we are being debugged, every suspension in process 2526 * will cause all KSEs to schedule an upcall in kernel, unless the 2527 * KSE is in critical region. 2528 * If the function is being called, it means the KSE is no longer 2529 * in critical region, if the TMDF_SUSPEND is set by debugger 2530 * before KSE leaves critical region, we will catch it here, else 2531 * if the flag is changed during testing, it also not a problem, 2532 * because the change only occurs after a process suspension event 2533 * occurs. A suspension event will always cause KSE to schedule an 2534 * upcall, in the case, because we are not in critical region, 2535 * upcall will be scheduled sucessfully, the flag will be checked 2536 * again in kse_sched_multi, we won't back until the flag 2537 * is cleared by debugger, the flag will be cleared in next 2538 * suspension event. 2539 */ 2540 if (!DBG_CAN_RUN(curthread)) { 2541 if ((curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) == 0) 2542 _thr_sched_switch(curthread); 2543 else 2544 kse_thr_interrupt(&curthread->tcb->tcb_tmbx, 2545 KSE_INTR_DBSUSPEND, 0); 2546 } 2547} 2548