/* * Copyright (C) 2003 Daniel M. Eischen * Copyright (C) 2002 Jonathon Mini * Copyright (c) 1995-1998 John Birrell * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by John Birrell. * 4. Neither the name of the author nor the names of any co-contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ #include __FBSDID("$FreeBSD: head/lib/libkse/thread/thr_kern.c 114187 2003-04-28 23:56:12Z deischen $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include "atomic_ops.h" #include "thr_private.h" #include "pthread_md.h" #include "libc_private.h" /*#define DEBUG_THREAD_KERN */ #ifdef DEBUG_THREAD_KERN #define DBG_MSG stdout_debug #else #define DBG_MSG(x...) #endif /* * Define a high water mark for the maximum number of threads that * will be cached. Once this level is reached, any extra threads * will be free()'d. * * XXX - It doesn't make sense to worry about the maximum number of * KSEs that we can cache because the system will limit us to * something *much* less than the maximum number of threads * that we can have. Disregarding KSEs in their own group, * the maximum number of KSEs is the number of processors in * the system. */ #define MAX_CACHED_THREADS 100 #define KSE_STACKSIZE 16384 #define KSE_SET_MBOX(kse, thrd) \ (kse)->k_mbx.km_curthread = &(thrd)->tmbx #define KSE_SET_EXITED(kse) (kse)->k_flags |= KF_EXITED /* * Macros for manipulating the run queues. The priority queue * routines use the thread's pqe link and also handle the setting * and clearing of the thread's THR_FLAGS_IN_RUNQ flag. */ #define KSE_RUNQ_INSERT_HEAD(kse, thrd) \ _pq_insert_head(&(kse)->k_schedq->sq_runq, thrd) #define KSE_RUNQ_INSERT_TAIL(kse, thrd) \ _pq_insert_tail(&(kse)->k_schedq->sq_runq, thrd) #define KSE_RUNQ_REMOVE(kse, thrd) \ _pq_remove(&(kse)->k_schedq->sq_runq, thrd) #define KSE_RUNQ_FIRST(kse) _pq_first(&(kse)->k_schedq->sq_runq) #define KSE_RUNQ_THREADS(kse) ((kse)->k_schedq->sq_runq.pq_threads) /* * We've got to keep track of everything that is allocated, not only * to have a speedy free list, but also so they can be deallocated * after a fork(). */ static TAILQ_HEAD(, kse) active_kseq; static TAILQ_HEAD(, kse) free_kseq; static TAILQ_HEAD(, kse_group) free_kse_groupq; static TAILQ_HEAD(, kse_group) active_kse_groupq; static TAILQ_HEAD(, kse_group) gc_ksegq; static struct lock kse_lock; /* also used for kseg queue */ static int free_kse_count = 0; static int free_kseg_count = 0; static TAILQ_HEAD(, pthread) free_threadq; static struct lock thread_lock; static int free_thread_count = 0; static int inited = 0; static int active_kse_count = 0; static int active_kseg_count = 0; static void kse_check_completed(struct kse *kse); static void kse_check_waitq(struct kse *kse); static void kse_check_signals(struct kse *kse); static void kse_fini(struct kse *curkse); static void kse_reinit(struct kse *kse); static void kse_sched_multi(struct kse *curkse); #ifdef NOT_YET static void kse_sched_single(struct kse *curkse); #endif static void kse_switchout_thread(struct kse *kse, struct pthread *thread); static void kse_wait(struct kse *kse, struct pthread *td_wait); static void kse_free_unlocked(struct kse *kse); static void kseg_free_unlocked(struct kse_group *kseg); static void kseg_init(struct kse_group *kseg); static void kseg_reinit(struct kse_group *kseg); static void kse_waitq_insert(struct pthread *thread); static void kse_wakeup_multi(struct kse *curkse); static void kse_wakeup_one(struct pthread *thread); static void thr_cleanup(struct kse *kse, struct pthread *curthread); static void thr_resume_wrapper(int unused_1, siginfo_t *unused_2, ucontext_t *ucp); static void thr_resume_check(struct pthread *curthread, ucontext_t *ucp, struct pthread_sigframe *psf); static int thr_timedout(struct pthread *thread, struct timespec *curtime); /* * This is called after a fork(). * No locks need to be taken here since we are guaranteed to be * single threaded. */ void _kse_single_thread(struct pthread *curthread) { struct kse *kse, *kse_next; struct kse_group *kseg, *kseg_next; struct pthread *thread, *thread_next; kse_critical_t crit; int i; /* * Disable upcalls and clear the threaded flag. * XXX - I don't think we need to disable upcalls after a fork(). * but it doesn't hurt. */ crit = _kse_critical_enter(); __isthreaded = 0; /* * Enter a loop to remove and free all threads other than * the running thread from the active thread list: */ for (thread = TAILQ_FIRST(&_thread_list); thread != NULL; thread = thread_next) { /* * Advance to the next thread before the destroying * the current thread. */ thread_next = TAILQ_NEXT(thread, tle); /* * Remove this thread from the list (the current * thread will be removed but re-added by libpthread * initialization. */ TAILQ_REMOVE(&_thread_list, thread, tle); /* Make sure this isn't the running thread: */ if (thread != curthread) { _thr_stack_free(&thread->attr); if (thread->specific != NULL) free(thread->specific); for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { _lockuser_destroy(&thread->lockusers[i]); } _lock_destroy(&thread->lock); free(thread); } } TAILQ_INIT(&curthread->mutexq); /* initialize mutex queue */ curthread->joiner = NULL; /* no joining threads yet */ sigemptyset(&curthread->sigpend); /* clear pending signals */ if (curthread->specific != NULL) { free(curthread->specific); curthread->specific = NULL; curthread->specific_data_count = 0; } /* Free the free KSEs: */ while ((kse = TAILQ_FIRST(&free_kseq)) != NULL) { TAILQ_REMOVE(&free_kseq, kse, k_qe); _ksd_destroy(&kse->k_ksd); if (kse->k_stack.ss_sp != NULL) free(kse->k_stack.ss_sp); free(kse); } free_kse_count = 0; /* Free the active KSEs: */ for (kse = TAILQ_FIRST(&active_kseq); kse != NULL; kse = kse_next) { kse_next = TAILQ_NEXT(kse, k_qe); TAILQ_REMOVE(&active_kseq, kse, k_qe); for (i = 0; i < MAX_KSE_LOCKLEVEL; i++) { _lockuser_destroy(&kse->k_lockusers[i]); } if (kse->k_stack.ss_sp != NULL) free(kse->k_stack.ss_sp); _lock_destroy(&kse->k_lock); free(kse); } active_kse_count = 0; /* Free the free KSEGs: */ while ((kseg = TAILQ_FIRST(&free_kse_groupq)) != NULL) { TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe); _lock_destroy(&kseg->kg_lock); _pq_free(&kseg->kg_schedq.sq_runq); free(kseg); } free_kseg_count = 0; /* Free the active KSEGs: */ for (kseg = TAILQ_FIRST(&active_kse_groupq); kseg != NULL; kseg = kseg_next) { kseg_next = TAILQ_NEXT(kseg, kg_qe); TAILQ_REMOVE(&active_kse_groupq, kseg, kg_qe); _lock_destroy(&kseg->kg_lock); _pq_free(&kseg->kg_schedq.sq_runq); free(kseg); } active_kseg_count = 0; /* Free the free threads. */ while ((thread = TAILQ_FIRST(&free_threadq)) != NULL) { TAILQ_REMOVE(&free_threadq, thread, tle); if (thread->specific != NULL) free(thread->specific); for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { _lockuser_destroy(&thread->lockusers[i]); } _lock_destroy(&thread->lock); free(thread); } free_thread_count = 0; /* Free the to-be-gc'd threads. */ while ((thread = TAILQ_FIRST(&_thread_gc_list)) != NULL) { TAILQ_REMOVE(&_thread_gc_list, thread, gcle); for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { _lockuser_destroy(&thread->lockusers[i]); } _lock_destroy(&thread->lock); free(thread); } TAILQ_INIT(&gc_ksegq); _gc_count = 0; if (inited != 0) { /* * Destroy these locks; they'll be recreated to assure they * are in the unlocked state. */ _lock_destroy(&kse_lock); _lock_destroy(&thread_lock); _lock_destroy(&_thread_list_lock); inited = 0; } /* * After a fork(), the leftover thread goes back to being * scope process. */ curthread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; curthread->attr.flags |= PTHREAD_SCOPE_PROCESS; /* * After a fork, we are still operating on the thread's original * stack. Don't clear the THR_FLAGS_USER from the thread's * attribute flags. */ /* Initialize the threads library. */ curthread->kse = NULL; curthread->kseg = NULL; _kse_initial = NULL; _libpthread_init(curthread); } /* * This is used to initialize housekeeping and to initialize the * KSD for the KSE. */ void _kse_init(void) { if (inited == 0) { TAILQ_INIT(&active_kseq); TAILQ_INIT(&active_kse_groupq); TAILQ_INIT(&free_kseq); TAILQ_INIT(&free_kse_groupq); TAILQ_INIT(&free_threadq); TAILQ_INIT(&gc_ksegq); if (_lock_init(&kse_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup) != 0) PANIC("Unable to initialize free KSE queue lock"); if (_lock_init(&thread_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup) != 0) PANIC("Unable to initialize free thread queue lock"); if (_lock_init(&_thread_list_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup) != 0) PANIC("Unable to initialize thread list lock"); active_kse_count = 0; active_kseg_count = 0; _gc_count = 0; inited = 1; } } int _kse_isthreaded(void) { return (__isthreaded != 0); } /* * This is called when the first thread (other than the initial * thread) is created. */ int _kse_setthreaded(int threaded) { if ((threaded != 0) && (__isthreaded == 0)) { /* * Locking functions in libc are required when there are * threads other than the initial thread. */ __isthreaded = 1; /* * Tell the kernel to create a KSE for the initial thread * and enable upcalls in it. */ _kse_initial->k_flags |= KF_STARTED; if (kse_create(&_kse_initial->k_mbx, 0) != 0) { _kse_initial->k_flags &= ~KF_STARTED; __isthreaded = 0; /* may abort() */ DBG_MSG("kse_create failed\n"); return (-1); } KSE_SET_MBOX(_kse_initial, _thr_initial); _thr_setmaxconcurrency(); } return (0); } /* * Lock wait and wakeup handlers for KSE locks. These are only used by * KSEs, and should never be used by threads. KSE locks include the * KSE group lock (used for locking the scheduling queue) and the * kse_lock defined above. * * When a KSE lock attempt blocks, the entire KSE blocks allowing another * KSE to run. For the most part, it doesn't make much sense to try and * schedule another thread because you need to lock the scheduling queue * in order to do that. And since the KSE lock is used to lock the scheduling * queue, you would just end up blocking again. */ void _kse_lock_wait(struct lock *lock, struct lockuser *lu) { struct kse *curkse = (struct kse *)_LCK_GET_PRIVATE(lu); struct timespec ts; int saved_flags; if (curkse->k_mbx.km_curthread != NULL) PANIC("kse_lock_wait does not disable upcall.\n"); /* * Enter a loop to wait until we get the lock. */ ts.tv_sec = 0; ts.tv_nsec = 1000000; /* 1 sec */ KSE_SET_WAIT(curkse); while (_LCK_BUSY(lu)) { /* * Yield the kse and wait to be notified when the lock * is granted. */ saved_flags = curkse->k_mbx.km_flags; curkse->k_mbx.km_flags |= KMF_NOUPCALL | KMF_NOCOMPLETED; kse_release(&ts); curkse->k_mbx.km_flags = saved_flags; /* * Make sure that the wait flag is set again in case * we wokeup without the lock being granted. */ KSE_SET_WAIT(curkse); } KSE_CLEAR_WAIT(curkse); } void _kse_lock_wakeup(struct lock *lock, struct lockuser *lu) { struct kse *curkse; struct kse *kse; curkse = _get_curkse(); kse = (struct kse *)_LCK_GET_PRIVATE(lu); if (kse == curkse) PANIC("KSE trying to wake itself up in lock"); else if (KSE_WAITING(kse)) { /* * Notify the owning kse that it has the lock. */ KSE_WAKEUP(kse); } } /* * Thread wait and wakeup handlers for thread locks. These are only used * by threads, never by KSEs. Thread locks include the per-thread lock * (defined in its structure), and condition variable and mutex locks. */ void _thr_lock_wait(struct lock *lock, struct lockuser *lu) { struct pthread *curthread = (struct pthread *)lu->lu_private; int count; /* * Spin for a bit. * * XXX - We probably want to make this a bit smarter. It * doesn't make sense to spin unless there is more * than 1 CPU. A thread that is holding one of these * locks is prevented from being swapped out for another * thread within the same scheduling entity. */ count = 0; while (_LCK_BUSY(lu) && count < 300) count++; while (_LCK_BUSY(lu)) { THR_LOCK_SWITCH(curthread); if (_LCK_BUSY(lu)) { /* Wait for the lock: */ atomic_store_rel_int(&curthread->need_wakeup, 1); THR_SET_STATE(curthread, PS_LOCKWAIT); _thr_sched_switch(curthread); } THR_UNLOCK_SWITCH(curthread); } } void _thr_lock_wakeup(struct lock *lock, struct lockuser *lu) { struct pthread *thread; struct pthread *curthread; int unlock; curthread = _get_curthread(); thread = (struct pthread *)_LCK_GET_PRIVATE(lu); unlock = 0; if (curthread->kseg == thread->kseg) { /* Not already locked */ if (curthread->lock_switch == 0) { THR_SCHED_LOCK(curthread, thread); unlock = 1; } } else { THR_SCHED_LOCK(curthread, thread); unlock = 1; } _thr_setrunnable_unlocked(thread); atomic_store_rel_int(&thread->need_wakeup, 0); if (unlock) THR_SCHED_UNLOCK(curthread, thread); } kse_critical_t _kse_critical_enter(void) { kse_critical_t crit; crit = _ksd_readandclear_tmbx; return (crit); } void _kse_critical_leave(kse_critical_t crit) { struct pthread *curthread; _ksd_set_tmbx(crit); if ((crit != NULL) && ((curthread = _get_curthread()) != NULL)) THR_YIELD_CHECK(curthread); } int _kse_in_critical(void) { return (_ksd_get_tmbx() == NULL); } void _thr_critical_enter(struct pthread *thread) { thread->critical_count++; } void _thr_critical_leave(struct pthread *thread) { thread->critical_count--; THR_YIELD_CHECK(thread); } /* * XXX - We may need to take the scheduling lock before calling * this, or perhaps take the lock within here before * doing anything else. */ void _thr_sched_switch(struct pthread *curthread) { struct pthread_sigframe psf; struct kse *curkse; volatile int once = 0; /* We're in the scheduler, 5 by 5: */ THR_ASSERT(curthread->lock_switch, "lock_switch"); THR_ASSERT(_kse_in_critical(), "not in critical region"); curkse = _get_curkse(); curthread->need_switchout = 1; /* The thread yielded on its own. */ curthread->critical_yield = 0; /* No need to yield anymore. */ curthread->slice_usec = -1; /* Restart the time slice. */ /* * The signal frame is allocated off the stack because * a thread can be interrupted by other signals while * it is running down pending signals. */ sigemptyset(&psf.psf_sigset); curthread->curframe = &psf; _thread_enter_uts(&curthread->tmbx, &curkse->k_mbx); /* * This thread is being resumed; check for cancellations. */ if ((once == 0) && (!THR_IN_CRITICAL(curthread))) { once = 1; curthread->critical_count++; THR_UNLOCK_SWITCH(curthread); curthread->critical_count--; thr_resume_check(curthread, &curthread->tmbx.tm_context, &psf); THR_LOCK_SWITCH(curthread); } } /* * This is the scheduler for a KSE which runs a scope system thread. * The multi-thread KSE scheduler should also work for a single threaded * KSE, but we use a separate scheduler so that it can be fine-tuned * to be more efficient (and perhaps not need a separate stack for * the KSE, allowing it to use the thread's stack). * * XXX - This probably needs some work. */ #ifdef NOT_YET static void kse_sched_single(struct kse *curkse) { struct pthread *curthread = curkse->k_curthread; struct pthread *td_wait; struct timespec ts; int level; if (curthread->active == 0) { if (curthread->state != PS_RUNNING) { /* Check to see if the thread has timed out. */ KSE_GET_TOD(curkse, &ts); if (thr_timedout(curthread, &ts) != 0) { curthread->timeout = 1; curthread->state = PS_RUNNING; } } } /* This thread no longer needs to yield the CPU: */ curthread->critical_yield = 0; curthread->need_switchout = 0; /* * Lock the scheduling queue. * * There is no scheduling queue for single threaded KSEs, * but we need a lock for protection regardless. */ KSE_SCHED_LOCK(curkse, curkse->k_kseg); /* * This has to do the job of kse_switchout_thread(), only * for a single threaded KSE/KSEG. */ switch (curthread->state) { case PS_DEAD: /* Unlock the scheduling queue and exit the KSE. */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); kse_fini(curkse); /* does not return */ break; case PS_COND_WAIT: case PS_SLEEP_WAIT: /* Only insert threads that can timeout: */ if (curthread->wakeup_time.tv_sec != -1) { /* Insert into the waiting queue: */ KSE_WAITQ_INSERT(curkse, curthread); } break; case PS_LOCKWAIT: level = curthread->locklevel - 1; if (_LCK_BUSY(&curthread->lockusers[level])) KSE_WAITQ_INSERT(curkse, curthread); else THR_SET_STATE(curthread, PS_RUNNING); break; case PS_JOIN: case PS_MUTEX_WAIT: case PS_RUNNING: case PS_SIGSUSPEND: case PS_SIGWAIT: case PS_SUSPENDED: case PS_DEADLOCK: default: /* * These states don't timeout and don't need * to be in the waiting queue. */ break; } while (curthread->state != PS_RUNNING) { curthread->active = 0; td_wait = KSE_WAITQ_FIRST(curkse); kse_wait(curkse, td_wait); if (td_wait != NULL) { KSE_GET_TOD(curkse, &ts); if (thr_timedout(curthread, &ts)) { /* Indicate the thread timedout: */ td_wait->timeout = 1; /* Make the thread runnable. */ THR_SET_STATE(td_wait, PS_RUNNING); KSE_WAITQ_REMOVE(curkse, td_wait); } } KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); kse_check_signals(curkse); KSE_SCHED_LOCK(curkse, curkse->k_kseg); } /* Remove the frame reference. */ curthread->curframe = NULL; /* Unlock the scheduling queue. */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); /* * Continue the thread at its current frame: */ DBG_MSG("Continuing bound thread %p\n", curthread); _thread_switch(&curthread->tmbx, &curkse->k_mbx.km_curthread); PANIC("Thread has returned from _thread_switch"); } #endif void dump_queues(struct kse *curkse) { struct pthread *thread; DBG_MSG("Threads in waiting queue:\n"); TAILQ_FOREACH(thread, &curkse->k_kseg->kg_schedq.sq_waitq, pqe) { DBG_MSG(" thread %p, state %d, blocked %d\n", thread, thread->state, thread->blocked); } } /* * This is the scheduler for a KSE which runs multiple threads. */ static void kse_sched_multi(struct kse *curkse) { struct pthread *curthread, *td_wait; struct pthread_sigframe *curframe; int ret; THR_ASSERT(curkse->k_mbx.km_curthread == NULL, "Mailbox not null in kse_sched_multi"); /* Check for first time initialization: */ if ((curkse->k_flags & KF_INITIALIZED) == 0) { /* Setup this KSEs specific data. */ _ksd_setprivate(&curkse->k_ksd); _set_curkse(curkse); /* Set this before grabbing the context. */ curkse->k_flags |= KF_INITIALIZED; } /* This may have returned from a kse_release(). */ if (KSE_WAITING(curkse)) { DBG_MSG("Entered upcall when KSE is waiting."); KSE_CLEAR_WAIT(curkse); } curthread = curkse->k_curthread; if (curthread == NULL || curthread->lock_switch == 0) { /* * curthread was preempted by upcall, it is not a volunteer * context switch. Lock the scheduling lock. */ KSE_SCHED_LOCK(curkse, curkse->k_kseg); } /* * If the current thread was completed in another KSE, then * it will be in the run queue. Don't mark it as being blocked. */ if ((curthread != NULL) && ((curthread->flags & THR_FLAGS_IN_RUNQ) == 0) && (curthread->need_switchout == 0)) { /* * Assume the current thread is blocked; when the * completed threads are checked and if the current * thread is among the completed, the blocked flag * will be cleared. */ curthread->blocked = 1; } /* Check for any unblocked threads in the kernel. */ kse_check_completed(curkse); /* * Check for threads that have timed-out. */ kse_check_waitq(curkse); /* * Switchout the current thread, if necessary, as the last step * so that it is inserted into the run queue (if it's runnable) * _after_ any other threads that were added to it above. */ if (curthread == NULL) ; /* Nothing to do here. */ else if ((curthread->need_switchout == 0) && (curthread->blocked == 0) && (THR_IN_CRITICAL(curthread))) { /* * Resume the thread and tell it to yield when * it leaves the critical region. */ curthread->critical_yield = 1; curthread->active = 1; if ((curthread->flags & THR_FLAGS_IN_RUNQ) != 0) KSE_RUNQ_REMOVE(curkse, curthread); curkse->k_curthread = curthread; curthread->kse = curkse; DBG_MSG("Continuing thread %p in critical region\n", curthread); if (curthread->lock_switch) { KSE_SCHED_LOCK(curkse, curkse->k_kseg); ret = _thread_switch(&curthread->tmbx, 0); } else { KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); ret = _thread_switch(&curthread->tmbx, &curkse->k_mbx.km_curthread); } if (ret != 0) PANIC("Can't resume thread in critical region\n"); } else if ((curthread->flags & THR_FLAGS_IN_RUNQ) == 0) kse_switchout_thread(curkse, curthread); curkse->k_curthread = NULL; kse_wakeup_multi(curkse); /* This has to be done without the scheduling lock held. */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); kse_check_signals(curkse); KSE_SCHED_LOCK(curkse, curkse->k_kseg); dump_queues(curkse); /* Check if there are no threads ready to run: */ while (((curthread = KSE_RUNQ_FIRST(curkse)) == NULL) && (curkse->k_kseg->kg_threadcount != 0)) { /* * Wait for a thread to become active or until there are * no more threads. */ td_wait = KSE_WAITQ_FIRST(curkse); kse_wait(curkse, td_wait); kse_check_completed(curkse); kse_check_waitq(curkse); KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); kse_check_signals(curkse); KSE_SCHED_LOCK(curkse, curkse->k_kseg); } /* Check for no more threads: */ if (curkse->k_kseg->kg_threadcount == 0) { /* * Normally this shouldn't return, but it will if there * are other KSEs running that create new threads that * are assigned to this KSE[G]. For instance, if a scope * system thread were to create a scope process thread * and this kse[g] is the initial kse[g], then that newly * created thread would be assigned to us (the initial * kse[g]). */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); kse_fini(curkse); KSE_SCHED_LOCK(curkse, curkse->k_kseg); curthread = KSE_RUNQ_FIRST(curkse); } THR_ASSERT(curthread != NULL, "Return from kse_wait/fini without thread."); THR_ASSERT(curthread->state != PS_DEAD, "Trying to resume dead thread!"); KSE_RUNQ_REMOVE(curkse, curthread); /* * Make the selected thread the current thread. */ curkse->k_curthread = curthread; /* * Make sure the current thread's kse points to this kse. */ curthread->kse = curkse; /* * Reset accounting. */ curthread->tmbx.tm_uticks = 0; curthread->tmbx.tm_sticks = 0; /* * Reset the time slice if this thread is running for the first * time or running again after using its full time slice allocation. */ if (curthread->slice_usec == -1) curthread->slice_usec = 0; /* Mark the thread active. */ curthread->active = 1; /* Remove the frame reference. */ curframe = curthread->curframe; curthread->curframe = NULL; kse_wakeup_multi(curkse); /* Unlock the scheduling queue: */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); /* * The thread's current signal frame will only be NULL if it * is being resumed after being blocked in the kernel. In * this case, and if the thread needs to run down pending * signals or needs a cancellation check, we need to add a * signal frame to the thread's context. */ #ifdef NOT_YET if ((curframe == NULL) && ((curthread->check_pending != 0) || (((curthread->cancelflags & THR_AT_CANCEL_POINT) == 0) && ((curthread->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0)))) signalcontext(&curthread->tmbx.tm_context, 0, (__sighandler_t *)thr_resume_wrapper); #else if ((curframe == NULL) && (curthread->check_pending != 0)) signalcontext(&curthread->tmbx.tm_context, 0, (__sighandler_t *)thr_resume_wrapper); #endif #ifdef GS_HACK /* XXX - The kernel sometimes forgets to restore %gs properly. */ _ksd_setprivate(&curkse->k_ksd); #endif /* * Continue the thread at its current frame: */ if (curthread->lock_switch) { KSE_SCHED_LOCK(curkse, curkse->k_kseg); ret = _thread_switch(&curthread->tmbx, 0); } else { ret = _thread_switch(&curthread->tmbx, &curkse->k_mbx.km_curthread); } if (ret != 0) PANIC("Thread has returned from _thread_switch"); /* This point should not be reached. */ PANIC("Thread has returned from _thread_switch"); } static void kse_check_signals(struct kse *curkse) { sigset_t sigset; int i; /* Deliver posted signals. */ for (i = 0; i < _SIG_WORDS; i++) { atomic_swap_int(&curkse->k_mbx.km_sigscaught.__bits[i], 0, &sigset.__bits[i]); } if (SIGNOTEMPTY(sigset)) { /* * Dispatch each signal. * * XXX - There is no siginfo for any of these. * I think there should be, especially for * signals from other processes (si_pid, si_uid). */ for (i = 1; i < NSIG; i++) { if (sigismember(&sigset, i) != 0) { DBG_MSG("Dispatching signal %d\n", i); _thr_sig_dispatch(curkse, i, NULL /* no siginfo */); } } sigemptyset(&sigset); __sys_sigprocmask(SIG_SETMASK, &sigset, NULL); } } static void thr_resume_wrapper(int unused_1, siginfo_t *unused_2, ucontext_t *ucp) { struct pthread *curthread = _get_curthread(); thr_resume_check(curthread, ucp, NULL); } static void thr_resume_check(struct pthread *curthread, ucontext_t *ucp, struct pthread_sigframe *psf) { /* Check signals before cancellations. */ while (curthread->check_pending != 0) { /* Clear the pending flag. */ curthread->check_pending = 0; /* * It's perfectly valid, though not portable, for * signal handlers to munge their interrupted context * and expect to return to it. Ensure we use the * correct context when running down signals. */ _thr_sig_rundown(curthread, ucp, psf); } #ifdef NOT_YET if (((curthread->cancelflags & THR_AT_CANCEL_POINT) == 0) && ((curthread->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0)) pthread_testcancel(); #endif } /* * Clean up a thread. This must be called with the thread's KSE * scheduling lock held. The thread must be a thread from the * KSE's group. */ static void thr_cleanup(struct kse *curkse, struct pthread *thread) { struct pthread *joiner; if ((joiner = thread->joiner) != NULL) { thread->joiner = NULL; if ((joiner->state == PS_JOIN) && (joiner->join_status.thread == thread)) { joiner->join_status.thread = NULL; /* Set the return status for the joining thread: */ joiner->join_status.ret = thread->ret; /* Make the thread runnable. */ if (joiner->kseg == curkse->k_kseg) _thr_setrunnable_unlocked(joiner); else { KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); KSE_SCHED_LOCK(curkse, joiner->kseg); _thr_setrunnable_unlocked(joiner); KSE_SCHED_UNLOCK(curkse, joiner->kseg); KSE_SCHED_LOCK(curkse, curkse->k_kseg); } } thread->attr.flags |= PTHREAD_DETACHED; } if ((thread->attr.flags & PTHREAD_SCOPE_PROCESS) == 0) { /* * Remove the thread from the KSEG's list of threads. */ KSEG_THRQ_REMOVE(thread->kseg, thread); /* * Migrate the thread to the main KSE so that this * KSE and KSEG can be cleaned when their last thread * exits. */ thread->kseg = _kse_initial->k_kseg; thread->kse = _kse_initial; } thread->flags |= THR_FLAGS_GC_SAFE; /* * We can't hold the thread list lock while holding the * scheduler lock. */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); DBG_MSG("Adding thread %p to GC list\n", thread); KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); THR_GCLIST_ADD(thread); KSE_LOCK_RELEASE(curkse, &_thread_list_lock); KSE_SCHED_LOCK(curkse, curkse->k_kseg); } void _thr_gc(struct pthread *curthread) { struct pthread *td, *td_next; kse_critical_t crit; TAILQ_HEAD(, pthread) worklist; TAILQ_INIT(&worklist); crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock); /* Check the threads waiting for GC. */ for (td = TAILQ_FIRST(&_thread_gc_list); td != NULL; td = td_next) { td_next = TAILQ_NEXT(td, gcle); if ((td->flags & THR_FLAGS_GC_SAFE) == 0) continue; #ifdef NOT_YET else if (((td->attr.flags & PTHREAD_SCOPE_PROCESS) != 0) && (td->kse->k_mbx.km_flags == 0)) { /* * The thread and KSE are operating on the same * stack. Wait for the KSE to exit before freeing * the thread's stack as well as everything else. */ continue; } #endif /* * Remove the thread from the GC list. If the thread * isn't yet detached, it will get added back to the * GC list at a later time. */ THR_GCLIST_REMOVE(td); DBG_MSG("Freeing thread %p stack\n", td); /* * We can free the thread stack since it's no longer * in use. */ _thr_stack_free(&td->attr); if (((td->attr.flags & PTHREAD_DETACHED) != 0) && (td->refcount == 0)) { /* * The thread has detached and is no longer * referenced. It is safe to remove all * remnants of the thread. */ THR_LIST_REMOVE(td); TAILQ_INSERT_HEAD(&worklist, td, gcle); } } KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock); _kse_critical_leave(crit); while ((td = TAILQ_FIRST(&worklist)) != NULL) { TAILQ_REMOVE(&worklist, td, gcle); if ((td->attr.flags & PTHREAD_SCOPE_PROCESS) != 0) { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); kse_free_unlocked(td->kse); kseg_free_unlocked(td->kseg); KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); } DBG_MSG("Freeing thread %p\n", td); _thr_free(curthread, td); } } /* * Only new threads that are running or suspended may be scheduled. */ int _thr_schedule_add(struct pthread *curthread, struct pthread *newthread) { struct kse *curkse; kse_critical_t crit; int need_start; int ret; /* * If this is the first time creating a thread, make sure * the mailbox is set for the current thread. */ if ((newthread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) { #ifdef NOT_YET /* We use the thread's stack as the KSE's stack. */ new_thread->kse->k_mbx.km_stack.ss_sp = new_thread->attr.stackaddr_attr; new_thread->kse->k_mbx.km_stack.ss_size = new_thread->attr.stacksize_attr; #endif /* * No need to lock the scheduling queue since the * KSE/KSEG pair have not yet been started. */ KSEG_THRQ_ADD(newthread->kseg, newthread); TAILQ_INSERT_TAIL(&newthread->kseg->kg_kseq, newthread->kse, k_kgqe); newthread->kseg->kg_ksecount = 1; if (newthread->state == PS_RUNNING) THR_RUNQ_INSERT_TAIL(newthread); newthread->kse->k_curthread = NULL; newthread->kse->k_mbx.km_flags = 0; newthread->kse->k_mbx.km_func = (kse_func_t *)kse_sched_multi; newthread->kse->k_mbx.km_quantum = 0; /* * This thread needs a new KSE and KSEG. */ crit = _kse_critical_enter(); curkse = _get_curkse(); _ksd_setprivate(&newthread->kse->k_ksd); newthread->kse->k_flags |= KF_INITIALIZED; ret = kse_create(&newthread->kse->k_mbx, 1); if (ret != 0) ret = errno; _ksd_setprivate(&curkse->k_ksd); _kse_critical_leave(crit); } else { /* * Lock the KSE and add the new thread to its list of * assigned threads. If the new thread is runnable, also * add it to the KSE's run queue. */ need_start = 0; KSE_SCHED_LOCK(curthread->kse, newthread->kseg); KSEG_THRQ_ADD(newthread->kseg, newthread); if (newthread->state == PS_RUNNING) THR_RUNQ_INSERT_TAIL(newthread); if ((newthread->kse->k_flags & KF_STARTED) == 0) { /* * This KSE hasn't been started yet. Start it * outside of holding the lock. */ newthread->kse->k_flags |= KF_STARTED; newthread->kse->k_mbx.km_func = (kse_func_t *)kse_sched_multi; newthread->kse->k_mbx.km_flags = 0; need_start = 1; } KSE_SCHED_UNLOCK(curthread->kse, newthread->kseg); if (need_start != 0) kse_create(&newthread->kse->k_mbx, 0); else if ((newthread->state == PS_RUNNING) && KSE_IS_IDLE(newthread->kse)) { /* * The thread is being scheduled on another KSEG. */ kse_wakeup_one(newthread); } ret = 0; } return (ret); } void kse_waitq_insert(struct pthread *thread) { struct pthread *td; if (thread->wakeup_time.tv_sec == -1) TAILQ_INSERT_TAIL(&thread->kse->k_schedq->sq_waitq, thread, pqe); else { td = TAILQ_FIRST(&thread->kse->k_schedq->sq_waitq); while ((td != NULL) && (td->wakeup_time.tv_sec != -1) && ((td->wakeup_time.tv_sec < thread->wakeup_time.tv_sec) || ((td->wakeup_time.tv_sec == thread->wakeup_time.tv_sec) && (td->wakeup_time.tv_nsec <= thread->wakeup_time.tv_nsec)))) td = TAILQ_NEXT(td, pqe); if (td == NULL) TAILQ_INSERT_TAIL(&thread->kse->k_schedq->sq_waitq, thread, pqe); else TAILQ_INSERT_BEFORE(td, thread, pqe); } thread->flags |= THR_FLAGS_IN_WAITQ; } /* * This must be called with the scheduling lock held. */ static void kse_check_completed(struct kse *kse) { struct pthread *thread; struct kse_thr_mailbox *completed; if ((completed = kse->k_mbx.km_completed) != NULL) { kse->k_mbx.km_completed = NULL; while (completed != NULL) { thread = completed->tm_udata; DBG_MSG("Found completed thread %p, name %s\n", thread, (thread->name == NULL) ? "none" : thread->name); thread->blocked = 0; if (thread != kse->k_curthread) KSE_RUNQ_INSERT_TAIL(kse, thread); completed = completed->tm_next; } } } /* * This must be called with the scheduling lock held. */ static void kse_check_waitq(struct kse *kse) { struct pthread *pthread; struct timespec ts; KSE_GET_TOD(kse, &ts); /* * Wake up threads that have timedout. This has to be * done before adding the current thread to the run queue * so that a CPU intensive thread doesn't get preference * over waiting threads. */ while (((pthread = KSE_WAITQ_FIRST(kse)) != NULL) && thr_timedout(pthread, &ts)) { /* Remove the thread from the wait queue: */ KSE_WAITQ_REMOVE(kse, pthread); DBG_MSG("Found timedout thread %p in waitq\n", pthread); /* Indicate the thread timedout: */ pthread->timeout = 1; /* Add the thread to the priority queue: */ THR_SET_STATE(pthread, PS_RUNNING); KSE_RUNQ_INSERT_TAIL(kse, pthread); } } static int thr_timedout(struct pthread *thread, struct timespec *curtime) { if (thread->wakeup_time.tv_sec < 0) return (0); else if (thread->wakeup_time.tv_sec > curtime->tv_sec) return (0); else if ((thread->wakeup_time.tv_sec == curtime->tv_sec) && (thread->wakeup_time.tv_nsec > curtime->tv_nsec)) return (0); else return (1); } /* * This must be called with the scheduling lock held. * * Each thread has a time slice, a wakeup time (used when it wants * to wait for a specified amount of time), a run state, and an * active flag. * * When a thread gets run by the scheduler, the active flag is * set to non-zero (1). When a thread performs an explicit yield * or schedules a state change, it enters the scheduler and the * active flag is cleared. When the active flag is still seen * set in the scheduler, that means that the thread is blocked in * the kernel (because it is cleared before entering the scheduler * in all other instances). * * The wakeup time is only set for those states that can timeout. * It is set to (-1, -1) for all other instances. * * The thread's run state, aside from being useful when debugging, * is used to place the thread in an appropriate queue. There * are 2 basic queues: * * o run queue - queue ordered by priority for all threads * that are runnable * o waiting queue - queue sorted by wakeup time for all threads * that are not otherwise runnable (not blocked * in kernel, not waiting for locks) * * The thread's time slice is used for round-robin scheduling * (the default scheduling policy). While a SCHED_RR thread * is runnable it's time slice accumulates. When it reaches * the time slice interval, it gets reset and added to the end * of the queue of threads at its priority. When a thread no * longer becomes runnable (blocks in kernel, waits, etc), its * time slice is reset. * * The job of kse_switchout_thread() is to handle all of the above. */ static void kse_switchout_thread(struct kse *kse, struct pthread *thread) { int level; /* * Place the currently running thread into the * appropriate queue(s). */ DBG_MSG("Switching out thread %p, state %d\n", thread, thread->state); if (thread->blocked != 0) { thread->active = 0; thread->need_switchout = 0; /* This thread must have blocked in the kernel. */ /* thread->slice_usec = -1;*/ /* restart timeslice */ /* * XXX - Check for pending signals for this thread to * see if we need to interrupt it in the kernel. */ /* if (thread->check_pending != 0) */ if ((thread->slice_usec != -1) && (thread->attr.sched_policy != SCHED_FIFO)) thread->slice_usec += (thread->tmbx.tm_uticks + thread->tmbx.tm_sticks) * _clock_res_usec; } else { switch (thread->state) { case PS_DEAD: /* * The scheduler is operating on a different * stack. It is safe to do garbage collecting * here. */ thread->active = 0; thread->need_switchout = 0; thr_cleanup(kse, thread); return; break; case PS_RUNNING: /* Nothing to do here. */ break; case PS_COND_WAIT: case PS_SLEEP_WAIT: /* Insert into the waiting queue: */ KSE_WAITQ_INSERT(kse, thread); break; case PS_LOCKWAIT: /* * This state doesn't timeout. */ thread->wakeup_time.tv_sec = -1; thread->wakeup_time.tv_nsec = -1; level = thread->locklevel - 1; if (_LCK_BUSY(&thread->lockusers[level])) KSE_WAITQ_INSERT(kse, thread); else THR_SET_STATE(thread, PS_RUNNING); break; case PS_JOIN: case PS_MUTEX_WAIT: case PS_SIGSUSPEND: case PS_SIGWAIT: case PS_SUSPENDED: case PS_DEADLOCK: default: /* * These states don't timeout. */ thread->wakeup_time.tv_sec = -1; thread->wakeup_time.tv_nsec = -1; /* Insert into the waiting queue: */ KSE_WAITQ_INSERT(kse, thread); break; } if (thread->state != PS_RUNNING) { /* Restart the time slice: */ thread->slice_usec = -1; } else { if (thread->need_switchout != 0) /* * The thread yielded on its own; * restart the timeslice. */ thread->slice_usec = -1; else if ((thread->slice_usec != -1) && (thread->attr.sched_policy != SCHED_FIFO)) { thread->slice_usec += (thread->tmbx.tm_uticks + thread->tmbx.tm_sticks) * _clock_res_usec; /* Check for time quantum exceeded: */ if (thread->slice_usec > TIMESLICE_USEC) thread->slice_usec = -1; } if (thread->slice_usec == -1) { /* * The thread exceeded its time quantum or * it yielded the CPU; place it at the tail * of the queue for its priority. */ KSE_RUNQ_INSERT_TAIL(kse, thread); } else { /* * The thread hasn't exceeded its interval * Place it at the head of the queue for its * priority. */ KSE_RUNQ_INSERT_HEAD(kse, thread); } } } thread->active = 0; thread->need_switchout = 0; } /* * This function waits for the smallest timeout value of any waiting * thread, or until it receives a message from another KSE. * * This must be called with the scheduling lock held. */ static void kse_wait(struct kse *kse, struct pthread *td_wait) { struct timespec ts, ts_sleep; int saved_flags; KSE_GET_TOD(kse, &ts); if ((td_wait == NULL) || (td_wait->wakeup_time.tv_sec < 0)) { /* Limit sleep to no more than 1 minute. */ ts_sleep.tv_sec = 60; ts_sleep.tv_nsec = 0; } else { TIMESPEC_SUB(&ts_sleep, &td_wait->wakeup_time, &ts); if (ts_sleep.tv_sec > 60) { ts_sleep.tv_sec = 60; ts_sleep.tv_nsec = 0; } } /* Don't sleep for negative times. */ if ((ts_sleep.tv_sec >= 0) && (ts_sleep.tv_nsec >= 0)) { KSE_SET_IDLE(kse); kse->k_kseg->kg_idle_kses++; KSE_SCHED_UNLOCK(kse, kse->k_kseg); saved_flags = kse->k_mbx.km_flags; kse->k_mbx.km_flags |= KMF_NOUPCALL; kse_release(&ts_sleep); kse->k_mbx.km_flags = saved_flags; KSE_SCHED_LOCK(kse, kse->k_kseg); if (KSE_IS_IDLE(kse)) { KSE_CLEAR_IDLE(kse); kse->k_kseg->kg_idle_kses--; } } } /* * Avoid calling this kse_exit() so as not to confuse it with the * system call of the same name. */ static void kse_fini(struct kse *kse) { struct timespec ts; struct kse_group *free_kseg = NULL; if ((kse->k_kseg->kg_flags & KGF_SINGLE_THREAD) != 0) kse_exit(); /* * Check to see if this is one of the main kses. */ else if (kse->k_kseg != _kse_initial->k_kseg) { /* Remove this KSE from the KSEG's list of KSEs. */ KSE_SCHED_LOCK(kse, kse->k_kseg); TAILQ_REMOVE(&kse->k_kseg->kg_kseq, kse, k_kgqe); kse->k_kseg->kg_ksecount--; if (TAILQ_EMPTY(&kse->k_kseg->kg_kseq)) free_kseg = kse->k_kseg; KSE_SCHED_UNLOCK(kse, kse->k_kseg); /* * Add this KSE to the list of free KSEs along with * the KSEG if is now orphaned. */ #ifdef NOT_YET KSE_LOCK_ACQUIRE(kse, &kse_lock); if (free_kseg != NULL) kseg_free_unlocked(free_kseg); kse_free_unlocked(kse); KSE_LOCK_RELEASE(kse, &kse_lock); #endif kse_exit(); /* Never returns. */ } else { /* * Wait for the last KSE/thread to exit, or for more * threads to be created (it is possible for additional * scope process threads to be created after the main * thread exits). */ ts.tv_sec = 120; ts.tv_nsec = 0; KSE_SET_WAIT(kse); KSE_SCHED_LOCK(kse, kse->k_kseg); if ((active_kse_count > 1) && (kse->k_kseg->kg_threadcount == 0)) { KSE_SCHED_UNLOCK(kse, kse->k_kseg); kse_release(&ts); /* The above never returns. */ } else KSE_SCHED_UNLOCK(kse, kse->k_kseg); /* There are no more threads; exit this process: */ if (kse->k_kseg->kg_threadcount == 0) { /* kse_exit(); */ __isthreaded = 0; exit(0); } } } void _thr_sig_add(struct pthread *thread, int sig, siginfo_t *info, ucontext_t *ucp) { struct kse *curkse; curkse = _get_curkse(); KSE_SCHED_LOCK(curkse, thread->kseg); /* * A threads assigned KSE can't change out from under us * when we hold the scheduler lock. */ if (THR_IS_ACTIVE(thread)) { /* Thread is active. Can't install the signal for it. */ /* Make a note in the thread that it has a signal. */ sigaddset(&thread->sigpend, sig); thread->check_pending = 1; } else { /* Make a note in the thread that it has a signal. */ sigaddset(&thread->sigpend, sig); thread->check_pending = 1; if (thread->blocked != 0) { /* Tell the kernel to interrupt the thread. */ kse_thr_interrupt(&thread->tmbx); } } KSE_SCHED_UNLOCK(curkse, thread->kseg); } void _thr_set_timeout(const struct timespec *timeout) { struct pthread *curthread = _get_curthread(); struct timespec ts; /* Reset the timeout flag for the running thread: */ curthread->timeout = 0; /* Check if the thread is to wait forever: */ if (timeout == NULL) { /* * Set the wakeup time to something that can be recognised as * different to an actual time of day: */ curthread->wakeup_time.tv_sec = -1; curthread->wakeup_time.tv_nsec = -1; } /* Check if no waiting is required: */ else if ((timeout->tv_sec == 0) && (timeout->tv_nsec == 0)) { /* Set the wake up time to 'immediately': */ curthread->wakeup_time.tv_sec = 0; curthread->wakeup_time.tv_nsec = 0; } else { /* Calculate the time for the current thread to wakeup: */ KSE_GET_TOD(curthread->kse, &ts); TIMESPEC_ADD(&curthread->wakeup_time, &ts, timeout); } } void _thr_panic_exit(char *file, int line, char *msg) { char buf[256]; snprintf(buf, sizeof(buf), "(%s:%d) %s\n", file, line, msg); __sys_write(2, buf, strlen(buf)); abort(); } void _thr_setrunnable(struct pthread *curthread, struct pthread *thread) { kse_critical_t crit; crit = _kse_critical_enter(); KSE_SCHED_LOCK(curthread->kse, thread->kseg); _thr_setrunnable_unlocked(thread); KSE_SCHED_UNLOCK(curthread->kse, thread->kseg); _kse_critical_leave(crit); } void _thr_setrunnable_unlocked(struct pthread *thread) { if ((thread->kseg->kg_flags & KGF_SINGLE_THREAD) != 0) /* No silly queues for these threads. */ THR_SET_STATE(thread, PS_RUNNING); else if (thread->state != PS_RUNNING) { if ((thread->flags & THR_FLAGS_IN_WAITQ) != 0) KSE_WAITQ_REMOVE(thread->kse, thread); THR_SET_STATE(thread, PS_RUNNING); if ((thread->blocked == 0) && (thread->flags & THR_FLAGS_IN_RUNQ) == 0) THR_RUNQ_INSERT_TAIL(thread); } /* * XXX - Threads are not yet assigned to specific KSEs; they are * assigned to the KSEG. So the fact that a thread's KSE is * waiting doesn't necessarily mean that it will be the KSE * that runs the thread after the lock is granted. But we * don't know if the other KSEs within the same KSEG are * also in a waiting state or not so we err on the side of * caution and wakeup the thread's last known KSE. We * ensure that the threads KSE doesn't change while it's * scheduling lock is held so it is safe to reference it * (the KSE). If the KSE wakes up and doesn't find any more * work it will again go back to waiting so no harm is done. */ kse_wakeup_one(thread); } static void kse_wakeup_one(struct pthread *thread) { struct kse *ke; if (KSE_IS_IDLE(thread->kse)) { KSE_CLEAR_IDLE(thread->kse); thread->kseg->kg_idle_kses--; KSE_WAKEUP(thread->kse); } else { TAILQ_FOREACH(ke, &thread->kseg->kg_kseq, k_kgqe) { if (KSE_IS_IDLE(ke)) { KSE_CLEAR_IDLE(ke); ke->k_kseg->kg_idle_kses--; KSE_WAKEUP(ke); return; } } } } static void kse_wakeup_multi(struct kse *curkse) { struct kse *ke; int tmp; if ((tmp = KSE_RUNQ_THREADS(curkse)) && curkse->k_kseg->kg_idle_kses) { TAILQ_FOREACH(ke, &curkse->k_kseg->kg_kseq, k_kgqe) { if (KSE_IS_IDLE(ke)) { KSE_CLEAR_IDLE(ke); ke->k_kseg->kg_idle_kses--; KSE_WAKEUP(ke); if (--tmp == 0) break; } } } } struct pthread * _get_curthread(void) { return (_ksd_curthread); } /* This assumes the caller has disabled upcalls. */ struct kse * _get_curkse(void) { return (_ksd_curkse); } void _set_curkse(struct kse *kse) { _ksd_setprivate(&kse->k_ksd); } /* * Allocate a new KSEG. * * We allow the current thread to be NULL in the case that this * is the first time a KSEG is being created (library initialization). * In this case, we don't need to (and can't) take any locks. */ struct kse_group * _kseg_alloc(struct pthread *curthread) { struct kse_group *kseg = NULL; kse_critical_t crit; if ((curthread != NULL) && (free_kseg_count > 0)) { /* Use the kse lock for the kseg queue. */ crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); if ((kseg = TAILQ_FIRST(&free_kse_groupq)) != NULL) { TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe); free_kseg_count--; active_kseg_count++; TAILQ_INSERT_TAIL(&active_kse_groupq, kseg, kg_qe); } KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); if (kseg) kseg_reinit(kseg); } /* * If requested, attempt to allocate a new KSE group only if the * KSE allocation was successful and a KSE group wasn't found in * the free list. */ if ((kseg == NULL) && ((kseg = (struct kse_group *)malloc(sizeof(*kseg))) != NULL)) { if (_pq_alloc(&kseg->kg_schedq.sq_runq, THR_MIN_PRIORITY, THR_LAST_PRIORITY) != 0) { free(kseg); kseg = NULL; } else { kseg_init(kseg); /* Add the KSEG to the list of active KSEGs. */ if (curthread != NULL) { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); active_kseg_count++; TAILQ_INSERT_TAIL(&active_kse_groupq, kseg, kg_qe); KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); } else { active_kseg_count++; TAILQ_INSERT_TAIL(&active_kse_groupq, kseg, kg_qe); } } } return (kseg); } /* * This must be called with the kse lock held and when there are * no more threads that reference it. */ static void kseg_free_unlocked(struct kse_group *kseg) { TAILQ_REMOVE(&active_kse_groupq, kseg, kg_qe); TAILQ_INSERT_HEAD(&free_kse_groupq, kseg, kg_qe); free_kseg_count++; active_kseg_count--; } void _kseg_free(struct kse_group *kseg) { struct kse *curkse; kse_critical_t crit; crit = _kse_critical_enter(); curkse = _get_curkse(); KSE_LOCK_ACQUIRE(curkse, &kse_lock); kseg_free_unlocked(kseg); KSE_LOCK_RELEASE(curkse, &kse_lock); _kse_critical_leave(crit); } /* * Allocate a new KSE. * * We allow the current thread to be NULL in the case that this * is the first time a KSE is being created (library initialization). * In this case, we don't need to (and can't) take any locks. */ struct kse * _kse_alloc(struct pthread *curthread) { struct kse *kse = NULL; kse_critical_t crit; int need_ksd = 0; int i; if ((curthread != NULL) && (free_kse_count > 0)) { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); /* Search for a finished KSE. */ kse = TAILQ_FIRST(&free_kseq); #ifdef NOT_YET #define KEMBX_DONE 0x04 while ((kse != NULL) && ((kse->k_mbx.km_flags & KEMBX_DONE) == 0)) { kse = TAILQ_NEXT(kse, k_qe); } #undef KEMBX_DONE #endif if (kse != NULL) { TAILQ_REMOVE(&free_kseq, kse, k_qe); free_kse_count--; TAILQ_INSERT_TAIL(&active_kseq, kse, k_qe); active_kse_count++; } KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); if (kse != NULL) kse_reinit(kse); } if ((kse == NULL) && ((kse = (struct kse *)malloc(sizeof(*kse))) != NULL)) { bzero(kse, sizeof(*kse)); /* Initialize the lockusers. */ for (i = 0; i < MAX_KSE_LOCKLEVEL; i++) { _lockuser_init(&kse->k_lockusers[i], (void *)kse); _LCK_SET_PRIVATE2(&kse->k_lockusers[i], NULL); } /* _lock_init(kse->k_lock, ...) */ /* We had to malloc a kse; mark it as needing a new ID.*/ need_ksd = 1; /* * Create the KSE context. * * XXX - For now this is done here in the allocation. * In the future, we may want to have it done * outside the allocation so that scope system * threads (one thread per KSE) are not required * to have a stack for an unneeded kse upcall. */ kse->k_mbx.km_func = (kse_func_t *)kse_sched_multi; kse->k_mbx.km_stack.ss_sp = (char *)malloc(KSE_STACKSIZE); kse->k_mbx.km_stack.ss_size = KSE_STACKSIZE; kse->k_mbx.km_udata = (void *)kse; kse->k_mbx.km_quantum = 20000; /* * We need to keep a copy of the stack in case it * doesn't get used; a KSE running a scope system * thread will use that thread's stack. */ kse->k_stack.ss_sp = kse->k_mbx.km_stack.ss_sp; kse->k_stack.ss_size = kse->k_mbx.km_stack.ss_size; if (kse->k_mbx.km_stack.ss_sp == NULL) { for (i = 0; i < MAX_KSE_LOCKLEVEL; i++) { _lockuser_destroy(&kse->k_lockusers[i]); } /* _lock_destroy(&kse->k_lock); */ free(kse); kse = NULL; } } if ((kse != NULL) && (need_ksd != 0)) { /* This KSE needs initialization. */ if (curthread != NULL) { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); } /* Initialize KSD inside of the lock. */ if (_ksd_create(&kse->k_ksd, (void *)kse, sizeof(*kse)) != 0) { if (curthread != NULL) { KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); } free(kse->k_mbx.km_stack.ss_sp); for (i = 0; i < MAX_KSE_LOCKLEVEL; i++) { _lockuser_destroy(&kse->k_lockusers[i]); } free(kse); return (NULL); } kse->k_flags = 0; TAILQ_INSERT_TAIL(&active_kseq, kse, k_qe); active_kse_count++; if (curthread != NULL) { KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); } } return (kse); } static void kse_reinit(struct kse *kse) { bzero(&kse->k_mbx, sizeof(struct kse_mailbox)); kse->k_curthread = 0; kse->k_kseg = 0; kse->k_schedq = 0; kse->k_locklevel = 0; sigemptyset(&kse->k_sigmask); bzero(&kse->k_sigq, sizeof(kse->k_sigq)); kse->k_check_sigq = 0; kse->k_flags = 0; kse->k_waiting = 0; kse->k_error = 0; kse->k_cpu = 0; kse->k_done = 0; } void kse_free_unlocked(struct kse *kse) { TAILQ_REMOVE(&active_kseq, kse, k_qe); active_kse_count--; kse->k_kseg = NULL; kse->k_mbx.km_quantum = 20000; kse->k_flags &= ~KF_INITIALIZED; TAILQ_INSERT_HEAD(&free_kseq, kse, k_qe); free_kse_count++; } void _kse_free(struct pthread *curthread, struct kse *kse) { kse_critical_t crit; if (curthread == NULL) kse_free_unlocked(kse); else { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); kse_free_unlocked(kse); KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); } } static void kseg_init(struct kse_group *kseg) { kseg_reinit(kseg); _lock_init(&kseg->kg_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup); } static void kseg_reinit(struct kse_group *kseg) { TAILQ_INIT(&kseg->kg_kseq); TAILQ_INIT(&kseg->kg_threadq); TAILQ_INIT(&kseg->kg_schedq.sq_waitq); kseg->kg_threadcount = 0; kseg->kg_ksecount = 0; kseg->kg_idle_kses = 0; kseg->kg_flags = 0; } struct pthread * _thr_alloc(struct pthread *curthread) { kse_critical_t crit; struct pthread *thread = NULL; if (curthread != NULL) { if (GC_NEEDED()) _thr_gc(curthread); if (free_thread_count > 0) { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &thread_lock); if ((thread = TAILQ_FIRST(&free_threadq)) != NULL) { TAILQ_REMOVE(&free_threadq, thread, tle); free_thread_count--; } KSE_LOCK_RELEASE(curthread->kse, &thread_lock); _kse_critical_leave(crit); } } if (thread == NULL) thread = (struct pthread *)malloc(sizeof(struct pthread)); return (thread); } void _thr_free(struct pthread *curthread, struct pthread *thread) { kse_critical_t crit; int i; DBG_MSG("Freeing thread %p\n", thread); if ((curthread == NULL) || (free_thread_count >= MAX_CACHED_THREADS)) { for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { _lockuser_destroy(&thread->lockusers[i]); } _lock_destroy(&thread->lock); free(thread); } else { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &thread_lock); TAILQ_INSERT_HEAD(&free_threadq, thread, tle); free_thread_count++; KSE_LOCK_RELEASE(curthread->kse, &thread_lock); _kse_critical_leave(crit); } }