/* * 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("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "atomic_ops.h" #include "thr_private.h" #include "libc_private.h" #ifdef NOTYET #include "spinlock.h" #endif /* #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. */ #define MAX_CACHED_THREADS 100 /* * Define high water marks for the maximum number of KSEs and KSE groups * that will be cached. Because we support 1:1 threading, there could have * same number of KSEs and KSE groups as threads. Once these levels are * reached, any extra KSE and KSE groups will be free()'d. */ #define MAX_CACHED_KSES ((_thread_scope_system <= 0) ? 50 : 100) #define MAX_CACHED_KSEGS ((_thread_scope_system <= 0) ? 50 : 100) #define KSE_SET_MBOX(kse, thrd) \ (kse)->k_kcb->kcb_kmbx.km_curthread = &(thrd)->tcb->tcb_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) \ ((_libkse_debug == 0) ? \ _pq_first(&(kse)->k_schedq->sq_runq) : \ _pq_first_debug(&(kse)->k_schedq->sq_runq)) #define KSE_RUNQ_THREADS(kse) ((kse)->k_schedq->sq_runq.pq_threads) #define THR_NEED_CANCEL(thrd) \ (((thrd)->cancelflags & THR_CANCELLING) != 0 && \ ((thrd)->cancelflags & PTHREAD_CANCEL_DISABLE) == 0 && \ (((thrd)->cancelflags & THR_AT_CANCEL_POINT) != 0 || \ ((thrd)->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0)) #define THR_NEED_ASYNC_CANCEL(thrd) \ (((thrd)->cancelflags & THR_CANCELLING) != 0 && \ ((thrd)->cancelflags & PTHREAD_CANCEL_DISABLE) == 0 && \ (((thrd)->cancelflags & THR_AT_CANCEL_POINT) == 0 && \ ((thrd)->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0)) /* * 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 u_int64_t next_uniqueid = 1; LIST_HEAD(thread_hash_head, pthread); #define THREAD_HASH_QUEUES 127 static struct thread_hash_head thr_hashtable[THREAD_HASH_QUEUES]; #define THREAD_HASH(thrd) ((unsigned long)thrd % THREAD_HASH_QUEUES) /* Lock for thread tcb constructor/destructor */ static pthread_mutex_t _tcb_mutex; #ifdef DEBUG_THREAD_KERN static void dump_queues(struct kse *curkse); #endif static void kse_check_completed(struct kse *kse); static void kse_check_waitq(struct kse *kse); static void kse_fini(struct kse *curkse); static void kse_reinit(struct kse *kse, int sys_scope); static void kse_sched_multi(struct kse_mailbox *kmbx); static void kse_sched_single(struct kse_mailbox *kmbx); static void kse_switchout_thread(struct kse *kse, struct pthread *thread); static void kse_wait(struct kse *kse, struct pthread *td_wait, int sigseq); static void kse_free_unlocked(struct kse *kse); static void kse_destroy(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 kseg_destroy(struct kse_group *kseg); static void kse_waitq_insert(struct pthread *thread); static void kse_wakeup_multi(struct kse *curkse); static struct kse_mailbox *kse_wakeup_one(struct pthread *thread); static void thr_cleanup(struct kse *kse, struct pthread *curthread); static void thr_link(struct pthread *thread); static void thr_resume_wrapper(int sig, siginfo_t *, ucontext_t *); static void thr_resume_check(struct pthread *curthread, ucontext_t *ucp); static int thr_timedout(struct pthread *thread, struct timespec *curtime); static void thr_unlink(struct pthread *thread); static void thr_destroy(struct pthread *curthread, struct pthread *thread); static void thread_gc(struct pthread *thread); static void kse_gc(struct pthread *thread); static void kseg_gc(struct pthread *thread); static __inline void thr_accounting(struct pthread *thread) { if ((thread->slice_usec != -1) && (thread->slice_usec <= TIMESLICE_USEC) && (thread->attr.sched_policy != SCHED_FIFO)) { thread->slice_usec += (thread->tcb->tcb_tmbx.tm_uticks + thread->tcb->tcb_tmbx.tm_sticks) * _clock_res_usec; /* Check for time quantum exceeded: */ if (thread->slice_usec > TIMESLICE_USEC) thread->slice_usec = -1; } thread->tcb->tcb_tmbx.tm_uticks = 0; thread->tcb->tcb_tmbx.tm_sticks = 0; } /* * This is called after a fork(). * No locks need to be taken here since we are guaranteed to be * single threaded. * * XXX * POSIX says for threaded process, fork() function is used * only to run new programs, and the effects of calling functions * that require certain resources between the call to fork() and * the call to an exec function are undefined. * * It is not safe to free memory after fork(), because these data * structures may be in inconsistent state. */ void _kse_single_thread(struct pthread *curthread) { #ifdef NOTYET struct kse *kse; struct kse_group *kseg; struct pthread *thread; _thr_spinlock_init(); *__malloc_lock = (spinlock_t)_SPINLOCK_INITIALIZER; if (__isthreaded) { _thr_rtld_fini(); _thr_signal_deinit(); } __isthreaded = 0; /* * Restore signal mask early, so any memory problems could * dump core. */ __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); _thread_active_threads = 1; curthread->kse->k_kcb->kcb_kmbx.km_curthread = NULL; curthread->attr.flags &= ~PTHREAD_SCOPE_PROCESS; curthread->attr.flags |= PTHREAD_SCOPE_SYSTEM; /* * Enter a loop to remove and free all threads other than * the running thread from the active thread list: */ while ((thread = TAILQ_FIRST(&_thread_list)) != NULL) { THR_GCLIST_REMOVE(thread); /* * 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); thr_destroy(curthread, thread); } } TAILQ_INIT(&curthread->mutexq); /* initialize mutex queue */ curthread->joiner = NULL; /* no joining threads yet */ curthread->refcount = 0; SIGEMPTYSET(curthread->sigpend); /* clear pending signals */ /* Don't free thread-specific data as the caller may require it */ /* Free the free KSEs: */ while ((kse = TAILQ_FIRST(&free_kseq)) != NULL) { TAILQ_REMOVE(&free_kseq, kse, k_qe); kse_destroy(kse); } free_kse_count = 0; /* Free the active KSEs: */ while ((kse = TAILQ_FIRST(&active_kseq)) != NULL) { TAILQ_REMOVE(&active_kseq, kse, k_qe); kse_destroy(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); kseg_destroy(kseg); } free_kseg_count = 0; /* Free the active KSEGs: */ while ((kseg = TAILQ_FIRST(&active_kse_groupq)) != NULL) { TAILQ_REMOVE(&active_kse_groupq, kseg, kg_qe); kseg_destroy(kseg); } active_kseg_count = 0; /* Free the free threads. */ while ((thread = TAILQ_FIRST(&free_threadq)) != NULL) { TAILQ_REMOVE(&free_threadq, thread, tle); thr_destroy(curthread, 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); thr_destroy(curthread, 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; } /* We're no longer part of any lists */ curthread->tlflags = 0; /* * 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); #else int i; /* Reset the current thread and KSE lock data. */ for (i = 0; i < curthread->locklevel; i++) { _lockuser_reinit(&curthread->lockusers[i], (void *)curthread); } curthread->locklevel = 0; for (i = 0; i < curthread->kse->k_locklevel; i++) { _lockuser_reinit(&curthread->kse->k_lockusers[i], (void *)curthread->kse); _LCK_SET_PRIVATE2(&curthread->kse->k_lockusers[i], NULL); } curthread->kse->k_locklevel = 0; /* * Reinitialize the thread and signal locks so that * sigaction() will work after a fork(). */ _lock_reinit(&curthread->lock, LCK_ADAPTIVE, _thr_lock_wait, _thr_lock_wakeup); _lock_reinit(&_thread_signal_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup); _thr_spinlock_init(); if (__isthreaded) { _thr_rtld_fini(); _thr_signal_deinit(); } __isthreaded = 0; curthread->kse->k_kcb->kcb_kmbx.km_curthread = NULL; curthread->attr.flags |= PTHREAD_SCOPE_SYSTEM; /* * After a fork, it is possible that an upcall occurs in * the parent KSE that fork()'d before the child process * is fully created and before its vm space is copied. * During the upcall, the tcb is set to null or to another * thread, and this is what gets copied in the child process * when the vm space is cloned sometime after the upcall * occurs. Note that we shouldn't have to set the kcb, but * we do it for completeness. */ _kcb_set(curthread->kse->k_kcb); _tcb_set(curthread->kse->k_kcb, curthread->tcb); /* After a fork(), there child should have no pending signals. */ sigemptyset(&curthread->sigpend); /* * Restore signal mask early, so any memory problems could * dump core. */ sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); _thread_active_threads = 1; #endif } /* * 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, calloc) != 0) PANIC("Unable to initialize free KSE queue lock"); if (_lock_init(&thread_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup, calloc) != 0) PANIC("Unable to initialize free thread queue lock"); if (_lock_init(&_thread_list_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup, calloc) != 0) PANIC("Unable to initialize thread list lock"); _pthread_mutex_init(&_tcb_mutex, NULL); active_kse_count = 0; active_kseg_count = 0; _gc_count = 0; inited = 1; } } /* * This is called when the first thread (other than the initial * thread) is created. */ int _kse_setthreaded(int threaded) { sigset_t sigset; if ((threaded != 0) && (__isthreaded == 0)) { SIGFILLSET(sigset); __sys_sigprocmask(SIG_SETMASK, &sigset, &_thr_initial->sigmask); /* * Tell the kernel to create a KSE for the initial thread * and enable upcalls in it. */ _kse_initial->k_flags |= KF_STARTED; if (_thread_scope_system <= 0) { _thr_initial->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; _kse_initial->k_kseg->kg_flags &= ~KGF_SINGLE_THREAD; _kse_initial->k_kcb->kcb_kmbx.km_curthread = NULL; } else { /* * For bound thread, kernel reads mailbox pointer * once, we'd set it here before calling kse_create. */ _tcb_set(_kse_initial->k_kcb, _thr_initial->tcb); KSE_SET_MBOX(_kse_initial, _thr_initial); _kse_initial->k_kcb->kcb_kmbx.km_flags |= KMF_BOUND; } /* * Locking functions in libc are required when there are * threads other than the initial thread. */ _thr_rtld_init(); __isthreaded = 1; if (kse_create(&_kse_initial->k_kcb->kcb_kmbx, 0) != 0) { _kse_initial->k_flags &= ~KF_STARTED; __isthreaded = 0; PANIC("kse_create() failed\n"); return (-1); } _thr_initial->tcb->tcb_tmbx.tm_lwp = _kse_initial->k_kcb->kcb_kmbx.km_lwp; _thread_activated = 1; #ifndef SYSTEM_SCOPE_ONLY if (_thread_scope_system <= 0) { /* Set current thread to initial thread */ _tcb_set(_kse_initial->k_kcb, _thr_initial->tcb); KSE_SET_MBOX(_kse_initial, _thr_initial); _thr_start_sig_daemon(); _thr_setmaxconcurrency(); } else #endif __sys_sigprocmask(SIG_SETMASK, &_thr_initial->sigmask, NULL); } 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 __unused, struct lockuser *lu) { struct kse *curkse = (struct kse *)_LCK_GET_PRIVATE(lu); struct timespec ts; int saved_flags; if (curkse->k_kcb->kcb_kmbx.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 */ while (!_LCK_GRANTED(lu)) { /* * Yield the kse and wait to be notified when the lock * is granted. */ saved_flags = curkse->k_kcb->kcb_kmbx.km_flags; curkse->k_kcb->kcb_kmbx.km_flags |= KMF_NOUPCALL | KMF_NOCOMPLETED; kse_release(&ts); curkse->k_kcb->kcb_kmbx.km_flags = saved_flags; } } void _kse_lock_wakeup(struct lock *lock, struct lockuser *lu) { struct kse *curkse; struct kse *kse; struct kse_mailbox *mbx; curkse = _get_curkse(); kse = (struct kse *)_LCK_GET_PRIVATE(lu); if (kse == curkse) PANIC("KSE trying to wake itself up in lock"); else { mbx = &kse->k_kcb->kcb_kmbx; _lock_grant(lock, lu); /* * Notify the owning kse that it has the lock. * It is safe to pass invalid address to kse_wakeup * even if the mailbox is not in kernel at all, * and waking up a wrong kse is also harmless. */ kse_wakeup(mbx); } } /* * 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 __unused, struct lockuser *lu) { struct pthread *curthread = (struct pthread *)lu->lu_private; do { THR_LOCK_SWITCH(curthread); THR_SET_STATE(curthread, PS_LOCKWAIT); _thr_sched_switch_unlocked(curthread); } while (!_LCK_GRANTED(lu)); } void _thr_lock_wakeup(struct lock *lock __unused, struct lockuser *lu) { struct pthread *thread; struct pthread *curthread; struct kse_mailbox *kmbx; curthread = _get_curthread(); thread = (struct pthread *)_LCK_GET_PRIVATE(lu); THR_SCHED_LOCK(curthread, thread); _lock_grant(lock, lu); kmbx = _thr_setrunnable_unlocked(thread); THR_SCHED_UNLOCK(curthread, thread); if (kmbx != NULL) kse_wakeup(kmbx); } kse_critical_t _kse_critical_enter(void) { kse_critical_t crit; crit = (kse_critical_t)_kcb_critical_enter(); return (crit); } void _kse_critical_leave(kse_critical_t crit) { struct pthread *curthread; _kcb_critical_leave((struct kse_thr_mailbox *)crit); if ((crit != NULL) && ((curthread = _get_curthread()) != NULL)) THR_YIELD_CHECK(curthread); } int _kse_in_critical(void) { return (_kcb_in_critical()); } void _thr_critical_enter(struct pthread *thread) { thread->critical_count++; } void _thr_critical_leave(struct pthread *thread) { thread->critical_count--; THR_YIELD_CHECK(thread); } void _thr_sched_switch(struct pthread *curthread) { struct kse *curkse; (void)_kse_critical_enter(); curkse = _get_curkse(); KSE_SCHED_LOCK(curkse, curkse->k_kseg); _thr_sched_switch_unlocked(curthread); } /* * 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_unlocked(struct pthread *curthread) { struct kse *curkse; volatile int resume_once = 0; ucontext_t *uc; /* We're in the scheduler, 5 by 5: */ curkse = curthread->kse; curthread->need_switchout = 1; /* The thread yielded on its own. */ curthread->critical_yield = 0; /* No need to yield anymore. */ /* Thread can unlock the scheduler lock. */ curthread->lock_switch = 1; if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) kse_sched_single(&curkse->k_kcb->kcb_kmbx); else { if (__predict_false(_libkse_debug != 0)) { /* * Because debugger saves single step status in thread * mailbox's tm_dflags, we can safely clear single * step status here. the single step status will be * restored by kse_switchin when the thread is * switched in again. This also lets uts run in full * speed. */ ptrace(PT_CLEARSTEP, curkse->k_kcb->kcb_kmbx.km_lwp, (caddr_t) 1, 0); } KSE_SET_SWITCH(curkse); _thread_enter_uts(curthread->tcb, curkse->k_kcb); } /* * Unlock the scheduling queue and leave the * critical region. */ /* Don't trust this after a switch! */ curkse = curthread->kse; curthread->lock_switch = 0; KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); _kse_critical_leave(&curthread->tcb->tcb_tmbx); /* * This thread is being resumed; check for cancellations. */ if (THR_NEED_ASYNC_CANCEL(curthread) && !THR_IN_CRITICAL(curthread)) { uc = alloca(sizeof(ucontext_t)); resume_once = 0; THR_GETCONTEXT(uc); if (resume_once == 0) { resume_once = 1; curthread->check_pending = 0; thr_resume_check(curthread, uc); } } THR_ACTIVATE_LAST_LOCK(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). */ static void kse_sched_single(struct kse_mailbox *kmbx) { struct kse *curkse; struct pthread *curthread; struct timespec ts; sigset_t sigmask; int i, sigseqno, level, first = 0; curkse = (struct kse *)kmbx->km_udata; curthread = curkse->k_curthread; if (__predict_false((curkse->k_flags & KF_INITIALIZED) == 0)) { /* Setup this KSEs specific data. */ _kcb_set(curkse->k_kcb); _tcb_set(curkse->k_kcb, curthread->tcb); curkse->k_flags |= KF_INITIALIZED; first = 1; curthread->active = 1; /* Setup kernel signal masks for new thread. */ __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); /* * Enter critical region, this is meanless for bound thread, * It is used to let other code work, those code want mailbox * to be cleared. */ (void)_kse_critical_enter(); } else { /* * Bound thread always has tcb set, this prevent some * code from blindly setting bound thread tcb to NULL, * buggy code ? */ _tcb_set(curkse->k_kcb, curthread->tcb); } 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. */ if (curthread->lock_switch == 0) 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_MUTEX_WAIT: case PS_COND_WAIT: if (THR_NEED_CANCEL(curthread)) { curthread->interrupted = 1; curthread->continuation = _thr_finish_cancellation; THR_SET_STATE(curthread, PS_RUNNING); } break; case PS_LOCKWAIT: /* * This state doesn't timeout. */ curthread->wakeup_time.tv_sec = -1; curthread->wakeup_time.tv_nsec = -1; level = curthread->locklevel - 1; if (_LCK_GRANTED(&curthread->lockusers[level])) THR_SET_STATE(curthread, PS_RUNNING); break; case PS_DEAD: /* Unlock the scheduling queue and exit the KSE and thread. */ thr_cleanup(curkse, curthread); KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); PANIC("bound thread shouldn't get here\n"); break; case PS_JOIN: if (THR_NEED_CANCEL(curthread)) { curthread->join_status.thread = NULL; THR_SET_STATE(curthread, PS_RUNNING); } else { /* * This state doesn't timeout. */ curthread->wakeup_time.tv_sec = -1; curthread->wakeup_time.tv_nsec = -1; } break; case PS_SUSPENDED: if (THR_NEED_CANCEL(curthread)) { curthread->interrupted = 1; THR_SET_STATE(curthread, PS_RUNNING); } else { /* * These states don't timeout. */ curthread->wakeup_time.tv_sec = -1; curthread->wakeup_time.tv_nsec = -1; } break; case PS_RUNNING: if ((curthread->flags & THR_FLAGS_SUSPENDED) != 0 && !THR_NEED_CANCEL(curthread)) { THR_SET_STATE(curthread, PS_SUSPENDED); /* * These states don't timeout. */ curthread->wakeup_time.tv_sec = -1; curthread->wakeup_time.tv_nsec = -1; } break; case PS_SIGWAIT: PANIC("bound thread does not have SIGWAIT state\n"); case PS_SLEEP_WAIT: PANIC("bound thread does not have SLEEP_WAIT state\n"); case PS_SIGSUSPEND: PANIC("bound thread does not have SIGSUSPEND state\n"); case PS_DEADLOCK: /* * These states don't timeout and don't need * to be in the waiting queue. */ curthread->wakeup_time.tv_sec = -1; curthread->wakeup_time.tv_nsec = -1; break; default: PANIC("Unknown state\n"); break; } while (curthread->state != PS_RUNNING) { sigseqno = curkse->k_sigseqno; if (curthread->check_pending != 0) { /* * Install pending signals into the frame, possible * cause mutex or condvar backout. */ curthread->check_pending = 0; SIGFILLSET(sigmask); /* * Lock out kernel signal code when we are processing * signals, and get a fresh copy of signal mask. */ __sys_sigprocmask(SIG_SETMASK, &sigmask, &curthread->sigmask); for (i = 1; i <= _SIG_MAXSIG; i++) { if (SIGISMEMBER(curthread->sigmask, i)) continue; if (SIGISMEMBER(curthread->sigpend, i)) (void)_thr_sig_add(curthread, i, &curthread->siginfo[i-1]); } __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); /* The above code might make thread runnable */ if (curthread->state == PS_RUNNING) break; } THR_DEACTIVATE_LAST_LOCK(curthread); kse_wait(curkse, curthread, sigseqno); THR_ACTIVATE_LAST_LOCK(curthread); if (curthread->wakeup_time.tv_sec >= 0) { KSE_GET_TOD(curkse, &ts); if (thr_timedout(curthread, &ts)) { /* Indicate the thread timedout: */ curthread->timeout = 1; /* Make the thread runnable. */ THR_SET_STATE(curthread, PS_RUNNING); } } } if (curthread->lock_switch == 0) { /* Unlock the scheduling queue. */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); } DBG_MSG("Continuing bound thread %p\n", curthread); if (first) { _kse_critical_leave(&curthread->tcb->tcb_tmbx); pthread_exit(curthread->start_routine(curthread->arg)); } } #ifdef DEBUG_THREAD_KERN static 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); } } #endif /* * This is the scheduler for a KSE which runs multiple threads. */ static void kse_sched_multi(struct kse_mailbox *kmbx) { struct kse *curkse; struct pthread *curthread, *td_wait; int ret; curkse = (struct kse *)kmbx->km_udata; THR_ASSERT(curkse->k_kcb->kcb_kmbx.km_curthread == NULL, "Mailbox not null in kse_sched_multi"); /* Check for first time initialization: */ if (__predict_false((curkse->k_flags & KF_INITIALIZED) == 0)) { /* Setup this KSEs specific data. */ _kcb_set(curkse->k_kcb); /* Set this before grabbing the context. */ curkse->k_flags |= KF_INITIALIZED; } /* * No current thread anymore, calling _get_curthread in UTS * should dump core */ _tcb_set(curkse->k_kcb, NULL); /* If this is an upcall; take the scheduler lock. */ if (!KSE_IS_SWITCH(curkse)) KSE_SCHED_LOCK(curkse, curkse->k_kseg); else KSE_CLEAR_SWITCH(curkse); if (KSE_IS_IDLE(curkse)) { KSE_CLEAR_IDLE(curkse); curkse->k_kseg->kg_idle_kses--; } /* * Now that the scheduler lock is held, get the current * thread. The KSE's current thread cannot be safely * examined without the lock because it could have returned * as completed on another KSE. See kse_check_completed(). */ curthread = curkse->k_curthread; /* * 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; DBG_MSG("Running thread %p is now blocked in kernel.\n", curthread); } /* 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) && DBG_CAN_RUN(curthread) && (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); kse_wakeup_multi(curkse); KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1); if (ret != 0) PANIC("Can't resume thread in critical region\n"); } else if ((curthread->flags & THR_FLAGS_IN_RUNQ) == 0) { curthread->tcb->tcb_tmbx.tm_lwp = 0; kse_switchout_thread(curkse, curthread); } curkse->k_curthread = NULL; #ifdef DEBUG_THREAD_KERN dump_queues(curkse); #endif /* Check if there are no threads ready to run: */ while (((curthread = KSE_RUNQ_FIRST(curkse)) == NULL) && (curkse->k_kseg->kg_threadcount != 0) && ((curkse->k_flags & KF_TERMINATED) == 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, 0); kse_check_completed(curkse); kse_check_waitq(curkse); } /* Check for no more threads: */ if ((curkse->k_kseg->kg_threadcount == 0) || ((curkse->k_flags & KF_TERMINATED) != 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_wakeup_multi(curkse); KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); kse_fini(curkse); /* never returns */ } 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 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; /* * 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. */ if (curthread->lock_switch == 0 && curthread->state == PS_RUNNING && (curthread->check_pending != 0 || THR_NEED_ASYNC_CANCEL(curthread)) && !THR_IN_CRITICAL(curthread)) { curthread->check_pending = 0; signalcontext(&curthread->tcb->tcb_tmbx.tm_context, 0, (__sighandler_t *)thr_resume_wrapper); } kse_wakeup_multi(curkse); /* * Continue the thread at its current frame: */ if (curthread->lock_switch != 0) { /* * This thread came from a scheduler switch; it will * unlock the scheduler lock and set the mailbox. */ ret = _thread_switch(curkse->k_kcb, curthread->tcb, 0); } else { /* This thread won't unlock the scheduler lock. */ KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1); } 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 thr_resume_wrapper(int sig __unused, siginfo_t *siginfo __unused, ucontext_t *ucp) { struct pthread *curthread = _get_curthread(); struct kse *curkse; int ret, err_save = errno; DBG_MSG(">>> sig wrapper\n"); if (curthread->lock_switch) PANIC("thr_resume_wrapper, lock_switch != 0\n"); thr_resume_check(curthread, ucp); errno = err_save; _kse_critical_enter(); curkse = curthread->kse; curthread->tcb->tcb_tmbx.tm_context = *ucp; ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1); if (ret != 0) PANIC("thr_resume_wrapper: thread has returned " "from _thread_switch"); /* THR_SETCONTEXT(ucp); */ /* not work, why ? */ } static void thr_resume_check(struct pthread *curthread, ucontext_t *ucp) { _thr_sig_rundown(curthread, ucp); if (THR_NEED_ASYNC_CANCEL(curthread)) pthread_testcancel(); } /* * 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; struct kse_mailbox *kmbx = NULL; int sys_scope; thread->active = 0; thread->need_switchout = 0; thread->lock_switch = 0; thread->check_pending = 0; if ((joiner = thread->joiner) != NULL) { /* Joinee scheduler lock held; joiner won't leave. */ if (joiner->kseg == curkse->k_kseg) { if (joiner->join_status.thread == thread) { joiner->join_status.thread = NULL; joiner->join_status.ret = thread->ret; (void)_thr_setrunnable_unlocked(joiner); } } else { KSE_SCHED_UNLOCK(curkse, curkse->k_kseg); /* The joiner may have removed itself and exited. */ if (_thr_ref_add(thread, joiner, 0) == 0) { KSE_SCHED_LOCK(curkse, joiner->kseg); if (joiner->join_status.thread == thread) { joiner->join_status.thread = NULL; joiner->join_status.ret = thread->ret; kmbx = _thr_setrunnable_unlocked(joiner); } KSE_SCHED_UNLOCK(curkse, joiner->kseg); _thr_ref_delete(thread, joiner); if (kmbx != NULL) kse_wakeup(kmbx); } KSE_SCHED_LOCK(curkse, curkse->k_kseg); } thread->attr.flags |= PTHREAD_DETACHED; } if (!(sys_scope = (thread->attr.flags & PTHREAD_SCOPE_SYSTEM))) { /* * 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; } /* * 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); thread->tlflags |= TLFLAGS_GC_SAFE; THR_GCLIST_ADD(thread); KSE_LOCK_RELEASE(curkse, &_thread_list_lock); if (sys_scope) { /* * System scope thread is single thread group, * when thread is exited, its kse and ksegrp should * be recycled as well. * kse upcall stack belongs to thread, clear it here. */ curkse->k_stack.ss_sp = 0; curkse->k_stack.ss_size = 0; kse_exit(); PANIC("kse_exit() failed for system scope thread"); } KSE_SCHED_LOCK(curkse, curkse->k_kseg); } void _thr_gc(struct pthread *curthread) { thread_gc(curthread); kse_gc(curthread); kseg_gc(curthread); } static void thread_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->tlflags & TLFLAGS_GC_SAFE) == 0) continue; else if (((td->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) && ((td->kse->k_kcb->kcb_kmbx.km_flags & KMF_DONE) == 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; } /* * 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); /* * XXX we don't free initial thread and its kse * (if thread is a bound thread), because there might * have some code referencing initial thread and kse. */ if (td == _thr_initial) { DBG_MSG("Initial thread won't be freed\n"); continue; } if ((td->attr.flags & PTHREAD_SCOPE_SYSTEM) != 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); } } static void kse_gc(struct pthread *curthread) { kse_critical_t crit; TAILQ_HEAD(, kse) worklist; struct kse *kse; if (free_kse_count <= MAX_CACHED_KSES) return; TAILQ_INIT(&worklist); crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); while (free_kse_count > MAX_CACHED_KSES) { kse = TAILQ_FIRST(&free_kseq); TAILQ_REMOVE(&free_kseq, kse, k_qe); TAILQ_INSERT_HEAD(&worklist, kse, k_qe); free_kse_count--; } KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); while ((kse = TAILQ_FIRST(&worklist))) { TAILQ_REMOVE(&worklist, kse, k_qe); kse_destroy(kse); } } static void kseg_gc(struct pthread *curthread) { kse_critical_t crit; TAILQ_HEAD(, kse_group) worklist; struct kse_group *kseg; if (free_kseg_count <= MAX_CACHED_KSEGS) return; TAILQ_INIT(&worklist); crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); while (free_kseg_count > MAX_CACHED_KSEGS) { kseg = TAILQ_FIRST(&free_kse_groupq); TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe); free_kseg_count--; TAILQ_INSERT_HEAD(&worklist, kseg, kg_qe); } KSE_LOCK_RELEASE(curthread->kse, &kse_lock); _kse_critical_leave(crit); while ((kseg = TAILQ_FIRST(&worklist))) { TAILQ_REMOVE(&worklist, kseg, kg_qe); kseg_destroy(kseg); } } /* * Only new threads that are running or suspended may be scheduled. */ int _thr_schedule_add(struct pthread *curthread, struct pthread *newthread) { kse_critical_t crit; int ret; /* Add the new thread. */ thr_link(newthread); /* * 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) { /* We use the thread's stack as the KSE's stack. */ newthread->kse->k_kcb->kcb_kmbx.km_stack.ss_sp = newthread->attr.stackaddr_attr; newthread->kse->k_kcb->kcb_kmbx.km_stack.ss_size = newthread->attr.stacksize_attr; /* * No need to lock the scheduling queue since the * KSE/KSEG pair have not yet been started. */ KSEG_THRQ_ADD(newthread->kseg, newthread); /* this thread never gives up kse */ newthread->active = 1; newthread->kse->k_curthread = newthread; newthread->kse->k_kcb->kcb_kmbx.km_flags = KMF_BOUND; newthread->kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_single; newthread->kse->k_kcb->kcb_kmbx.km_quantum = 0; KSE_SET_MBOX(newthread->kse, newthread); /* * This thread needs a new KSE and KSEG. */ newthread->kse->k_flags &= ~KF_INITIALIZED; newthread->kse->k_flags |= KF_STARTED; /* Fire up! */ ret = kse_create(&newthread->kse->k_kcb->kcb_kmbx, 1); if (ret != 0) ret = errno; } 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. */ crit = _kse_critical_enter(); 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_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_multi; newthread->kse->k_kcb->kcb_kmbx.km_flags = 0; kse_create(&newthread->kse->k_kcb->kcb_kmbx, 0); } else if ((newthread->state == PS_RUNNING) && KSE_IS_IDLE(newthread->kse)) { /* * The thread is being scheduled on another KSEG. */ kse_wakeup_one(newthread); } KSE_SCHED_UNLOCK(curthread->kse, newthread->kseg); _kse_critical_leave(crit); ret = 0; } if (ret != 0) thr_unlink(newthread); 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; int sig; if ((completed = kse->k_kcb->kcb_kmbx.km_completed) != NULL) { kse->k_kcb->kcb_kmbx.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) { thr_accounting(thread); if ((thread->flags & THR_FLAGS_SUSPENDED) != 0) THR_SET_STATE(thread, PS_SUSPENDED); else KSE_RUNQ_INSERT_TAIL(kse, thread); if ((thread->kse != kse) && (thread->kse->k_curthread == thread)) { /* * Remove this thread from its * previous KSE so that it (the KSE) * doesn't think it is still active. */ thread->kse->k_curthread = NULL; thread->active = 0; } } if ((sig = thread->tcb->tcb_tmbx.tm_syncsig.si_signo) != 0) { if (SIGISMEMBER(thread->sigmask, sig)) SIGADDSET(thread->sigpend, sig); else if (THR_IN_CRITICAL(thread)) kse_thr_interrupt(NULL, KSE_INTR_SIGEXIT, sig); else (void)_thr_sig_add(thread, sig, &thread->tcb->tcb_tmbx.tm_syncsig); thread->tcb->tcb_tmbx.tm_syncsig.si_signo = 0; } 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: */ if ((pthread->flags & THR_FLAGS_SUSPENDED) != 0) THR_SET_STATE(pthread, PS_SUSPENDED); else { 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; int i; int restart; siginfo_t siginfo; /* * Place the currently running thread into the * appropriate queue(s). */ DBG_MSG("Switching out thread %p, state %d\n", thread, thread->state); THR_DEACTIVATE_LAST_LOCK(thread); if (thread->blocked != 0) { thread->active = 0; thread->need_switchout = 0; /* This thread must have blocked in the kernel. */ /* * Check for pending signals and cancellation for * this thread to see if we need to interrupt it * in the kernel. */ if (THR_NEED_CANCEL(thread)) { kse_thr_interrupt(&thread->tcb->tcb_tmbx, KSE_INTR_INTERRUPT, 0); } else if (thread->check_pending != 0) { for (i = 1; i <= _SIG_MAXSIG; ++i) { if (SIGISMEMBER(thread->sigpend, i) && !SIGISMEMBER(thread->sigmask, i)) { restart = _thread_sigact[i - 1].sa_flags & SA_RESTART; kse_thr_interrupt(&thread->tcb->tcb_tmbx, restart ? KSE_INTR_RESTART : KSE_INTR_INTERRUPT, 0); break; } } } } else { switch (thread->state) { case PS_MUTEX_WAIT: case PS_COND_WAIT: if (THR_NEED_CANCEL(thread)) { thread->interrupted = 1; thread->continuation = _thr_finish_cancellation; THR_SET_STATE(thread, PS_RUNNING); } else { /* 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_GRANTED(&thread->lockusers[level])) KSE_WAITQ_INSERT(kse, thread); else THR_SET_STATE(thread, PS_RUNNING); break; case PS_SLEEP_WAIT: case PS_SIGWAIT: if (THR_NEED_CANCEL(thread)) { thread->interrupted = 1; THR_SET_STATE(thread, PS_RUNNING); } else { KSE_WAITQ_INSERT(kse, thread); } break; case PS_JOIN: if (THR_NEED_CANCEL(thread)) { thread->join_status.thread = NULL; THR_SET_STATE(thread, PS_RUNNING); } else { /* * This state doesn'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; case PS_SIGSUSPEND: case PS_SUSPENDED: if (THR_NEED_CANCEL(thread)) { thread->interrupted = 1; THR_SET_STATE(thread, PS_RUNNING); } else { /* * 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; case PS_DEAD: /* * The scheduler is operating on a different * stack. It is safe to do garbage collecting * here. */ thr_cleanup(kse, thread); return; break; case PS_RUNNING: if ((thread->flags & THR_FLAGS_SUSPENDED) != 0 && !THR_NEED_CANCEL(thread)) THR_SET_STATE(thread, PS_SUSPENDED); break; case PS_DEADLOCK: /* * 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; default: PANIC("Unknown state\n"); break; } thr_accounting(thread); if (thread->state == PS_RUNNING) { 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; if (thread->check_pending != 0) { /* Install pending signals into the frame. */ thread->check_pending = 0; KSE_LOCK_ACQUIRE(kse, &_thread_signal_lock); for (i = 1; i <= _SIG_MAXSIG; i++) { if (SIGISMEMBER(thread->sigmask, i)) continue; if (SIGISMEMBER(thread->sigpend, i)) (void)_thr_sig_add(thread, i, &thread->siginfo[i-1]); else if (SIGISMEMBER(_thr_proc_sigpending, i) && _thr_getprocsig_unlocked(i, &siginfo)) { (void)_thr_sig_add(thread, i, &siginfo); } } KSE_LOCK_RELEASE(kse, &_thread_signal_lock); } } /* * 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, int sigseqno) { struct timespec ts, ts_sleep; int saved_flags; 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 { KSE_GET_TOD(kse, &ts); 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); if ((kse->k_kseg->kg_flags & KGF_SINGLE_THREAD) && (kse->k_sigseqno != sigseqno)) ; /* don't sleep */ else { saved_flags = kse->k_kcb->kcb_kmbx.km_flags; kse->k_kcb->kcb_kmbx.km_flags |= KMF_NOUPCALL; kse_release(&ts_sleep); kse->k_kcb->kcb_kmbx.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 kse_group *free_kseg = NULL; */ struct timespec ts; struct pthread *td; /* * Check to see if this is one of the main kses. */ if (kse->k_kseg != _kse_initial->k_kseg) { PANIC("shouldn't get here"); /* This is for supporting thread groups. */ #ifdef NOT_YET /* 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. */ 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); kse_exit(); /* Never returns. */ PANIC("kse_exit()"); #endif } else { /* * We allow program to kill kse in initial group (by * lowering the concurrency). */ if ((kse != _kse_initial) && ((kse->k_flags & KF_TERMINATED) != 0)) { KSE_SCHED_LOCK(kse, kse->k_kseg); TAILQ_REMOVE(&kse->k_kseg->kg_kseq, kse, k_kgqe); kse->k_kseg->kg_ksecount--; /* * Migrate thread to _kse_initial if its lastest * kse it ran on is the kse. */ td = TAILQ_FIRST(&kse->k_kseg->kg_threadq); while (td != NULL) { if (td->kse == kse) td->kse = _kse_initial; td = TAILQ_NEXT(td, kle); } KSE_SCHED_UNLOCK(kse, kse->k_kseg); KSE_LOCK_ACQUIRE(kse, &kse_lock); kse_free_unlocked(kse); KSE_LOCK_RELEASE(kse, &kse_lock); /* Make sure there is always at least one is awake */ KSE_WAKEUP(_kse_initial); kse_exit(); /* Never returns. */ PANIC("kse_exit() failed for initial kseg"); } KSE_SCHED_LOCK(kse, kse->k_kseg); KSE_SET_IDLE(kse); kse->k_kseg->kg_idle_kses++; KSE_SCHED_UNLOCK(kse, kse->k_kseg); ts.tv_sec = 120; ts.tv_nsec = 0; kse->k_kcb->kcb_kmbx.km_flags = 0; kse_release(&ts); /* Never reach */ } } 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; struct kse_mailbox *kmbx; crit = _kse_critical_enter(); KSE_SCHED_LOCK(curthread->kse, thread->kseg); kmbx = _thr_setrunnable_unlocked(thread); KSE_SCHED_UNLOCK(curthread->kse, thread->kseg); _kse_critical_leave(crit); if ((kmbx != NULL) && (__isthreaded != 0)) kse_wakeup(kmbx); } struct kse_mailbox * _thr_setrunnable_unlocked(struct pthread *thread) { struct kse_mailbox *kmbx = NULL; if ((thread->kseg->kg_flags & KGF_SINGLE_THREAD) != 0) { /* No silly queues for these threads. */ if ((thread->flags & THR_FLAGS_SUSPENDED) != 0) THR_SET_STATE(thread, PS_SUSPENDED); else { THR_SET_STATE(thread, PS_RUNNING); kmbx = kse_wakeup_one(thread); } } else if (thread->state != PS_RUNNING) { if ((thread->flags & THR_FLAGS_IN_WAITQ) != 0) KSE_WAITQ_REMOVE(thread->kse, thread); if ((thread->flags & THR_FLAGS_SUSPENDED) != 0) THR_SET_STATE(thread, PS_SUSPENDED); else { THR_SET_STATE(thread, PS_RUNNING); if ((thread->blocked == 0) && (thread->active == 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. */ kmbx = kse_wakeup_one(thread); } } return (kmbx); } static struct kse_mailbox * 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--; return (&thread->kse->k_kcb->kcb_kmbx); } 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--; return (&ke->k_kcb->kcb_kmbx); } } } return (NULL); } 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; } } } } /* * 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); } static void kseg_init(struct kse_group *kseg) { kseg_reinit(kseg); _lock_init(&kseg->kg_lock, LCK_ADAPTIVE, _kse_lock_wait, _kse_lock_wakeup, calloc); } 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; } /* * 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); } static void kseg_destroy(struct kse_group *kseg) { _lock_destroy(&kseg->kg_lock); _pq_free(&kseg->kg_schedq.sq_runq); free(kseg); } /* * 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, int sys_scope) { struct kse *kse = NULL; char *stack; kse_critical_t crit; 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); while ((kse != NULL) && ((kse->k_kcb->kcb_kmbx.km_flags & KMF_DONE) == 0)) { kse = TAILQ_NEXT(kse, k_qe); } if (kse != NULL) { DBG_MSG("found an unused kse.\n"); 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, sys_scope); } if ((kse == NULL) && ((kse = (struct kse *)malloc(sizeof(*kse))) != NULL)) { if (sys_scope != 0) stack = NULL; else if ((stack = malloc(KSE_STACKSIZE)) == NULL) { free(kse); return (NULL); } bzero(kse, sizeof(*kse)); /* Initialize KCB without the lock. */ if ((kse->k_kcb = _kcb_ctor(kse)) == NULL) { if (stack != NULL) free(stack); free(kse); return (NULL); } /* 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, ...) */ if (curthread != NULL) { crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock); } 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); } /* * Create the KSE context. * Scope system threads (one thread per KSE) are not required * to have a stack for an unneeded kse upcall. */ if (!sys_scope) { kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_multi; kse->k_stack.ss_sp = stack; kse->k_stack.ss_size = KSE_STACKSIZE; } else { kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_single; kse->k_stack.ss_sp = NULL; kse->k_stack.ss_size = 0; } kse->k_kcb->kcb_kmbx.km_udata = (void *)kse; kse->k_kcb->kcb_kmbx.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_kcb->kcb_kmbx.km_stack = kse->k_stack; } return (kse); } static void kse_reinit(struct kse *kse, int sys_scope) { if (!sys_scope) { kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_multi; if (kse->k_stack.ss_sp == NULL) { /* XXX check allocation failure */ kse->k_stack.ss_sp = (char *) malloc(KSE_STACKSIZE); kse->k_stack.ss_size = KSE_STACKSIZE; } kse->k_kcb->kcb_kmbx.km_quantum = 20000; } else { kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_single; if (kse->k_stack.ss_sp) free(kse->k_stack.ss_sp); kse->k_stack.ss_sp = NULL; kse->k_stack.ss_size = 0; kse->k_kcb->kcb_kmbx.km_quantum = 0; } kse->k_kcb->kcb_kmbx.km_stack = kse->k_stack; kse->k_kcb->kcb_kmbx.km_udata = (void *)kse; kse->k_kcb->kcb_kmbx.km_curthread = NULL; kse->k_kcb->kcb_kmbx.km_flags = 0; kse->k_curthread = NULL; kse->k_kseg = 0; kse->k_schedq = 0; kse->k_locklevel = 0; kse->k_flags = 0; kse->k_error = 0; kse->k_cpu = 0; kse->k_sigseqno = 0; } void kse_free_unlocked(struct kse *kse) { TAILQ_REMOVE(&active_kseq, kse, k_qe); active_kse_count--; kse->k_kseg = NULL; kse->k_kcb->kcb_kmbx.km_quantum = 20000; kse->k_flags = 0; 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 kse_destroy(struct kse *kse) { int i; if (kse->k_stack.ss_sp != NULL) free(kse->k_stack.ss_sp); _kcb_dtor(kse->k_kcb); for (i = 0; i < MAX_KSE_LOCKLEVEL; ++i) _lockuser_destroy(&kse->k_lockusers[i]); _lock_destroy(&kse->k_lock); free(kse); } struct pthread * _thr_alloc(struct pthread *curthread) { kse_critical_t crit; struct pthread *thread = NULL; int i; 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 = malloc(sizeof(struct pthread))) != NULL)) { bzero(thread, sizeof(struct pthread)); thread->siginfo = calloc(_SIG_MAXSIG, sizeof(siginfo_t)); if (thread->siginfo == NULL) { free(thread); return (NULL); } if (curthread) { _pthread_mutex_lock(&_tcb_mutex); thread->tcb = _tcb_ctor(thread, 0 /* not initial tls */); _pthread_mutex_unlock(&_tcb_mutex); } else { thread->tcb = _tcb_ctor(thread, 1 /* initial tls */); } if (thread->tcb == NULL) { free(thread->siginfo); free(thread); return (NULL); } /* * Initialize thread locking. * Lock initializing needs malloc, so don't * enter critical region before doing this! */ if (_lock_init(&thread->lock, LCK_ADAPTIVE, _thr_lock_wait, _thr_lock_wakeup, calloc) != 0) PANIC("Cannot initialize thread lock"); for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { _lockuser_init(&thread->lockusers[i], (void *)thread); _LCK_SET_PRIVATE2(&thread->lockusers[i], (void *)thread); } } return (thread); } void _thr_free(struct pthread *curthread, struct pthread *thread) { kse_critical_t crit; DBG_MSG("Freeing thread %p\n", thread); if (thread->name) { free(thread->name); thread->name = NULL; } if ((curthread == NULL) || (free_thread_count >= MAX_CACHED_THREADS)) { thr_destroy(curthread, thread); } else { /* Add the thread to the free thread list. */ crit = _kse_critical_enter(); KSE_LOCK_ACQUIRE(curthread->kse, &thread_lock); TAILQ_INSERT_TAIL(&free_threadq, thread, tle); free_thread_count++; KSE_LOCK_RELEASE(curthread->kse, &thread_lock); _kse_critical_leave(crit); } } static void thr_destroy(struct pthread *curthread, struct pthread *thread) { int i; for (i = 0; i < MAX_THR_LOCKLEVEL; i++) _lockuser_destroy(&thread->lockusers[i]); _lock_destroy(&thread->lock); if (curthread) { _pthread_mutex_lock(&_tcb_mutex); _tcb_dtor(thread->tcb); _pthread_mutex_unlock(&_tcb_mutex); } else { _tcb_dtor(thread->tcb); } free(thread->siginfo); free(thread); } /* * Add an active thread: * * o Assign the thread a unique id (which GDB uses to track * threads. * o Add the thread to the list of all threads and increment * number of active threads. */ static void thr_link(struct pthread *thread) { kse_critical_t crit; struct kse *curkse; crit = _kse_critical_enter(); curkse = _get_curkse(); KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); /* * Initialize the unique id (which GDB uses to track * threads), add the thread to the list of all threads, * and */ thread->uniqueid = next_uniqueid++; THR_LIST_ADD(thread); _thread_active_threads++; KSE_LOCK_RELEASE(curkse, &_thread_list_lock); _kse_critical_leave(crit); } /* * Remove an active thread. */ static void thr_unlink(struct pthread *thread) { kse_critical_t crit; struct kse *curkse; crit = _kse_critical_enter(); curkse = _get_curkse(); KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); THR_LIST_REMOVE(thread); _thread_active_threads--; KSE_LOCK_RELEASE(curkse, &_thread_list_lock); _kse_critical_leave(crit); } void _thr_hash_add(struct pthread *thread) { struct thread_hash_head *head; head = &thr_hashtable[THREAD_HASH(thread)]; LIST_INSERT_HEAD(head, thread, hle); } void _thr_hash_remove(struct pthread *thread) { LIST_REMOVE(thread, hle); } struct pthread * _thr_hash_find(struct pthread *thread) { struct pthread *td; struct thread_hash_head *head; head = &thr_hashtable[THREAD_HASH(thread)]; LIST_FOREACH(td, head, hle) { if (td == thread) return (thread); } return (NULL); } void _thr_debug_check_yield(struct pthread *curthread) { /* * Note that TMDF_SUSPEND is set after process is suspended. * When we are being debugged, every suspension in process * will cause all KSEs to schedule an upcall in kernel, unless the * KSE is in critical region. * If the function is being called, it means the KSE is no longer * in critical region, if the TMDF_SUSPEND is set by debugger * before KSE leaves critical region, we will catch it here, else * if the flag is changed during testing, it also not a problem, * because the change only occurs after a process suspension event * occurs. A suspension event will always cause KSE to schedule an * upcall, in the case, because we are not in critical region, * upcall will be scheduled sucessfully, the flag will be checked * again in kse_sched_multi, we won't back until the flag * is cleared by debugger, the flag will be cleared in next * suspension event. */ if (!DBG_CAN_RUN(curthread)) { if ((curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) == 0) _thr_sched_switch(curthread); else kse_thr_interrupt(&curthread->tcb->tcb_tmbx, KSE_INTR_DBSUSPEND, 0); } }