/* $NetBSD: pthread.c,v 1.41 2005/02/26 20:33:06 nathanw Exp $ */ /*- * Copyright (c) 2001,2002,2003 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Nathan J. Williams. * * 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 the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 __RCSID("$NetBSD: pthread.c,v 1.41 2005/02/26 20:33:06 nathanw Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #ifdef PTHREAD_MLOCK_KLUDGE #include #endif #include #include "pthread.h" #include "pthread_int.h" #ifdef PTHREAD_MAIN_DEBUG #define SDPRINTF(x) DPRINTF(x) #else #define SDPRINTF(x) #endif static void pthread__create_tramp(void *(*start)(void *), void *arg); static void pthread__dead(pthread_t, pthread_t); int pthread__started; pthread_spin_t pthread__allqueue_lock = __SIMPLELOCK_UNLOCKED; struct pthread_queue_t pthread__allqueue; pthread_spin_t pthread__deadqueue_lock = __SIMPLELOCK_UNLOCKED; struct pthread_queue_t pthread__deadqueue; struct pthread_queue_t *pthread__reidlequeue; static int nthreads; static int nextthread; static pthread_spin_t nextthread_lock = __SIMPLELOCK_UNLOCKED; static pthread_attr_t pthread_default_attr; enum { DIAGASSERT_ABORT = 1<<0, DIAGASSERT_STDERR = 1<<1, DIAGASSERT_SYSLOG = 1<<2 }; static int pthread__diagassert = DIAGASSERT_ABORT | DIAGASSERT_STDERR; pthread_spin_t pthread__runqueue_lock = __SIMPLELOCK_UNLOCKED; struct pthread_queue_t pthread__runqueue; struct pthread_queue_t pthread__idlequeue; struct pthread_queue_t pthread__suspqueue; int pthread__concurrency, pthread__maxconcurrency; __strong_alias(__libc_thr_self,pthread_self) __strong_alias(__libc_thr_create,pthread_create) __strong_alias(__libc_thr_exit,pthread_exit) __strong_alias(__libc_thr_errno,pthread__errno) __strong_alias(__libc_thr_setcancelstate,pthread_setcancelstate) /* * Static library kludge. Place a reference to a symbol any library * file which does not already have a reference here. */ extern int pthread__cancel_stub_binder; extern int pthread__sched_binder; extern struct pthread_queue_t pthread__nanosleeping; void *pthread__static_lib_binder[] = { &pthread__cancel_stub_binder, pthread_cond_init, pthread_mutex_init, pthread_rwlock_init, pthread_barrier_init, pthread_key_create, pthread_setspecific, &pthread__sched_binder, &pthread__nanosleeping }; /* * This needs to be started by the library loading code, before main() * gets to run, for various things that use the state of the initial thread * to work properly (thread-specific data is an application-visible example; * spinlock counts for mutexes is an internal example). */ void pthread_init(void) { pthread_t first; char *p; int i, mib[2], ncpu; size_t len; extern int __isthreaded; #ifdef PTHREAD_MLOCK_KLUDGE int ret; #endif mib[0] = CTL_HW; mib[1] = HW_NCPU; len = sizeof(ncpu); sysctl(mib, 2, &ncpu, &len, NULL, 0); /* Initialize locks first; they're needed elsewhere. */ pthread__lockprim_init(ncpu); /* Find out requested/possible concurrency */ p = getenv("PTHREAD_CONCURRENCY"); pthread__maxconcurrency = p ? atoi(p) : 1; if (pthread__maxconcurrency < 1) pthread__maxconcurrency = 1; if (pthread__maxconcurrency > ncpu) pthread__maxconcurrency = ncpu; /* Allocate data structures */ pthread__reidlequeue = (struct pthread_queue_t *)malloc (pthread__maxconcurrency * sizeof(struct pthread_queue_t)); if (pthread__reidlequeue == NULL) err(1, "Couldn't allocate memory for pthread__reidlequeue"); /* Basic data structure setup */ pthread_attr_init(&pthread_default_attr); PTQ_INIT(&pthread__allqueue); PTQ_INIT(&pthread__deadqueue); #ifdef PTHREAD_MLOCK_KLUDGE ret = mlock(&pthread__deadqueue, sizeof(pthread__deadqueue)); pthread__assert(ret == 0); #endif PTQ_INIT(&pthread__runqueue); PTQ_INIT(&pthread__idlequeue); for (i = 0; i < pthread__maxconcurrency; i++) PTQ_INIT(&pthread__reidlequeue[i]); nthreads = 1; /* Create the thread structure corresponding to main() */ pthread__initmain(&first); pthread__initthread(first, first); first->pt_state = PT_STATE_RUNNING; sigprocmask(0, NULL, &first->pt_sigmask); PTQ_INSERT_HEAD(&pthread__allqueue, first, pt_allq); /* Start subsystems */ pthread__signal_init(); PTHREAD_MD_INIT #ifdef PTHREAD__DEBUG pthread__debug_init(ncpu); #endif for (p = getenv("PTHREAD_DIAGASSERT"); p && *p; p++) { switch (*p) { case 'a': pthread__diagassert |= DIAGASSERT_ABORT; break; case 'A': pthread__diagassert &= ~DIAGASSERT_ABORT; break; case 'e': pthread__diagassert |= DIAGASSERT_STDERR; break; case 'E': pthread__diagassert &= ~DIAGASSERT_STDERR; break; case 'l': pthread__diagassert |= DIAGASSERT_SYSLOG; break; case 'L': pthread__diagassert &= ~DIAGASSERT_SYSLOG; break; } } /* Tell libc that we're here and it should role-play accordingly. */ __isthreaded = 1; } static void pthread__child_callback(void) { /* * Clean up data structures that a forked child process might * trip over. Note that if threads have been created (causing * this handler to be registered) the standards say that the * child will trigger undefined behavior if it makes any * pthread_* calls (or any other calls that aren't * async-signal-safe), so we don't really have to clean up * much. Anything that permits some pthread_* calls to work is * merely being polite. */ pthread__started = 0; } static void pthread__start(void) { pthread_t self, idle; int i, ret; self = pthread__self(); /* should be the "main()" thread */ /* * Per-process timers are cleared by fork(); despite the * various restrictions on fork() and threads, it's legal to * fork() before creating any threads. */ pthread__alarm_init(); pthread__signal_start(); pthread_atfork(NULL, NULL, pthread__child_callback); /* * Create idle threads * XXX need to create more idle threads if concurrency > 3 */ for (i = 0; i < NIDLETHREADS; i++) { ret = pthread__stackalloc(&idle); if (ret != 0) err(1, "Couldn't allocate stack for idle thread!"); pthread__initthread(self, idle); sigfillset(&idle->pt_sigmask); idle->pt_type = PT_THREAD_IDLE; PTQ_INSERT_HEAD(&pthread__allqueue, idle, pt_allq); pthread__sched_idle(self, idle); } /* Start up the SA subsystem */ pthread__sa_start(); SDPRINTF(("(pthread__start %p) Started.\n", self)); } /* General-purpose thread data structure sanitization. */ void pthread__initthread(pthread_t self, pthread_t t) { int id; pthread_spinlock(self, &nextthread_lock); id = nextthread; nextthread++; pthread_spinunlock(self, &nextthread_lock); t->pt_num = id; t->pt_magic = PT_MAGIC; t->pt_type = PT_THREAD_NORMAL; t->pt_state = PT_STATE_RUNNABLE; pthread_lockinit(&t->pt_statelock); pthread_lockinit(&t->pt_flaglock); t->pt_spinlocks = 0; t->pt_next = NULL; t->pt_exitval = NULL; t->pt_flags = 0; t->pt_cancel = 0; t->pt_errno = 0; t->pt_parent = NULL; t->pt_heldlock = NULL; t->pt_switchto = NULL; t->pt_trapuc = NULL; sigemptyset(&t->pt_siglist); sigemptyset(&t->pt_sigmask); pthread_lockinit(&t->pt_siglock); PTQ_INIT(&t->pt_joiners); pthread_lockinit(&t->pt_join_lock); PTQ_INIT(&t->pt_cleanup_stack); memset(&t->pt_specific, 0, sizeof(int) * PTHREAD_KEYS_MAX); t->pt_name = NULL; #ifdef PTHREAD__DEBUG t->blocks = 0; t->preempts = 0; t->rescheds = 0; #endif } int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*startfunc)(void *), void *arg) { pthread_t self, newthread; pthread_attr_t nattr; struct pthread_attr_private *p; char *name; #ifdef PTHREAD_MLOCK_KLUDGE int ret; #endif PTHREADD_ADD(PTHREADD_CREATE); /* * It's okay to check this without a lock because there can * only be one thread before it becomes true. */ if (pthread__started == 0) { pthread__start(); pthread__started = 1; } if (attr == NULL) nattr = pthread_default_attr; else if (attr->pta_magic == PT_ATTR_MAGIC) nattr = *attr; else return EINVAL; /* Fetch misc. attributes from the attr structure. */ name = NULL; if ((p = nattr.pta_private) != NULL) if (p->ptap_name[0] != '\0') if ((name = strdup(p->ptap_name)) == NULL) return ENOMEM; self = pthread__self(); pthread_spinlock(self, &pthread__deadqueue_lock); if (!PTQ_EMPTY(&pthread__deadqueue)) { newthread = PTQ_FIRST(&pthread__deadqueue); PTQ_REMOVE(&pthread__deadqueue, newthread, pt_allq); pthread_spinunlock(self, &pthread__deadqueue_lock); } else { pthread_spinunlock(self, &pthread__deadqueue_lock); /* Set up a stack and allocate space for a pthread_st. */ ret = pthread__stackalloc(&newthread); if (ret != 0) { if (name) free(name); return ret; } #ifdef PTHREAD_MLOCK_KLUDGE ret = mlock(newthread, sizeof(struct __pthread_st)); pthread__assert(ret == 0); #endif } /* 2. Set up state. */ pthread__initthread(self, newthread); newthread->pt_flags = nattr.pta_flags; newthread->pt_sigmask = self->pt_sigmask; /* 3. Set up misc. attributes. */ newthread->pt_name = name; /* * 4. Set up context. * * The pt_uc pointer points to a location safely below the * stack start; this is arranged by pthread__stackalloc(). */ _INITCONTEXT_U(newthread->pt_uc); #ifdef PTHREAD_MACHINE_HAS_ID_REGISTER pthread__uc_id(newthread->pt_uc) = newthread; #endif newthread->pt_uc->uc_stack = newthread->pt_stack; newthread->pt_uc->uc_link = NULL; makecontext(newthread->pt_uc, pthread__create_tramp, 2, startfunc, arg); /* 5. Add to list of all threads. */ pthread_spinlock(self, &pthread__allqueue_lock); PTQ_INSERT_HEAD(&pthread__allqueue, newthread, pt_allq); nthreads++; pthread_spinunlock(self, &pthread__allqueue_lock); SDPRINTF(("(pthread_create %p) Created new thread %p (name pointer %p).\n", self, newthread, newthread->pt_name)); /* 6. Put on appropriate queue. */ if (newthread->pt_flags & PT_FLAG_SUSPENDED) { pthread_spinlock(self, &newthread->pt_statelock); pthread__suspend(self, newthread); pthread_spinunlock(self, &newthread->pt_statelock); } else pthread__sched(self, newthread); *thread = newthread; return 0; } static void pthread__create_tramp(void *(*start)(void *), void *arg) { void *retval; retval = (*start)(arg); pthread_exit(retval); /*NOTREACHED*/ pthread__abort(); } int pthread_suspend_np(pthread_t thread) { pthread_t self = pthread__self(); if (self == thread) { fprintf(stderr, "suspend_np: can't suspend self\n"); return EDEADLK; } SDPRINTF(("(pthread_suspend_np %p) Suspend thread %p (state %d).\n", self, thread, thread->pt_state)); pthread_spinlock(self, &thread->pt_statelock); if (thread->pt_blockgen != thread->pt_unblockgen) { /* XXX flaglock? */ thread->pt_flags |= PT_FLAG_SUSPENDED; pthread_spinunlock(self, &thread->pt_statelock); return 0; } switch (thread->pt_state) { case PT_STATE_RUNNING: pthread__abort(); /* XXX */ break; case PT_STATE_SUSPENDED: pthread_spinunlock(self, &thread->pt_statelock); return 0; case PT_STATE_RUNNABLE: pthread_spinlock(self, &pthread__runqueue_lock); PTQ_REMOVE(&pthread__runqueue, thread, pt_runq); pthread_spinunlock(self, &pthread__runqueue_lock); break; case PT_STATE_BLOCKED_QUEUE: pthread_spinlock(self, thread->pt_sleeplock); PTQ_REMOVE(thread->pt_sleepq, thread, pt_sleep); pthread_spinunlock(self, thread->pt_sleeplock); break; default: break; /* XXX */ } pthread__suspend(self, thread); pthread_spinunlock(self, &thread->pt_statelock); return 0; } int pthread_resume_np(pthread_t thread) { pthread_t self = pthread__self(); SDPRINTF(("(pthread_resume_np %p) Resume thread %p (state %d).\n", self, thread, thread->pt_state)); pthread_spinlock(self, &thread->pt_statelock); /* XXX flaglock? */ thread->pt_flags &= ~PT_FLAG_SUSPENDED; if (thread->pt_state == PT_STATE_SUSPENDED) { pthread_spinlock(self, &pthread__runqueue_lock); PTQ_REMOVE(&pthread__suspqueue, thread, pt_runq); pthread_spinunlock(self, &pthread__runqueue_lock); pthread__sched(self, thread); } pthread_spinunlock(self, &thread->pt_statelock); return 0; } /* * Other threads will switch to the idle thread so that they * can dispose of any awkward locks or recycle upcall state. */ void pthread__idle(void) { pthread_t self; PTHREADD_ADD(PTHREADD_IDLE); self = pthread__self(); SDPRINTF(("(pthread__idle %p).\n", self)); /* * The drill here is that we want to yield the processor, * but for the thread itself to be recovered, we need to be on * a list somewhere for the thread system to know about us. */ pthread_spinlock(self, &pthread__deadqueue_lock); PTQ_INSERT_TAIL(&pthread__reidlequeue[self->pt_vpid], self, pt_runq); pthread__concurrency--; SDPRINTF(("(yield %p concurrency) now %d\n", self, pthread__concurrency)); /* Don't need a flag lock; nothing else has a handle on this thread */ self->pt_flags |= PT_FLAG_IDLED; pthread_spinunlock(self, &pthread__deadqueue_lock); /* * If we get to run this, then no preemption has happened * (because the upcall handler will not continue an idle thread with * PT_FLAG_IDLED set), and so we can yield the processor safely. */ SDPRINTF(("(pthread__idle %p) yielding.\n", self)); sa_yield(); /* NOTREACHED */ self->pt_spinlocks++; /* XXX make sure we get to finish the assert! */ SDPRINTF(("(pthread__idle %p) Returned! Error.\n", self)); pthread__abort(); } void pthread_exit(void *retval) { pthread_t self; struct pt_clean_t *cleanup; char *name; int nt; self = pthread__self(); SDPRINTF(("(pthread_exit %p) Exiting (status %p, flags %x, cancel %d).\n", self, retval, self->pt_flags, self->pt_cancel)); /* Disable cancellability. */ pthread_spinlock(self, &self->pt_flaglock); self->pt_flags |= PT_FLAG_CS_DISABLED; self->pt_cancel = 0; pthread_spinunlock(self, &self->pt_flaglock); /* Call any cancellation cleanup handlers */ while (!PTQ_EMPTY(&self->pt_cleanup_stack)) { cleanup = PTQ_FIRST(&self->pt_cleanup_stack); PTQ_REMOVE(&self->pt_cleanup_stack, cleanup, ptc_next); (*cleanup->ptc_cleanup)(cleanup->ptc_arg); } /* Perform cleanup of thread-specific data */ pthread__destroy_tsd(self); self->pt_exitval = retval; /* * it's safe to check PT_FLAG_DETACHED without pt_flaglock * because it's only set by pthread_detach with pt_join_lock held. */ pthread_spinlock(self, &self->pt_join_lock); if (self->pt_flags & PT_FLAG_DETACHED) { self->pt_state = PT_STATE_DEAD; pthread_spinunlock(self, &self->pt_join_lock); name = self->pt_name; self->pt_name = NULL; if (name != NULL) free(name); pthread_spinlock(self, &pthread__allqueue_lock); PTQ_REMOVE(&pthread__allqueue, self, pt_allq); nthreads--; nt = nthreads; pthread_spinunlock(self, &pthread__allqueue_lock); if (nt == 0) { /* Whoah, we're the last one. Time to go. */ exit(0); } /* Yeah, yeah, doing work while we're dead is tacky. */ pthread_spinlock(self, &pthread__deadqueue_lock); PTQ_INSERT_HEAD(&pthread__deadqueue, self, pt_allq); pthread__block(self, &pthread__deadqueue_lock); } else { self->pt_state = PT_STATE_ZOMBIE; /* Note: name will be freed by the joiner. */ pthread_spinlock(self, &pthread__allqueue_lock); nthreads--; nt = nthreads; pthread_spinunlock(self, &pthread__allqueue_lock); if (nt == 0) { /* Whoah, we're the last one. Time to go. */ exit(0); } /* * Wake up all the potential joiners. Only one can win. * (Can you say "Thundering Herd"? I knew you could.) */ pthread__sched_sleepers(self, &self->pt_joiners); pthread__block(self, &self->pt_join_lock); } /*NOTREACHED*/ pthread__abort(); exit(1); } int pthread_join(pthread_t thread, void **valptr) { pthread_t self; char *name; int num; self = pthread__self(); SDPRINTF(("(pthread_join %p) Joining %p.\n", self, thread)); if (pthread__find(self, thread) != 0) return ESRCH; if (thread->pt_magic != PT_MAGIC) return EINVAL; if (thread == self) return EDEADLK; pthread_spinlock(self, &thread->pt_flaglock); if (thread->pt_flags & PT_FLAG_DETACHED) { pthread_spinunlock(self, &thread->pt_flaglock); return EINVAL; } num = thread->pt_num; pthread_spinlock(self, &thread->pt_join_lock); while (thread->pt_state != PT_STATE_ZOMBIE) { if ((thread->pt_state == PT_STATE_DEAD) || (thread->pt_flags & PT_FLAG_DETACHED) || (thread->pt_num != num)) { /* * Another thread beat us to the join, or called * pthread_detach(). If num didn't match, the * thread died and was recycled before we got * another chance to run. */ pthread_spinunlock(self, &thread->pt_join_lock); pthread_spinunlock(self, &thread->pt_flaglock); return ESRCH; } /* * "I'm not dead yet!" * "You will be soon enough." */ pthread_spinunlock(self, &thread->pt_flaglock); pthread_spinlock(self, &self->pt_statelock); if (self->pt_cancel) { pthread_spinunlock(self, &self->pt_statelock); pthread_spinunlock(self, &thread->pt_join_lock); pthread_exit(PTHREAD_CANCELED); } self->pt_state = PT_STATE_BLOCKED_QUEUE; self->pt_sleepobj = thread; self->pt_sleepq = &thread->pt_joiners; self->pt_sleeplock = &thread->pt_join_lock; pthread_spinunlock(self, &self->pt_statelock); PTQ_INSERT_TAIL(&thread->pt_joiners, self, pt_sleep); pthread__block(self, &thread->pt_join_lock); pthread_spinlock(self, &thread->pt_flaglock); pthread_spinlock(self, &thread->pt_join_lock); } /* All ours. */ thread->pt_state = PT_STATE_DEAD; name = thread->pt_name; thread->pt_name = NULL; pthread_spinunlock(self, &thread->pt_join_lock); pthread_spinunlock(self, &thread->pt_flaglock); if (valptr != NULL) *valptr = thread->pt_exitval; SDPRINTF(("(pthread_join %p) Joined %p.\n", self, thread)); pthread__dead(self, thread); if (name != NULL) free(name); return 0; } int pthread_equal(pthread_t t1, pthread_t t2) { /* Nothing special here. */ return (t1 == t2); } int pthread_detach(pthread_t thread) { pthread_t self; int doreclaim = 0; char *name = NULL; self = pthread__self(); if (pthread__find(self, thread) != 0) return ESRCH; if (thread->pt_magic != PT_MAGIC) return EINVAL; pthread_spinlock(self, &thread->pt_flaglock); pthread_spinlock(self, &thread->pt_join_lock); if (thread->pt_flags & PT_FLAG_DETACHED) { pthread_spinunlock(self, &thread->pt_join_lock); pthread_spinunlock(self, &thread->pt_flaglock); return EINVAL; } thread->pt_flags |= PT_FLAG_DETACHED; /* Any joiners have to be punted now. */ pthread__sched_sleepers(self, &thread->pt_joiners); if (thread->pt_state == PT_STATE_ZOMBIE) { thread->pt_state = PT_STATE_DEAD; name = thread->pt_name; thread->pt_name = NULL; doreclaim = 1; } pthread_spinunlock(self, &thread->pt_join_lock); pthread_spinunlock(self, &thread->pt_flaglock); if (doreclaim) { pthread__dead(self, thread); if (name != NULL) free(name); } return 0; } static void pthread__dead(pthread_t self, pthread_t thread) { SDPRINTF(("(pthread__dead %p) Reclaimed %p.\n", self, thread)); pthread__assert(thread != self); pthread__assert(thread->pt_state == PT_STATE_DEAD); pthread__assert(thread->pt_name == NULL); /* Cleanup time. Move the dead thread from allqueue to the deadqueue */ pthread_spinlock(self, &pthread__allqueue_lock); PTQ_REMOVE(&pthread__allqueue, thread, pt_allq); pthread_spinunlock(self, &pthread__allqueue_lock); pthread_spinlock(self, &pthread__deadqueue_lock); PTQ_INSERT_HEAD(&pthread__deadqueue, thread, pt_allq); pthread_spinunlock(self, &pthread__deadqueue_lock); } int pthread_getname_np(pthread_t thread, char *name, size_t len) { pthread_t self; self = pthread__self(); if (pthread__find(self, thread) != 0) return ESRCH; if (thread->pt_magic != PT_MAGIC) return EINVAL; pthread_spinlock(self, &thread->pt_join_lock); if (thread->pt_name == NULL) name[0] = '\0'; else strlcpy(name, thread->pt_name, len); pthread_spinunlock(self, &thread->pt_join_lock); return 0; } int pthread_setname_np(pthread_t thread, const char *name, void *arg) { pthread_t self = pthread_self(); char *oldname, *cp, newname[PTHREAD_MAX_NAMELEN_NP]; int namelen; if (pthread__find(self, thread) != 0) return ESRCH; if (thread->pt_magic != PT_MAGIC) return EINVAL; namelen = snprintf(newname, sizeof(newname), name, arg); if (namelen >= PTHREAD_MAX_NAMELEN_NP) return EINVAL; cp = strdup(newname); if (cp == NULL) return ENOMEM; pthread_spinlock(self, &thread->pt_join_lock); if (thread->pt_state == PT_STATE_DEAD) { pthread_spinunlock(self, &thread->pt_join_lock); free(cp); return EINVAL; } oldname = thread->pt_name; thread->pt_name = cp; pthread_spinunlock(self, &thread->pt_join_lock); if (oldname != NULL) free(oldname); return 0; } /* * XXX There should be a way for applications to use the efficent * inline version, but there are opacity/namespace issues. */ pthread_t pthread_self(void) { return pthread__self(); } int pthread_cancel(pthread_t thread) { pthread_t self; if (!(thread->pt_state == PT_STATE_RUNNING || thread->pt_state == PT_STATE_RUNNABLE || thread->pt_state == PT_STATE_BLOCKED_QUEUE)) return ESRCH; self = pthread__self(); pthread_spinlock(self, &thread->pt_flaglock); thread->pt_flags |= PT_FLAG_CS_PENDING; if ((thread->pt_flags & PT_FLAG_CS_DISABLED) == 0) { thread->pt_cancel = 1; pthread_spinunlock(self, &thread->pt_flaglock); pthread_spinlock(self, &thread->pt_statelock); if (thread->pt_blockgen != thread->pt_unblockgen) { /* * It's sleeping in the kernel. If we can wake * it up, it will notice the cancellation when * it returns. If it doesn't wake up when we * make this call, then it's blocked * uninterruptably in the kernel, and there's * not much to be done about it. */ _lwp_wakeup(thread->pt_blockedlwp); } else if (thread->pt_state == PT_STATE_BLOCKED_QUEUE) { /* * We're blocked somewhere (pthread__block() * was called). Cause it to wake up; it will * check for the cancellation if the routine * is a cancellation point, and loop and reblock * otherwise. */ pthread_spinlock(self, thread->pt_sleeplock); PTQ_REMOVE(thread->pt_sleepq, thread, pt_sleep); pthread_spinunlock(self, thread->pt_sleeplock); pthread__sched(self, thread); } else { /* * Nothing. The target thread is running and will * notice at the next deferred cancellation point. */ } pthread_spinunlock(self, &thread->pt_statelock); } else pthread_spinunlock(self, &thread->pt_flaglock); return 0; } int pthread_setcancelstate(int state, int *oldstate) { pthread_t self; int retval; self = pthread__self(); retval = 0; pthread_spinlock(self, &self->pt_flaglock); if (oldstate != NULL) { if (self->pt_flags & PT_FLAG_CS_DISABLED) *oldstate = PTHREAD_CANCEL_DISABLE; else *oldstate = PTHREAD_CANCEL_ENABLE; } if (state == PTHREAD_CANCEL_DISABLE) { self->pt_flags |= PT_FLAG_CS_DISABLED; if (self->pt_cancel) { self->pt_flags |= PT_FLAG_CS_PENDING; self->pt_cancel = 0; } } else if (state == PTHREAD_CANCEL_ENABLE) { self->pt_flags &= ~PT_FLAG_CS_DISABLED; /* * If a cancellation was requested while cancellation * was disabled, note that fact for future * cancellation tests. */ if (self->pt_flags & PT_FLAG_CS_PENDING) { self->pt_cancel = 1; /* This is not a deferred cancellation point. */ if (self->pt_flags & PT_FLAG_CS_ASYNC) { pthread_spinunlock(self, &self->pt_flaglock); pthread_exit(PTHREAD_CANCELED); } } } else retval = EINVAL; pthread_spinunlock(self, &self->pt_flaglock); return retval; } int pthread_setcanceltype(int type, int *oldtype) { pthread_t self; int retval; self = pthread__self(); retval = 0; pthread_spinlock(self, &self->pt_flaglock); if (oldtype != NULL) { if (self->pt_flags & PT_FLAG_CS_ASYNC) *oldtype = PTHREAD_CANCEL_ASYNCHRONOUS; else *oldtype = PTHREAD_CANCEL_DEFERRED; } if (type == PTHREAD_CANCEL_ASYNCHRONOUS) { self->pt_flags |= PT_FLAG_CS_ASYNC; if (self->pt_cancel) { pthread_spinunlock(self, &self->pt_flaglock); pthread_exit(PTHREAD_CANCELED); } } else if (type == PTHREAD_CANCEL_DEFERRED) self->pt_flags &= ~PT_FLAG_CS_ASYNC; else retval = EINVAL; pthread_spinunlock(self, &self->pt_flaglock); return retval; } void pthread_testcancel() { pthread_t self; self = pthread__self(); if (self->pt_cancel) pthread_exit(PTHREAD_CANCELED); } /* * POSIX requires that certain functions return an error rather than * invoking undefined behavior even when handed completely bogus * pthread_t values, e.g. stack garbage or (pthread_t)666. This * utility routine searches the list of threads for the pthread_t * value without dereferencing it. */ int pthread__find(pthread_t self, pthread_t id) { pthread_t target; pthread_spinlock(self, &pthread__allqueue_lock); PTQ_FOREACH(target, &pthread__allqueue, pt_allq) if (target == id) break; pthread_spinunlock(self, &pthread__allqueue_lock); if (target == NULL) return ESRCH; return 0; } void pthread__testcancel(pthread_t self) { if (self->pt_cancel) pthread_exit(PTHREAD_CANCELED); } void pthread__cleanup_push(void (*cleanup)(void *), void *arg, void *store) { pthread_t self; struct pt_clean_t *entry; self = pthread__self(); entry = store; entry->ptc_cleanup = cleanup; entry->ptc_arg = arg; PTQ_INSERT_HEAD(&self->pt_cleanup_stack, entry, ptc_next); } void pthread__cleanup_pop(int ex, void *store) { pthread_t self; struct pt_clean_t *entry; self = pthread__self(); entry = store; PTQ_REMOVE(&self->pt_cleanup_stack, entry, ptc_next); if (ex) (*entry->ptc_cleanup)(entry->ptc_arg); } int * pthread__errno(void) { pthread_t self; self = pthread__self(); return &(self->pt_errno); } ssize_t _sys_write(int, const void *, size_t); void pthread__assertfunc(const char *file, int line, const char *function, const char *expr) { char buf[1024]; int len; SDPRINTF(("(af)\n")); /* * snprintf should not acquire any locks, or we could * end up deadlocked if the assert caller held locks. */ len = snprintf(buf, 1024, "assertion \"%s\" failed: file \"%s\", line %d%s%s%s\n", expr, file, line, function ? ", function \"" : "", function ? function : "", function ? "\"" : ""); _sys_write(STDERR_FILENO, buf, (size_t)len); (void)kill(getpid(), SIGABRT); _exit(1); } void pthread__errorfunc(const char *file, int line, const char *function, const char *msg) { char buf[1024]; size_t len; if (pthread__diagassert == 0) return; /* * snprintf should not acquire any locks, or we could * end up deadlocked if the assert caller held locks. */ len = snprintf(buf, 1024, "%s: Error detected by libpthread: %s.\n" "Detected by file \"%s\", line %d%s%s%s.\n" "See pthread(3) for information.\n", getprogname(), msg, file, line, function ? ", function \"" : "", function ? function : "", function ? "\"" : ""); if (pthread__diagassert & DIAGASSERT_STDERR) _sys_write(STDERR_FILENO, buf, len); if (pthread__diagassert & DIAGASSERT_SYSLOG) syslog(LOG_DEBUG | LOG_USER, "%s", buf); if (pthread__diagassert & DIAGASSERT_ABORT) { (void)kill(getpid(), SIGABRT); _exit(1); } }