thr_find_thread.c revision 114187
1/* 2 * Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org> 3 * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by John Birrell. 17 * 4. Neither the name of the author nor the names of any co-contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $FreeBSD: head/lib/libkse/thread/thr_find_thread.c 114187 2003-04-28 23:56:12Z deischen $ 34 */ 35#include <errno.h> 36#include <pthread.h> 37#include "thr_private.h" 38 39/* 40 * Find a thread in the linked list of active threads and add a reference 41 * to it. Threads with positive reference counts will not be deallocated 42 * until all references are released. 43 */ 44int 45_thr_ref_add(struct pthread *curthread, struct pthread *thread, 46 int include_dead) 47{ 48 kse_critical_t crit; 49 struct pthread *pthread; 50 51 if (thread == NULL) 52 /* Invalid thread: */ 53 return (EINVAL); 54 55 crit = _kse_critical_enter(); 56 KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock); 57 TAILQ_FOREACH(pthread, &_thread_list, tle) { 58 if (pthread == thread) { 59 if ((include_dead == 0) && 60 ((pthread->state == PS_DEAD) || 61 ((pthread->state == PS_DEADLOCK) || 62 ((pthread->flags & THR_FLAGS_EXITING) != 0)))) 63 pthread = NULL; 64 else { 65 thread->refcount++; 66 curthread->critical_count++; 67 } 68 break; 69 } 70 } 71 KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock); 72 _kse_critical_leave(crit); 73 74 /* Return zero if the thread exists: */ 75 return ((pthread != NULL) ? 0 : ESRCH); 76} 77 78void 79_thr_ref_delete(struct pthread *curthread, struct pthread *thread) 80{ 81 kse_critical_t crit; 82 83 if (thread != NULL) { 84 crit = _kse_critical_enter(); 85 KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock); 86 thread->refcount--; 87 curthread->critical_count--; 88 if ((thread->refcount == 0) && 89 (thread->flags & THR_FLAGS_GC_SAFE) != 0) 90 THR_GCLIST_ADD(thread); 91 KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock); 92 _kse_critical_leave(crit); 93 } 94} 95