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. Neither the name of the author nor the names of any co-contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD$
31 */
32
33 #include "namespace.h"
34 #include <errno.h>
35 #include <pthread.h>
36 #include "un-namespace.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 */
44 int
_thr_ref_add(struct pthread * curthread,struct pthread * thread,int include_dead)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 struct kse *curkse;
51
52 if (thread == NULL)
53 /* Invalid thread: */
54 return (EINVAL);
55
56 crit = _kse_critical_enter();
57 curkse = _get_curkse();
58 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock);
59 pthread = _thr_hash_find(thread);
60 if (pthread) {
61 if ((include_dead == 0) &&
62 ((pthread->state == PS_DEAD) ||
63 ((pthread->state == PS_DEADLOCK) ||
64 ((pthread->flags & THR_FLAGS_EXITING) != 0))))
65 pthread = NULL;
66 else {
67 pthread->refcount++;
68 if (curthread != NULL)
69 curthread->critical_count++;
70 }
71 }
72 KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
73 _kse_critical_leave(crit);
74
75 /* Return zero if the thread exists: */
76 return ((pthread != NULL) ? 0 : ESRCH);
77 }
78
79 void
_thr_ref_delete(struct pthread * curthread,struct pthread * thread)80 _thr_ref_delete(struct pthread *curthread, struct pthread *thread)
81 {
82 kse_critical_t crit;
83 struct kse *curkse;
84
85 if (thread != NULL) {
86 crit = _kse_critical_enter();
87 curkse = _get_curkse();
88 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock);
89 thread->refcount--;
90 if (curthread != NULL)
91 curthread->critical_count--;
92 if ((thread->refcount == 0) &&
93 (thread->tlflags & TLFLAGS_GC_SAFE) != 0)
94 THR_GCLIST_ADD(thread);
95 KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
96 _kse_critical_leave(crit);
97 }
98 }
99