1 /*
2 * pthread_key_delete.c
3 *
4 * Description:
5 * POSIX thread functions which implement thread-specific data (TSD).
6 *
7 * --------------------------------------------------------------------------
8 *
9 * Pthreads-win32 - POSIX Threads Library for Win32
10 * Copyright(C) 1998 John E. Bossom
11 * Copyright(C) 1999,2005 Pthreads-win32 contributors
12 *
13 * Contact Email: rpj@callisto.canberra.edu.au
14 *
15 * The current list of contributors is contained
16 * in the file CONTRIBUTORS included with the source
17 * code distribution. The list can also be seen at the
18 * following World Wide Web location:
19 * http://sources.redhat.com/pthreads-win32/contributors.html
20 *
21 * This library is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU Lesser General Public
23 * License as published by the Free Software Foundation; either
24 * version 2 of the License, or (at your option) any later version.
25 *
26 * This library is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
29 * Lesser General Public License for more details.
30 *
31 * You should have received a copy of the GNU Lesser General Public
32 * License along with this library in the file COPYING.LIB;
33 * if not, write to the Free Software Foundation, Inc.,
34 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
35 */
36
37 #include "pthread.h"
38 #include "implement.h"
39
40
41 int
pthread_key_delete(pthread_key_t key)42 pthread_key_delete (pthread_key_t key)
43 /*
44 * ------------------------------------------------------
45 * DOCPUBLIC
46 * This function deletes a thread-specific data key. This
47 * does not change the value of the thread specific data key
48 * for any thread and does not run the key's destructor
49 * in any thread so it should be used with caution.
50 *
51 * PARAMETERS
52 * key
53 * pointer to an instance of pthread_key_t
54 *
55 *
56 * DESCRIPTION
57 * This function deletes a thread-specific data key. This
58 * does not change the value of the thread specific data key
59 * for any thread and does not run the key's destructor
60 * in any thread so it should be used with caution.
61 *
62 * RESULTS
63 * 0 successfully deleted the key,
64 * EINVAL key is invalid,
65 *
66 * ------------------------------------------------------
67 */
68 {
69 ptw32_mcs_local_node_t keyLock;
70 int result = 0;
71
72 if (key != NULL)
73 {
74 if (key->threads != NULL && key->destructor != NULL)
75 {
76 ThreadKeyAssoc *assoc;
77 ptw32_mcs_lock_acquire (&(key->keyLock), &keyLock);
78 /*
79 * Run through all Thread<-->Key associations
80 * for this key.
81 *
82 * While we hold at least one of the locks guarding
83 * the assoc, we know that the assoc pointed to by
84 * key->threads is valid.
85 */
86 while ((assoc = (ThreadKeyAssoc *) key->threads) != NULL)
87 {
88 ptw32_mcs_local_node_t threadLock;
89 ptw32_thread_t * thread = assoc->thread;
90
91 if (assoc == NULL)
92 {
93 /* Finished */
94 break;
95 }
96
97 ptw32_mcs_lock_acquire (&(thread->threadLock), &threadLock);
98 /*
99 * Since we are starting at the head of the key's threads
100 * chain, this will also point key->threads at the next assoc.
101 * While we hold key->keyLock, no other thread can insert
102 * a new assoc via pthread_setspecific.
103 */
104 ptw32_tkAssocDestroy (assoc);
105 ptw32_mcs_lock_release (&threadLock);
106 ptw32_mcs_lock_release (&keyLock);
107 }
108 }
109
110 TlsFree (key->key);
111 if (key->destructor != NULL)
112 {
113 /* A thread could be holding the keyLock */
114 ptw32_mcs_lock_acquire (&(key->keyLock), &keyLock);
115 ptw32_mcs_lock_release (&keyLock);
116 }
117
118 #if defined( _DEBUG )
119 memset ((char *) key, 0, sizeof (*key));
120 #endif
121 free (key);
122 }
123
124 return (result);
125 }
126