1 /*
2 * pthread_key_create.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 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
35 */
36
37 #include "pthread.h"
38 #include "implement.h"
39
40
41 /* TLS_OUT_OF_INDEXES not defined on WinCE */
42 #if !defined(TLS_OUT_OF_INDEXES)
43 #define TLS_OUT_OF_INDEXES 0xffffffff
44 #endif
45
46 int
pthread_key_create(pthread_key_t * key,void (PTW32_CDECL * destructor)(void *))47 pthread_key_create (pthread_key_t * key, void (PTW32_CDECL *destructor) (void *))
48 /*
49 * ------------------------------------------------------
50 * DOCPUBLIC
51 * This function creates a thread-specific data key visible
52 * to all threads. All existing and new threads have a value
53 * NULL for key until set using pthread_setspecific. When any
54 * thread with a non-NULL value for key terminates, 'destructor'
55 * is called with key's current value for that thread.
56 *
57 * PARAMETERS
58 * key
59 * pointer to an instance of pthread_key_t
60 *
61 *
62 * DESCRIPTION
63 * This function creates a thread-specific data key visible
64 * to all threads. All existing and new threads have a value
65 * NULL for key until set using pthread_setspecific. When any
66 * thread with a non-NULL value for key terminates, 'destructor'
67 * is called with key's current value for that thread.
68 *
69 * RESULTS
70 * 0 successfully created semaphore,
71 * EAGAIN insufficient resources or PTHREAD_KEYS_MAX
72 * exceeded,
73 * ENOMEM insufficient memory to create the key,
74 *
75 * ------------------------------------------------------
76 */
77 {
78 int result = 0;
79 pthread_key_t newkey;
80
81 if ((newkey = (pthread_key_t) calloc (1, sizeof (*newkey))) == NULL)
82 {
83 result = ENOMEM;
84 }
85 else if ((newkey->key = TlsAlloc ()) == TLS_OUT_OF_INDEXES)
86 {
87 result = EAGAIN;
88
89 free (newkey);
90 newkey = NULL;
91 }
92 else if (destructor != NULL)
93 {
94 /*
95 * Have to manage associations between thread and key;
96 * Therefore, need a lock that allows competing threads
97 * to gain exclusive access to the key->threads list.
98 *
99 * The mutex will only be created when it is first locked.
100 */
101 newkey->keyLock = 0;
102 newkey->destructor = destructor;
103 }
104
105 *key = newkey;
106
107 return (result);
108 }
109