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
46int
47pthread_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