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 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
35 */
36
37#include "pthread.h"
38#include "implement.h"
39
40
41int
42pthread_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