summaryrefslogtreecommitdiff
path: root/pthread_key_delete.c
blob: 0737e9e397e995d168affd008701f39198db1ce2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/*
 * pthread_key_delete.c
 *
 * Description:
 * POSIX thread functions which implement thread-specific data (TSD).
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 * 
 *      Contact Email: rpj@callisto.canberra.edu.au
 * 
 *      The current list of contributors is contained
 *      in the file CONTRIBUTORS included with the source
 *      code distribution. The list can also be seen at the
 *      following World Wide Web location:
 *      http://sources.redhat.com/pthreads-win32/contributors.html
 * 
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation; either
 *      version 2 of the License, or (at your option) any later version.
 * 
 *      This library is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *      Lesser General Public License for more details.
 * 
 *      You should have received a copy of the GNU Lesser General Public
 *      License along with this library in the file COPYING.LIB;
 *      if not, write to the Free Software Foundation, Inc.,
 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include "pthread.h"
#include "implement.h"


int
pthread_key_delete (pthread_key_t key)
     /*
      * ------------------------------------------------------
      * DOCPUBLIC
      *      This function deletes a thread-specific data key. This
      *      does not change the value of the thread specific data key
      *      for any thread and does not run the key's destructor
      *      in any thread so it should be used with caution.
      *
      * PARAMETERS
      *      key
      *              pointer to an instance of pthread_key_t
      *
      *
      * DESCRIPTION
      *      This function deletes a thread-specific data key. This
      *      does not change the value of the thread specific data key
      *      for any thread and does not run the key's destructor
      *      in any thread so it should be used with caution.
      *
      * RESULTS
      *              0               successfully deleted the key,
      *              EINVAL          key is invalid,
      *
      * ------------------------------------------------------
      */
{
  int result = 0;

  if (key != NULL)
    {
      if (key->threads != NULL &&
	  key->destructor != NULL &&
	  pthread_mutex_lock (&(key->keyLock)) == 0)
	{
	  ThreadKeyAssoc *assoc;
	  /*
	   * Run through all Thread<-->Key associations
	   * for this key.
	   *
	   * While we hold at least one of the locks guarding
	   * the assoc, we know that the assoc pointed to by
	   * key->threads is valid.
	   */
	  while ((assoc = (ThreadKeyAssoc *) key->threads) != NULL)
	    {
	      ptw32_thread_t * thread = assoc->thread;

	      if (assoc == NULL)
		{
		  /* Finished */
		  break;
		}

	      if (pthread_mutex_lock (&(thread->threadLock)) == 0)
		{
		  /*
		   * Since we are starting at the head of the key's threads
		   * chain, this will also point key->threads at the next assoc.
		   * While we hold key->keyLock, no other thread can insert
		   * a new assoc via pthread_setspecific.
		   */
		  ptw32_tkAssocDestroy (assoc);
		  (void) pthread_mutex_unlock (&(thread->threadLock));
		}
	      else
		{
		  /* Thread or lock is no longer valid? */
		  ptw32_tkAssocDestroy (assoc);
		}
	    }
	  pthread_mutex_unlock (&(key->keyLock));
	}

      TlsFree (key->key);
      if (key->destructor != NULL)
	{
	  /* A thread could be holding the keyLock */
	  while (EBUSY == pthread_mutex_destroy (&(key->keyLock)))
	    {
	      Sleep(0); /* Ugly */
	    }
	}

#if defined( _DEBUG )
      memset ((char *) key, 0, sizeof (*key));
#endif
      free (key);
    }

  return (result);
}