/
sem_destroy.c
146 lines (134 loc) · 4.37 KB
/
sem_destroy.c
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
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
* -------------------------------------------------------------
*
* Module: sem_destroy.c
*
* Purpose:
* Semaphores aren't actually part of the PThreads standard.
* They are defined by the POSIX Standard:
*
* POSIX 1003.1b-1993 (POSIX.1b)
*
* -------------------------------------------------------------
*
* --------------------------------------------------------------------------
*
* 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 "semaphore.h"
#include "implement.h"
int
sem_destroy (sem_t * sem)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function destroys an unnamed semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* DESCRIPTION
* This function destroys an unnamed semaphore.
*
* RESULTS
* 0 successfully destroyed semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore,
* ENOSYS semaphores are not supported,
* EBUSY threads (or processes) are currently
* blocked on 'sem'
*
* ------------------------------------------------------
*/
{
int result = 0;
sem_t s = NULL;
if (sem == NULL || *sem == NULL)
{
result = EINVAL;
}
else
{
s = *sem;
*sem = NULL;
if ((result = pthread_mutex_trylock (&s->lock)) == 0)
{
if (s->value >= 0)
{
(void) pthread_mutex_unlock (&s->lock);
if (!CloseHandle (s->sem))
{
*sem = s;
result = EINVAL;
}
else if ((result = pthread_mutex_destroy (&s->lock)) != 0)
{
#ifdef NEED_SEM
s->sem = CreateEvent (NULL,
PTW32_FALSE, /* manual reset is false */
PTW32_FALSE, /* initial state is unset */
NULL);
#else
s->sem = CreateSemaphore (NULL, /* Always NULL */
(long) 0, /* Force threads to wait */
(long) _POSIX_SEM_VALUE_MAX, /* Maximum value */
NULL); /* Name */
#endif
if (s->sem == 0)
{
/* We just have to pretend that we've destroyed the semaphore
* even though we're leaving a mutex around.
*/
result = 0;
}
else
{
*sem = s;
if (result != EBUSY)
result = EINVAL;
}
}
}
else
{
(void) pthread_mutex_unlock (&s->lock);
result = EBUSY;
}
}
}
if (result != 0)
{
errno = result;
return -1;
}
free (s);
return 0;
} /* sem_destroy */