blob: d66e1942c984c75684ab9db76a4449e89570abcd (
plain) (
blame)
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
|
/**
* @file
*
* @brief Function does Actual creation and Initialization of POSIX Semaphore
* @ingroup POSIXAPI
*/
/*
* COPYRIGHT (c) 1989-2009.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdarg.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <limits.h>
#include <string.h> /* strlen */
#include <rtems/system.h>
#include <rtems/score/wkspace.h>
#include <rtems/posix/semaphoreimpl.h>
#include <rtems/seterr.h>
/*
* _POSIX_Semaphore_Create_support
*
* This routine does the actual creation and initialization of
* a poxix semaphore. It is a support routine for sem_init and
* sem_open.
*/
int _POSIX_Semaphore_Create_support(
const char *name_arg,
size_t name_len,
int pshared,
unsigned int value,
POSIX_Semaphore_Control **the_sem
)
{
POSIX_Semaphore_Control *the_semaphore;
char *name;
/* Sharing semaphores among processes is not currently supported */
if (pshared != 0)
rtems_set_errno_and_return_minus_one( ENOSYS );
/*
* Make a copy of the user's string for name just in case it was
* dynamically constructed.
*/
if ( name_arg != NULL ) {
name = _Workspace_String_duplicate( name_arg, name_len );
if ( !name ) {
rtems_set_errno_and_return_minus_one( ENOMEM );
}
} else {
name = NULL;
}
the_semaphore = _POSIX_Semaphore_Allocate_unprotected();
if ( !the_semaphore ) {
_Workspace_Free( name );
rtems_set_errno_and_return_minus_one( ENOSPC );
}
the_semaphore->process_shared = pshared;
if ( name ) {
the_semaphore->named = true;
the_semaphore->open_count = 1;
the_semaphore->linked = true;
} else {
the_semaphore->named = false;
the_semaphore->open_count = 0;
the_semaphore->linked = false;
}
/*
* POSIX does not appear to specify what the discipline for
* blocking tasks on this semaphore should be. It could somehow
* be derived from the current scheduling policy. One
* thing is certain, no matter what we decide, it won't be
* the same as all other POSIX implementations. :)
*/
_CORE_semaphore_Initialize( &the_semaphore->Semaphore, value );
/*
* Make the semaphore available for use.
*/
_Objects_Open_string(
&_POSIX_Semaphore_Information,
&the_semaphore->Object,
name
);
*the_sem = the_semaphore;
return 0;
}
|
