1 /***************************************************************************
2 * Copyright (c) 2024 Microsoft Corporation
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the MIT License which is available at
6 * https://opensource.org/licenses/MIT.
7 *
8 * SPDX-License-Identifier: MIT
9 **************************************************************************/
10
11
12 /**************************************************************************/
13 /**************************************************************************/
14 /** */
15 /** POSIX wrapper for THREADX */
16 /** */
17 /** */
18 /** */
19 /**************************************************************************/
20 /**************************************************************************/
21
22 /* Include necessary system files. */
23
24 #include "tx_api.h" /* Threadx API */
25 #include "pthread.h" /* Posix API */
26 #include "px_int.h" /* Posix helper functions */
27
28
29 /**************************************************************************/
30 /* */
31 /* FUNCTION RELEASE */
32 /* */
33 /* sem_close PORTABLE C */
34 /* 6.1.7 */
35 /* AUTHOR */
36 /* */
37 /* William E. Lamie, Microsoft Corporation */
38 /* */
39 /* DESCRIPTION */
40 /* */
41 /* This routine is called to indicate that the calling thread is */
42 /* finished with the specified named semaphore, sem. */
43 /* */
44 /* INPUT */
45 /* */
46 /* sem type of semaphore */
47 /* */
48 /* OUTPUT */
49 /* */
50 /* OK If successful */
51 /* ERROR If error occurs */
52 /* */
53 /* CALLS */
54 /* */
55 /* posix_internal_error Generic error handler */
56 /* posix_sem_reset Resets the semaphore structure */
57 /* tx_thread_identify Returns currently running thread */
58 /* */
59 /* CALLED BY */
60 /* */
61 /* Application Code */
62 /* */
63 /* RELEASE HISTORY */
64 /* */
65 /* DATE NAME DESCRIPTION */
66 /* */
67 /* 06-02-2021 William E. Lamie Initial Version 6.1.7 */
68 /* */
69 /**************************************************************************/
sem_close(sem_t * sem)70 INT sem_close(sem_t * sem)
71 {
72
73 TX_SEMAPHORE * TheSem;
74 TX_THREAD * Thethread;
75
76 /* Make sure we're calling this routine from a thread context. */
77 Thethread = tx_thread_identify();
78
79 if (!Thethread)
80 {
81 /* Return appropriate error. */
82 posix_internal_error(240);
83
84 /* there is no error defined for this in POSIX, hence give default. */
85 return(ERROR);
86 }
87
88 /* Get ThreadX semaphore. */
89 TheSem = (TX_SEMAPHORE * )sem;
90
91 /* Check for an invalid semaphore pointer. */
92 if ((!TheSem) || (TheSem -> tx_semaphore_id != TX_SEMAPHORE_ID))
93 {
94
95 /* Return appropriate error. */
96 posix_errno = EINVAL;
97 posix_set_pthread_errno(EINVAL);
98
99 /* return error. */
100 return(ERROR);
101 }
102 if(sem)
103 sem->count -= 1;
104
105 if(! (sem->count) )
106 {
107
108 if(sem->unlink_flag == TX_TRUE)
109 {
110 posix_sem_reset(sem );
111 sem = NULL;
112 }
113 }
114 return(OK);
115 }
116
