1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** POSIX wrapper for THREADX */
17 /** */
18 /** */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 /* Include necessary system files. */
24
25 #include "tx_api.h" /* Threadx API */
26 #include "pthread.h" /* Posix API */
27 #include "px_int.h" /* Posix helper functions */
28
29
30 /**************************************************************************/
31 /* */
32 /* FUNCTION RELEASE */
33 /* */
34 /* sem_close PORTABLE C */
35 /* 6.1.7 */
36 /* AUTHOR */
37 /* */
38 /* William E. Lamie, Microsoft Corporation */
39 /* */
40 /* DESCRIPTION */
41 /* */
42 /* This routine is called to indicate that the calling thread is */
43 /* finished with the specified named semaphore, sem. */
44 /* */
45 /* INPUT */
46 /* */
47 /* sem type of semaphore */
48 /* */
49 /* OUTPUT */
50 /* */
51 /* OK If successful */
52 /* ERROR If error occurs */
53 /* */
54 /* CALLS */
55 /* */
56 /* posix_internal_error Generic error handler */
57 /* posix_sem_reset Resets the semaphore structure */
58 /* tx_thread_identify Returns currently running thread */
59 /* */
60 /* CALLED BY */
61 /* */
62 /* Application Code */
63 /* */
64 /* RELEASE HISTORY */
65 /* */
66 /* DATE NAME DESCRIPTION */
67 /* */
68 /* 06-02-2021 William E. Lamie Initial Version 6.1.7 */
69 /* */
70 /**************************************************************************/
sem_close(sem_t * sem)71 INT sem_close(sem_t * sem)
72 {
73
74 TX_SEMAPHORE * TheSem;
75 TX_THREAD * Thethread;
76
77 /* Make sure we're calling this routine from a thread context. */
78 Thethread = tx_thread_identify();
79
80 if (!Thethread)
81 {
82 /* Return appropriate error. */
83 posix_internal_error(240);
84
85 /* there is no error defined for this in POSIX, hence give default. */
86 return(ERROR);
87 }
88
89 /* Get ThreadX semaphore. */
90 TheSem = (TX_SEMAPHORE * )sem;
91
92 /* Check for an invalid semaphore pointer. */
93 if ((!TheSem) || (TheSem -> tx_semaphore_id != TX_SEMAPHORE_ID))
94 {
95
96 /* Return appropriate error. */
97 posix_errno = EINVAL;
98 posix_set_pthread_errno(EINVAL);
99
100 /* return error. */
101 return(ERROR);
102 }
103 if(sem)
104 sem->count -= 1;
105
106 if(! (sem->count) )
107 {
108
109 if(sem->unlink_flag == TX_TRUE)
110 {
111 posix_sem_reset(sem );
112 sem = NULL;
113 }
114 }
115 return(OK);
116 }
117
