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 /*    pthread_mutex_lock                                   PORTABLE C     */
35 /*                                                           6.1.7        */
36 /*  AUTHOR                                                                */
37 /*                                                                        */
38 /*    William E. Lamie, Microsoft Corporation                             */
39 /*                                                                        */
40 /*  DESCRIPTION                                                           */
41 /*                                                                        */
42 /*    This function locks the mutex object referenced. If the mutex is    */
43 /*    already locked, the calling thread shall block until the mutex      */
44 /*    becomes available. This operation shall return with the mutex object*/
45 /*    referenced by mutex in the locked state with the calling thread as  */
46 /*    its owner.                                                          */
47 /*                                                                        */
48 /*  INPUT                                                                 */
49 /*                                                                        */
50 /*    mutex                          Address of the mutex                 */
51 /*                                                                        */
52 /*  OUTPUT                                                                */
53 /*                                                                        */
54 /*     0                             if successful                        */
55 /*     Value                         in case of any error                 */
56 /*                                                                        */
57 /*  CALLS                                                                 */
58 /*                                                                        */
59 /*  tx_thread_identify               Get calling thread's pointer         */
60 /*  tx_mutex_get                     ThreadX Mutex Service                */
61 /*                                                                        */
62 /*  CALLED BY                                                             */
63 /*                                                                        */
64 /*    Application Code                                                    */
65 /*                                                                        */
66 /*  RELEASE HISTORY                                                       */
67 /*                                                                        */
68 /*    DATE              NAME                      DESCRIPTION             */
69 /*                                                                        */
70 /*  06-02-2021     William E. Lamie         Initial Version 6.1.7         */
71 /*                                                                        */
72 /**************************************************************************/
pthread_mutex_lock(pthread_mutex_t * mutex)73 INT pthread_mutex_lock(pthread_mutex_t *mutex )
74 {
75 
76 TX_MUTEX         *mutex_ptr;
77 TX_THREAD        *thread_ptr;
78 INT               retval,status;
79 
80     mutex_ptr = (TX_MUTEX*)mutex;
81 
82     thread_ptr = tx_thread_identify();
83     if ( (mutex_ptr->tx_mutex_ownership_count > 0 ) && (thread_ptr == (mutex_ptr->tx_mutex_owner )))
84     {
85         posix_errno = EDEADLK;
86 	    posix_set_pthread_errno(EINVAL);
87         return (EDEADLK);
88     }
89     status = tx_mutex_get( mutex_ptr, TX_WAIT_FOREVER);
90     switch ( status)
91     {
92     case TX_SUCCESS:
93         retval = OK;
94         break;
95 
96     default:
97         posix_errno = EINVAL;
98 	    posix_set_pthread_errno(EINVAL);
99         retval = EINVAL;
100         break;
101     }
102     return(retval);
103 }
104